Download Externship Report: Rwanda

 Impact of climate change and climate variability
on altitudinal ranging movements of Mountain
Gorillas in Volcanoes National Park, Rwanda
Externship Report: Rwanda
2011
Submitted by:
Abel Musana
Alphonse Mutuyeyezu
Education and Training Program on
Climate Change and Biodiversity in the Albertine Rift
Published by:
The International START Secretariat, 2000 Florida Avenue NW, Suite 200, Washington DC 20009, USA
in collaboration with:
The Pan African START Secretariat, Institute of Resource Assessment, University of Dar es Salaam,
Tanzania
With support from:
The John D. and Catherine T. MacArthur Foundation
(Disclaimer: The sole responsibility for the content of this publication lies with the authors. START,
PASS/IRA and the MacArthur Foundation are not responsible for the information contained herein)
Table of Contents
About ............................................................................................................................................... v
Summary Project Information ..................................................................................................... vi
Executive Summary ..................................................................................................................... vii
1
Introduction ............................................................................................................................ 1
1.1
2
Objectives of the study ........................................................................................................ 1
Conservation Status of Mountain Gorillas in Volcanoes National Park ........................... 3
2.1
Non-climatic stressors on mountain gorillas and their habitat ............................................ 3
2.2
Climatic threats to the Volcanoes National Park ................................................................ 7
2.3
Research questions .............................................................................................................. 8
2.4
Research hypothesis ............................................................................................................ 9
3
Material and Methods .......................................................................................................... 10
3.1
Problem statement ............................................................................................................. 10
3.2
Study area .......................................................................................................................... 11
3.3
Data collection .................................................................................................................. 12
4
Results and Discussions........................................................................................................ 14
4.1
Current climatology of the Mountain Gorilla’s domain ................................................... 14
4.2
Climate change projections for VNP region ..................................................................... 15
4.3
Possible factors influencing mountain gorillas ranging patterns ...................................... 16
5
Possible Implications of Climate Change on VNP’s Ecosysystem Services and
Livelihoods ............................................................................................................................ 21
5.1
Role of VNP in providing goods and services .................................................................. 21
5.2
Possible impacts of climate change and variability on VNP surroundings ...................... 22
5.3
Relationship between climate and non climate threats in VNP ........................................ 24
5.4
Mechanisms of the conservation of mountain gorillas’ habitat in changing climate ........ 25
6
Discussion and Recommendations ...................................................................................... 27
6.1
Discussion ......................................................................................................................... 27
6.2
Recommendations ............................................................................................................. 28
7
References ............................................................................................................................. 29
8
Appendices ............................................................................................................................ 31
8.1
Appendix 1: Externship data collection field sheet........................................................... 31
8.2
Appendix 2: Distribution of gorilla groups and precipitation trends ................................ 33
8.3
Appendix 3: List of Acronyms and Abbreviations ........................................................... 34
List of figures
Fig. 1: Habitat degradation in bamboo zone along Karisimbi Electrification trail. ....................... 4
Fig. 2: Snares (wire) removed in VNP from 2007 – 2009. .............................................................. 5
Fig. 3: Illegal activities distribution in VNP in 2009. ...................................................................... 5
Fig. 4: Spatial Evolution of VNP from 1974-2010........................................................................... 6
Fig. 5: Population density around VNP in 2007 .............................................................................. 7
Fig. 6: Landslide in Volcanoes National Park in October 2010 ..................................................... 8
Fig. 7: Location of the study area .................................................................................................. 11
Fig. 8: VNP Rwanda hydrological year precipitation, 2009 – 2010 ............................................. 14
Fig. 9: VNP Rwanda temperatures variation in 2009- 2010 ......................................................... 15
Fig. 10: Projected changes in temperature in VNP region............................................................ 15
Fig. 11: Projected changes in rainfall in VNP region ................................................................... 16
Fig. 12: Long term use of home range by Susa and Kwitonda (2005 – 2009) .............................. 19
Fig. 13: Landslide in Volcanoes National Park ............................................................................. 23
Fig. 14: Wild Fire in Volcanoes National Park , July 2009. ......................................................... 24
Fig. 15: Weather monitoring station in VNP ................................................................................. 25
Fig. 16 : Collective and domestic water tanks around VNP ......................................................... 26
List of tables
Table 1: Beehives removed in VNP .................................................................................................. 3 Table 2: Evolution of the water harvesters in VNP ......................................................................... 4 Table 3: Vegetation characteristics of the study area.................................................................... 16 Table 4: Frequency in the use of vegetation zones during the period of observation ................... 17 Table 5: Daily traveling distance .................................................................................................. 20 Table 6: Primary food of Gorillas during the study period. ......................................................... 20 Table 7: Main ecosystems functions goods and services provided by the VNP ............................. 21 About the Education and Training Program on Climate Change and Biodiversity in
the Albertine Rift
This capacity building program addresses the challenge of managing emerging risks to
biodiversity from climate change in the Albertine Rift region of Africa, which encompasses parts
of Tanzania, Burundi, Rwanda, Congo, and Uganda. The program, hosted at the Institute of
Resource Assessment (IRA), University of Dar es Salaam, offers MS-level courses and
externships for conservation practitioners and researchers from the region. The MS-level courses
focus on climate change risks to ecosystems and biodiversity and explore strategies for
conserving biodiversity in a changing climate. Externships allow program participants, working
in country teams, to apply knowledge from the classroom to field-based assessments in the
Albertine Rift. Findings from the externship research are documented in reports such as this. A
special training of trainers’ module equips faculty from regional universities with information,
tools and resources to help them to develop courses on climate change and biodiversity at their
universities.
Two rounds of the program have been held to date, in 2008 and 2010 respectively. More than 45
participants have successfully received training from expert faculty drawn mainly from regional
universities. As a result the program has helped foster a network of individuals and institutions in
the Albertine Rift region engaged in addressing climate change risks to biodiversity. The existing
Masters Program in Natural Resource Assessment and Management at IRA has also benefited
from the integration of courses from this capacity building initiative into that program’s
curriculum.
The International START Secretariat and the Pan-African START Secretariat (PASS), based at
the Institute of Resource Assessment (IRA), University of Dar es Salaam, jointly implement this
effort with funding from the MacArthur Foundation.
Additional information on the program is available at: http://start.org/programs/biodiversity.
v Summary Project Information
Project Title:
Impact of climate change and climate variability on altitudinal ranging movements of Mountain Gorillas
in Volcanoes National Park, Rwanda
Project Investigators:
1. Abel Musana: MSc. Student Biodiversity Conservation, Department of Biology, Faculty of
Science, National University of Rwanda AND Research and Monitoring WardenVolcanoes
National Park, Rwanda; Email: [email protected]
2. Alphonse Mutuyeyezu: Regional Post-graduate Training School on Integrated Management and
Economics of Tropical Forests and Lands (ERAIFT / UNESCO; www.eraift.org), University of
Kinshasa (UNIKIN; www.unikin.cd); Email: [email protected]
Project Supervisor:
Dr. Elias Bizuru: Department of Biology, National University of Rwanda, Coordinator – MSc Programme
in Biodiversity conservation; Email: [email protected]
Externship host institution:
Department of Biology, National University of Rwanda
vi Impact of climate change and climate variability on altitudinal ranging
movements of Mountain Gorillas in Volcanoes National Park, Rwanda
Executive Summary
The mountain gorilla (Gorilla beringei beringei) belongs to the eastern gorilla species and its
characteristic habitat is high-altitude montane forests. A number of vegetation zones have been identified
in the mountain gorilla habitat of the Volcanoes region. Mountain gorillas show a seasonal use of these
vegetation zones. This variation in use of vegetation zones can depend on the availability of food sources,
which is a function of seasons and altitudinal climate zone. Earlier studies have documented mountain
gorilla feeding behavior, but less attention was given to the effects of climate change and variability on
mountain gorilla altitudinal ranging behavior. We tracked two groups of mountain gorillas in Volcanoes
National Park for the month of November. We studied the possible effects of climate parameters (rainfall
and temperatures) on the altitudinal ranging behavior of mountain gorillas. Ranger-based monitoring data
helped to analyze trends in seasonal movements. During the 30 days of observation, although one group
of mountain gorillas had an altitudinal range of 2,400-2,600m and another group of 2,900-3,050m, both
groups most commonly occupied the lower forest belt. Results showed that mountain gorillas have
complicated seasonal movement patterns. Long-term data show a correlation between mountain gorilla
movement and seasonal changes.
Furthermore, as Volcanoes National Park provides different types of ecosystem goods and services, a
short survey was conducted outside of the protected area in order to assess how climate change and
variability affect the different goods and services offered by the park. Water resources are the most
problematic in the Volcanoes National Park region in the era of climate change.
vii 1
Introduction
Climate change is the most serious challenge facing the world today. Climate change is a challenge for
nature conservation as it impacts both species and ecosystems. There is a growing consensus in the
scientific community that climate change is occurring and is one of many possible causes of biodiversity
loss as the world is entering a period of warmer and less predictable climate (Lockwood et al, 2006). With
changes in the climate, protecting biodiversity is critical for maintaining ecosystem services and for
promoting resilience. Climate change is expected to significantly alter African biodiversity as species
struggle to adapt to changing climate conditions (Lovett et al., 2005).
In Rwanda region, changes in extreme events such as droughts and floods have affected various
ecosystems. Mountain gorillas (Gorilla beringei beringei) are critically endangered. This species of Great
Apes is endemic to the Albertine rift region and was first brought to international attention by the
conservation efforts of Dian Fossey in the 1960s and ‘70s. In Volcanoes National Park (VNP), climate
change has been thought to be one of the main causes for the increasing number of deaths of gorillas and
an influence on their use of habitat (Basabose, 2009). Only about 700 individuals are left in two isolated
populations (Bwindi and Virunga) in east-central Africa. Their charismatic and immensely appealing
nature, sheer size (the largest primate on earth) and great endangerment make them a flagship species par
excellence. After facing many threats for a long time, enhanced protection efforts have led to an increase
from 250 gorillas in the mid-1980s to 380 in 2003 (Gray et al ,2002).
While climate and seasonal change in temperature and rainfall continue to have considerable impact on
species and their conservation, mountain environments are likely to be among the most severely impacted
ecosystems as a result of climate change (IUCN/WCPA, 2006). High-altitude species on mountains will
be lost and potentially displaced by lower altitude species or weeds (Price and Neville, 2004). As far as
mountainous ecosystems in VNP are concerned, previous studies conducted in the Virunga Massif have
shown changes in temperature, rainfall and frequency and timing of wildfires (Plumptre et al, 2010).
In VNP, uncertainties remain about climatic change and ecological systems - how regional climate will
change and how species and ecological systems will respond to climate change. Until today, only a small
number of studies have focused on the effects of climate change on mountain gorillas and their habitat.
Climate change is suggested to be one of the main causes for the migration of gorillas to higher altitudes
and other areas not used in the past, and could potentially have a significant impact on this endangered
species in the future (Basabose, 2009, Voir ref in Donat and Yessoufou).
This study focuses on the current impacts of climate change on mountain gorillas by assessing how
climate change and climate variability stressors are affecting the altitudinal ranging of mountain gorillas.
It also proposes a toolbox of adaptation measures.
1.1
Objectives of the study
General objective
- To assess the implications and impacts of climate change and climate variability stressors on
mountain gorillas’ ranging behaviors and ecosystem services in Volcanoes National Park
Specific objectives
- To identify climatic and non-climatic threats and their impacts on mountain gorilla behavior
- To assess the effect of climate change and seasonality on mountain gorillas’ altitudinal ranging
and implications for the future survival of mountain gorillas
1 -
To determine the relationship between climatic and non-climatic threats in VNP and their
implications for the park’s ecosystem services and livelihoods
To make recommendations for mountain gorilla conservation and the sustainability of the park’s
ecosystem services under climatic and non-climatic threats identified in VNP
2 2
2.1
Conservation Status of Mountain Gorillas in Volcanoes National Park
Non-climatic stressors on mountain gorillas and their habitat
The threats to mountain gorillas and their habitat are many. Poaching, unsustainable harvesting of wood
for fuel, construction and other human activities all threaten their habitat. Furthermore, humans are a
potential source of diseases that, once transmitted to gorillas, could devastate the population.
Direct threats
Mountain gorilla (gorilla beringei beringei) populations are threatened throughout their range, primarily
by human activities, and in particular as a result of increasing human populations. The major threats to
gorillas are habitat loss, modification or fragmentation; hunting or poaching; disease transmission from
humans; and war or political unrest. The mountain gorillas in VNP have been exposed to each of these
threats since their discovery by Western science. This chapter reviews the threats gorillas have faced in
VNP over time and summarizes some of the conservation measures that have been taken to address these
threats. It also provides information to park managers for better gorilla conservation.
A. Habitat loss, modification and degradation
Degradation of the VNP forest occurs mainly through human modification, such as the collection of fuel
wood and non-timber forest products, beekeeping and honey collection inside the park, and water
collection. Today the whole Virunga region, including the Ugandan, Rwandan and Congolese sections,
covers an area of about 425 km2, although much of the high-altitude vegetation is not particularly suitable
for gorillas (Weber & Vedder, 1990).
a. Fuel wood and non-timber forest product collection: Humans have used the forest extensively in
the past as a source of building and handicraft materials, firewood, water and grazing land for
cattle. Bamboo in particular is in high demand for construction and production of different art
crafts: baskets, mats, enclosures, etc. Regeneration of vegetation at high altitudes (2,600-4,500
meters) in these mountains is slow, and consequently even low levels of human activity can have
a long lasting impact
b. Beekeeping and honey collection inside the park: Traditional beehives are regularly discovered in
VNP and are destroyed by mangement.
Table 1: Beehives removed in VNP
Year
2005
2006
Beehives
446
185
removed
2007
57
2008
114
2009
234
2010
196
Total
1,232
(Source: VNP monitoring department data)
From 2005 to 2010, a total of 1,232 beehives were removed from VNP. Beekeepers lay their
hives in the forest and even if this activity does not presently represent a direct threat, it remains
as the cause of related threats, such as the risk of fire while burning the hives; the possibility of
beekeepers being involved in activities such as poaching or bamboo cutting; and the fatal risk of
bees stinging gorillas are all related concerns.
3 c. Water collection: Water collection is one of the main reasons for trespassing into Volcanoes
National Park. This not only disturbs and pollutes the forest but also has a negative effect on the
mountain gorillas.
Table 2: Evolution of the water harvesters in VNP
Year
Number
2005
1,106
2006
1,027
2007
727
2008
1,519
2009
2,417
2010
1,781
Total
8,577
(Source: VNP monitoring department data)
The problem of water is seasonal in the volcano region, where porous soil does not enable the
retention of water on the surface nor enable the permanent flow of water. The population is
therefore forced to penetrate the forest to get the water necessary for survival. This activity,
however illegal, is tolerated by RDB – T&C.
d. Uncontrolled fires: Forest fires constitute a serious threat of degradation of the habitat because
affected areas take many years, sometimes decades, to recover after the fire. Although fires are
rare, the effects are devastating. The eastern side of Muhabura has developed typical
characteristics of regeneration probably due to repeated burning in the region. Bush fires in VNP
are usually caused by poachers and illegal honey collection activities.
e. Human presence in the park: The presence of human movements inside the park constitutes
another risk to the ecosystem that cannot be neglected due to associated possibilities of pollution
and disturbance that can have important impacts on animal behaviour, including that of gorillas.
Fig. 1: Habitat degradation in bamboo zone along Karisimbi Electrification trail.
B. Poaching
Hunting can be direct or indirect, depending on whether gorillas are targeted or they become
unintentionally ensnared by traps. The major reasons for killing gorillas are a) meat, b) capture of animals
for zoos and c) body parts for trophies or religious rites. The hunting of mountain gorillas for meat has
occurred in the past but is rare. Rwandans traditionally do not consume primate meat. Infant gorillas have
been captured for foreign zoos. For example, in 1968-69, 18 gorillas were killed in attempts to capture
infants (Fossey, 1983). Although there have been no known deliberate gorilla killings in Rwanda since
1982, gorillas are still very much at risk from poaching even where gorilla tourism has brought in foreign
currency.
4 Fig. 2: Snares (wire) removed in VNP from 2007 – 2009.
Direct killings of mountain gorillas have been very rare in the last 20 years, but indirect killing still
occurs. Accidental entrapment in wire snares used to trap other wild animals is also a threat to the
mountains gorillas. Plumptre et al. (1997) stated that the setting of snares for ungulates in Volcanoes
National Park in Rwanda is one of the greatest threats to Gorilla beringei beringei. If the resulting
wounds become infected, the animal can easily die.
Fig. 3: Illegal activities distribution in VNP in 2009.
5 B. Disease transmission from humans
Gorillas are susceptible to human diseases, and many in zoos are vaccinated against common human
ailments. With small populations of gorillas, any infectious disease could devastate the population.
Diseases transmitted to immunologically vulnerable populations have resulted in high mortality in other
species - up to entire populations (Macdonald, 1996; Thorne & Williams, 1988). Primates are especially
vulnerable due to their slow reproductive rates (Young, 1994). Disease outbreaks and subsequent deaths
of habituated mountain gorillas include respiratory outbreaks and scabies (Hastings et al, 1991; Kalema et
al, 1998). The gorillas in the Virungas have probably been exposed to human parasites from the local
human population for decades.
C. Loss of protected parkland
Although loss of parkland is no longer happening in VNP since tourism has boosted the local economy
and provided a source of hard currency to maintain the park, it was a serious problem in 1970s. Though a
home for this rare species, VNP, like any other park, has lost much of its parkland. In 1960, the park size
was 34,000 ha; by 1970, the park had shrunk to 16,000 ha and to 15,000 ha in 1980.
Fig. 4: Spatial Evolution of VNP from 1974-2010
(Source: Rwanyiziri G., 2009)
The bulk of this parkland loss in Rwanda was due to a pyrethrum project that excised 10,000 hectares of
land in 1968. All forest between the altitudes of 1,600 m and 2,600 m has been removed. Following this
habitat loss, it was estimated in 1976-78 that there had been a 40-50% decline in the number of gorillas
(Plumptre, A.J. & Williamson, E.A.: 2001).
Indirect threats
6 A. Demographic pressure
Volcanoes National Park is located in the most densely populated region of Rwanda. The average
population density is more than 500 inhabitants/km² (Rwanyiziri, G., 2009). As result, several forms of
human presence are registered in the park, posing direct and indirect threats to natural resources (from
water collection, bamboo and tree cutting, honey collection, etc.).
Fig. 5: Population density around VNP in 2007
(Source: Rwanyiziri G., 2009)
B. Poverty
It is widely accepted that biodiversity loss and poverty are linked problems, and that conservation and
poverty reduction should be tackled together. A high percentage of people living near VNP live in
poverty, characterized by the following indicators: low education levels, households with many members,
very small farms, shortage of food products, no access to basic infrastructure (water, markets, hospitals,
roads, etc.) (Plumptre, A. and al., 2004; Rwanyiziri G., 2008).
2.2
Climatic threats to the Volcanoes National Park
Volcanoes National Park ecosystems are among the most important areas for biodiversity conservation
and community livelihoods. However, these fragile ecosystems are prone to several threats that
increasingly result from climate change, as observed in most mountain ecosystems around the world.
Irregularities in season succession
The Volcanoes National Park ecosystem in Rwanda has been experiencing worsening irregularity and
unpredictability of rainfall over the past decades due to climate irregularities. During two of the past three
years, the area experienced unusually excessive rains. The resulting floods led to significant economic,
environmental and social damage in the park and surrounding areas. Some cases of floods were also
observed within the park.
7 Fig. 6: Landslide in Volcanoes National Park in October 2010
(Photo: A. Musana)
[Water gushing from the Virunga Mountains hit the nearby regions, leading to the deaths of dozens, the
destruction of roads and other infrastructure, and a significant reduction in agricultural production, threatening
food security.]
Extreme weather conditions
Sometimes the Rwandan region is affected by the El Niño and La Niña phenomena (ENSO). These
extreme weather events (EWEs) often create conditions conducive to outbreaks of infectious diseases.
“Floods, landslides, drought episodes constitute the major repetitive natural disasters for Rwanda
associated with climate change often linked with ENSO episodes. These phenomena take birth from the
Pacific far from African coastal zones, but this doesn’t spare these continental regions including Rwanda
under the shelf of their effects such as among others, the disturbance of pluviometric regime. External
factors linked to El Niño and La Niña episodes often influence the climate variability in Rwanda and
connexed effects such as famines” (NAPA – Rwanda, 2006). For instance, following the April-May 2010
rains, one mother gorilla and three infants are reported to have died due to extreme weather conditions
characterized by heavy rains.
2.3
Research questions
Research objective
To identify climate change and nonclimate stressors on mountain gorillas
and the impacts on their behavior
To assess the effect of climate change
and seasonality on mountain gorillas’
altitudinal ranging and implications for
the future survival of mountain gorillas
Research Question
1. What are climate change and variability and nonclimate change threats to mountain gorillas in
Volcanoes National Park?
2. Did the feeding ecology of mountain gorillas change
over time or space due to climate change or variability?
1. To what extent are climate change and variability
affecting mountain gorillas’ altitudinal ranging
movements throughout different altitudinal vegetation
zones in VNP?
2. Did the ranging pattern of mountain gorillas increase
over time due to climate change or variability?
3. How will the mountain gorillas’ ranging patterns in
Volcanoes National Park change in the future if all
actual climatic conditions and trends are maintained?
8 To determine the relationship between
climatic and non-climatic stressors in
VNP and their implications for the
park’s ecosystem services and
livelihoods
To suggest the mechanisms of
mountain gorilla conservation and the
sustainability of the park’s ecosystem
services vis-à-vis the climatic and nonclimatic threats identified in VNP
2.4
1. What is the relationship between climate change and
non-climate change threats in VNP?
2. What are the implications for the park’s ecosystem
services and livelihoods?
1. What are conservation strategies for mountain gorillas
vis-a-vis the climatic threats identified?
2. What are mechanisms to maintain VNP’s ecosystem
services in the era of climate change?
Research hypothesis
Ho: The mountain gorillas are affected by the current climate change and variability.
Ha: The mountain gorillas are not affected by the current climate change and variability.
Ho: Effects of climate change and vulnerability influence altitudinal movements of mountain gorillas
throughout different altitudinal vegetation zones.
Ha: Effects of climate change and vulnerability do not influence altitudinal movements of mountain
gorillas throughout different altitudinal vegetation zones.
9 3
3.1
Material and Methods
Problem statement
There seems to be almost a consensus among scientists that temperatures on earth are increasingly
disrupting the planet’s climate system and causing shifts in regional patterns of temperature and
precipitation (Hulme, 2005). Changes in climate threaten to decrease biodiversity, the sum of species and
their genetic diversity, by altering environmental conditions so quickly that species cannot readily adapt
(McLaughlin et al, 2002). Because each species plays an important role in the life web of its biotic
community, there should be increased concern about the responses of species to changes exacerbated by
climate variation. Species already under stress from habitat loss and fragmentation, the introduction of
exotic species, and pollution are especially vulnerable to the detrimental influences of global warming
(Hannah et al, 2005).
The mountainous forest system in the Virunga region, the sole habitat of mountain gorillas, is isolated
from similar ecosystems by vast areas of lowland habitats. With their steep and varied topography and
distinct altitudinal and ecological zones, the Virunga Mountains support a high diversity of species and
ecosystems, and a large percentage of global endemic species (REMA: 2009). The current climate of
these mountains is much wetter than the surrounding lands, with perhumid conditions and rainfall up to
3,000 mm per year (UNEP / CMS, 2008). This makes the Virunga region the main water tank for the
surrounding population. However, as the global climate changes, temperatures in the Virunga region are
projected to increase, and observed trends show a change in the seasonal pattern of rainfall
(Mukankomeje, 2009).
Protected areas and national parks ensure a continuous flow of ecosystem services (benefits). These
include provision of clean water and the protection of soil resources. They provide significant economic
benefits to surrounding communities and contribute to spiritual, mental and physical well being, as well
as helping to fulfill an ethical responsibility to respect nature and providing opportunities to learn about
nature and the environment (IUCN, 2000). Volcanoes National Park plays the same role for the
population living around the park and in its region. Volcanoes National Park delivers numerous ecosystem services: provision of clean air and water;
supporting species of fauna and flora; regulating climate change through carbon sequestration, flood
control and water purification; and cultural services for recreational, aesthetic, spiritual and religious use.
Like all ecosystems and biodiversity, VNP ecosystem services are also vulnerable to the effects of global
climate change and climate variability.
Mountain gorillas have been subject to a loss of habitat that has constrained them in high altitudes and
exposed them to different environments and habitats, some of which are unsuitable for them (Kayijamahe,
2006). In fact, in relation to the initial size of the forest, between 1958 and 1979 VNP lost approximately
55 percent of its natural habitat, mainly as a result of the demand for land for growing pyrethrum (Harroy,
1981 in Bouché, 1998; Bouché, 1998). When tourism proved to be a boost to the local economy and a
source of hard currency, the steady shrinking of VNP’s surface area stopped. This loss of habitat, coupled
with other natural and human stressors (forest fires, most of the time resulting from honey collection,
tree/bamboo cutting, poaching, and water and fuel wood collection), has further contributed to the decline
of their population over the last century. The population stands at 800 individuals, and the reproductive
rate is very low. These factors cause the mountain gorillas inhabiting higher elevations to be highly
vulnerable to the effects of climate change.
10 Endemic species such as mountain gorillas are highly at risk from minor climate changes. Since they are
confined to a relatively small habitat within a high altitudinal range, changes of the habitat can severely
impact the gorilla population (CARPE, 2005). Research carried out on mountain gorillas has focused on
food availability as the only factor influencing ranging patterns and much emphasis has been placed on
horizontal movements. However, since mountain gorillas live in a mountainous region they are expected
to have altitudinal movements, and consequently there may be differences in altitudinal ranging through
time and space. On other hand, horizontal movements may vary according to climate conditions, affecting
ranging patterns such as daily travel distance, home range size, altitudinal use, habitat type use, etc.
Climate parameters like temperature, rainfall and humidity are expected to change with global climate
change, and thus may affect the ranging patterns of the mountain gorillas. Assessing the effects of climate
change and climate variability on mountain gorillas’ ranging behavior as well as the effects on livelihoods
and ecosystem services of VNP will contribute to understanding how global climate change is affecting
this endangered species and its habitat.
3.2
Study area
The study will be conducted in the Parc National des Volcans, Rwanda (1°50’S, 29°30’E). The site
ranges in altitude from 2,300 to 4,507 m and supports a patchwork of quite distinct vegetation types (Mc
Neilage et al, 2001). Along an ascending altitudinal gradient, the vegetation varies markedly, from a
bamboo zone at the lowest altitude to afro-montane vegetation at the highest altitude. It borders Virunga
National Park in the Democratic Republic of Congo and Mgahinga Gorilla National Park in Uganda.
Fig. 7: Location of the study area
11 The national park is known as a haven for the mountain gorillas. It is also home to five of the eight
volcanoes of the Virunga mountains (Karisimbi, Bisoke, Muhabura, Gahinga and Sabyinyo), which are
covered in rainforest and bamboo.
The park was first established in 1925 as a small area bounded by Karisimbi, Visoke and Mikeno,
intended to protect the gorillas from poachers. It was the very first national park to be created in Africa.
Subsequently, in 1929, the borders of the park were extended further into Rwanda and into the Belgian
Congo to form Albert National Park, with a huge area of 8,090 km² and run by the Belgian colonial
authorities, who were in charge of both colonies (Philip Briggs & Janice Booth: 2001 in conservation
plan). Today, Volcanoes National Park is the most popular destination for tourists in Rwanda and as such,
plays a crucial role in the development and promotion of tourism and ecotourism in Rwanda.
3.3
Data collection
Pre-field work
Pre-field work exercises allowed us to review existing data, articles, books and reports on mountain
gorillas’ conservation, behavior and altitudinal ranging, and climate change effects on ecosystems in
general, and in Rwanda and the VNP area in particular. This gave us a better understanding of existing
problems related to climate change in Rwanda and the impact on biodiversity conservation, especially
mountain gorillas. In addition, it contributed to documentation of non-climate stressors that threaten the
VNP and an assessment of their impact on the survival of the park’s fauna and flora.
Field work and data collection
Fieldwork was carried out from 1-30 November 2010. Information of interest was collected using
appropriate methods.
Sampling design and selection procedure
A. Quantitative data
For data on the gorillas, the sampling unit was two gorilla groups. Selection of the sample groups was
done based on geographical location. Two gorilla group were selected, one in the east and another in the
west of the park. The study was carried out on two groups of mountain gorillas in VNP referred to here as
the East and West Ridge groups. Data collection lasted for 1 month, starting on 1 November 2010 and
ending on 30 November.
Susa is an old group among the 7 groups visited by tourists in Volcanoes National Park. The Susa group
was initially formed in 1974 with 7 individuals. The Susa group’s home range is situated in the western
part of the park close to the steep slopes of Mt. Karisimbi, the highest peak of the Virunga chain. The
family is now composed of 28 individuals.
Kwitonda has been in Rwanda since 2004, but the group originally inhabited the DRC side of the Virunga
massif. The group has settled well in Rwanda; it has used the same home range since 2004 and has never
returned to the Congo side for a single day. The group’s domain is located at the feet Sabyinyo and
Gahinga Volcanoes in the east-central region of Volcanoes National Park.
Climate change and variability data were collected from regional climatologic data collection centers. The
meteorological observatories of the Higher Institute of Agriculture and Animal Husbandry and the
Volcanoes National Park were used for both the Kwitonda and Susa groups. Data collected on rainfall and
temperature permit the understanding of climate patterns in the study area.
Addendum: In this category of quantitative data, we also used existing data and records available in the
department of ecological monitoring at the park level to document current non-climate threats to the VNP
12 that may interact with climate stressors and exacerbate future conservation of biodiversity in the park,
including mountain gorillas.
Qualitative data
For this category of data, we focused on the communities surrounding the park, park management and
local non-government organizations like the Gorilla Organization, International Gorilla Conservation
Program, which intervenes in park conservation and management. This category deals with the
description of climate and non-climate change issues in the protected area and local stakeholder
observations. Furthermore, direct observations were made to get a clear perception of what is really
happening in the park as far as climate change is concerned. We also used Geographic Information
Systems (GIS) techniques for geo-spatial data processing and visualization.
Data Collection
During the study both quantitative and qualitative methods were used. The qualitative method was used to
understand the perceptions of park managers and conservation stakeholders with regard to the effects of
climate change and variability on mountain gorillas, and then to assess the existing measures of
mitigation and adaptation. A structured questionnaire was used to collect quantitative data in order to
assess the effects of climate change and variability on altitudinal ranging movements of mountain gorillas
in VNP. This questionnaire was completed by the park’s trackers, who follow mountain gorillas on a
daily basis. They were briefed beforehand about the protocol of data recording. One aspect of the
questionnaire was related to the altitudinal ranging behavior of mountain gorillas to assess if climate
change and variability are impacting gorillas’ movements in Volcanoes National Park. We used the scan
sampling method to record data on the activities of each gorilla group. GPS records were taken every 30
minutes to identify the habitat type, vegetation type and the topography.
Data analysis methods
This study used both primary and secondary data in the analysis of all information gathered. Microsoft
Excel was used for the statistical analysis of the data on gorilla groups’ altitudinal movements and
climatic data records, while GIS techniques were used to produce relevant maps.
Limitations
The findings of the study are limited because of limited existing meteorological data collection and the
lack of local climate change models.
Delimitations
The delimitations of this study will be only Volcanoes National Park and in terms of time, we will use
survey data and long-term mountain gorillas’ ecological monitoring data, where we will limit our analysis
to the last 5 years.
13 4
4.1
Results and Discussions
Current climatology of the Mountain Gorilla’s domain
Climatological data collected through the field survey that covers the period of 2009-2010, coupled with
long-term data analyzed in previous research, permits us to examine climate trends. We have analyzed
patterns of precipitation and temperatures. The VNP region has a tropical climate altered by altitude, but
micro-climate zones are observable within the park. The climate is generally fresh and humid, and is drier
in the eastern part of the ranges. The climate pattern in VNP is bimodal with 2 rainy seasons and 2 dry
seasons.
VNP annual rainfall climatology
As in other equatorial regions, there is a seasonality that mostly involves variation in rainfall. Annual
rainfall data recorded from 2009-2010 are shown in the chart below.
Fig. 8: VNP Rwanda hydrological year precipitation, 2009 – 2010
[VNP has two rainy seasons (March-May and September-December), a dry season in June-August and a
shorter, less observed dry period in January-February.]
VNP annual temperatures climatology
Rwanda’s average temperature varies according its topography. In VNP, the average temperature is 09°C
at 2,600 m. Low temperatures are observed in higher altitudes (the peaks of volcanoes), with average
temperatures ranging between 5 and 0°C. In some parts of the volcanic region, for instance at the peak of
Karisimbi volcano, temperatures can go below 0°C.
14 Fig. 9: VNP Rwanda temperatures variation in 2009- 2010
Seasonal variation in temperature is much less pronounced. Daily maximum and minimum temperatures
change little across months.
4.2
Climate change projections for VNP region
In mountain ecosystems of the Albertine rift (VNP included), it is projected that temperatures will
increase and will be associated with changes in rainfall and snowfall patterns. Data on current climate
were obtained from historical regional records, and future climate was predicted from general circulation
models.
Projected changes in temperatures
Observations show that there has been an increase in average temperature in the VNP region over the last
30 years. This is shown in Figure 10. An average rise of 0.7°C is projected for the VNP area by the year
2030, 2°C in 2060 and approximately 3°C rise by the year 2090.
Fig. 10: Projected changes in temperature in VNP region
(Source: Adapted from Seimon at al, 2010)
Projected changes in rainfall in VNP region
15 Fig. 11: Projected changes in rainfall in VNP region
(Source: Adapted from Seimon at al, 2010)
Wet extremes (precipitations) are projected to increase during both the short (September-December) and
long (March-May) rainy periods. In general, a positive shift in the whole rainfall distribution is simulated
by the models over most of the Virunga massif region during both rainy seasons.
4.3
Possible factors influencing mountain gorillas ranging patterns
Rainfall and temperatures in study area during the study period
For the Susa group, climatic data recorded at the nearest weather station, located at Busogo, showed that
the daily mean temperature varied between 14.7 and 17.9°C. The average monthly temperature for the
period of study was 16.13°C. Mean daily rainfall ranged from 0mm to 15mm, and total monthly rainfall
was 108.7mm. For the Kwitonda group, daily temperatures varied between 14.6 to18.7°C, with a monthly
mean of 16.46°C. Rainfall varied between 0 and 14.6mm, with a total monthly rainfall of 98.65mm.
During the observation period, the Kwitonda group had an altitudinal range of approximately 2,4002,600m and the Susa group an altitudinal range of 2,900-3,050m, but both groups most frequently
occupied the lower forest belt.
The vegetation type of the study area
Vegetation varies considerably due to the large altitudinal range within the park. There is some lower
montane forest, but it has been mostly lost to agriculture.
Table 3: Vegetation characteristics of the study area
Altitude
Vegetation Zone
Canopy type
Dominant plant species
2400 - 2500 m
Neoboutonia
Closed
Neoboutonia buchananii
2500 - 3200 m
Bamboo
Closed
Arundinaria alpine
Caridus nyasaanus
3200 - 3600 m
Hagenia - Hypercum
Semi – open
Hagenia abyssinica
Hypercum revoltum
3500 - 4200 m
Lobelia Senecio
Open
Lobelia wallastonii
Lobelia lanurensis
Senecio erici manii
16 The composition of the forest, shown in Table 3, varies with altitude from neoboutonia forests
(remaining only in the Kwitonda group’s home range) at the lowest elevations to Senecio erici-rosenii
forests above 3,500m grading, to grassland above 4200m (only on the Susa group’s side of the park).
Altitudinal ranging behavior of the study groups
Data collected through the field survey in November 2010 indicated that mountain gorillas (gorilla
beringei beringei) generally reside at higher altitudes (>2,390m). The Susa group had an altitudinal range
of between 2,942-3,050m while Kwitonda group’s range was between 2,394-2,629m. The Susa group
moved between 108m in altitude, while the Kwitonda group moved 235m. The difference between the
lowest altitudes reached by the 2 groups was 548, and 421m for the highest altitudes reached.
Utilization of altitudinal Vegetation zones
The Susa group’s altitudinal home range extended from the bamboo zone at the lower latitude to the
Senecio-lobelia (Lobelia giberroa) zone at the higher altitude. The Kwitonda group’s home range extends
from the neoboutonia buchananii zone at the lower altitude to the senecio-lobelia at the higher altitudes.
Table 4: Frequency in the use of vegetation zones during the period of observation
Neoboutonia
zone
Bamboo Zone
Hagenia Hypercum zone
# of
# of
days
%
days
%
# of days
%
Other zones
# of days
%
Susa
0
0
26
86.66%
4
13.33
2
6%
Kwitonda
22
73.33%
8
26.66%
0
0
0
0
During this study period, the Susa group used the bamboo (arundinaria alpina) forest for 76.66% of the
days of observation (30 days). 13.33% of their time was spent in the hagenia hypercum zone located in
higher altitudes. The allocation of time in higher vegetation zones reflected at 6.66% (2/30 times) of the
days on which daily mean temperatures were a bit higher than the other days. Bamboo shoots were the
main food attraction for gorillas throughout this period of observation.
The Kwitonda group spent 22 days (73.33%) in the Neoboutonia buchanii zone and only 8 (26.66%) days
in the bamboo zone. According to long-term records, the Susa group spent 82.4% of the days during the
two rainy seasons in the bamboo forest. For the same periods, the Kwitonda group’s home range was
located in the neoboutonia buchananii zone 43.6% of the time.
During the 2 dry seasons, the Susa group spent 58.6% of the time in the hagenia hypercum forest, 30.5%
in the giant Senecio manii and lobelia forest and only 10.9% in the bamboo forest. The home range of the
Kwitonda group during the dry seasions is 77.5% in mixed neoboutonia-bamboo forest, 20.8% in hagenia
hypercum zone and only 1.7% in upper forest.
The frequency of home range utilization
Estimates of home range size using MCP fit the area visited by the mountain gorillas in both groups. For
each gorilla group, we collected 2 GPS points per day of observation, which means 60 points were used
to calculate the home range size per group. For the whole period of observation (30 days), the monthly
home range of the west ridge group (Susa group with 28 individuals) was calculated at 12.42 km2 located
in both bamboo and hagenia hypercum zones. Monthly home range size of the Kwitonda group with 20
individuals was estimated at 5.9 km2.
17 To verify possible changes in the seasonal use of home ranges, we combined the data collected from 2005
to 2009 because of the similar geographical range utilization throughout the years and in different
seasons. The size of the home range varied significantly in different seasons. The long dry season (JuneAugust) home range, with an area of 19.93km2 for the Susa group and 6.19 km2 for Kwitonda group was
the largest for each group. The long rainy season home range was the smallest, with an area of 14.1km2
for the Susa group and 5.2km2 for Kwitonda group.
The short dry season and rainy season home ranges were different in size: 12.1 km2 for the Susa group
and 6.96 km2 for the Kwitonda group. In addition, there were overlaps between ranges in different
seasons.
These groups showed a significant difference in occupying altitudinal belts according to season (Figure
12). The relationship that was observed between altitudinal ranging behaviors of mountain gorillas may
suggest seasonality in altitudinal use, which may be related to seasonal food availability and distribution
across altitudinal ranges.
18 Fig. 12: Long term use of home range by Susa and Kwitonda (2005 – 2009)
Daily Traveling Distance
The Susa group travelled a long distance daily, where the minimum per day was 430m and the maximu
was 861m, with an average of 630.47m (± 50.67). The Kwitonda group moved a daily distance ranging
from a 201m minimum to 1,492m as the daily maximum, with an average of 572.25m (± 141.73).
Table 5: Daily traveling distance
Month
November
Group
N DTD
Min (m)
Max (m)
Mean ± SE
Kwitonda
30
201
1492
572.25 ± 141.73
Susa
30
430
861
630.47 ± 50.67
Observed feeding ecology of the study gorilla groups
Mountain gorillas are primarily folivorous. The majority of their diet is composed of the leaves, sho
and stems (85.8%) of 142 plant species. They also feed on bark (6.9%), roots (3.3%), flowers (2.3%)
fruit (1.7%), as well as larvae, snails and ants (0.1%) (Fossey and Harcourt 1977). The home range
(the area used by one group of gorillas during a determined period) is influenced by the availability
food sources and usually includes several vegetation zones.
During 30 days of observation, we collected different types of food items eaten by the gorillas each da
it is summarized in following table:
Table 6: Primary food of Gorillas during the study period.
Frequency per days
Kwitonda
%
Susa
%
Bamboo ( Shoots and
leaves)
30
100
30
100
Larvae, snails and ants
12
40
0
0
Dung
16
53.3
4
13.3
Fruits
26
66.6
1
3.33
8
26.6
0
0
12
40
1
3.33
Mushroom
Wild bananas
(Source: Field Survey, November 2010)
Watts (1984) and McNeilage (2001) found that mountain gorillas in different habitats concentrate o
relatively small number of food items; however, the specific foods exploited do vary with habitat, lead
to speculation that dietary flexibility is possibly the key factor in allowing them to occupy a range
different habitats within the Virungas.
Home utilization and illegal activities
Numerous authors have indicated that illegal human activities may have profound effects on the rangin
patterns of mountain gorillas. During this period, only 2 snares were removed from the home range use
by the Susa group. In our survey we were not able to assess the effect of illegal activities on mountain
gorilla ranging patterns, as it was a rainy season so water collection was limited.
20 5
Possible Implications of Climate Change on VNP’s Ecosystem Services
and Livelihoods
Changes in climate are expected to be a threat to VNP’s ecosystems and the livelihoods that depend on
them. The main impacts of a 1.5°C temperature rise and of more extreme and/or more frequent
occurrences of climatic incidents will be on food security; the quantity and quality of water and other
natural resources; human health; settlements; and infrastructure. Climate is a valuable but neglected
environmental resource (UNDP, 2005). Intact and robust ecosystems are critical for managing climate
change. This section analyzes the possible impact of climate change on the Volcanoes National Park
ecosystems services and livelihoods based on the survey conducted in the area surrounding Volcanoes
National Park.
5.1
Role of VNP in providing goods and services
Volcanoes National Park and the surrounding ecosystems are very crucial in providing goods and services
to nearby communities and even to communities far away from the boundaries of the park. The park
provides wood for various uses by both human and animal communities. Furthermore, the park provides
natural grasslands that are vital as feeding, breeding and escape grounds for wild animals.
Table 7: Main ecosystems functions goods and services provided by the VNP
Function
Good and services
Regulation
Climate regulation
Water regulation
Pollination
Soil regulation
Water supply
Habitat
Refugium
Nursery
Provision
Medicinal resources
Ornamental resources
Economic resources
Genetic resources
Cultural
Aesthetic information
Recreation and ecotourism
Scientific and education information
(Source: Field survey, November 2010)
Apart from tangible goods and services, Volcanoes National Park provides some intangible services.
Volcanoes National Park ecosystems also play an important role in the hydrology of lowland ecosystems
and thus their integrity has broader conservation implications. The afro montane vegetation characterized
by high evapotranspiration plays an important role in the high level of rainfall registered in the region as
well as in water catchment, releasing water slowly throughout the year for crops around the park
(Kayijamahe, 2007). For instance, the park on the Rwandan side covers 0.6% of the country’s area but
provides 10% of the water for Rwanda (Weber 1987).
VNP provides economic resources to the country and surrounding population. Mountain gorilla-based
tourism is the third source of income for the country, earning around $200 millions per year since 2007. Since 2005, park management has been sharing the benefits accrued from tourism activities with the local
communities through revenue sharing schemes in different fields, e.g. education, health, water or
economic ventures that are environmentally friendly. This is to ensure that the local people consider the
21 parks as essential to their own welfare (Nielsen, 2010). The revenue sharing has the objective of ensuring
sustainable conservation of the National Parks, with the participation of neighboring communities, by
contributing to the improvement of their living conditions (ORTPN, 2005). Other services include an
open-air laboratory for scientific research in various sectors.
5.2
Possible impacts of climate change and variability on VNP surroundings
Respondents expressed differing views of the current possible climate change threats to VNP ecosystems.
The following table summarizes the different answers given by people who responded to the
questionnaire.
Table 8: Possible impacts of climate change and variability on VNP and surroundings
Possible climate threats
Frequency of responses
Percentage
1. Food insecurity
2. Landslides and soil erosion
3. Water shortage
4. Biodiversity loss
5. Shifts in species distribution
6. Energy insecurity
7. Extractive use of forest resources
8. Increase in fire frequency/Intensity
6
8
13
4
9
3
11
7
30
40
65
20
45
15
55
35
(Source: Field survey, November 2010)
Food insecurity
The perceptions of surveyed people at 35% (n = 20) are that areas surrounding VNP may experience
changes in crop potential depending on the changing weather patterns.
Landslides and soil erosion
In the Volcanoes National Park region landslides are exacerbated by extremes of climate, including heavy
rainfall. This was reported by 40% of respondents based on their experience and indigenous knowledge of
the VNP region. The adverse impacts of this phenomenon include complication of water management
issues, loss of arable land, food shortages, and loss of infrastructure and human lives.
In recent times it has been challenging to manage the water resulting from heavy rains and accumulated in
the ravines originating from VNP. These ravines sometimes extend outside of the park, either as
intermittent or permanent rivers. In 2010 alone, at least 2 people died because of the water gushing from
the volcanoes region; many houses and crop plots have been devastated in the region surrounding
Volcanoes National Park. Local people and protected areas managers expect there will be an increase in
frequency of these events in the uplands, especially above 3,000m. This will provoke increased exposure
of VNP ecosystems and the surrounding population to extreme weather conditions.
22 Fig. 13: Landslide in Volcanoes National Park
Photo Abel MUSANA
Water shortage
Sixty-five percent of respondents think climate change is likely to affect both the availability and the
quality of water, which in turn impacts livelihoods. They added that near Volcanoes National Park, people
are used to going to fetch water from within the park during the long dry season. Furthermore, they noted
that rainfall is the primary source of water in the areas surrounding VNP. Increased temperature, seasonal
shifts and possible reduced rainfall, especially in the dry seasons, are increasingly leading to scarcity of
water resources for human and livestock consumption. This is already evident in some zones around
VNP.
Biodiversity loss
VNP is of both national and international interest with respect to biodiversity. Twenty percent of survey
respondents think the possible warming of mountainous areas will dramatically affect wildlife species.
For instance, the mountain gorilla is under threat, as are other endemic species found only in the VNP
region.
Shifts in species distribution
In Volcanoes National Park, mountain gorillas have been observed shifting their home ranges from lower
altitudes to higher altitudes during the dry season. This could be considered a precursor of what will
happen with climate change, as it has been proven that species typically respond to climatic stressors by
migrating and shifting their ranges to areas with more favorable conditions. Climate change is one factor
that conservationists in Volcanoes National park argue to be the cause of the seasonal movements
observed in wildlife. One of the facts given to prove the effects of climate change in Volcanoes National
Park is the reduction in the number of days there is snow at the peak of Karisimbi Volcano. While it used
to snow for many days during the long rainy season, it is now reported to be very rare.
Energy insecurity and extraction of parks resources
23 Forests, woodlands and wooded grasslands play an important role in climate regulation, but woody
vegetation cover seems to decline in the VNP surrounding region due to intense agricultural activities, as
has been noted by 15% of the respondents. Most energy resources in the surroundings of VNP are
obtained from woody biomass, which puts forests under tremendous pressure. Contributing to this
pressure is the very limited use of alternatives to wood as fuel. The end result of this high demand for
energy resources is the extraction of park resources, as 55% of respondents confirm.
Increase in fire frequency
Thirty-five percent of respondents were concerned about the possible increase of fires if current climate
projections are maintained. They stressed that fire is a major climate-related disturbance in the
mountainous forest, with pervasive ecological effects.
Fig. 14: Wild Fire in Volcanoes National Park , July 2009.
(Photo: A. Musana)
Habitat degradation increases the sensitivity of the protected area to extreme weather events that may
result in increased severity of wildfires. Some of these phenomena have already begun to be recorded in
the VNP region.
5.3
Relationship between climate and non-climate threats in VNP
Climate change will aggravate existing threats to Volcanoes National Park and worsen the current
situation where the protected area is facing serious illegal activities. It is important to recognize that
climate change has always impacted ecosystems and that human activities have been impacting
ecosystems for tens of thousands of years. It’s thought that global climate change may have significant
effects on species and ecosystems in Volcanoes National Park. Traditional threats may be superseded or
exacerbated by climate change and possible changes in rainfall patterns and higher temperatures, which
may result in significant changes in forest cover.
24 5.4
Mechanisms of the conservation of mountain gorillas’ habitat in changing climate
To mitigate the possible effects of climate change in VNP, some actions have been undertaken. The
following are the main efforts identified during the field survey.
Installation of weather monitoring stations
Climate change has been considered among lower priorities for biodiversity conservation in mountain
gorilla parks until very recently.
Fig. 15: Weather monitoring station in VNP
(Photo: Abel MUSANA)
In the past, there was a knowledge gap in the form of systematic records of climatic data to consolidate
long-term climate data within the range of the mountain gorillas. This was due to the many years of
insecurity the region has faced. Recently, to fill the gap, protected area authorities have set permanent
weather-monitoring stations in mountain gorilla parks to assess long-term climate trends in mountain
gorilla habitats and assess how climate affects mountain gorilla behavior (including ranging and feeding
patterns), plant phenology, etc. Three weather-monitoring stations have been installed in VNP since 2008.
Supporting local community to find alternatives to firewood
Upon realizing that there is a high demand for firewood among the population around Volcanoes National
Park, which attracts people to harvest resources from within the park, VNP authorities, with the support
of the International Gorilla Conservation Program (IGCP), have helped local community become familiar
with energy saving stoves. In total, 139 energy saving stoves have been constructed since 2007 in 3
sectors surrounding Volcanoes National Park.
Construction of water tanks around the park
By providing resources like water around VNP, the protected area authorities aim to reduce the impact of
the water shortage that happens in region, especially during the rainy season. This shortage also affects
water resources within the protected park. A seasonal shortage of water in areas surrounding VNP pushes
25 people to enter the park to fetch water. When people approach or enter the park to collect water, they can
opportunistically take advantage and collect other resources as well, such as bamboo or firewood.
Reducing the opportunity for casual resource extraction improves the integrity of the park as well as parkcommunity relations.
Fig. 16 : Collective and domestic water tanks around VNP
Through the revenue sharing scheme and with the support of conservation-oriented non-governmental
organisations like the International Gorilla Conservation Programme, Dian Fossey Gorilla Fund
International and the Gorillla Organization, a total of 71 collective water tanks have been constructed. In
addition, 34 small familiar cisterns have been constructed.
26 6
6.1
Discussion and Recommendations
Discussion
Mountain gorillas’ altitudinal ranging behavior
Many primatologists have pointed out that the distribution and abundance of palatable plant species are
among the main factors that affect the home range size of a primate. Milton and May (1976) found that
the home ranges of frugivorous and omnivorous species are larger than those of leaf eaters. The mountain
gorilla changes its diet through the seasons, subsisting mainly on bamboo and bamboo shoots during the
rainy shooting period, but utilizing a variety of fruits and seeds in the autumn. Seasonality of food
resources is probably a central factor in the range size and use.
The upper edge of the mountain gorilla ranging area is determined somehow by food availability.
Distribution of plants is assumed to be a function of climate. Actual ranging patterns of gorillas can be
determined by suitable vegetation for food availability. Fossey (1974) found that mountain gorillas
(Gorilla beringei beringei) appear to use altitudes in their home range differently in relation to the density
of available foods. Therefore, altitudinal distribution of food resources may play an important role in
regulating patterns of altitudinal range.
Spatial variation in food abundance and nutritional quality strongly influenced habitat use by all groups.
A change of home range size may also be the result of changing food resource distribution and abundance
as well as inter-population interactions. Vedder (1984) found that a mountain gorilla group at the
Karisoke Research Center, Rwanda, increased monthly home range size with decreasing rainfall, although
this was attributed to the relationship between rainfall and food abundance.
There is also a relationship between the number of individuals within the group and the size of the home
range. The Susa group, with 28 individuals, used more space than the Kwitonda group of 20 individuals.
The results of this study agree with the pattern of home range utilization relative to vegetation
distribution, which also depends on the climate. Mountain gorillas have an obvious seasonal vertical
migration and their home range size changes seasonally. Considering short- and long-term data for both
the Susa and Kwitonda groups, it can be concluded that during the dry season, the general trend for
mountain gorillas is to move large distances in search of food. In the wet season, mountain gorillas tend
to have smaller ranges as preferred foods like bamboo shoots are more available. New bamboo shoots
usually appear twice yearly (in May-June, and November-December or January) (Watt: 1998). However,
this trend is not always seen.
According to observation, the most frequently visited vegetation zone was the bamboo zone, which may
be attributed to two main factors. First, it could be because bamboo shoots are a preferred food for the
Susa group. Second, one might suppose the consequences of thermoregulatory constraints oblige
mountain gorillas to colonize lower altitudes in order to avoid the cold of higher altitudes. Additionally,
although the gorilla groups used all vegetation types within their home ranges, the proportion of use
differed among habitat types. A comparison between the proportion of different habitat types within the
home range and their use by the group showed a clear preference for the bamboo zone among the Susa
group and the Neoboutonia zone for the Kwitonda Group.
Nevertheless, it seems that effective use of the lower altitudes could be limited by the existence of forest.
The habitat where the Kwitonda group spends the most time is located at lower altitudes, but this belt
does not exist for the Susa group because the forest at lower altitudes in their home range has been
cleared during different deforestation periods. The upper edge of the ranging area is determined by food
27 availability and the presence of a suitable substratum. Short- and long-term historical ranging records of
mountain gorillas show that they’ve never ranged beyond the lobelia-senecio zone.
To conclude, comparing the results of this study to previous ones, there is little seasonal variation in the
diet of the mountain gorilla, probably due to the fact that most of their food is available throughout the
year (Watts, 1984), with bamboo shoots being the only food source that is only seasonally available
(Vedder, 1984; Watts, 1984).
As changes in climate are likely to result in the forest becoming warmer and drier (before becoming
wetter), this has the potential to affect the gorillas’ food sources. The gorillas could possibly respond to
such changes by altering their home ranges or possibly initiating a shift in diet to encompass different
plant species. A study conducted by Vedder (1984) in Volcanoes National Park indicated that in response
to decreases in the quantity of food available, mountain gorillas expand their range and travel further in
addition to altering their diet.
Climate change effects on ecosystems services in VNP region
“Ecosystem services are the conditions and processes through which natural ecosystems, and the species
that make them up, sustain and fulfill human life. They maintain biodiversity and the production of
ecosystem goods, such as seafood, forage, timber, biomass fuels, natural fiber, and many pharmaceuticals,
industrial products and their precursors” (Daily, 1997).
As ecosystem services provided by Volcanoes National Park are documented, it becomes apparent that
changes in climate parameters like rainfall and temperature are already having a negative impact. Extreme
weather conditions and irregularities in season succession are negatively impacting the services rendered
by VNP to the surrounding areas. Direct ecosystem services like erosion prevention have already been
affected by an altered rainfall pattern in recent years. Based on recent experiences of fire events recorded
in the park, it is predicted that if current climate trends are maintained, fire events will inevitably become
more frequent in the VNP zone.
6.2
Recommendations
The completed survey shows that there is some acknowledgement of signs of climate change in and
around Volcanoes National Park, and there are proposals for small scale piloting of adaptation strategies
proposed by people who contributed to the completion of the study. Respondents stressed that there are
inadequate data on climate change, especially in the zone surrounding the protected areas and in VNP in
particular.
The following are the suggestions formulated by respondents to this issue:
1. Establish or set up local data collection and monitoring centers according to agro-ecological
zoning in each district.
2. Improve accuracy of information by training and equipping local monitors and park staff to
collect and analyze data for local application.
3. Ensure that collection, interpretation and use of the data are accurate and timely.
4. Make the formally established collaborative mechanisms between the protected area and other
partners responsible for climate, hydrological and ecosystem data more effective.
5. Incorporate climate change issues in agriculture planning
6. Develop contingency planning for extreme fire hazard
28 7
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30 8
8.1
Appendices
Appendix 1: Externship data collection field sheet
AVERAGE DAILY TEMPERATURE:
AVERAGE DAILY RAINFALL: 1.Gorilla ranging movement data collection ( Questionnaire to Gorilla trackers) = Primary data
Date:
Time start:
Time end:
Group Name:
Name of the area ( Toponym): ____________________
Location: 35M
UTM________________
Altitude reached: _____________m
Vegetation zone where the observation has been made :
Neoboutonia
Bamboo
Type of Observation
Diet
Bamboo
Soil
Hagenia
HageniaHypercum
Nest
Direct observation of individuals
Fruits
Wild bananas
mushrooms
Ants
Hypercum
Senecio
Alpine
Tracks
Drinking Water
Invasive plants (which)
2.Open Questions to Park and Conservation partners managers:
Identification:
Name of the Organization.........................................................................
Type of Organization - Public
Non Governmental Organization
Area of intervention : Research
Ecological monitoring
Protection
Community livelihoods
Health
1. In your area of intervention,
what
are
non
climatic
stressors
that
are
impacting
on
mountain
gorillas
conservation
and VNP
ecosystem services
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
2. How do the mentioned non climatic threats affect mountain gorillas’ conservation and VNP ecosystem services?
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
3. Are you facing problems related to climate change and climate variability in your area of intervention?
.........................................................................................................................................................................................yes.....................
.........................................................................................................................................................................................................................
.........................................................................................................................................................................................................................
31 4. What are the threats linked to climate change are you facing in your area of intervention in the conservation of MG?
.........................................................................................................................................................................................................................
.........................................................................................................................................................................................................................
.........................................................................................................................................................................................................................
5. How do they affect the conservation of mountain gorillas in Volcanoes National Park?
.........................................................................................................................................................................................................................
.........................................................................................................................................................................................................................
.........................................................................................................................................................................................................................
6. What is the impact of climate change on the conservation of mountain gorillas based on your field of intervention
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
7. What is the linkage between climatic and non climatic threats that you’re observing in your area of intervention?
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
8. What is your institution has/ is or is planning to do to mitigate/ adapt to the climate change versus gorilla conservation?
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
..........................................................................................................................................................................................................................
Thank you
32 8.2
Appendix 2: Distribution of gorilla groups and precipitation trends
1. Location of Mountain gorillas groups in Virunga Massif
2. The monthly mean and 9-day average precipitation (mm/day) in VNP at 3000m a.s.l. (Seimon et
Al, 2010)
33 8.3
Appendix 3: List of Acronyms and Abbreviations
CARPE: Central African Regional Program for the Environment
DFGFI: Dian Fossey Gorilla Fund International
DTD: Daily Travelling Distance
E: East
GO: The Gorilla Organization
ICCN: Institut Congolais pour la Conservation de la Nature
IGCP: International Gorilla Conservation Programme
IPCC: International Panel on Climate Change
IUCN: International Union for Conservation of Nature
Km2: Square Kilometer
m: meter
MCP: Minimum Convex Polygon
n: Sample
ORTPN: Office Rwandais du Tourisme et des Park Nationaux
RDB – T&C: Rwanda Development Board - Tourism and Conservation
S: South
$: United States dollar
Tmax : Maximum temperature
Tmin: Minimum temperature
UNDP: United Nations Development Programme
UWA: Uganda Wildlife Authority
VNP: Volcanoes National Park
#: number
34 Acknowledgements
We would like to express our sincere gratitude to different people who helped us in some ways or other during this
research process.
First and foremost, our supervisor Doctor Elias Bizuru, for his guidance, good comments and rich discussions all
along the research process.
To the MacArthur Foundation, for their financial support to attend the climate change training course and for having
financed this research. We deeply acknowledge their contribution in this process.
To the Volcanoes National Park authorities for the immense support during our field work. Our sincere gratitude
goes to Prosper Uwingeli, the Chief Park Warden and to the dedicated team of trackers and rangers who contribute a
lot to the conservation of mountain gorillas and assisted us during the period of data collection.
To the National University of Rwanda, Department of Biology, for having played a facilitation role during this
research process.
Last but not the least, to friends and classmates that we met at the University of Dar es Salaam during the climate
change training. We shared the good and hard life of academic environment.
35