Download Observed bias in the Endangered Species Act list Aaron Johnston

Observed bias in the Endangered Species Act list
Aaron Johnston ([email protected])
Jennifer Rickwalt ([email protected])
Jesse Spivack ([email protected])
Florence van Tulder ([email protected])
ESRM 458 Winter 2011
Professors Marc Miller, John Marzluff, Vincent Gallucci
Abstract
We use this opportunity to examine two problems with the Endangered Species
Act (ESA), which may create a bias in the list of endangered species. (1) Public interest is
biased towards charismatic species and (2) knowledge of all species and their population
statuses are incomplete. We used chi-square analysis for all tests to evaluate the presence
of bias towards charismatic species within the list. Our results show that charismatic
species are listed more often (1) than expected, (2) as endangered rather than threatened,
(3) despite their modest quantity within extant species, and (4) than other non-charismatic
species within taxonomic groups. It is apparent from our findings that the species listed
on the ESA do not accurately represent extant endangered species. Our analyses illustrate
the ethical need to reevaluate the mechanisms that qualify a species to be listed on the
ESA. The lack of knowledge concerning the population dynamics of all extant species
coupled with a bias in the ESA listing process is catalyzing a rapid decrease in the health
and function of the Earths’ species and ecosystems. We recommend reassessment of
species jurisdiction, increasing environmental education, completing a census of all
species, and reinstituting the US Biological Survey.
Introduction
The intent of the Endangered Species Act (ESA) is to protect and maintain
species by preventing extinctions. As such, the U.S. Fish and Wildlife Services
(USFWS) declares “working with others to conserve, protect, and enhance fish, wildlife,
plants, and their habitats for the continued benefit of the American people,” as their
mission statement. We recognize positive and hopeful intent in this claim, however there
is a discernible bias for charismatic species within the list of endangered species
(hereafter, the list) that should be brought to light. However, some researchers have
suggested that endangered species protection is biased towards charismatic species,
which may conflict with the USFWS’s mission (Czech et al. 1998, DeShazo and Freeman
2003, Wilcove et al. 1993). Listing species based upon favorable qualities rather than risk
of extinction is inconsistent with the ESA’s mission and ignores potentially important
ecosystem functions of non-charismatic species.
Three spheres of influence that affect how the ESA is comprised include (1) at
risk species, categorized by their relative charisma, (2) media influenced public support,
and (3) governance institutions (i.e. USFWS and National Marine Fisheries Service,
Figure 1). Species interactions with the public sector lead to their nomination and funding
support, while involvement in the scientific community and with the rare biospheres add
a biodiversity component to listing decisions. This dichotomy of influences on decisions
about the protection of one species over another is a topic that will be addressed in the
paper. The ESA list falls under the policy domain of the USFWS, while being heavily
influenced by the general public, Non-government Organizations (NGO’s), and research
sectors. These sectors influence the actual mechanism of listing at risk species.
Our objective is to evaluate the effect of charisma on the list of endangered
species. Specifically, we examined the proportion of extant versus listed species with in
taxonomic groups. We hypothesized that there are more charismatic species listed on the
ESA. In addition, we determined (1) whether charismatic species were more likely to be
listed as endangered rather than threatened, (2) if more sub-species were listed for
charismatic species, and (3) if the proportion of charismatic species has changed since the
ESA was enacted. We assert that equality in the listing process for all taxonomic groups
will increase biodiversity, and consequently strengthen ecosystem function and stability.
Methods
First we classified all listed animal species (n = 1240) as charismatic or noncharismatic based on aesthetics, human interactions, and size. Charismatic species tend to
be large, pleasing to look upon, and have positive interactions with people. In addition,
several nuanced judgments were made regarding charisma. We determined turtles and
crocodilians to be charismatic (Babbit 1995). Due to common visibility, we listed all
birds as charismatic. Salmonids were assessed as charismatic due to their important
cultural value, but other fish were not. Insects, snails, and clams were all evaluated as
non-charismatic taxa.
Second, we created contingency tables to evaluate effects of charisma on list
membership (α = 0.05) using chi-square analyses. We estimated null proportions for each
test by applying our criteria for charisma to the number of extant species for taxonomic
groups represented on the list (speciesaccounts.org). Because charisma varies greatly
among mammals, we estimated a null proportion by applying our criteria to a list of the
mammals of Washington State as a surrogate for the entire class (The Burke Museum of
Natural History and Culture). We first compared the proportions of species within
taxonomic groups on the list versus those of extant species. We repeated this test
considering only vertebrates (null = 0.25) and vertebrates excluding fish (null = 0.46)
because the number of invertebrates and fish without listing status was overwhelmingly
high. We then compared the proportions of charismatic species on the list to a null
proportion of extant charismatic species, 0.014. Since charisma varied among mammals,
reptiles, and fish, we tested for biased within these groups separately. We determined
whether charismatic species outweighed non-charismatic species in terms of subspecies
listings. Finally, we analyzed the differences in proportions of charismatic species
between the original 1967 and the current list.
Results
The number of listed species within each taxonomic group was different from
expected when considering all groups (χ210 = 30,685; P < 0.001), vertebrates only (χ24 =
1,295; P < 0.001), and vertebrates excluding fish (χ23 = 588; P < 0.001; Table 1). The
numbers of listed species for most groups dominated by non-charismatic species (e.g.
insects, crustaceans, arachnids) were lower than expected, whereas the numbers for
charismatic groups (e.g. birds and mammals) exceed expected values. More charismatic
species were listed than expected (χ21 = 25,467; P < 0.001, Figure 2) and within the
taxonomic groups of mammals (χ21 = 67.3; P < 0.001), reptiles (χ21 = 583; P < 0.001),
and fish (χ21 = 857; P < 0.001). More charismatic species were listed as endangered
versus threatened than expected (χ21 = 15.1; P < 0.001). Charismatic species were also
more likely to be listed as a subspecies than non-charismatic species (χ21 = 3.03; P >
0.064). Finally, the proportion of charismatic species on the list has decreased over time
(χ21 = 5.42; P = 0.020).
Discussion
The results of our study support our hypothesis that charismatic species are given
ranking priority within the ESA. Our results are in agreement with other studies that
suggested a bias for charismatic megafauna on the list of endangered species (Wilcove et
al. 1993, Czech et al. 1998, DeShazo and Freeman 2003). Bias for charismatic species in
the list of threatened and endangered species is a product of many sources including
social constructions, the evolution of conservation biology, policy domains, and
incomplete knowledge. Interplay among these factors has influenced the list of species
since its inception perhaps more so than the statutory criteria upon which a species is
warranted for listing (DeShazo and Freeman 2003). We acknowledge that charismatic
species may be declining disproportionately because of their charisma or other associated
reasons such as economic value. Habitat loss, for example, is often the primary cause of
decline for species, and charismatic species tend to be large species that require large
amounts of habitat. In addition, many charismatic species on the list were game species
suffering from overharvest. Nevertheless, we believe the weight of evidence for bias
associated with charisma indicated the aforementioned factors are important. Here, we
examine each of these factors and discuss their effects on the current list of species.
Social constructions
People ascribe value to species based on many attributes including economic
worth, cultural value, recreational-use, aesthetics, danger, and charisma (Burghardt and
Herzog 1980, Kellert 1985). It should be expected that these social constructions would
be reflected in policies for conservation of species and particularly the list of species.
Czech et al. (1998) found high correspondence between beneficiaries of the Endangered
Species Act and social constructions of species. They derived social constructions of
species by surveying a random selection of people in the United States where individuals
were asked to rate and rank major taxonomic groups (e.g. birds, mammals, fish)
according to their importance for conservation. Social construction varied across groups
such that birds, mammals, and fish were classified as advantaged (ie. favored and
beneficiaries), whereas reptiles, amphibians, invertebrates, and microorganisms were
identified as deviants (ie. not favored and ignored). Some groups such as plants and some
mammals fell into intermediate categories and were considered as dependents and
contenders, respectively. Dependent species had favorable social constructions but did
not receive protection, whereas contenders had variable social constructions but
benefitted from species protections anyway. Consequently, some discrepancies between
the allocation of benefits and social constructions are evident, with plants and amphibians
holding the greatest potential for gains in benefits. Our criteria for charisma generally
followed taxonomic groups, so studies of distribution of species across taxonomic classes
(Wilcove et al. 1993, Czech et al. 1998, DeShavo and Freeman 2003) are relevant to our
discussion of charisma. Interestingly, the classification of some mammals as contenders
reflects the variability of social constructions for this group similar to our assertion of
high variability in charisma among mammals. Undoubtedly, the range of mammalian
species constituting pests and non-pests is wide and contributes to classifications of
contenders, but we suggest the range of charisma is also wide within this group.
Although Czech et al. (1998) classified invertebrates, microorganisms, and others
as deviants, survey participants indicated conservation efforts were warranted for these
species and that ecological importance and rarity were the highest priority criteria for
species conservation. Such responses may suggest that the public has always intended for
conservation efforts to afford unbiased protection of all species or signal a shift toward
this ideal. If the original list of species was indicative of historical social constructs, then
our finding of more non-charismatic species on the current list compared to the original
list suggests a shift in public views of conservation.
Evolution of conservation biology
Conservation biology is a young and multidisciplinary science that incorporates
other new sciences (e.g. genetics) in developing management goals and strategies. Over
the past century, ecological discoveries (e.g. island biogeography theory, source-sink
dynamics) and identification of ecological problems (e.g. climate-change, fire
suppression) have led to a rapid succession of ideas about conservation priorities that
ultimately affect which species are listed. While conservationists debate the importance
of conserving genetic versus ecological diversity for species (Crandall et al. 2000) and
whether single-species or ecosystem management is best, the most important
development in conservation biology affecting the list has been the concept of
biodiversity (Takacs 1996, Sarkar and Margules 2002). Many conservation biologists
believe stability lies in diversity because systems that become overly simplified are prone
to failure. Because we rely on ecosystems for resources, it is important to maintain
biodiversity. Whereas conservation goals focused on game management during the early
20th century, maintenance of biodiversity has emerged as a primary goal greatly
expanding the range of taxa considered a priority. Accordingly, recent studies have found
that lower taxa such as invertebrates, fungi, and insects play important roles in ecosystem
and food web dynamics (Maser et al. 2008). Although these ecosystem components have
captured the attention of conservation biologists, the list of species has been slow to
accumulate rare species of these groups.
Policy domains
Although Czech et al. (1998) found that the American public advocates
conservation of all species, bias for charismatic species on the list remains a product of
policy domains and obstacles in the listing process. Scott et al. (2006) argue that the
expansion of eligible species for listing was the most important factor for increasing
numbers of species on the list. The original list was composed solely of vertebrates
because the Endangered Species Preservation Act (1967) protected only “native fish and
wildlife”. The Endangered Species Conservation Act (1969) added mollusks, crustaceans,
foreign species, and subspecies. Plants and “smaller taxa” became eligible for protection
under the Endanger Species Act (1973). Still, few species other than vertebrates were
added to the list over the next two decades for several reasons. In 1978, distinct
population segments became eligible for listing but only for vertebrates. By this time, the
public and the USFWS had proposed listing for several thousand species (Greenwald et
al. 2006). In 1978, an amendment placed a time limit for listing decisions by the USFWS
resulting in withdrawal of many listing proposals. In 1981, the Reagan administration
proposed that vertebrates and vascular plants be prioritized for listing over invertebrates
and nonvascular plants (Tobin 1990). The proposal was never officially adopted, but few
invertebrates and nonvascular plants were added to the list during the 1980’s due to
political pressures on the USFWS (Greenwald et al. 2006). The Reagan administration
used legal maneuvers and political pressure on agency officials to delay and deny listing
to proposed species. A wave of species listed in the early 1990’s due to a new
multispecies listing approach and lawsuits by NGO’s ended with a moratorium on listing
species from 1995-1996. New administrative policies were subsequently implemented
restricting submission of petitions and exploiting loopholes that allowed USFWS to
circumvent lawsuits that led to high numbers of listings in previous years. Consequently,
few species have been listed in recent years, and many groups (e.g. invertebrates, insects)
dominated by non-charismatic species remain poorly represented on the list.
DeShazo and Freeman (2003) found significant effects on listing procedures
associated with oversight and appropriations committees. They modeled the odds of
listing as a subspecies versus species from 1989-1993 as a function of variables
describing species attributes (e.g. size, taxonomic group), responsiveness to statutory
directives, and influence of members on oversight committees. Party affiliation of
members on oversight committees rather than statutory directives dictated whether a
subspecies was listed and the allocation of funds. The number of Republicans on a
committee was positively associated with diversion from statutory criteria for listing and
negatively associated with the odds of subspecies listing. These results suggested that
decisions on whether to list a species were influenced by politics rather than species
endangerment. DeShazo and Freeman (2003) also found a positive correlation between
the size of species and their odds of listing and funding support. Committees with more
members generated greater funds for support of listed species regardless of party
affiliation. Since charismatic species are often large and have large homeranges that
cover several congressional districts, they likely garner more support from the multiple
representatives on oversight and appropriations committees adding to a bias in favor of
charismatic-megafauna (Restani and Marzluff 2002).
The petition process for proposing to list species incurs bias for charismatic
species because petitions are often submitted by special interest groups. The USFWS has
rarely proposed listing of new species since the first decade of the ESA because of backlogs of proposed species and poor funding to process proposals (Greenwald et al. 2006).
Most petitions are submitted by the public or NGO’s, and the number of NGO’s that
focus on charismatic species (e.g. birds) far outnumber those representing other species
(Table 2). Motivation and the capacity to organize relevant information for an effective
petition are likely greater for NGO’s than individuals. For example, the International
Council for Bird Preservation submitted petitions that proposed adding over 100 bird
species to the list in the early 1980’s. Furthermore, lawsuits from NGO’s have been
effective for adding species to the list which demonstrates the power of special interests
to influence the list (Greenwald et al. 2006).
Incomplete knowledge
Our limited state of knowledge about the population status of species is a serious
setback for recognizing declines of non-charismatic species. Most charismatic species are
large and conspicuous (e.g. condor), so population declines have been relatively obvious.
Some charismatic species were game species (e.g. salmon) that have been monitored
intensively to regulate harvests, so declines in their abundances were well-documented.
Knowledge of the existence of a species is a bare necessity for consideration of listing,
yet it is unlikely that this simple criterion has not been met for the majority of extant
species (Wilson 2003). Between 1.5 and 1.8 million species have been identified, but an
estimated 3.6 to 100 million species currently exist. The wide interval for estimates of
extant species is indicative of the uncertainty about unknown species; however, it is clear
a significant proportion of species remain undiscovered. Notably, about 80% of animal
species are nematode worms, yet no species are represented on the list. Moreover, the
number of bacteria species found in a small soil sample can exceed that for the class
Mammalia, but no bacteria are listed. Some species remain poorly understood but have
profound ecological functions such as Prochlorococcus that account for significant
organic production in the ocean (Wilson 2003). New discoveries of species for better
known taxa are still common. Approximately 2000 new plants are discovered each year
and the list of known amphibians has grown exponentially over the past century (Figure
3; Glaw and Kohler 1998, Wilson 2003). In contrast, discoveries of new mammal species
have leveled off. Clearly, knowledge of species increases with size and serious
knowledge gaps exist for small species that also generally lack charisma (Dunn 2005).
Dunn et al. (2009) indicated most extinctions are coextinctions of parasites following loss
of hosts. Furthermore, the disproportionate representation of birds and mammals by
NGO’s biases the knowledge base for these species because these organizations support
or conduct demographic research.
Recommendations for Action:
Having presented all this evidence, we come to the conclusion of our study and
would like to offer some recommendations for further action. There are many reasons
why the issue of bias in the ESA list needs to be addressed and solved. Firstly, we will
examine Aldo Leopold’s essay “The Land Ethic.” Leopold famously argues “a thing is
right when it tends to preserve the integrity, stability and beauty of the biotic community.
It is wrong when it tends otherwise.” Although this argument is over half a century old,
his logic still holds true. As a race, humans are therefore morally bound to ensure the
health of all planetary ecosystems, including the protection and preservation of species.
Expanding on this concept of species value is P.W. Taylor who in 1981 argues the
inherent worth of all animals. Taylor expresses the idea that we are responsible for
promoting good for the sake of the species needing protection, and not solely our own.
The well-being of each species, as well as our own is an end in and of itself in this lifecentered theory.
Realistically however, humanity is an essentially selfish race, and economics may
prove a stronger argument for many. The physical law of entropy says that natural
systems will tend towards chaos. Extrapolated to apply to ecosystems, it can be argued
that there is stability in diversity, and that those environments with the most interconnections and well adapted organisms in specific niches, will tend to be the most
productive (i.e. rainforests and coral reefs). This truth affects both our agriculture and
fisheries industries. It is difficult to argue with a growling stomach, and empty bellies are
a likely result of mismanaged crop and fishing systems. The only way to ensure that
these circles continue to produce enough food for humanity is to care not only for the
species and crops of interest, but for the environment in which they grow and multiply. It
is simple logic, but, if we ensure that each part of the circle, from clean soils and waters
to oft-overlooked invertebrates such as bugs and krill, is healthy, we ensure the
sustainability of the entire system, and the continuation of our food sources. Another
persuasive economic reason for species conservation is the blooming industry known as
eco-tourism. Growing rapidly, this is a sector of tourism that seeks low-impact and small
scale interactions with the environment. Typically, there is an educational component that
focuses on safe management of potentially rare-species, human rights activism and
respect for local tradition and culture. Rare-species conservation has the potential for
large attraction values and can bring new life and money into small communities.
Unfortunately, we are incapable from preventing extinctions. The best we can do
is to work to identify ecosystem engineers and keystone species for priority protection.
At the same time we can identify which species we can afford to lose (without too many
negative effects to the overall systems) so that we are able to distribute our resources
effectively. The best and quickest way to achieve this goal is to fill the knowledge gap
about the earth’s species. We suggest that a census of all biospheres be conducted using
the recent Census of Marine Life as a template study. This would provide an accurate
representation of the cycles and connections between systems around the globe. If this
project is too ambitious, we recommend the reinstatement of the US biological survey so
that we may at least categorize those species within our own borders. Educational classes
about ecosystems and the environment should be offered and public forums created to
raise awareness about the need for sustainable use of our resources.
For the science sector, it would be wise to determine the sensitivity of the tests we
ran to varying definitions of charisma. However, our results are so strong, that
significant variation is unlikely. Jurisdiction of the endangered species act list should
then be divided into appropriate eco-regions so that each system-type may be more
effectively managed (Figure 4). This will help resolve problems of “blanket policy”
trying to address vastly different problems in dissimilar areas and allow for more
effective attention to species of concern. The list, and its budget and funding also need to
be analyzed to determine the number of species which can truly be protected
simultaneously. It is better to recover one keystone species rather than to waste money
and resources in failed attempts to rehabilitate many.
It is important to act now, as soon as the bias has been identified in order to
prevent the loss of biodiversity, ecosystem engineers and keystone species. By removing
bias for charismatic species from the endangered species list, it will be possible to
increase the effectiveness of the act in protecting species that truly need help.
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Table 1. Number of extant species and the observed and expected values for those listed
as threatened or endangered under the Endangered Species Act by major taxonomic
groups.
Birds
Mammals
Amphibs
Reptiles
Fish
Clams
Snails
Crustaceans
Coral
Insects
Arachnids
Extant
9624
4452
5619
7914
24580
8000
40000
35000
6800
688136
53957
Listed
307
367
33
124
166
104
39
22
2
64
12
13.7
6.3
8.0
11.3
35.0
11.4
57.0
49.8
9.7
961.0
76.8
EVV
183.9
85.0
107.3
151.2
469.6
EVVEF
289.7
134.0
169.1
238.2
EV
1
1
Expected values (EV) for the number of listed species when considering all groups,
vertebrates only (EVVEF), and vertebrates excluding fish (EVVEF).
Table 2. Number of NGO’s specializing on taxonomic groups (Czech et al. 1998).
No. NGO's
Birds Mammals Fish
57
40
32
Plants
19
Reptiles Invertebrates Amphibians Microorganisms
5
4
1
0
U.S. Fish and Wildlife
Rare Species
Endangered Species Act/ List
Charisma
determined
Nomination to list/
funding derived
Public Support
Figure 1. Influences on the list of endangered species list.
Figure 2. Percentage of charismatic species on the list and for extant species.
Figure 3. Increase of valid recognized amphibian species from 1758 to 1995 (Glaw and
Kohler 1998).
Figure 4. Eco-region divisions proposed for jurisdiction of the endangered species list.