Download Bekker - Mammals

Some notes on the terrestrial
mammals of Aruba Jan Piet Bekker
Known mammals on Aruba until 1992
• Sac-winged bat
Peropteryx macrotis
• Black rat
Rattus rattus
• Leaf chinned bat
• House mouse
Mormoops m. intermedia
Mus musculus
• Long tongued bat
• Vesper mouse
Glossophaga l. elongata
Calomys hummelincki
• Longnosed bat
Leptonycteris curasoae
• Arubian cottontail
Sylvilagus f. nigronuchalis
A little history
* 1894 Hartert: shot at
Noord: Arubian cottontail
Sylvilagus floridanus
nigronuchalis
* alike specimens around
lake Maracaibo
Venezuela
Continuing of history
* 1930-1940 P. Wagenaar Hummelinck:
studies on the fauna of the Neth. Antilles
* 1945 J. van Zijl: collected Sac winged bat
Peropteryx macrotis (2) at Seru Canashito
* 1960 A.M. Husson: Calomys hummelincki
and „Zoogdieren van de Nederlandse
Antillen‟.
Dr. A.M. Husson SJ
* Baiomys hummelincki
* 2 spec. 1930 collected
by W. Hummelinck
* Museum collection study
* Structure of M3 and penis
of C. hummelincki
* Three finger like proc.
of baculum: Calomys
hummelincki
Activities 1992-1995
•
•
•
•
•
•
Field observation
Batdetector
Live-trap
Hand capture
Hoop capture
Mist net
•
•
•
•
•
•
Tuttle trap
Traffic victims
Found dead
Owl pellets
Other predation
Tracks & droppings
Some results of bat trappings
*: new species for Aruba
bat species
harp trap
mist net
Pteronotus davyi*
other
2
Mormoops megalophylla
49
Natalus tumidirostris*
2
Molossus molossus*
5
1
1
8
Glossophaga longirostris
164
26
5
Leptonycteris curasoae
89
2
2
Total
304
34
18
Insectivorous bat
• Naked back bat Pteronotus davyi
Insectivorous
bat
* Leaf-chin bat Mormoops
megalophylla intermedia
* “T”-structure on back
* colony in cueva
Quadirikiri with 97% rel.
humidity
* present at two other
caves in low numbers
Question?
* Leafchin
bat:
what is
up and
what is
down?
Insectivorous
bat
• Funnel-eared bat
Natalus tumidorostris
Wela quarry ♂ and ♀
• possible exchange
between Paraguana
(Venezuela) and
Aruba
Insectivorous bat
• Mastiff bat Molossus molossus
Fructivorous
bats
* Long tongued bat
Glossophaga longirostris
intermedia
* sedentary species
* visits cactusses and other
flowers
* takes sometimes insects
* most frequent species
Longnosed bat Leptonycteris curasoae
Leptonycetris
curasoae
• Foraging on
columnar cactus
flowers & fruit
• Intermittent
presence on Aruba
• Ca. 1000
individuals
• Migrating species
from Mexico and
Paraguana (Ven.)
Inventarisation Aruba per km2
• 237 square km-blocks
• Live traps (60 + 4)
• Other animals as:
Hermit crabs, landcrabs,
Cnemidophorus arubensis,
Tropical centipede,
Pega pega
item
number
trapping nights
4381
C. hummelincki
18 (0,4%)
R. rattus
39 (0,8%)
M. musculus
130 (3%)
total mammals
187 (4,3%)
House mouse Mus musculus
House mouse Mus musculus
• General
characteristics of
distribution:
– in urban area‟s
– heavy grassy area‟s
– garbage
Calomys hummelincki
Calomys hummelincki
• General
characteristics of
distribution:
– not in urban area‟s
– on sparsely grown
grassy area‟s
Population
study at Vader Piet of
Calomys hummelincki
Home ranges:
adult male 4100 m2
adult female 713 m2
juv. male 700 m2
juv. female 1175 m2
Rattus rattus
relationship with
trees, urban areas
and caves
S. f. nigronuchalis
During 1992-1995:
widespread on Aruba
based on signs & tracks
sightings & dead spec.
- off urban area
- sufficient cover Opuntia cactus
threats
- urbanisation
- recent introduction of
Boa constrictor
Future mammals on Aruba
balanced
•
Threats:
•
Chances:
- Urbanisation
- Immigration (e.g. bats)
- Loss of cunucu
- Antropog. cosmopolitics
(e.g. Rattus norvegicus)
- Disturbance of caves
- Extinction
- Introduction or immigration
of new species
(e.g. Boa constrictor)
- Light or building depended
(e.g. M. molossus)
 Advice
-
Red list of Aruba
Closing
remarks
• Thanks to
• Richard & Edith van der
Wal
• Howard Reinert
• above all: Lize de Hoog