At least 50 species of fruit trees
in Madagascar depend on black lemurs
to distribute their seeds. This is
a vital contribution primates make
to their natural habitat ? without
them, many seeds would not be removed
from their tough husks. Furthermore,
some seeds can only grow after they
have been through the digestive system
of a primate! Just like bees, black
lemurs are also responsible for pollinating
plants.
Physical description:
The name “black lemurs”
is deceptive, in that only males are
actually black. Females are golden
to reddish-brown with dark faces,
light undersides and long white ear
tufts. They have yellow or orange
eyes, but another black lemur species
has blue eyes. Their average body
length is 41cm and tail length is
55cm, although females may be slightly
larger. On average, they weigh just
under 2.5kg.
Habitat: Black
lemurs live around the area of Narinda
Bay in northwestern Madagascar and
on the islands of Nosy Bé and
Nosy Komba. They like to live in primary
and secondary rainforest, but due
to ever-increasing destruction of
their preferred habitats, some have
adapted to timber, nut or fruit plantations.
Diet:
An estimated 78% of the black lemur
diet consists of fruit, and they have
been observed to eat fruit from at
least 70 different tree species. They
also eat leaves, flowers, nectar,
mushrooms and millipedes. Black lemurs
may also consume cashews, mangos,
papaya, citrus or coffee fruits grown
on plantations. Lemurs often feed
by suspending themselves upside down
from branches by their feet.
Life history:
Black lemurs are born after a gestation
period of just over 4 months. Females
have their first offspring around
the age of 2 years and subsequently
give birth no more than once a year,
around September to November. Offspring
can be a single infant or twins, which
are carried around by the mother for
up to 1.5 years. Young males and females
have been observed to leave the group
between the ages of 1–2 years.
On average, black lemurs live about
27 years in
captivity.
Associations:
Black lemurs share their habitat with
several nocturnal lemur species, with
which they presumably interact very
little. However, during the dry season
when there is less fruit available,
black lemurs have been found to be
“cathemeral”, which means
active at night as well as in the
day.
Social structure:
Group size ranges between around 4–14
individuals, depending on the composition
of the forest and fruit availability.
Larger groups are dominant over small
ones, and groups may split if they
become too large. Furthermore, males
often leave their group during the
mating season and females also sometimes
move to different groups. There are
roughly equal numbers of males and
females in a group, though a higher
proportion of males may also be found,
which is extremely rare amongst primate
groups. As with most prosimians, females
are dominant over males, which may
result in males being chased or even
physically assaulted!
Communication:
Black lemurs scent-mark by
rubbing their ano-genital region on
branches or tree trunks. The males
have additional scent glands on their
wrists and head, with which they vigorously
mark their territories. By scent-marking,
they can communicate things like “Where
am I?”, “How am I?”
and “Am I interesting for you?”
Black lemurs also communicate with
various calls to keep the group together,
some of which sound surprisingly like
quacking ducks! They also make small
grunting noises when travelling through
their habitat and purr like cats during
grooming.
Territorial calls are reported to
be given by entire troops at dusk,
but these vocalisations have not been
heard at Monkeyland. However, loud
calls may be heard in response to
territorial calls from our black &
white ruffed lemurs, who would not
normally share the same territory
as black lemurs in Madagascar. Loud
calls ending in a whistle are given
as alarm calls to warn the group about
predators such as birds of prey or
dogs.
In the case of humans, who are also
a serious threat to black lemurs,
huff-grunts have been recorded accompanied
by rapid swishing of the tail back
and forth. Subsequently, the whole
group flees
from sight.
Mating: Aggression
between groups increases during the
mating season (April–June),
presumably due to males competing
for female attention. Generally, a
dominant male will try to monopolise
mating. However, one subordinate male
was observed to mate with a female
6 times in 30 minutes whilst the dominant
male was not around!
Other behaviour:
Our resident black lemur Brad
was very shy when he arrived from
a Canadian zoo with severe cataracts
in both eyes. He could hardly see
and kept bumping into things in the
quarantine enclosure. We worried that
he could never be released. Everyone
was very relieved when his eyes were
successfully operated on by a specialist
in Johannesburg. When he recovered
from the operation, Brad was released
into Monkeyland along with the female
black lemur, Angelina. In their cage,
Angelina had always been the bouncier
one of the two and was dominant over
Brad. Upon release, however, Brad
immediately explored his new habitat
whilst a terrified Angelina clung
to the same tree for several days!
They are now both happily integrated
into the Monkeyland forest.
Conservation:
Black lemurs are classified
as Vulnerable to extinction by the
IUCN. They are also listed on Appendix
1 of CITES. Major threats are habitat
loss and degradation due to agriculture,
crops, wood plantations and wood extraction,
as well ongoing development of infrastructure
for humans. There are also reports
of illegal hunting of the black lemur.
One intensively researched group lost
40% of its members in a five-year
gap between studies. The black lemur
population is considered to range
between 10,000–100,000 individuals.
Their close relatives, the Sclater’s
black lemurs (Eulemur flavifrons),
are Critically Endangered since there
are only an estimated 100–1,000
of them left in the wild. Sclater’s
lemurs are also referred to as blue-eyed
black lemurs since they have bright
blue or turquoise eyes. Apart from
that and the absence of ear tufts,
they look exactly the same as normal
black lemurs.
Did you know?
Monkeyland is exactly the size of
a normal black lemur group’s
territory in Madagascar (12ha). Unfortunately,
their natural habitats are continuously
shrinking, mainly due to slash-and-burn
agriculture. Therefore, many more
lemurs are crammed into small areas
than can be sustained.
