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Abstract.— Several key
locations were researched on the Ampasindava peninsula,
north-western Madagascar in June 2004. These locations were chosen
for their probability of having remaining patches of primary
vegetation. Next to the unexpected records of
Phelsuma quadriocellata, a
species normally occurring on Madagascar’s eastern coast, a new
species, P. vanheygeni (Lerner
2004) was discovered. Known distribution ranges for other
species were extended, however there presence on the peninsula was
expected. These species are; P.
abbotti, P. dubia, P. laticauda, P. madagascariensis, P. klemmeri
and P. seippi. The
first detailed report on the habitat of
P. klemmeri is made since
the description of the species by
Seipp in 1991.
Keywords.—
Phelsuma, Ampasindava
peninsula, Madagascar
Introduction
The Ampasindava peninsula is located in north-western Madagascar and
is part of the district (fivondronana) of Ambanja, province of
Antsiranana. Very few primary vegetation is present, except for a
few lower altitude rainforests in the higher regions of the
peninsula. The 18.000 inhabitants, composed of fisherman, farmers
and herdsmen, live in smaller villages spread over the region,
resulting in a high rate of “tavy” or slash-and-burn technique.
Large patches of forest are cut and burned to plant crops like rice
and coffee. The region is very poor and almost entirely depending on
its natural resources, increasing the pressure on the unique
ecology. There are several footpaths, not wider then 1 m, connecting
the villages and sea accesses.
Due to its isolation, the region has been very poorly researched for
its herpetofauna in contrast to Nosy Be, which lies about 20 km
north of the peninsula, particularly Lokobé forest, the only
remaining primary forest area of significance on the island. As late
as 1987 a new distinct species, P.
seippi (Meier 1987),
was described from the reserve. P.
klemmeri, also recently described (Seipp
1991) holds an even more taxonomically isolated position.
P. klemmeri was so far only
known from the type locality, indicated by
Seipp (1991) as the
coast of north-western Madagascar. A previous survey in 1994 (E.
Van Heygen unpubl.)
revealed that P. laticauda
laticauda and P.
madagascariensis grandis are present in the coastal areas
(beaches) of the peninsula.
The peninsula lies within the Sambirano climate belt, like the
island of Nosy Be and is climatologically influenced by the Massif
of Tsaratanana. The Sambirano domain (White
1983) has a typical microclimate with frequent heavy rain
alternating with clear skies. Nosy Be gets an average rainfall of
2030 mm a year on 175 days. The temperatures at higher elevations
are mainly moderate, between 15° and 25°C. There is a cool, dry
season between June and September and a warmer wet season during the
rest of the year.
The Sambirano domain is a centre of endemism and a biogeographical
transition zone between the species compositions of plants and
animals, of the western deciduous forests and eastern rainforests (Goodman
et al.
2003). Relatively little remains of the lowland forest
between sea level and about 800 m on the mainland. The highest peak
on the Ampasindava peninsula is 730 m, situated in the central part
and is still covered by a relatively large lowland forest. The
other primary forest patches are highly fragmented and confined to
the higher elevation areas. Some
Phelsuma species seem to benefit from deforestation and are
more abundant in open or cultivated areas then in their natural
habitat (Glaw &Vences
1994), but others like P. seippi
are only found in or on the edge of primary forests. The
Ampasindava peninsula has a high degree of secondary mature
vegetation which also can be considered as beneficial for many
species of Phelsuma, since
they seem to be more adaptive then other reptile genera or their
predators.
Methods
Prior to the survey,
maps and satellite images where compared to locate the remaining
patches of primary vegetation and mature secondary forests on the
Ampasindava peninsula. Detailed maps of the region were composed,
including rivers, footpaths, equal altitudes and other topographic
features. A total 5 different survey areas were selected for their
isolation, vegetation type and altitude spread over the peninsula.
When a survey area
was reached, the different vegetation types were determined and the
localities selected. Endemic palms,
Cocos nucifera,
Ravenala madagascariensis
and bamboo patches
were the main focus next to the primary forests. These localities
were surveyed for several days, during different hours of the day
for possible
Phelsuma
populations.
Results
The different sites and species are individually described below.
Exact and accurate locations are not given due to respect for
R. Seipp’s decision to
not reveal the type locality for P.
klemmeri for conservation purposes. It has to be mentioned
however that neither this species is as critically endangered as
previously suggested, nor is P.
seippi and P. vanheygeni.
Site 1
The first area surveyed is located along the western coast of the
peninsula ranging from 0 to 200m altitude. It concerns a relatively
long patch of primary forest on a mountain ridge along the
coastline. The long beaches are separated from the inland by long
rows of C. nucifera with
underlying low scrub and grasses. The coconut palms are inhabited
mainly by Phelsuma laticauda
laticauda. Surprisingly, P.
dubia is rather rare in this region and only a few isolated
animals were found. The lower regions more inland, up to 50 m, are
covered by secondary vegetation and extensive grasslands for Zebu
grazing near the few villages along the coast. A few immense bamboo
patches were examined near a small river; these were inhabited by
P. laticauda laticauda and
P. madagascariensis grandis.
In the mature secondary vegetation on trees up to 5 m
P. quadriocellata parva was
found, basking on a ø 4cm branch.
P. quadriocellata parva was so far only known from
Madagascar’s eastern coast. In a coffee plantation nearby many
juveniles of P. q. parva
were sighted, indicating it is certainly an established population.
Considering the remoteness of the area and the little economic
activity, it is very unlikely that this is a case of anthropogenic
dispersal. Within the primary forest itself very few
Phelsuma were found, except
for the occasional P. abbotti
chekei on the larger deciduous trees.
Site 2
This site is situated at higher elevations at the edge and in the
primary rainforest on a major mountain slope. The lower slopes are
all cleared, mainly for rice and coffee plantations. In the forest
are small patches of medium sized bamboo (ø 5 cm), confined by
larger deciduous trees and lush and thick vegetation. There where
the forest has been cleared by “tavy”, all vegetation has been
destroyed, except for the bamboo roots, which lie deep enough under
ground to survive the flames. Large bamboo forests are formed (Fig.
4) there since the competition for light and space is non existent,
especially not at the growing rate of this bamboo. In bamboo patches
within the thick forest, as well as in the secondary bamboo
forests, Phelsuma klemmeri,
Phelsuma madagascariensis grandis,
Phelsuma seippi and the new
species Phelsuma vanheygeni
was found. Phelsuma abbotti chekei
was not present, although it is mentioned by
Seipp (1991) that
Phelsuma klemmeri shares its
habitat with this species in the type locality. Only one
Phelsuma quadriocellata parva
was found at the edge of one of the bamboo forests and does
not seem to be common at this site. The presence of
Phelsuma klemmeri, Phelsuma seippi
and Phelsuma vanheygeni
in the secondary bamboo forests indicates that these species
are less vulnerable then suggested earlier. Before their habitat was
confined in fragmented bamboo “islands” within the primary forest,
but the destructive slash-and-burn technique of the Malagasy farmers
gave at least these species new opportunities because new bamboo
forests arose in previously cleared areas.
Site 3
Site 3 was chosen for its interesting setting; the primary forest
remains lie isolated within a valley, completely surrounded by
lower mountains of max. 300 m altitude. This site was only briefly
examined during the day and only P.
abbotti chekei and P.
madagascariensis grandis was found on the larger deciduous
trees and P. laticauda laticauda
on Cocos nucifera and
Ravenala madagascariensis. A
nightly survey of the area exposed a large specimen (300 mm) of
Uroplates henkeli with
orange coloured eyes . Animals found on Nosy Be are noticeably
smaller, around 250 mm, and have less conspicuous eye patterns (Glaw
& Vences, 2004).
Site 4
This site had the highest human population density resulting in a
limited amount of pristine forest, however bamboo forest were
abundant as expected. The terrain was relatively flat with minor
hills up to 150 m, covered with very dense bamboo forests. Within
these forests was a relatively high number of
Ravenala madagascariensis
present. On the Ravenala,
P. laticauda laticauda
and P. seippi was
found in high numbers. The bamboo itself was inhabited by
P. seippi as well and by
P. vanheygeni. The latter
was found only on the medium sized bamboo, never on any other type
of vegetation. Extensive searches for
P. klemmeri were
unrewarding, although it seemed to be the ideal habitat. An unknown,
rather small species of
Lygodactylus was also spotted on the bamboo to which it
seemed very well adapted. Down at the river, a mangrove patch was
inspected and a very blue form of
P. abbotti chekei (fig. 10) was found on one of the bigger
mangrove trees. One P. dubia,
several P. laticauda laticauda
and P. madagascariensis grandis
occupied the palm trees around the villages.
Site 5
This site was located within a pristine forest area at higher
altitudes (400 m). Within this forest a high number of endemic palms
(Dypsis sp.) could be found
including several bamboo and
Ravenala patches. The palms were only populated by
P. quadriocellata parva
while the other two types of vegetation were inhabited by mainly
P. seippi. On some of the
mature deciduous trees P. abbotti
chekei and P.
madagascariensis grandis was found. On one of the mountain
slopes a exceedingly large bamboo forest was surveyed. The searches
for P. klemmeri and
P. vanheygeni were rewarded
and several animals were carefully observed. Within the same habitat
P. madagascariensis grandis
and P. seippi were found.
The unknown Lygodactylus
sp., as found at site 4, was also present.
Climate
This survey was carried out in June-July, within the typical dry
season for the Sambirano domain. There was very little rain in this
period, and the relative humidity during the day measured as low as
45-50% at all sites. Even it did not rain for over a week, the
relative humidity at night was always around 75%. Towards dawn, it
rose even above 90%, generating high amounts of dew, turning
everything wet as if it had just rained. This phenomenon was caused
by the extreme drop in temperature at night, especially in the early
morning were temperatures as low as 16 ° C were recorded at all
inland sites. Daytime temperatures varied between 28 and 32° C. The
maximum relative humidity and maximum temperature values are
constant all year round (see Fig. 9) while during the dry season,
from June till September, the minimum temperatures (night time) drop
drastically, up to 50 %.
Phelsuma species
Phelsuma abbotti chekei
Börner & Minuth, 1984
The coloration of P. abbotti chekei
varies from one individual to the other. It ranges from blue
to green or grey, with marbled flanks and legs. The dorsal pattern
consists of red-brown dots and sometimes a median vertebral line is
present. It is a medium sized species that reaches lengths up to 145
mm, the females are generally a little smaller and duller in
colouration.
Their distribution range is for a Malagasy form quite extensive, it
occurs along Madagascar’s western coast from Antsiranana in the
north, as far south as Antsalova.
Phelsuma abbotti chekei is
mainly found on large sun exposed tree trunks outside and at the
edge of primary forest patches. On Nosy Be and on the Ampasindava
peninsula the species is also found in the coastal mangroves and
mangrove trees along swamps and rivers. In western Madagascar, in
the seasonal dry forests near Antsalova, the animals are found in
the larger deciduous trees. In urban areas like Antsiranana and
southern Nosy Be, they can be found on houses and in gardens.
Two further subspecies or known;
Phelsuma abbotti abbotti
(Stejneger, 1893) from
the Aldabra Atoll, Seychelles and
Phelsuma abbotti sumptio
(Cheke, 1982) from
Assumption Island, Seychelles.
Phelsuma dubia
(Boettger, 1881)
Phelsuma dubia is a medium
sized day gecko, males can reach a total length of 155 mm; females
remain somewhat smaller with 140 mm. These altogether flat, however
strongly built animals, possess a variable colouring, which can go
from light grey over grey green up to leafy green. The tail can in
some males appear bluish. On the back appear usually small spots,
only consisting of a few scales, which are brown to reddish-brown.
The ventral side is bright, partially dirty white coloured. A
distinguishing feature is the blue eye ring and the enlarged
dorsolateral scales. There is no substantial sexual dichromatism
except that the anal region of the males is yellowish .
Phelsuma dubia has the
largest distribution area within the genus. In Madagascar the
species occurs along the western coast, more concentrated in the
north west. Phelsuma dubia
is also found on all four Comoro Islands, the south Kenyan coast
near Mombassa, along the Tanzanian coast and its offshore islands;
Pemba, Zanzibar and Mafia Island. On the Ampasindava
Phelsuma dubia is not that
abundant
This species is extremely flexible, can inhabit a variety of
different habitats and is extremely anthropophilic.
Phelsuma dubia has a strong
preference for palm trees, Cocos
nucifera, for which it competes with
P. laticauda laticauda. It
can also be found on coastal
Ravenala madagascariensis and banana trees
Phelsuma
laticauda laticauda
(Boettger, 1880)
Phelsuma laticauda laticauda
can reach about 130 mm in total. The main coloration is vivid green
to yellowish green, with three pear shaped spots on the lower back.
The neck region is speckled with fine yellow dots, forming often
two parallel lines along the vertebrae. Two red lines are present on
the head, one is V-shaped before the eye, the other runs from eye to
eye. Sometimes a third line is present behind the eyes. The eye
rings are blue. Males sometimes can posses a bluish tail, normally
it is yellowish with fine reddish dots.
P. laticauda laticauda is
without doubt the most abundant species of the Sambirano Domain. It
is mainly found in the humid regions of northern Madagascar. Outside
Madagascar it occurs, on two of the Comoro Islands; Anjouan and
Mayotte, on the Farquhar atoll in Seychelles and it has been
introduced onto the Hawaiian Islands.
Like P. dubia, it can be
found in a variety of habitats except in denser forest regions.
Palms and banana trees are the preferred vegetation, but they can
also be found on Ravenala
madagascariensis, smaller deciduous trees and often in
gardens and on houses. Juvenile P.
laticauda laticauda was sometimes found on medium sized
bamboo, where the adults were also found only on the bigger species
of bamboo.
Phelsuma
madagascariensis grandis
Gray, 1870
This is the largest species found on the Ampasindava peninsula and
in the Sambirano domain with a total length up to 300 mm. The main
coloration is bright green with irregular patterns of red dots on
the back. A red line is present from the nostril to the eye, not
behind the eye like in the nominate form.
The southern part of the Ampasindava peninsula is the start of the
transition zone between P.
madagascariensis grandis and
P. madagascariensis kochi as some animals found clearly
showed the latter’s characteristics; marbled flanks and smaller red
spots on the lower back.
The distribution area is similar to
P. laticauda laticauda and restricted to the humid parts of
northern Madagascar. These two species are very abundant in the
Sambirano domain and the Ampasindava peninsula.
P. madagascariensis grandis
is found on a wide variety of vegetation, also within the primary
forest regions. Here it is found on
Ravenala madagascariensis, bamboo and the larger deciduous
trees. In the secondary vegetation areas the species can be found on
the larger trees, Cocos nucifera,
Ravenala madagascariensis
and in the bamboo forests together with
P. klemmeri,
P. seippi and
P. vanheygeni. The species
is also common in gardens, on houses and in cultivated areas.
No aggression was noticed towards the other smaller species of the
genus even not when they share the same tree. On one occasion a
Ravenala madagascariensis
contained three species, P.
laticauda laticauda, P.
seippi and P.
madagascariensis grandis.
Phelsuma
klemmeri
Seipp, 1991
Without doubt the most conspicuous of all species is
Phelsuma klemmeri. The
dorsal coloration is brown to turquoise with turquoise dorsilateral
bands. A black lateral line runs from the eyes towards the hind legs
and is interrupted at the ear openings. Before and after the ear
P. klemmeri has one or more
larger turquoise tubercle scales. This unique feature is only found
this explicit in two other species of the genus;
P. nigistriata, a bamboo
dwelling endemic to Mayotte and P.
pronki, a recently discovered arboreal species of central
Madagascar. The head and neck are yellow, the ventral coloration is
whitish while the region of the femoral pores is yellow in males.
P. klemmeri has a very flat
appearance and the scales are extremely small and smooth.
P. klemmeri was so far only
known from the type locality, indicated by
Seipp (1991) as the
coast of northern Madagascar. The species is widespread on the
Ampasinadava peninsula and is not as endangered as previously
suggested due to the fact that its habitat is actually extended by
human action as described earlier in the “Site 2” section.
This gecko could only be found on medium sized bamboo. When
disturbed they immediately retrieve in their hiding, usually one of
the many cracks in older dead bamboo which they easily can access
due to their flattened bodies. This species is very well adapted to
bamboo. Eggs are deposited in these cracks as well. They avoid the
hotter parts of the day and can only be seen in the early mornings,
in late afternoon or right after a shower when the sun comes through
again.
Phelsuma
quadriocellata parva
Meier, 1983
Phelsuma quadriocellata parva
is one of the smallest forms within the genus with a total
length of maximum 80 mm. The main coloration is green with an
irregular pattern of large red dots on the back. These dots often
form a line along the upper vertebrae. A post humeral black spot is
present often surrounded by a bluish ring. The eye ring is yellow,
the tail is strongly segmented and bluish in males.
The distribution of P.
quadriocellata parva was so far restricted to eastern
Madagascar around Toamasina.
Hallmann (1997) reports from a population in south-eastern
Madagascar in a primary rainforest patch near Befasy.
Budzinski (2001)
reported a population on Nosy Be, but assumed its presence was due
to anthropogenic dispersal since it was only found at one location
near a hotel which might had used building materials from eastern
Madagascar. The new records of the Ampasindava peninsula indicate a
natural occurrence in the region and probably also on the island
Nosy Be. This considerably expands the known distribution range of
the form and suggests a distribution pattern similar to
P. laticauda laticauda and
P. madagascariensis grandis.
On the peninsula P. quadriocellata
parva was mainly found within the primary forests on high
indigenous palms and in the secondary vegetation on smaller
deciduous trees and coffee plantations. Populations seem to be very
fragmented.
Phelsuma
seippi
Meier, 1987
Phelsuma seippi is a small
species, males reach up to 117 mm in length (Glaw
& Vences, 1994) whereas females are slightly smaller. The
main colour is green with scattered smaller red dots that often form
a median line along the vertebrae. A red chevron is present on the
head and a darker red stripe runs from the nostril through the eye.
The ventral coloration is pinkish with two dark chevrons on the
throat. Its closest relative is the from the east coast known
Phelsuma guttata
This gecko was known from its type locality on Nosy Be, Nosy Komba
and from Benavony (Glaw &
Vences, 1994) in the Sambirano domain. Phelsuma seippi is
actually widespread on the Ampasindava peninsula and seems to be
more abundant then on Nosy Be.
P. seippi prefers like
P. klemmeri and
P. vanheygeni bamboo patches
located in the primary forests or secondary bamboo forests and
Ravenala madagascariensis.
Phelsuma
vanheygeni
Lerner, 2004
This recently discovered species is one of the smallest of the
genus. The total length is about 75-80 mm in both sexes. The main
coloration is bright green with sometimes tiny red dots near the
lower back and tail. The ventral coloration is white, yellow around
the femoral pores in males. Characteristic is the yellow lateral
line, separating the ventral and the dorsal coloration that is
continued on the upper lip.
P. vanheygeni is only known
from the Ampasindava peninsula where it occupies similar habitats
like P. klemmeri and
P. seippi. It was found at
three sites out of five during the survey.
The species is confined to the medium sized bamboo (ø 5 cm). They
are very well adapted to the bamboo, when disturbed they immediately
retreat to smaller bamboo branches that are covered with small
leaves. These leaves have the same shape and colour as the animals,
making it almost impossible to locate them.
Reproduction.— The eggs of
P. vanheygeni are glued on
the inside of bamboo. The young hatch within 25 days at a daytime
temperature of about 27° C. The coloration of the juveniles is gold
brown with 4 fine green to dark brown median stripes. The young are
extremely small and measure about 25 mm. Regenerated skin of the
adults is coloured gold brown like in the juvenile stage.
Acknowledgements
I would like to thank my good friend and travel companion
Achim Lerner who
accompanied me during this trip and who also described
P. vanheygeni. Further I am
grateful to all Malagasy people we met during our trip and who were
extremely helpful, especially Laurent, Paul and “Hercule”.
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