Download the 2013 programme - Operation Wallacea

throughout the day to record their activity budgets and foraging patterns. The number of
tourists present will be recorded at regular intervals to determine the relationship between the
number of tourists present and turtle behaviour. Sea grass samples will also be collected, dried
and analysed for nutrient content.
MI219 Reptile community ecology and behaviour in Madagascar spiny forest (Weeks 1 – 6)
The Malagasy reptile fauna has incredibly high levels of endemism, estimated at 94% but in
recent years a great deal of research has dealt with the issues of taxonomy and distribution
resulting in many new species discoveries and the identification of sites with localised
endemism. Work on the community ecology and behaviour of reptiles has received much
less research attention and it is these issues which students choosing this theme for
dissertation work will deal with. The skinks, geckos and iguanids of Ifotaka are the principal
focus and dissertations will be examining the communities of these taxa between different
habitat types and areas with differing levels of disturbance. The portfolio of methods being
used includes drift fences, pitfall traps, tree and ground cover objects and directed searching
on transects. A further set of dissertations will focus on the feeding ecology, habitat use and
thermoregulation behaviour by iguanids using focal sampling.
MN220 Colour and colour change in the chameleons, Uroplatus geckos or Phelsuma
geckos of Mahamavo (Weeks 1 – 6)
This topic focuses on quantifying the colours and colour change abilities of the Oustalet’s
chameleon and Angel’s chameleon in the Mahamavo western dry forests. Oustalet’s
chameleon is one of the largest known chameleon, Angel’s chameleon is restricted to the dry
western forests of Madagascar. Colour and colour change of chameleons is well known
worldwide and is yet surprisingly poorly studied. Chameleons can be brightly coloured and
still be very cryptic. They often exhibit rapid colour change but it is almost exclusively used
for communicating social status to nearby males and females and not for background
matching. They often show tremendous geographical variation in colour both within and
between populations and genders as well. Recent work has established the kinds of pigment
cells and their arrangement in the skin of several colour morphs of the Panther chameleon
found in different localities in northern Madagascar. There are at least five classes of pigment
cells that have a stereotypical arrangement in the skin. The same general array of pigment
cells can be used to generate a wide range of colours ranging from blue, green, yellow, orange
or red. Organelles within cells are apparently rearranged in a very specific way to accomplish
colour change and only certain changes seem possible. Very little is known about the colours
and colour variation of natural populations of chameleons in spite of a large captive breeding
program for the different colour morphs of Panther chameleons in the USA. A field
spectrometer applied to the skin, photographs and video will be used to quantify colour and
colour change by measuring the wavelengths of light that are actually reflected from the skin.
There are a wide variety of different topics relating to chameleon colour that can be
addressed at Mahamavo. One is to use data from colour and colour change from both
species to test a model that has been proposed for colour change based on the arrangement
and reorganization of pigment cells in the skin of Panther chameleons. A second topic is to
assess the range of variability in colouration both within males and females in natural
populations to compare colour heterogeneity between the two species of chameleons. A third
would be to assess the ability of both adult males and adult females to undergo rapid colour
change. A fourth would be to study how colours are used in intraspecific interactions in these
two species. Males tend to display to other males/females and gravid females tend to display
to males. A fifth topic would be to compare the reflectances from the chameleons to the
reflectances of elements of their surroundings, both physical and biotic. Other aspects of the
patterns on the lizards and even behaviours to examine the concept of crypticity of
chameleons in their natural environment.
MN221 Population ecology of Nile crocodiles in Madagascar (Weeks 1 – 6)
In Madagascar, Nile crocodile, Crocodylus niloticus have a stronghold in isolated areas of the
west coast including the Mahamavo wetlands. However, crocodiles are threatened by egg
collection for crocodile farms and by local people killing large crocodiles perceived to be a
threat. For these reasons, crocodiles are currently listed on CITES Appendix II in
Madagascar and international trade in crocodile products from Madagascar is banned. Since
there is very limited information about the crocodile population in Mahamavo, it would be
very valuable to make a robust baseline estimate of population size and to begin a
monitoring programme. Students selecting this project will be able to use a speedboat to
undertake surveys in the wetlands by day and at night using distance sampling and taking
photographs of basking crocodiles. The photos can be used to uniquely identify crocodiles by
the scale patterns on the left and right sides of the base of the tail. This permits ‘capture’-
‘mark’-‘recapture’ analysis of the crocodile population without the danger associated with
handling these animals. It would be possible to compare population size estimates derived
form distance sampling and the detection histories of the ‘marked’ animals. Additionally, it
will be possible to explore ranging behaviour, territoriality and estimate densities.
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