Koch’s giant day gecko, Phelsuma kochi, is one of the most abundant lizards found in the Mahamavo forest. At mid-day adults are a bright green colour. Previous research has indicated that these lizards will change colour from green to brown when hearing a variety of sounds, including alarm-calls from the Paradise Flycatcher, calls from the Madagascar Buzzard (a potential predator) as well as simply white noise. The biological mechanism for this colour change is well characterized, but the triggering stimulus is not. Colour-change is quite rapid occurring in about fifteen seconds or so and returning to its original green in just a few minutes. Colour can be quantified using standardized photographs and statistical comparisons can be conducted comparing hue, saturation and lightness values from photographs taken before and after stimulation. Colour-change here is sensitive enough that the specific characteristics of sound that cause colour modulation will be addressed. Other bird (and lemur) calls will be tested as well sounds of different intensity and frequency to determine the threshold levels required to elicit colour-change in these lizards. It will also be determined if these lizards can change colour in a quantitative fashion or if this is more of an all-or-nothing response.
Madagascar has declared 17% of its land as protected areas, but much of this land is already severely degraded, so the actual area of land under protection is much smaller. An alternative approach to assigning protected area status and prohibiting usage is to develop community managed areas such as Mahamavo, where there is a mosaic of protected and managed areas. DTZ, the German Technical Support Agency, has established a series of community managed forests in the Mahamavo area that appear to be successful and may form the basis for conservation and improving livelihoods in other parts of Madagascar. The Opwall teams here are monitoring how the forest structure and biodiversity in these community managed forests are changing over time to identify whether this management strategy can provide a viable alternative to national parks in terms of protecting biodiversity. The dry forests around Mahamavo have exceptional diversity with two species of diurnal lemur and another five to six species of nocturnal lemurs, two spectacular species of chameleons, three known species of leaf-tailed geckos, and many endemic birds. In addition to the forest work, the Opwall teams are also carrying out long term monitoring surveys in the adjacent wetlands, which have recently been given Ramsar status (a Ramsar Site is a wetland site designated of international importance under the Ramsar Convention).
In Madagascar it is the dry season so it is hot during the day (temperatures between 25 and 30 degrees Celsius) with extremely little chance of rain. During the evenings the temperature does drop to around 18 degrees Celsius with occasional cold spells getting as low as 14 degrees Celsius.
Fitness level required
Moderate. This project requires you to walk long distances, and although the terrain is relatively flat you will be walking mostly on sand which can be tiring.
Facilities are basic (tents, bucket showers, long drop toilets). The site has no phone signal or wifi.