Distribution of the local form:
Ankarana national park is in northwest Madagascar in region Diana. It is separated into two large areas by the Tsingys, an impressive needlestone formation. One side is the east, and the other is the west with its extensive dry forests. In contrast to the eastern area, the western part of the Tsingys is difficult to access via offroad tracks or by boat via the Channel of Mozambique. This is the reason for only very few travelers visiting this part of the national park. In the dry forest of Ankarana west, male panther chameleons are rust red, which is completely different from the local form of the eastern part of the same park.
Appearance of the local form:
The male panther chameleons in Ankarana’s western dry forest have a rust red to yellow-orangeish colour that is massively different from the local form of the other side of the Tsingys.
Gewicht = weight in grams, Kopf-Rumpf-Länge = snout-vent-length in cm, Weibchen = females, Männchen = males
Since 2015 we have been measuring the weights of chameleons we have found in Madagascar, as far as the animals (and our scales) are participating. So far there are only a few weights, in the long term an average weight in relation to the snout-vent-length It is important to know that all weights were measured towards the end of the rainy season (= best food supply), so they are probably maximum weights in Madagascar. Triangular symbols in females do not mean pregnant, round symbols mean pregnant. In the case of Furcifer pardalis, contrary to our original assumption, there have been no serious differences in the ratio of SVL to the weight of the individual local forms.
We have collected the data given above over several years with thermometers and hygrometers at the finding places of the chameleons. "Average temperature" means that values of a whole month have been calculated to one average value per month. For example all measured minimum temperature values of February have been calculated to one average minimum temperature for February. In plain language, this means single peak values of a day may be a little higher or lower than the average minimum and maximum temperatures. It is possible that a location has an average maximum temperature of 29°C, but one day during that month it had 33°C or even 35°C there.
Ankarana is a dry forest divided in two halfs by the famous Tsingys, needle stone rocks. Inside the dry forest, it is very warm during daytime all year long. During rainy season from October to April, temperatures above 30°C are rather usual and it often rains.
During dry season from May to September days are a little cooler, but still very warm. At night, temperatures don't really drop in rainy season, but in dry season temperatures drop to 15°C at night. Dry season, by the way, means really dry in Ankarana: The major part of the trees looses its leaves and there is few precipitation only every couple of days. The rivers that have been torrentially in rainy season, dry up completely only leaving the bare stony river beds.
We have measured UVB data with a Solarmeter 6.5 in spring (beginning of April) at the peak of activity of chameleons in Madagascar. We always measured the values that a chameleon could maximally reach in its habitat.
The habitat of panther chameleons in Ankarana consists of old dry forest with huge trees and very dense undergrowth. The sandy ground is covered by foliage. Shrubs consist of endless extremely twined plants in which it is really difficult to find the animals. Sometimes the panther chameleons here come close to the edge of the Tsingys. There are several rivers in the forest that become wild rushing waters during the rainy season and completely dry up during dry season.