Saturday, 18 August 2012
Frogs of Bristol 7: Green Mantella
Green Mantellas come from the extreme North of Madagascar, where they live near streams in dry forests in limestone karst landscapes. Although they are still locally common, and can be found in commercial Mango plantations, their natural range is extremely small, and habitat degradation and deforestation is a considerable threat. In deforested areas, lack of ground cover results in permanent streams disappearing, and they have no adaptations to survive drought. As a result they are classed as Endangered by the IUCN.
Green Mantellas are fairly large for a mantella, with a body length of 25-30mm, and are usually to be found living in leaf litter. They can climb, but not well, and are almost always found on the ground. This is also where they lay their eggs in clutches of up to 60 eggs, in tree holes or under wet moss, with the tadpoles hatching after a few days to be washed into the streams. As with other mantellas, the tadpoles feed on algae and detritus in the wild. They metamorphose into froglets at 45-65 days old.
In captivity Green Mantellas are long lived as adults, but hard to breed. Some water movement in the enclosure and frequent misting, which simulates the rainy season, seem to encourage pairing, as does having more than one male per female to encourage nuptial combat and calling. As with almost all mantellas, they are prone to heat stress, and temperatures above normal room temperature are not required. They have big appetites for their size, and will feed on small crickets, fruit flies, hatchling roaches and similar size live food.
This year we managed to breed them for the first time, and visitors to the Amphipod can see the first batch of around 80 tadpoles, now around 1 month old. Hopefully we will be as successful with Green Mantellas as we were with M.aurantiaca, and will be able to distribute them to other collections once the froglets have grown on. In view of the status of all the mantellas, if any readers have this or other species (they were exported for the pet trade extensively) then your individuals represent a unique founder population and should if at all possible be in a breeding set up. If you are not up to breeding them yourself, please do your best to pass them on to someone who will.
For more information on captive care of mantellas, see Marc S Staniszewski’s page on the various mantella species at http://www.amphibian.co.uk/mantella.html
Next week, a new series on pheasants and gamebirds at Bristol and elsewhere
(images from wikipedia)