SCIENTIFIC NAME Leptodactylus fallax
KNOWN AS mountain chicken
LOCATION Montserrat and Dominica, Eastern Caribbean
CONSERVATION STATUS Critically Endangered
BIOLOGY & TAXONOMY
The Mountain Chicken is the largest of all living Leptodactylus species, and is one of the largest of all living frog species. It can reach a head and body length of over 20 cm, weigh over 900 g and live for up to 12 years. They have powerful hind legs, hence, their popularity as a traditional Caribbean dish and their common name of ‘mountain chicken.’ The frogs have striking patterns of dark bars and blotches which effectively camouflages them against the forest floor when they’re not hiding in burrows or rock crevices. Males
are extremely territorial and have wrestling contests to seize and defend territories.
Mountain chickens are the top endemic predator on Montserrat and are one of only two native frog species. They are most active after dusk when they hunt for insects, land snails, spiders, and even snakes. This is the time they also search for mates in the breeding season. Mountain chickens have an unusual breeding system with a high degree of maternal care. Females will produce a foam nest at the bottom of a male’s burrow into which her eggs are laid. The tadpoles develop within the foam nest as the male and female guard and defend the nest against intruders.
A mother will feed her tadpoles her own unfertilised eggs to enable them to grow (tadpoles reach an incredible 150 mm in length). Once individuals metamorphose and leave the parental nest, they receive no more care from either parent. In captivity, females have only been seen to produce one fertile nest of around 25-63 froglets per year, which is quite a low reproductive rate.
Interestingly the genetic composition of the Montserratian and Dominican Mountain Chickens is almost identical. This means they were either founded by the same stock or were introduced by man, presumably Amerindian settlers. As there is currently no effective treatment for the chytrid fungus the population of Montserratian Mountain Chickens seems to offer the best hope for the survival of the species in the wild.
The Mountain chicken is classified as ‘Critically Endangered’ in the IUCN Red List of Threatened Species. This means that they face ‘an extremely high risk of extinction in the wild,’ due to a drastic population decline (thought to be over 80 % over the last 10 years) as a result of hunting by people, volcanic activity, and the arrival of the chytrid fungus.
THREATS & PRESSURES
This is one of the most important threats to the surviving wild population of mountain chickens, on both Montserrat and Dominica. Mountain chicken is a traditional dish (and the national dish of Dominica) which makes it popular with both locals and tourists alike. In 1998 the mountain chicken was identified as one of the three most hunted species on Dominica by the Forestry and Wildlife Division. Although now hunting is banned on both islands due to the perilous state of the species.
The Soufriérè Hills volcano erupted in 1995 after 350 years of inactivity. Ash falls degrade the Centre Hills, whilst pyroclastic flows have all but wiped out the forests of the South Soufriérè Hills. Ash fall is thought to have a negative impact on insect populations which provide food for Mountain Chickens.
In Dominica chytrid was first identified in 2002 and the disease quickly spread across the island with the Mountain Chicken population declining by approximately 80 % within two years of the first confirmed cases. The Mountain Chicken population on Dominica is now very small and potentially not enough individuals are able to find each other to ensure that the wild population cab survive. So captive breeding and reintroduction may now be the only way for the species to persist in the long term. A captive breeding facility was established in Dominica and a breeding programme will be to be led by local Dominicans.
On Montserrat the first cases of dead frogs appeared in 2009 and chytrid was confirmed as the cause. Although the source of the fungus remains unknown, it is likely to have entered the island through frogs stowed away on shipments of fruit or vegetables. Within months of the dead frogs first being seen, mortality rates were similar to those witnessed on Dominica, with 80-90% of individuals dying. However as with Dominica there are a small number of frogs that survived and recent surveys indicate that they are in good health.
For more information about the chytrid please see the GLOBAL CRISIS page
Several species of invasive species occur on Montserrat including rats, cats, dogs, feral pigs, goats, cows and donkeys. Rats are one of the most devastating invasive species for the mountain chicken population as they are opportunistic omnivores. Rats will attack mountain chickens and leave them with nasty bites that can become infected, and also weaken them so that they become more susceptible to chytrid.
Montserrat’s water supply is fed by springs, so increased abstraction of water can reduce the moisture levels in ghauts and forests, thus reducing available water resources for the mountain chickens and possibly increasing the transmission of chytrid and frogs congregate around remaining pools. Feral livestock such as pigs can alter the vegetation structure of mountain chicken habitat, and goats grazing can prevent forests from regenerating. More research is needed into the effect of chemical contaminants from herbicides and pesticides on mountain chickens, but surface run-off through farmland could contaminate water courses used by them. Future development for housing could also threaten mountain chicken habitat.