Dormant, who's dormant?
The South East monsoon season in the Seychelles is generally the drier of the two wind seasons. Within this monsoon season, August/September is a time when many Lesser Noddy chicks are within a month or two of fledging. As one can imagine, thousands of nesting seabirds keep Nature Seychelles researchers working on Cousin Island Special Reserve very busy. However, just as many other islands have experienced, Cousin received outstanding amounts of rain over a four-week period. The island was transformed.
Although this makes life a little more difficult for the people living on the island (mosquito outbreaks and wading through paths), it has also provided the much needed water at this time. It has also brought out an animal that was previously scarcely seen: terrapins.
And this is how you identify a terrapin
The “Torti soupap” or terrapins of the African genus Pelusios are found throughout the Seychelles. Other common names they are referred to are hinged terrapins, African mud turtles, and mud terrapins. There are three species of terrapins in the Seychelles islands, one of which is considered extinct. The other two, the black mud terrapin (Pelusios subniger parietalis) and the yellow-bellied mud terrapin (Pelusios castanoides intergularis) (Mortimer & Bour 2002) are found in marsh habitats and rivers/streams, and they are quite cryptic, making it difficult to determine population sizes.
The Seychelles Black Mud Terrapin's plastrons is yellow-grey with black patches
During dry periods, terrapins will remain in a state of dormancy. Just before the rains, one of the Cousin wardens found a terrapin lying on the top of a dried up swamp. It was very slow to move and highly unresponsive- probably in this dormancy state. Once the rains came, two more were found, but this time they were very active. Finding these terrapins created a great opportunity for Nature Seychelles staff and volunteers on Cousin to practice species identification by examining facial scales and shell patterns. The terrapins were all identified as the Seychelles Black Mud Terrapin. The three found were three different individuals, as could be seen through patterns on the shell, and they were all adults.
Great news for Nature Seychelles that there are still some resident terrapins on Cousin
The fate of terrapins is similar to that of many of the other wildlife in the Seychelles islands. As with turtles and tortoises, they were historically hunted for food and to make curios. The current threats are those of habitat destruction, predation by introduced animals, and marsh takeover by invasive plants. The wild population of the black mud terrapin in the Seychelles went from nearly 1000 adults in the late 1990s to around 660 by 2005 leading to a Seychelles Terrapin Plan being created in order to prevent further declines of this species. Reintroductions to different islands, in order to establish additional populations, were proposed and have been undertaken. In 2008, this terrapin was listed as inhabiting Mahe, Cerf, Silhouette, Praslin, La Digue and Fregate, and it was listed as being wiped out on Cousin and St. Anne islands.
Although three individuals do not signify a population, finding them confirms that Cousin Island still has terrapins, and Cousin residents will be keeping their eyes out for more!
By Cheryl Sanchez
Science Coordinator, Nature Seychelles