Thursday, June 16, 2011

Greetings from London

16 June 2011

Hello and thanks for reading one of my many posts (stay tuned!) from London. During my first few weeks at the Zoological Society of London (ZSL, also known as the London Zoo), I have learned a bit about what goes on in a typical day for a keeper at the world’s oldest scientific zoo, did my best to understand what the Brits are saying (I’m slowly getting used to it), collaborated with a lot of great individuals maintaining the animal records for the partulid species management program, and of course – trying to get over my jet lag. Some of you are probably wondering what I’m doing in London if I’m supposed to be studying Tahitian partulid tree snails. The logical starting point would be to give you a bit of background information.


The problem

Keepers at the London Zoo maintain many of the records associated with the many vertebrates and invertebrates collection kept here. For the purposes of my project, I am only interested in the invertebrate collection, which also includes breeding programs for endangered species such as Partula snails. One of the most infamous recent cases of endemic mass extinctions has involved the well-known endemic partulid tree snail fauna of the Society Islands, French Polynesia. In the 1970s, a misguided biological control program introduced the carnivorous Rosy Wolf Snail (Euglandina rosea), a Florida native, to French Polynesia. The (misguided) rationale was that it would control another invasive (the Giant African land snail) that had become an agricultural pest. Unfortunately, the predator’s major impact was on the endemic snail fauna and it directly caused the mass extinction in the wild of all but 5 of 61 endemic Society Island partulids; approximately half of all species in this Pacific Island land snail family. Emergency interventions in the 1980s and 1990s led to the successful establishment of international captive populations for 15 Society Island species that are coordinated by the Partulid Global Species Management Programme headed by Paul Pearce-Kelly at the Zoological Society of London (ZSL).




Adult Partula with the fully formed lip





Elaine demonstrates how the Partula species database works and what the different parameters mean.


Don, one of the keepers responsible working on the global species management program for Partula cleans the containers and records all of the individuals as well as the different development stages (newborn, juvenile, subadult, and adult).

The role of a good zoo

Ongoing surveys in the island of Tahiti have shown that some of the partulid species (P. clara and P. hyalina) have continued to persist. This is most surprising because predation models predict partulid snail extirpation within three years of initial predator contact. The captive populations at the London Zoo provide a “common garden experiment” where environmental differences are minimized and endogenous differences in demography are tractable.
Fortunately, the zoo populations include Tahitian partulids: P. hyalina and P. clara as well as valley species that did not survive in the wild, e.g., P. nodosa & P. affinis. These captive lines have been carefully maintained for 20+ years and a large amount of demographic data has been recorded at the ZSL: growth rate, longevity and reproductive rate per holding tank of captive snails. However, these data are still in a raw form and have not been collated and analyzed comparatively. So, my primary goal would be to access and extract these captive demographic data and to analyze them quantitatively. Containers with individual species of Partula

That’s it for now, stay tuned for my many more snail adventures!!!

1 comment:

  1. Hi Cindy, I look forward to reading more snail tales :) I am traveling around the world this summer vicariously through you guys! Thanks for posting.

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