Thursday, March 8, 2012

The Science Behind the Drake Bay Project

The Drake Bay Team - Helen and Kate, Pablo and Juan

The main aim of the project here in Drake Bay is to study the relationship between medium sized vertebrate frugivores (fruit eating animals like monkeys and birds) and timber producing trees. A more thorough knowledge of the reproductive success and disperser assemblage (number of species and the role they play in dispersing seeds) will help to answer some of the questions about the impact of selective logging, clear felling, fragmentation of the forest, reduction in genetic diversity of the tree species present, climate change and other pressures impacting tropical forests. Equipped with this knowledge, it is hoped that appropriate management strategies can be put in place to protect and conserve what is a highly sensitive, complex and dynamic ecosystem.

The fruit of the Virola tree

Our work of counting flowers and fruits still continues in earnest. This data provides important quantitative results of the productivity of the 65 female Virola trees within the 60-hectare study area. (A hectare is 100 meters by 100 meters, or 330 feet by 330 feet). There are many variables that affect fruit production. By collecting this data, careful analysis can be undertaken to give an indication of how far pollen moves between male and female trees, what the impact of male-female density in the forest is and what other factors are significant for fruit production.

Our precious find: a Virola sapling!

Once the trees start producing viable seeds, data will be collected on the fruit morphology. The fruit of the Virola tree is quite unique in that it is very rich in protein and fat rather than just sugars as with other fruits. This makes it highly desirable to frugivorous visitors. The data collected will include what's eating the fruit, when, how far and where it goes after it eats it. This work includes continued trap checks and, importantly, observations of the frequency, duration and consumption habits of the visiting animals. This has been found to vary from year to year. Some years toucans are the most important frugivores for seed dispersal, some years it is the monkeys. These variations in themselves prompt other questions that can, hopefully in part be answered by the project here in Drake Bay!

-Helen, GVI intern in Drake Bay