Lhota Stanislay et al. researched the specialised use of the third and fourth finger digits in four Aye Aye of Mananara River from April through October of 2003. The researches were looking to find what foraging roles these fingers have and whether the fourth has a primary role in some of these behaviors. They hypothesized that the third finger is used for narrow space foraging, mobility and for sensitivity while the fourth larger digit would be used for scooping and penetrating into deeper spaces.
Finger functions were classified under four categories including probing, putting one digit in mouth, grooming with one digit and tapping with one finger on substrate. They then defined the foods consumed specifically for probing observations. These included coconut, kernels, jackfruit, soft tissue, and nectar.Using a combination of ad libitum sampling, for momentary behaviors, and instantaneous sampling, for 30 minute periods of observations,they were able to gather data. They used binomial tests on each individual and as a tally of the groups behaviors to come up with the following conclusions.
Both fingers were used for grooming and probing. The third finger primarily does tapping (almost solely). Only this finger is put into the mouth to take food off of it and may be used to pick teeth. It was used during nectar consumption and ant/insect consumption from within twigs, livewood, bamboo, and kernels. The fourth digit scoops coconut pulp into pieces for the third finger to extract, as well as being used to widen holes in softer woody substrates. Lastly, they discovered that the aye aye's fourth finger helps with supporting the animals position. This gives rise to the question that this may have led to the third fingers divergent form.
The Aye Aye's fascinating finger morphology and function is an interesting example of animal behavior and natural selection for specialized traits. I found this information to be very interesting. Please learn more here.
Posted by Shyla Morsbach(8)
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I was not aware of the aye aye before reading this, nevertheless it's extremely complex hand. Very cool! Could there be a selection for larger hands, since it seems like there would be a correlation between hand size and foraging success?
ReplyDeleteKevin Tse
It would be interesting to investigate patterns in history that could explain these divergent forms. Researchers could possibly look at how their diet changed over the years due to fluctuations in resources or migration to new areas. As a result, they would have to adapt to the new food sources and be able to handle them accordingly. Do you think researchers would find a link between the patterns and timing of the evolution?
ReplyDeletePosted by Katie Kalutkiewicz
I'm glad there are more research being done on these rare creatures. I only saw these primates on television and they don't even remotely look like primates we are familiar with. Do you think that because they are nocturnal has anything to do with their behavior?
ReplyDeletePosted by Leona Chan
What exactly is an aye aye? Even though I don's know what kind of animal this is, I think it is still interesting that there are specializations in fingers. Also where is the Mananara River? I'm assuming this is some sort of tropical area due to the food resources.
ReplyDelete-Katie Cyr
These are some strange creatures, but so fascinating! It's interesting that they have specialized fingers for a diet that seems quite broad.
ReplyDelete-Alex Sprague
Four aye-ayes seems like a small sample size to observe and draw conclusions about their behavior from. I wonder if in other environments, where there may be different food sources, if the use of each finger may change.
ReplyDelete-Muriel Herd
I was thinking the same thing. Is it possible that these aye ayes use the same fingers because of learned rather than innate traits.
ReplyDeleteCharles Carville