Tuesday 21 September 2010

A little more about the research....

So I haven't had any daily diaries in use this week because of the attachment problems, I am waiting for some (small) harnesses to arrive in the post - Thanks mum! They should be here any day now and so I plan to tape the devices onto them then fit them on the Sloths nice and tightly so they won't be savaged or moved around! In the meantime my observations are going well - I have noticed a few interesting things.

Firstly they scratch a LOT ... and it definitley appears to be a communal behaviour. Nothing is known about this and it seems strange since they are naturally solitary. But when one begins to scratch, several others in the area ALWAYS start scratching too - so I plan to figure this out during my time here. We came up with the idea that the slow motion of the Sloth has evolved in relation to the speed at which a Harpy eagle recognises prey - so they generally move below that threshold. But when they scratch, they move more rapidly - 2 scratches per second on average ! With Rory's help we plan to find out if these scratching movements are above that threshold for a Harpy eagle's vision, and so find out if it is the scratching behaviour that gives them away. (This will involve Rory finding himself an eagle and moving objects at different rates in front of it!) If this is the case then it is possible that communal scratching almost acts as a dilution effect, reducing the chance that they will get eaten! - But I'm not so sure because they are generally solitary in the wild. Something funny is definitley going on though.

Another strange behaviour that isn't really understood is how they come down from the canopy once a week to defecate. It has been suggested that this is to avoid attracting predators via sound, but surely by coming down to the ground and spending a good amount of time down there is more of a risk? Especially considering they often use the same tree - fairly dangerous for a sloth that can't run away! So there must be some big advantage to coming down to the ground, and I think this could either be the transfer of Sloth moths or for communication reasons. No one really knows what sloth moths do, but in the wild they are covered in them! It is most likely that they feed from the algae growing on the fur, but it could be dead skin or mites etc. When I return to England I plan to bring with me some frozen sloth moths and a sample of the skin/fur from the sloth they were taken from. Back home the DNA from the moths stomach can be extracted and so we can find out exactly what they do eat and if it is in fact beneficial for sloths to have lots of moths!

One final thing I have noticed is that they craaaave salt! They will go crazy licking the sweat from your hand and particularly the bracelet I have that is salty from the sea. This is made more interesting by the fact that a recent study has described two-toed sloths in Peru feeding from human toilets - http://news.bbc.co.uk/earth/hi/earth_news/newsid_8659000/8659239.stm
They have suggested this could be for the mineral content, i.e. used as a way to get salt! So do sloths in the wild get salt from somewhere? I am going to see how their behaviour changes when given limited access to salt licks as one of my variables.

So that is pretty much what I am working on at the moment besides my behaviour scans. Once I get the harnesses and a thermometer I will be able to collect the baseline data and start manipulating their conditions to see what produces the most natural behaviours - it could be interesting !! :)

2 comments:

  1. Hi! I'm doing a project about Sloth's reproduction on my Animal Reproduction course (I'm a student of Veterinary, 2nd year) and since you're researching about them I would like to ask you if you could give some information or tell me some things about sloth's reproduction; like how they nurse their babies, or whatever that is related to their reproduction. Thank you in advanced.

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  2. Yeah sure, you can email me on rebecca.cliffe@student.manchester.ac.uk with any questions and I will do my best to answer!

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