Hi!
Finally I am updating this blog after its slow beginnings a while ago.
I am currently an Animal Biology BSc (Hons) student, although graduation is getting ever closer. I am looking forward to it but I think I will always miss this stage of my life.
Anyway, on to animals! Here are the wikipedia entries for the animals I covered in my last ever BSc essay style assignment!
Amazon River Dolphin: http://en.wikipedia.org/wiki/Amazon_river_dolphin
Amazonian Manatee: http://en.wikipedia.org/wiki/Amazonian_manatee
They both live within the Amazon basin, where there is an extreme difference between wet and dry seasons. The forest floods in the wet season, but the water drains in the dry, leaving little water and oxygen for aquatic inhabitants. Therefore the wet season is fantastic for the manatee, that can explore more areas in search of vegetation, but the dry season suits the river dolphin more as fish are at a higher density and easier to catch.
My assignment was centred on adaptations, so I investigated this the most, obviously. I found that both animals were adapted to living in flooded forest, as they have large flippers that aid fast turning around tree trunks! The river dolphin also has a neck that can turn 180 degrees.
Most adaptations are trade offs though, and in the case of manouverability in these animals, it also limits the speeds that they can swim at.
In the dry season the Amazon river dolphin feasts on fish that have become trapped in the low waters. However the Amazonian manatee has a very slow metabolism, allowing them to fast in this time when vegetation is scarce.
Interestingly, although it might be a requirement for life instead of an adaptive trait, the Amazonian manatee is only suited to warm environments. If the Amazon basin were to dry up, as some have predicted, and these manatees were banished to colder water, it is highly unlikely that they would survive.
One final thing I thought was interesting is about fighting in Amazon river dolphins. Adult river dolphins, especially males, bear many white scars. Researchers believe these are from the teeth of other river dolphins. Young dolphins didn't have many or any of these marks, and females didn't have many, so it was suggested that the marks are from male to male aggression. It is thought that competition for females is high, and that the males become extremely aggressive in the breeding season. One paper even suggested that it is the sheer volume of scars that turns adult male Amazon fiver dolphins white!
So this has been an 'animals to look up' post. The next post will relate to my favourite topic, animal genetics. Although I plan to do more posts on individual species I think most posts will cover genetics!
