Tuesday, September 15, 2009

Crochameleon ----- Heard that before?

Our 2007 hatched Morelet's crocodile Crocodylus moreleti babies (10 in all) were out-growing their nursery enclosure. Soon five were transferred to one of the aquarium exhibits in ‘Turtle Haven’ to lower the density. After about 2-3 months post transfer, the two separate ‘gangs’ were showing a lot of difference in behavior. The ones in Turtle Haven were so much bolder now. They weren’t scared or stressed out when visitors go close to see them. This could be due to the constant exposure to people and now they just got used to it gradually. The ones in the nursery would just dive underwater when approached.

The Turtle Haven gang would look at me curiously every time I stopped by their enclosure. Since I am also looking into enrichment of our crocs, I thought it was a great opportunity to take advantage of this boldness combined with curiosity. I started making them jump out of water as part of their behavioral enrichment. It is an amazing sight to see these small crocs jump! Sometimes they miss their ‘reward’ (piece of meat) and the reward ends up underwater. Then they start their treasure hunt. It is so cool to see their capabilities to ‘scavenge’ underwater. When I saw them find a piece of meat underwater for the first time, I was thrilled. Amazing! I was even more amazed to see them swallow the meat underwater! I always thought that crocs always come to the surface to swallow otherwise they end up swallowing a lot of water unnecessarily. But these guys were doing it all the time! WOW. I still don’t get the logic. May be it’s a trait with young crocs but who knows…

Young crocs grow really fast. Now after about a year, they have again out-grown their enclosures. I could also see a difference in their growth rate as enclosure space is also one of the factors affecting growth. The Turtle Haven enclosure is a bit smaller than the nursery and thus the nursery gang is a bit bigger than the Turtle Haven gang. So now on 12 September 2009, we transferred both the ‘gangs’ into one biggish enclosure.

Interesting stuff till now, but why is the title of this article called “Crochameleon”?

Well, there is one more really interesting difference between the two gangs. Their body colors! The nursery gang is pretty light colored and the Turtle Haven gang is pretty dark colored! They looked so different (colorwise).

Morelet's crocodile from the Nursery enclosure. Note the 'light' coloration.

Morelet's crocodile from the Turtle Haven. Note the 'dark' coloration.

My logic behind this is that nursery enclosure gets a lot of sunlight throughout the day; almost 5 hours of direct sunlight; while on the other hand, the Turtle Haven enclosure gets very little sunlight; about 1 - 1.5 hours, that too sometimes dappled due to the trees above. The dark skin color probably helps them absorb more heat. Now the cool fact is that they can and they did change their skin color to a certain extent! That is one classic example of adaptability.

Now that they are all in the same enclosure, I expect the skin colors to even out soon.

Croc rule!


Anil Garg said...

Amazing..... Love your posts

Unknown said...

It was awesome to observe the same thing Soham.