Cozumel Caterpillars, Boa Constrictor & Iguana
We visited the Mayan ruins at San Gervasio on the island. On a side trail we came upon one of many sinkholes. In this case a significant overhang (almost a cave) was created around the sides of the depression. A large colony of brown bats roosted under the overhang. Several trees grew out of the middle of the sinkhole. On one of the trees we observed two groups of caterpillars displaying very odd behavior.
They were in these circles, all head in, with one caterpillar in the middle. They were undulating in place but not moving about. They were all the same size and the one in the middle did not seem any different than the others. Unfortunately these pictures were taken with cheap underwater cameras so the resolution is not great.
They were in these circles, all head in, with one caterpillar in the middle. They were undulating in place but not moving about. They were all the same size and the one in the middle did not seem any different than the others. Unfortunately these pictures were taken with cheap underwater cameras so the resolution is not great.
Updates from http://groups.yahoo.com/group/TILS-leps-talk/ :
Chris Durden says:
Looks like *Ascalapha odorata* (Linne, 1758) = *Erebus odora* Auct. = The Black Witch = Mariposa del Muerto = Cuetla, Chiancuetla, Tepolchichic. Believe it or not this is a culinary delicacy in some parts of Mexico. A paste made from the body contents is toasted on the comal and served with tortillas and salsa.
William A. Woods Jr. (Woody) says:
I wonder whether they are collectively mimicking something? The group does look a bit tarantula-like, as long as we aren't counting legs. At all events, I would have to be rather a hungry avian predator to target that...
I googled and otherwise searched for references with various combinations of caterpillar-larva-group-brood-mimic-mimicry etc but found nothing about this.
Chris Durden says:
I understand the larvae do feed in groups. I have seen similar behaviour - all lined up in a semicircle - among what were probably notodontid larvae in Rondonia, Brazil.
Jorge Bizarro says:
"Have you seen the circle forming behavior before, in these or any other caterpillars?"
Yes! - In many Saturnidae larvae that stay on tree trunks... [Lonomia obliqua hemorragic accidents occur when someone smashes a pool of caterpillars in a trunk!] and Pereute species larvae (Pieridae) also aggregate in a circle mass but not in palisade fashion. Euselasia (Riodinidae) also form circular masses and palisade like only when feeding... isolated larvae starve to death..
Dan spotted this blind snake during happy hour one night.
This is a Texas blind snake (pic found on the 'net).
We spotted a batfish while snorkeling - this is a pic from someone else as I didn't have my camera with me - Doh!
Interesting story about boa constrictors on Cozumel - they were introduced in 1971 by a movie crew and their population is rapidly growing. We spotted this one at the side of the road. When we stopped we found it had captured and was eating a large iguana.
Interesting story about boa constrictors on Cozumel - they were introduced in 1971 by a movie crew and their population is rapidly growing. We spotted this one at the side of the road. When we stopped we found it had captured and was eating a large iguana.
The iguana was gravid and some of the eggs were expelled in the struggle and constriction. Three were completely expelled and you can see two more still in membrane.
We rolled the boa and iguana off the road so nobody would run them over.
It was amazing to see that the snake could eat a prey item this big.
We watched for quite a while but left before the boa had appreciably swallowed the iguana.
Goodbye, Cozumel!