Saturday, June 09, 2012

Head-butting Bumphead Parrots!

What an awesome Fish! Source.

I always thought they looked like Buffalo, and now I know why.
Check this out.

From the paper.

Though rumored to use their forehead to ram corals prior to ingestion, the enlarged cephalic hump of Bolbometopon may be a classic example of a secondary sexual characteristic resulting from sexual selection, such as the massive horns in male bighorn sheep (Ovis canadensis). In addition, Bolbometopon males exhibit what appears to be an “ossified ridge” on the forehead that may serve a similar function as the cranial appendages of artiodactyls.

How could this dramatic aspect of its social and reproductive behavior have gone unnoticed?
We propose two reasons:
1) Low population densities resulting from overfishing dampen competition for resources (females or spawning territories) and/or disrupt the social system so that headbutting contests are uncommon and no longer advantageous.
2) Headbutting contests are common, but negative responses to humans in exploited populations preclude observations of natural behavior. Quantitative estimates of historical abundance are not readily available for Bolbometopon, but numerous sources employing indigenous ecological knowledge indicate that precipitous declines in giant bumphead parrotfish populations and decreases in catches correspond with increases in fishing pressure via the advent of spear guns and underwater flashlights

Story here.

The Bumphead Parrots are rare in Fiji.
Locally hunted to extinction by spearos who shoot them at night when they sleep among the corals, they can still be seen in Namena and above all, in the north at the Great Sea Reef.

Anyway, awesome stuff!

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