the end of the cozumel thrasher?

October 21, 2005

in Birds,Natural history

WilmaHurricane Wilma, a slow-moving category 4 storm, is currently spinning over Cozumel Island off Mexico’s Yucatan Peninsula.  It is expected to remain there for the next 24 to 36 hours.  At this point, we are all familiar with the damage this hurricane can and will do.  Homes and businesses will be destroyed.  And it is likely that a unique bird will also be wiped out. This may prove to be the end of the Cozumel Thrasher.

The Cozumel Thrasher (Toxostoma guttatum) is endemic to Cozumel Island, and so few are thought to exist that it is categorized as critically endangered.  It was fairly common on the island until Hurricane Gilbert hit in September 1988.  After that, few birds were seen.  Two researchers from the Universidad Nacional Autónoma de México (National Autonomous University of Mexico) made 15 visits to Cozumel between 1994-1998, and found only three birds, two of which were mist-netted, the last in July 1995.

That October, powerful Hurricane Roxanne hit the island, and for years, there were few credible sightings of the Cozumel Thrasher.  Then in July 2004, a single bird was seen by researchers, reigniting the hope that the species was hanging on in small numbers.

Hurricanes and Cozumel are no strangers. Thrashers obviously evolved with and adapted to these storms.  It is theorized that introduced boa constrictors, now established after being released by filmmakers at the end of a shoot in 1971, have become important predators on nesting thrashers (as well as other animals on the island).  This added pressure may have made the birds vulnerable to hurricanes, unable to successfully regain their numbers after especially strong storms.

The fact that two previous hurricanes had such apparent devastating impacts on Cozumel Thrasher populations does not bode well for this species, considering the strength of Wilma and the amount of time it is expected to lash the island.  We might not know for years whether or not the thrashers are gone.  For generations they were able to cope with nature’s blows, but our carelessness once again may have created a situation from which the birds cannot recover. Already, it is a great loss.

That what we have we prize not to the worth
Whiles we enjoy it, but being lack’d and lost,
Why, then we rack the value, then we find
The virtue that possession would not show us
Whiles it was ours.
Willliam Shakespeare, Much Ado about Nothing, Act IV, scene 1


Cindy M. October 22, 2005 at 12:35 pm

certainly doesn't sound promising for the thrasher does it.. what a tragic loss.

Alan October 22, 2005 at 1:42 pm

One tragedy after another; each traseable to mankind's stupidy, arrogance, greed and selfishness. Little wonder, then, that so many people suffer from depression in a world of massive ecological damage.

Bob Curry October 24, 2005 at 9:52 pm

We still have hope that some thrashers on Cozumel may persist. We plan to conduct new surveys in 2006, supported by American Bird Conservancy. Donations in support of the research welcome! For more information about our efforts and Cozumel's avifauna, visit

Liliana Velasco Ariza April 19, 2009 at 11:46 am

The worst enemy of Cozumel wild life are some of human inhabitants, building without any other concer but a quick buck, no respect fornature, over depredation, nature is very wise and species evolve, what they cannot overcome is human depredation!

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