Hart Beat by Hart Rufe

First published August 8, 2012 ... Contact Hart at hartrufe@gmail.com

Florida Scrub Jay

The Florida Scrub Jay has never been found outside the state.

Endemics

“Why are you writing a birding article about a medicine that makes you go to the john?” my non-birding friend asked. “ENDEMIC, you dolt, not enema!” “Ok, so what’s an endemic?” An endemic is any kind of bird, animal or plant species that is “native to or confined to a certain region,” and not found anywhere else in the world.

Florida Scrub JayIn Florida there is only one endemic bird species, the Florida Scrub-Jay (above and right), found nowhere else on earth, only in Florida. It has never been seen outside the state. “OK, so why is the Northern Mockingbird the state bird of Florida instead of the Florida Scrub-Jay?” Good question, maybe we need to start a state-bird campaign for the Jay. Campaign basis: It doesn’t make any sense, the Northern Mockingbird is the state bird of Florida and four other states, but the Florida Scrub-Jay is the only bird in the world with the word “Florida” in its name. And besides, it’s prettier than the Mockingbird anyway.

Island Scrub JayUntil 1995 there was only one species of Scrub-Jay in the United States even though there were three distinct and disconnected populations of Scrub-Jays that never came in contact with each other. That year the American Ornithological Union, the final arbiter of all things bird related, based on extensive studies and particularly DNA analysis, separated scrub-jays into three separate and distinct species.

Thus was born the endemic Florida Scrub-Jay; the endemic Island Scrub-Jay (left), found only on Santa Cruz Island, part of the Channel Islands National Park, 22 miles off the coast of California and nowhere Island Scrub Jayelse in the world; and the much more common Western Scrub-Jay, found across much of western United States, and not endemic anywhere. Current population estimates put Florida Scrub-Jays at less than 6,000 and declining and the Island Scrub-Jay at 9,000 – 12,500 and stable, although Jewel and I had to work like blazes to find the one and only one pictured here.

All three Scrub-Jay species (incidentally, writing this article I learned that “species” is one of those words like “deer” where the same word is used for both the singular and plural) look pretty much alike. The Florida brand is somewhat lighter and grayer, with a gray forehead, while the Western and Island versions are bluer overall, but particularly with a dark blue forehead. The Island Scrub-Jay is noticeably larger than the other two and has the richest coloring.

To make it even more confusing, there is some thought that the Western Scrub JayWestern Scrub-Jay (right and below) should be split into two species because those along the west coast are different from those in the western interior. Where they overlap they do interbreed, but research on this question is on-going.

So why are here two endemic Scrub-Jays so far apart? Believe it or not fossil records disclose that the Florida Scrub-Jay evolved from ancestors two million years ago during the Pliocene when a large band of ultra-dry scrub habitat extended from Florida to California. As the seas rose and isolated the Florida peninsula the Florida Scrub-Jays were similarly isolated. However, the Island Scrub-Jay evolved in a different way because the Channel Islands are off-shore mountain peaks that were never connected to any land mass. Consequently, the Jays arrived there some 11,000 years ago in some unknown manner, and have now evolved, Darwin like, into their own separate and distinct endemic species. Thank you for listening, now I hope you wouldn’t have preferred reading about enemas.

Western Scrub JayDavid Sibley’s update to his popular guide regarding the Western and Island Scrub-Jays can be found at: http://www.sibleyguides.com/2007/07/distinguishing-island-and-western-scrub-jays/. For more information on Florida Scrub-Jays see http://www.birds.cornell.edu/page.aspx?pid=1691 and http://markgelbart.wordpress.com/2012/03/23/florida-sand-scrub-habitat-hosts-pliocene-age-relicts/.         For a more detailed discussion of the differences between the three species of Scrub-Jays see http://creagrus.home.montereybay.com/scrub-jays.html.

(Click photos for larger versions)