January 20, 2013

Florida Scrub Jay

The predicted "arctic blast" of cold air that I mentioned in my last post has indeed materialized here in Ohio, so I'm going to think about warm Florida today! As I mentioned in a previous post, a handful of birds occur in Florida and nowhere else in the U.S. The Snail Kite and Limpkin from that post do, however, also occur in Central America. One bird, the Florida Scrub Jay, can ONLY be found in Florida.

In fact, its very specific habitat requirements have limited its range to sandy scrublands in central Florida, which look like this:

Plants which are characteristic of this habitat include a variety of small, evergreen oaks, taller slash pines and sand pines, and an understory which includes saw palmetto and sand palmetto. This habitat has been vastly reduced, probably since the mid-1800s, for development of towns, citrus groves and pastures, and more recently for military installations, phosphate mining, tourist attractions, shopping malls, the space center...and on and on. 

The habitat is dependent on periodic fires, and fire suppression has further reduced scrub jay habitat. All of these factors have severely reduced the bird's population, but they can be reliably seen at Merritt Island National Wildlife Refuge, just north of the Kennedy Space Center.

Florida Scrub Jays are about the same size and shape as the Blue Jays here in Ohio, but they lack the crest and bold black and white markings. They look similar to the Western Scrub Jays that we had in our backyard in San Diego, but the Florida birds have distinctly different DNA and are therefore considered to be a separate species. They eat almost anything they can find, with insects being their main food; acorns are also an important part of their diet. Here is a picture of one out looking for food:

Success! This bird may eat this item, but they also bury acorns and other seeds which in turn helps to regenerate their habitat:

A couple of interesting behavioral characteristics are quite different from those of the look-alike western population, and, in fact, from most birds. Florida Scrub Jays use what is called "cooperative breeding" in which juvenile birds help to raise their parents' later offspring. They live in family groups of between two (a mated pair) to larger groups of up to 8 adults and one to 4 juvenile helpers. Breeding success is significantly higher when helpers are present than when they are not. 

Another interesting characteristic of these birds is that they often station a "sentinel bird" on a high perch to watch for predators while the rest of the family looks for food, often in open areas on the ground:

If a hawk or other predator is spotted, the sentinel gives an alarm call and all find cover.

Florida Scrub Jays have been extensively studied (note the bands on these birds' legs) and since their population has been severely reduced they are considered "threatened" by the federal government. Because they live in family groups, if birders are lucky enough to find one bird they might see at least a couple more. 

Here is one more picture of this unusual bird:


  1. I loved learning about the family groups. Are there other birds with similar behavior and if so, are there any variables that connect them?

  2. I haven't read a whole lot about it but apparently between 3% and 10% (depending on what article you read) of bird species worldwide practice some form of cooperative breeding--there is a lot of variation. There is a lot of research and discussion about how and why this behavior evolved without a whole lot of agreement. More species seem to exhibit this behavior in arid areas, and some studies have shown that there is less promiscuity in cooperatively breeding species. It makes sense for the helpers to help if they are fostering individuals with a good chance of having their same genetic makeup--indirectly increasing the chances of passing down their genes to future generations--even though it may only be their siblings' genes if the helpers never successfully breed. An interesting topic for sure.

  3. I also enjoyed learning about this sophisticated, social behavior (family helpers and sentinels). Do our Ohio blue jays do this, too? I think our jays are the prettiest that I've seen when compared to those in other regions.


    1. Blue Jays don't breed cooperatively like Florida Scrub Jays. The two parents are on their own, but at least both help feed etc till the young fledge. I agree that our Blue Jay is a spectacularly beautiful bird--they would probably be appreciated more if they weren't quite so common!