Posts Tagged ‘Western Scrub Jay’

The American Ornithologists Union (AOU) is, among other things, the arbiter of avian taxonomy in Middle and North America. They are the organization that rules on whether a species should be split in two, or if two species should be lumped together. They are the organization that rules that Loons are no longer the most basal group of North American birds, but that they group that contains ducks, geese and swans holds that honor. The AOU releases all these decisions in the form of annual Supplements to the official AOU Checklist (which is a complete list of all bird species and subspecies listed in taxonomic order).

A lot of science has to be done before the AOU makes any of these ruling, and these ruling are subject to change as more science is done, but at any given time, the current AOU Checklist represents the best available knowledge on how many species of birds there are and on how they are  all related to one another.

Well, the AOU just released their most recent Checklist Supplement and it has, among the many updates and changes, an interesting change for California. Since that is where I live, I am particularly interested in this one. It concerns a common member of the corvid family that anyone who has spent any time outside has seen. The Western Scrub-Jay (Aphelocoma californica).

This species has actually already had an interesting history in the taxonomy world. Before 1995, there was one species recognized as a Scrub Jay (Aphelocoma coerulescen). This species was found across the western USA and also in Florida. In 1995, the AOU split the Scrub Jay into three distinct species. They were the Florida Scrub-Jay, which retained the original scientific name (Aphelocoma coerulescens), recognizing the Florida population as genetically distinct; the Island Scrub-Jay (Aphelocoma insularis) recognizing the population found on the Channel Islands off the coast of southern California as genetically distinct; and the Western Scrub-Jay (Aphelocoma californica) which included all the remaining populations in the western continental USA.

California Scrub-Jay - Frank Lang

California Scrub-Jay (Photo credit: Frank Lang)

Now, in the most recent AOU Checklist Supplement, the Western Scrub-Jay has been split again. We now have the California Scrub-Jay (Aphelocoma californica) recognizing that the population along the Pacific Coast is actually genetically distinct from the Woodhouse’s Scrub-Jay (Aphelocoma woodhouseii) found in the inter-mountain west.

Woodhouse's Scrub-Jay - Robert Mortensen

Woodhouse’s Srcub-Jay (Photo credit: Robert Mortensen)

In addition to the genetic distinctions, these two new Jay species also have behavioral and morphological differences. The California Scrub-Jay is darker in color, generally lives in Oak woodlands, and eats a range of seeds including a lot of acorns and so has a heavier bill. In contrast, Woodhouse’s Scrub-Jay is lighter in color, generally lives in the Great Basin pinon-juniper scrublands, and correspondingly eat a great deal of pinon pine nuts and juniper berries and so have a slimmer bill.

So, update your life lists, start getting used to using the new four-letter codes of CSJA (now standing for California Scrub-Jay) and WSJA (Now standing for Woodhouse’s Scub-Jay, and not Western Scrub-Jay that it used to identify), and enjoy picking apart the finer levels of identification between these two newly recognized species!

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For the past few days, a fledgling Western Scrub Jay has been hanging out in the bottlebrush just outside my office window. It has been pretty fun to watch this bird get used to the world at large.

A lot of time is spent screeching for its parents who make frequent visits to the bottlebrush to deliver food items. I can always tell when one parent is getting close because the screeching gets much louder and more intense as the parent approaches. Both adults visit this bush a lot, and I have not seen them take food anywhere else, so I suspect this youngster outside my window is their only fledgling this year. Hearing the screeching over even this short period of time has been interesting because the bird has been getting better at it. Each day, this young jay is sounding less and less like a young and inexperienced bird, and more and more like a normal, adult Western Scrub Jay. It is cool to be able to actually hear the practice paying off.

While it waits for it parents to bring it food, the young bird with its greyer and fluffier feathers, spends a good bit of time jumping from branch to branch within the bush. It has a bit of an obstacle course set up for itself as it bounces around and around in circles all covered by the protective foliage of the plant. As it moves around, it does some practice flapping and a lot of very precise movements as it improves it fine motor control. It also is practicing hunting. When it sees an insect or other potential prey in or around the bush, it jumps after it and attempts to catch it. It is sometimes successful, but usually these successes are made against pretty easy to catch animals. It did really well catching a snail.

It and I did have one funny interaction. Most of the time, I am sitting at my desk and the bird does not seem aware of me at all. At one point, however, it saw something on the glass or at the edge of the window and flew right to it perching on one of the small dividers between panes of glass. When it landed, clinging with just the tips of its toes rather awkwardly it pauses a moment and looked through the glass and into the room. That is when it saw me and was very surprised indeed! Whatever brought it over to the window in the first place was forgotten as the jay jumped right back into the bottlebrush. It certainly learned that there are humans in the world!

Hopefully, this young bird continues to improve its skills and makes it through its first winter (the hardest part of a birds life) and can teach its own young some of the valuable lessons it is learning.

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A bit after moving into our new place I cleared out the dead plants from the back yard and, on the 5th of September, I set up our bird feeders.  I was very eager to see what birds found the feeders and of what species they might be.  I waited and waited, watching the feeders every morning, but no birds found them.  Brewer’s Blackbirds, Red-winged Blackbirds, Western Scrub Jay, American Crows, and House Finches (all of which visit seed bird feeders at least occasionally) fly over our yard daily, yet none explored our yard.  I was quite surprised when a week passed without a single visitor.  I had fully expected the birds to search over their habitat regularly and thoroughly enough to find a new food source much faster than this.  To make our yard more attractive to passing birds I placed a few handfuls of seeds on top of garden wall that is near the spot where the feeders are hanging.  A couple more days passed without incident.  Then, two days ago, I say a Western Scrub Jay on our roof looking at the seeds on the wall.  It considered them briefly before flying off without coming down.  Yesterday, I saw what I am guessing to be the same bird on our roof again.  It flew back and forth from of the roof of the house to the roof of the garage a few times looking at the seeds from every angle, but again it flew away without coming down.  This morning, I again saw a Western Scrub Jay on the roof of the garage.  It perched there for a few minutes, and then made the decision to drop down onto the top of the wall where the black oil sunflower seeds lay scattered.  One by one, it quickly picked out about a half dozen in its bill and then departed to eat them elsewhere!  Our first avian visitor!  I wonder what will happen next!

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We have two bird feeders hanging above the little patio of our apartment, and the most regular species that we have as visitors are House Finches.  We have them all year round with large numbers in spring and fall as the waves of migrants move through central California, a smaller number that stays through winter, and just a handful of birds regularly come to the feeders during the summer breeding season.  I strongly suspect that this is because the House Finches space their breeding territories out to where only two or three are close enough to allow the birds access to the feeders without them having to cross into a neighbors territory too much.

Yesterday morning one of the pairs was accompanied for the first time by two fledglings!  These young birds were capable of a decent amount of flight, thought they were still doing so somewhat clumsily, but they are completely reliant on their parents for food.  Each of the two fledglings picked one of the parents and followed that adult around from fence top to ground and back again begging for food all the while. The parents are more then skilled enough to fly up and land on the feeders, but the young ones do not yet have the skills.  Instead, the young birds simply give their begging calls and tremble their wings in the hope that this behavior will trigger the adult they are following around to turn and feed them.  The adults spent most of their time picking seeds off the ground and, when they had gathered a crop full, feeding the fledgling trailing behind them.  The fledglings watched the adults picking seeds off the ground with obvious interest, but little understanding.  The second most common bird at our feeders are Western Scrub Jays.  We have one pair of Jays that have claimed out feeders and let no other Jays come anywhere close to them.  This pair built a nest in a Cottonwood tree just across the parking lot from out patio.  It is about 20 ft above the ground on a branch that is particularly dense with foliage.  Today, when they came to the feeders, they were accompanied for the first time by one fledgling of their own!  This young bird also has the occasional tuft of down still poking out through its course Juvenal feathers.  The young Jay also seems to have about the same level of understanding of the world as the young House Finches seem to.  It follows its parents and begs for food.  It watches the adults gather seeds and break them open with apparent curiosity, but does not have any understanding of how to go about actually performing this task.  Instead, it follows its parents and begs for food with fluttering wings.

It will take a little while for any of these fledglings to figure out that those hard black things are sunflower seeds and that there is food inside them.  It will take them all even a bit longer to figure out how to actually open the shell.  A very fun process to watch.

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