One of the things I’ve been noticing this year is that the number of Blue Jays in my neighborhood seems to have gone up a fair bit. When I first moved in, they were around, but not in huge numbers. This year, I’ve seen them quite a bit- on my feeder, on the ground, flying over the neighbors, playing canasta under the street lamps. There are a number of things I like about Jays, which is why they’re getting this post. I’ll come back with my Jay list in a few, but first: are Blue Jays increasing in number? The answer, it seems, isn’t so easy to find. Blue Jays are one of the species in North America that seems to have been on a decline over the past few decades. You can check out the following USGS site for more data on that:
What has been driving the decreases in these birds. Several people have discussed the role of West Nile virus on bird populations, including:
LaDeau, S.L, A.M. Kilpatrick & P.P. Marra. 2007. West Nile virus emergence and large-scale declines of North American bird populations. Nature 447: 710-713
But what becomes interesting (and sad) is that you go back to the USGS data on Blue Jays, you’ll see that their populations were in decline prior to the West Nile outbreak. And for many species, populations seem to have begun bouncing back since that happened. So is that what’s happening with the Blue Jays? Are they bouncing back? Unfortunately, I don’t know. What I do know, though, is that they’re getting more common in my yard and I like it. So, why do I like Blue Jays? Here’s the list:
- Great colors and a nice crest. It makes them both striking (and jaunty).
- They’re just so calm. Years ago, one of my jobs was working on a bird population study in Missouri. Every day, we went out and set up mist nets to catch birds, identify, band, and record data about their reproductive status. Some birds make themselves really hard to get out of the net because they fight and, when you get them in your hand, bite and peck, which can drag on the measurements. Only once did we catch a Blue Jay (though we saw a lot) and it was the calmest bird, almost eyeing me as handled it, measured it, and set it free. So calm, so nice, and really soft.
- Jays have good spatial memory, so it can be fun to see them move around. See the review in:
- They’re fun and quite clever. The thing that spurred me on thinking about them today was from sitting in my back yard and hearing a Red-shouldered Hawk the other day. Now I do get those birds around, occasionally, but not that often. I looked up to see where it was and then I realized it wasn’t a Hawk, but a Jay making that sound. Jays are good at mimicking hawks. There are several hypotheses that could explain this behavior, but Jack Railman points out that one that seems to be supported a lot is that Jays use these mimicked calls to eliminate competition. In fact, right after I heard that Red-shouldered Hawk call, I watched the Blue Jay fly right onto my now-devoid-of-competition bird feeder.
What a difference a Jay makes
Copying Cooper’s Hawks
Chasing birds off my feeder
Where there used to be lots
Well, I’m no song-writer. But there you go. Sing it out and go watch some birds.
Birding Without Binoculars 