For a while I fed a couple Blue Jays out my window. It was enough so that they weren’t reliant on me, but they did drop by every morning for shelled unsalted peanuts. I was originally targeting some corvids I saw occasionally, but I was not disappointed seeing the beautiful birds in the tree outside my window. At some point they would come up to my window when I put a peanut there and they had a small tolerance of being near my presence. If I moved too quickly they would fly away, and they only stepped there for a moment. I was happy for a time, but then I noticed that during these times in the morning no other bird would come to my window, including the corvids. I talked to my grandpa first about this, and he said the Blue Jays at his house would bully other birds away from their bird feeder. But my grandma recalled seeing a video of a bird (she believed to be a woodpecker) on Instagram, keeping the Blue Jay away from the bird food. Would the size of the other birds matter to an extent?
There was a study from the Cornell Lab of Ornithology about dominance hierarchy at bird feeders, and they found that generally size was the main factor, but there were exceptions. This article has an interactive graph that includes Blue Jay interactions with other birds. Looks like it loses to Red-bellied and Hairy woodpeckers, and sometimes European starlings. https://www.allaboutbirds.org/news/when-136-bird-species-show-up-at-a-feeder-which-one-wins/
Yes, thank you! The red bellied woodpecker in the article (I’m fairly positive) is the bird which was in the video my grandmother showed me. This would match with my grandpa’s view as well! (The source for the video is My BAckyard Birding on Instagram)
By corvids, I assume you mean crows or ravens? Blue jays are, in fact, members of the family corvidae, too. As for behavior corvids in general tend to be very possessive of food sources and will definitely bully smaller birds that want to partake. If the blue jays weren’t there to fight over peanuts, the crows would probably do it, too. Blue jays tend to have more of a reputation for it, though, as there’s more overlap in what they eat with the smaller birds. If you want variety, try putting up different types of food: small seed mix for little birds, peanuts in the shell for corvids, suet feeders for woodpeckers, etc. If the blue jays have plenty of food that they prefer over the little birds food, they’ll be less likely to bully them.
First off, I love Blue Jays. Beautiful, lots of energy, vocal virtuosos, etc. That said, Blue Jays can have an impact on a local bird community far beyond just dominance at feeders. My colleague Tom Engels and I published a research paper in 1994 regarding the “Negative Correlation of Blue Jays and Golden-cheeked Warblers near an Urbanizing Area” (Conservation Biology 8(1):286-290). I had noticed previously in my graduate field work that GCWAs were sparser or absent in patches of otherwise suitable juniper-oak woodlands around the perimeter of Austin. Tom did some very creative field experiments to show that, in essense, GCWA males trying to sing and establish nesting territories in otherwide suitable habitat avoided woodlands populated by Blue Jays. Although we still don’t know through what mechanism or biological interaction that outcome is mediated, our paper was one of the first to demonstrate the impact corvids can have on songbird populations–in this case, and endangered species which was losing habitat to urbanization rapidly in Central Texas.
The paper is available in pdf form (free for institutional accounts) here on Soc. for Conserv. Biol. website.
I’ll try to scan and upload a real free pdf on my ReseaerchGate account.
Oh, I didn’t know that, I’ll have to research corvidae more! :)
I also have smaller seeds, but I didn’t want to make too much of a mess on my roof, but if this means more bird variety, I believe it will be worth an attempt! I’ll also have to hang up some bird feeders :) TYSM!
Blue Jays are common in my area even without my short lived feeding routine, but this seems like a rather interesting topic! I’d for sure read this!
Chuck,
I know you have a professional obligation to only make evidence-based comments, but I would love to hear your speculation about the mechanism by which Blue Jays drive away Golden-cheeked Warblers: WHY they do it, HOW they do it, etc.
@adamwargon Great question; I’ve been mulling over that one for decades.
But I’m going to rephrase part of your question: There’s no “Why” question to answer. Jays are just going to be jays, and warbler will be warblers. Their behavioral interactions when they come into contact (or rather, when they find themselves in the same habitat patch) are what govern the outcome that Tom Engels and I documented.
I had typed up a very long-winded reply to your question but it is just too lengthy for the Forum so I will try to upload it as a journal post and link to it here.
Here you go:
https://www.inaturalist.org/journal/gcwarbler/105123-blue-jays-and-golden-cheeked-warblers-the-saga
And I have now added a pdf of the paper to my ResearchGate website.
For some of the newer members of iNat and the forum (which includes me!), you might not know who Chuck is.
He’s a humble guy, but he’s a prominent member of the iNat community, and he’s also an inspiring wildlife detective – untangling scientific puzzles one moth at a time.
Tony interviewed him a few years ago, and you can watch the video here: https://vimeo.com/276380582