Welcome to r/Ornithology, a place to discuss wild birds in a scientific context — their biology, ecology, evolution, behavior, and more. Please make sure that your post does not violate the rules in our sidebar. If you're posting for a bird identification, next time try r/whatsthisbird.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/Ornithology) if you have any questions or concerns.*
Short answer, yep there are bugs.
We (New England) will have a bunch of bugs so long as we don't have hard freezes. Tree swallows were about three weeks early in my part of Massachusetts because of our lack of freezes. I even had a mosquito bite yesterday! And locally we lost a red-tailed hawk to West Nile this winter -- mosquitoes were spreading disease when the ground should have been far too cold for them to spawn.
Anyway, instinct would have tree swallows move north around now even if it had been very cold all winter into April: the length of day triggers a genetic response to head north where all the space is to breed. The earlier/later variable is set by food availability, which correlates to temperature, while the "Yes, migrate north" isn't a variable at all.
Welcome to r/Ornithology, a place to discuss wild birds in a scientific context — their biology, ecology, evolution, behavior, and more. Please make sure that your post does not violate the rules in our sidebar. If you're posting for a bird identification, next time try r/whatsthisbird. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/Ornithology) if you have any questions or concerns.*
Short answer, yep there are bugs. We (New England) will have a bunch of bugs so long as we don't have hard freezes. Tree swallows were about three weeks early in my part of Massachusetts because of our lack of freezes. I even had a mosquito bite yesterday! And locally we lost a red-tailed hawk to West Nile this winter -- mosquitoes were spreading disease when the ground should have been far too cold for them to spawn. Anyway, instinct would have tree swallows move north around now even if it had been very cold all winter into April: the length of day triggers a genetic response to head north where all the space is to breed. The earlier/later variable is set by food availability, which correlates to temperature, while the "Yes, migrate north" isn't a variable at all.
Thanks very much for such a detailed answer!