“For gooooooooooooood,” I finished my rendition of the Wicked song with a flourish, leaning slightly out of the ATV and waving at imaginary spectators. My fieldmate gave a me a small round of applause.
This is the reality of ecological field work. Rather than watching random people on the internet do silly things, you watch each other do silly things. That’s just what happens after a couple days without cell reception.
A common form of entertainment on this particular excursion was reading the bird call descriptions in our field guides. Per the Peterson Field Guide, the American bittern sounds like, “a low, deep resonant oong-ka’ choonk.” I dare you to read it out loud without laughing.
We were into our second week of field work camping across Texas. We were taking avian blood samples (same as getting your blood drawn at the doctor) to assess avian malaria in Texas.
But to sample their blood, we had to catch them first. And thus, the reason I had time to sing entire Broadway Musical songs. The days went like this: set up the nets before sunup, take turns periodically checking the nets, take them down at night. And if you’re lucky, you catch birds. But for the most part, it’s just waiting.
We were in such a waiting period. Our field leader was off checking the nets. As I finished off my last note, she approached with a flustered expression.
“We caught an owl!”
No way.
Our nets are designed for songbirds–small birds like cardinals or vireos. Maybe an occasional blue jay. But an owl? We hurried to the net, and sure enough.
In an attempt to eat the painting bunting in our net, the owl got tangled himself.
And that’s how I wound up holding a screech owl. Read on for some Eastern Screech Owl fun facts!
1. Females Manipulate Hormones in Yolk in Order to Minimize Sibling Differences
Androgens, specific hormones found in egg yolks, have a key role in the growth of embryos: “High levels of yolk androgens have been shown to speed up embry development and nestling growth, increase hatchling muslce mass…” In addition, “begging levels have been found to increase.” (Gil et al. 2007) How fast you grow, how big you grow, how good you are at asking mom for food…These are all pretty important factors!
Eastern Screech owls can manipulate how many androgens are deposited in their egg yolks. Thus, the youngest offspring isn’t outcompeted by its own siblings. (Hahn, D. C. 2011). That doesn’t always stop the siblingcide though…
2. 94% Monogamous
Popular culture often cites birds as the prime example for monogamy. In reality, there’s usually a high amount of extra-pair copulations (read: cheating) and sometimes outright polygyny/polyandry. But Eastern Screech Owls actually live up to monogamy. Though some can’t overcome failed breeding attempts, leading to a 6% “divorce” rate (as cited in Birds of the World).
3. Starlings Can Kick Eastern Screech Owls Out of Their Nests…but owls EAT Starlings
Eastern Screech Owls are phenomenal birds of prey. They’ll often eat smaller songbirds (hence, how we caught the owl in the first place). But starlings, those small, unthreatening birds, can actually kick screech owls out of their nest and keep it for themselves! That’s like a cow driving you from your home and then living in it!
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Bird Lover's Musings 
Reblogged this on MARY CALVO .
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thanks so much. very interesting. 🙂
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So many bird facts!!!
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