Thursday, April 19, 2018

Urban Soundtrack

by Trina

Owls are all about silence. Their whole existence takes place in the stillness of night. Their world is quiet. Specialized feathers make their flight so completely, amazingly silent that an owl can fly right over your head and you won't know it until you feel the hairs on the back of your neck stir. Our nest box is on a tree between the sidewalk and street, in a (usually) quiet but populated downtown neighborhood with a sports field full of amplified announcers and cheering, horn-blowing spectators a block away in one direction, (making it less quiet on football weekends) and a school full of screaming children within a block in the other direction (making it less quiet during recess), and the occasional sound of cars gunning it from a stop sign for a one-block sprint to the next stop sign. Add in leaf blowers, barking dogs, chainsaws, the neighbor's table saw, utility trucks, the street sweeper, the train south of town, and you have the soundtrack for our very urban owls. They appear to be almost completely unperturbed by all of it.

When Boyle was living in the nest box alone, before DerOwl Hannah showed up, we'd watch him at dusk as he hopped up into the hole and sat for half an hour having coffee, which is to say slowly waking up, eyes half mast, sort of paying attention to the world outside, sort of dozing, until true dark when he would finally awake fully and leave for a night of hunting. Big, loud, jacked-up, coal-rolling trucks would blare past the nest box and he'd just watch with barely a hint of interest, and definitely a hint of disdain.

Countless people walk by on the sidewalk with no awareness of the life-and-death going on in the nest box and trees just above their heads. Last year, once the babies had hatched, DH took to attacking folks who walked too close to the nest. I can tell you from experience that you hear nothing, and you have no idea what hit you, and you think you just walked into a branch or some other overhead thing, except that when you look up after impact, there is no overhead thing there. It was DH nailing you in the head with her outstretched claws, and in my case, pulling my hair out of my ponytail. If you don't know there are resident owls in the area, you have no idea what just happened. (Let the record show, I was NOT getting too close to her nest; I was leaving my house to go get something out of my truck and she must've been hunting in my garden at that moment. I entered the scene, unaware of her presence, and BAM! No more ponytail for me!) At no point during the attack did I hear a thing. There was only silence.

Here's an audio tour of the urban soundtrack that our owls live with, starting with something that probably matches your idea of an appropriate environment for an idyllic, peaceful owl nest: the lovely sound of evening robin song. After that, you might be surprised.

Friday, April 13, 2018

Halfway to Hatch

by Trina

Two weeks of incubation down, two weeks to go... while we wait, patiently, here are a few highlights from the nest cam.

A nice, long daylight (!) view of this gorgeous creature preening, with a few reactions to street noise:

The noises B makes when he checks in at the nest and finds DH absent:

The sound of the eggs rustling together as DH snuggles onto them:

Tuesday, April 10, 2018

What Does it Sound Like When an Owl Talks with Her Mouth Full?

by Trina

That is but one of the many important questions about screech owls we didn't even realize we had, to which answers are streaming in each night via the nest cam.

DH always talks to B when he brings her food. It usually sounds like this:

Recently, however, he brought her something that seemed particularly hard to get down, and she tried to talk to him in the midst of chewing:

If you listen carefully here, you can hear B outside calling to DH at :46 and 1:00, before delivering food:

This is what it looks like when DH snuggles herself down onto the eggs. (She leaves the nest a couple of times a night for 15 minutes or so, usually when B hasn't brought her food for a few hours.This is what she does when she returns.)

On April 1, B made two dinner deliveries within less than a minute (unless that first interaction was merely him checking in...?)

Based on our outside-the-nest observations last year, we know that our screech owls eat a lot of cockroaches and sphinx moths, but the small things B has been delivering have been impossible to see in the nest cam videos. Once in a while it's possible to see that it was something small and black, but beyond that, we haven't been able to identify most of what they're eating. Now and then, however, B snags a bird, which we can see, briefly, before B sits right in front of the camera:

Tuesday, April 3, 2018

All Is (not actually) Lost

by Trina

It turns out that when an owl lays an egg and then vanishes at 8pm on a night when it’s 33 degrees, leaving the egg uncovered for the entire night, it doesn’t mean she has abandoned the nest after laying only a single egg. You can mourn and grieve and kick yourself for putting a strange new camera in the nest box and ruining everything, but in the morning you'll realize that all that fretting and despair was for naught.

It turns out that owls don’t lay all their eggs at once. They lay one every 2 or 3 days, and don’t start incubating them until the entire clutch is laid. And the eggs are just fine not being kept warm in the meantime. At least that's our theory at this point. There isn’t actually a lot of information available on the nesting behavior of screech owls, probably because all of their activity happens in the dark, making them hard to observe, so we haven’t found any official literature to confirm this theory. We did, however, find multiple sources citing this pattern in birds other than owls. Those sources say that birds do this so that the eggs don’t hatch all at once, suddenly giving the parents four or six or ten hungry mouths to feed. Ultimately they will  have all those chicks to feed at the same time, but staggering the hatching increases their survival rate.

This appears to be what’s happening here in our nest. On the night in question, when it looked like DH had abandoned the nest, and all was lost, so soon, after a mere three days, she came back at sunrise, preened a bit, finished off the last of something dead she had drug in with her, tucked her single egg underneath her, fluffed and ruffed, and dozed off to sleep. And then she did it again. Twice. She stayed out all night for the next two nights, with no apparent concern for the solitary, cold egg she’d left behind.

                                                                                   (That's a sparrow carcass in the lower right corner.)

And then, three days after the first egg, she laid a second one. A third egg came two days after that, a fourth in another three days, and THEN she started sitting on them for most of the night. With incubation apparently underway, we thought that must mean that the clutch was complete at four eggs. But on the night of March 29, ten days after the first egg was laid, a fifth egg appeared. 

Now she is definitely in incubation mode, staying on the eggs almost the entire night while B delivers cockroaches, crickets, moths and sparrows to her.

She does leave for up to an hour at a time, presumably to go find something to eat. This video shows one of those instances, when B arrived at the nest with a dead bird for her, only to find her absent:

Word on the internet is that incubation lasts 28 days, so if all goes well for the next few weeks, we can expect the first egg to hatch on April 25ish.