Three Eggs and Half an Owl

Not a lot to report, because we’re still at three eggs, and Mme. Owl is still in brooding mode, as she will be until the owlets are about three weeks old (although nest box temperatures will affect whether she’s actually brooding at any given time - if it's hot enough in there brooding becomes redundant).

Are more eggs still a possibility? Yup, but for a limited time only.

Meanwhile (for the technically inclined, the masochistic, or both), I continue to write Java implementations of the RTSP, RTP and RTCP protocols so that I can interface the streaming video coming from my new video capture device with the JCodec library which should be able to decode that video into a format that the traditional Owl Cam' software can enhance and upload to the owl cam' web site. The RTSP code is done. I can receive streams of RTP datagrams containing the video (I assume), and the RTCP code is receiving datagrams and partially decoding them. It's not yet clear to me how complete my RTCP implementation has to be in order for everything to work correctly long-term, given that I'm dealing with a very simple unicast situation. In principle, if I can wrap-up the RTCP code sufficiently for these purposes, and there are no more rude surprises (fellow programmers, try to stop laughing), still images could be restored to the web site pretty quickly.

Egg no. 3 Arrives

Egg no. 3 was laid this morning sometime between 12:27 AM and 2:17 AM CDT, at which point Mme. Owl went into brooding mode. Meanwhile, her mate is doing a good job of supplying food, most of which appears to be caterpillars (a possible benefit of the natural tall grass, etc. that I've allowed to develop in my yard, especially around the nest box tree).

Egg 1 and 2 Metrics

Mme. Owl made the mistake of spending the night out hunting, so I was able to do some basic science on her eggs while her back was turned.

I can't tell the eggs apart, so I can't say which is the first or second one laid. I can say the following: one of the eggs weighs 20.0 ±0.2 grams and measures roughly 36.44 x 31.75 mm, and the other egg weighs 20.6 ±0.2 grams and measures roughly 36.35 x 32.1 mm. (My uncertainty about the measurements is due to the difficulty of being sure that I was measuring the major and minor axes, and wasn't a little off in some direction. A measuring box with sliding sides would eliminate that problem, but I haven't seen such a thing.)

Comparing these numbers to Gehlbach’s (see The Eastern Screech Owl, pg. 92), these eggs are around 2 grams heavier, 1 mm longer on the major axis, and 2 mm on the minor axis.

Larger and heavier than average should be a good sign for the eggs. Exactly why, is a matter I'm debating with myself. Presumably, either slightly larger owlets will hatch-out, or a larger yolk sack will mean greater food reserves for the developing fetuses. I’ll have to consult my raptor rehabber, but any other bird experts are encouraged to weigh in.

Regrettably, routine weighing and measuring won’t be possible, as interesting as those numbers would be (the weight of an egg decreases as the embryo inside develops and uses-up its yolk sack, so charting the changes in weight over time would be interesting, for a start), because Mme. Owl will begin near-continous brooding with the arrival of the third egg. At that point, I'll be leaving the nest alone as much as possible.

Egg no. 2 Debuts

Visible for the first time at 8:13 PM CDT, egg no. 2 was laid sometime this afternoon (after 1:55 PM). Well done, Mme. Owl, and keep up the good work.

One of my screech owls once laid a clutch of six—as big as clutches come—and I’m still hoping to see that happen again, as rare and challenging for the parents (and owlets) as it is. That said, any clutch that produces healthy owlets is fine with me.

Egg no. 1 for 2012

I took down the nest box last night, March 25, not long after Mme. Owl exited for the evening. (Incubation of the eggs generally waits until the second or even third egg is laid, so Mme. Owl still has her nights free, provided they don’t become dangerously cold.) Debris deposited in the nest box by starlings was blocking the side vent (visible in the lower right hand corner of the far wall, a position that should maximize its utility for ventilation, but can lead to it being buried, which cancels-out its utility). So, I removed the obstructing materials, cleaned the camera compartment windows, adjusted the lighting to be more consistent across the whole interior, and took the opportunity to photograph egg no. 1.

Egg no. 1 cradled in a rubber ring, and bracketed by a 90° measuring device ruled in inches.

Looks like a good screech owl egg to me. (BTW, the 90° measuring device—can’t remember the tool’s name—is not bent or warped; photographing hand-held I just couldn’t make the focal plane of the camera precisely parallel to the surface on which the egg and measuring device were resting, so the geometry is distorted.)

To more precisely quantify the state of eggs in the future, I’ve ordered a micrometer and a small, high-sensitivity scale. Disturbing the nest on a regular basis is not part of my plans, but, when it’s necessary for some compelling reason, I’ll obtain all the measurements of eggs or owlets that I can. (BTW, micrometers and sensitive scales used to be expensive items; not so anymore.)

The only worrisome part of last night’s process was that when Mme. Owl returned to the nest around 5 AM (?) this morning, the first thing she did was kick and push the bedding material around to recreate a depression for the current egg and those to come. In doing so, she buried egg no. 1 and couldn’t find it for several hours. So, my female this year either has to work on her common sense, or there’s so little light in the nest box at night that even an owl can’t see clearly. [Additional: It has also been suggested by Sallie the raptor rehabber that owl near-field vision has some shortcomings, and that that may have been a factor.] That said, as someone who can walk the ten feet from my desk to the kitchen and arrive in the kitchen with no clue why I went there, I can’t really criticize Mme. Owl.

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Work continues to get the normal web site up. Unfortunately, there’s still some potentially troublesome software development to perform. However, the fact that a lot of people are waiting anxiously for the normal web site’s return is never far from my mind. I’ll get it going as soon as I can; that may turn out to be easy or hard based on the work done so far; there’s still room for rude surprises (or relatively quick and easy success, if you really want to risk being optimistic).

First Egg of 2012

Mme. Owl provides a glimpse of this year's first egg, not more than two hours after it was laid, I'd guess.

Both Owls Roosting

You don't see the following very often: The mated pair of screech owls roosting in the nest box together. In my experience it happens only one day early in the nesting process, but it always happens. Pair bonding shortly before the stress of the first egg's arrival? Just trying it out for size? I don't know.

I had hoped to to encourage this behavior on the part of the male by adding the internal perch (there were other motivations for it, too), because it's the male's job to sit guard duty somewhere, but my yard doesn't necessarily provide good places for him to do that, so I thought he could do it from inside the nest box. If he's dealing with a large predator (cat, possum, etc.), being inside the box either defeats the purpose, or requires a very quick exit so he can conduct his defense from outside where he has room to maneuver, but with smaller threats and pests, being in the box is an advantage as today's furious starlings demonstrated.

My schemes notwithstanding, the owls (as always) have their own ideas, and those dictate that this only happens once a year, within a few days of the start of nesting. Make of it what you will, but it's a beautiful sight.

No eggs yet, BTW.