Chris’ Eastern Screech Owl Nest Box Cam’

The 2010 eastern screech owl (Megascops asio, formerly Otus asio) nesting season has concluded in this urban Austin, Texas, nest box.

The views shown here were provided by one or more tiny monochrome video cameras that are sensitive to both visible and near-infrared light. During the day, the camera "sees" using the daylight that streams in through the entrance hole. At night, arrays of infrared illuminators take over from the sun. (Meet the nest box internals.)

Daily Image Archive

March 2010
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April 2010
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May 2010
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June 2010
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July 2010
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Start of Nesting: March 18 • Eggs Laid/Hatched/Failed: 4/2/2 • Weather / More Weather

Daily News

June 4Bees have moved into the nest box. At the request of some long-time viewers, I've brough the nest box camera back up, so people who want to watch bees may do so. Enjoy. (Or not. Your choice.)

May 24 – My thanks to Donna H. and Dot K. for the postcards.

May 22[10:04 PM] Owlet no. 3 safely climbing the nest box tree at 9:40 PM.

[9:46 PM] Owlet no. 3 has successfully left the nest box and is climbing in the nest tree under the watchful eyes of at least one of the parents. Photo soon.

My thanks to Dale P. for the card and art, and Nancy for the postcard.

May 21[8:26 PM] The sun sets as owlet no. 3 waits in the nest box entry hole for the first food delivery of the night.

May 20[9:48 PM] As soon as I finished writing the previous entry, I went outside with a powerful hand-held light and my camera to try to get a photo of owlet no. 1, but he/she was nowhere to be seen. Both adults were present - they moved around the yard keeping a constant watch on me, and they protested verbally when I walked under certain areas of the canopy of the two big hackberry trees at the back of my yard. That suggests that owlet no. 1 flew from the nest box tree to one of the hackberrys, a flight of something like 25 feet, if he flew between their closest branches. If so, that’s good; the dead nest box tree can’t provide much shelter, while the large, vibrant hackberrys can provide no end of places to hide.

At this age, a screech owl should be a very poor flier, but I saw this one easily gain altitude on both of her/his first two flights, so, perhaps, being one of only two owlets meant that he/she was fed so well that he/she developed more rapidly than the typical eastern screechlet, who would be competing with three siblings.

So, all indications are that things are going great for owlet no. 1. Next we’ll see how long owlet no. 2 (≅3 days younger than no. 1) remains in the nest.

[8:53 PM] Owlet no. 1 has left the nest and is safely perched in the nest box tree. He/she flew from the rail to a nearby tree limb with no difficulty.

May 20[3:02 AM] I brought the owls’ nest box down early this morning and attached the owlet rail outside the entry/exit hole. This was done in anticipation of the eldest owlet leaving the nest soon, and in the expectation that having a perch outside the hole must make that critical leap from nest to tree easier.

This also gave me an opportunity to open the nest box and take some family portraits. I also meant to photograph unhatched egg no. 3, but it wasn’t immediately evident, and searching the bedding materials for it seemed like it would be an unnecessary disturbance to the owlets. (I can dig it up after the owlets are gone.)

Needless to say, this threat to the nest and owlets resulted in repeated attacks by the adults, from which my scalp probably carries a good number of scratches, all well-deserved. And all in a good cause.

[1:21 AM] Here’re the promised photos of the adults. Don’t ask me which is the male and which is the female – unless I was lucky enough to observe sexually distinctive behavior (like tearing up prey and feeding it to the owlets, which only the female will do), there’s no way for me to know.

Alternately, if both owls suddenly took leave of their senses and let me get hold of them, I might be able to determine their sex by weighing them, because females are generally heavier than males. (That’s known as “reverse sexual size dimorphism”, if you want to impress your friends.) However, there’s some overlap of their normal weight ranges, so even weighing them doesn’t guarantee an answer. Fortunately, somehow, the owls have it all figured-out.

[12:40 AM] The owlets fooled me. Earlier tonight it looked like there was only one owlet left in the nest. That sent me out on a search (and, if necessary, rescue) mission. I looked everywhere I could think of for that owlet (three or four times), wanting to make sure it had found its way to a safe perch, or, if it hadn’t, to find it and put it on a safe perch. I had no luck finding the owlet, but I found both adults and was dealt a good, solid wallop to the head by one of them, and verbally warned away by the other. Having been walloped, I was sure the owlet had to have left the nest – in my experience, the adults never become so defensive until an owlet has left the nest. So much for experience ... when I returned to the house to write this, I looked at the owl cam’ images and found that both owlets were still in the nest. The previous impression that one was gone was merely caused by one owlet standing in a position that completely blocked the camera’s view of the other owlet. I’m not usually fooled by that, but the owlets stayed in the same position for a full five minutes (at least), and I thought that was too long for both to stay sufficiently stationary to maintain the single-owlet illusion. Show’s you what I know. (Heck, I thought I wouldn’t be attacked for wandering under the nest box tree until an owlet had left the nest. That’s been true every other year, but not this time. Well, owl personalities vary, just like people’s, so it seems that this year at least one of my adults is more defensive than I’m accustomed to. Good for them.)

Now there are two things I probably ought to do tonight. One is to post the pictures of the adults that I took while I was searching for the (not) missing owlet. And the other is to bring down the nest box (the parents really aren’t going to like me after that) and attach the owlet rail, which should make it easier for the owlets to jump from the nest box to a nearby tree limb, whenever they do decide to leave the nest.

Stay tuned.

May 16 – Nine days without writing anything is too long. Sorry about that. Life's been far too busy for my liking between work, personal stuff like a mortgage refinance, minor medical issues, and so on. The important thing to know about the owls is that owlet no. 1 has not only begun climbing in recent days, but has reached the entry hole (a major accomplishment). The upshot of that is that owlet no. 1 should be leaving the nest sometime this week. As of today, the 16th, he/she is 25 days old, so the age is consistent with that conclusion.

So, watch carefully. This week will be the most interesting of all.

Thanks, by the way, to the Shannon family, Diane G., and Nancy for the postcards.

May 7 – Temperatures in the next box hit 100 degrees Fahrenheit and stayed there for quite some time. That’s probably why Mme. Owl left the nest in the morning (during daylight hours), and didn't return until after sunset. Her absence will have probably have let more air circulate, and kept temperatures down a bit, so, it was probably beneficial to both herself and the owlets. Whether she was keeping an eye on the nest box from somewhere nearby, I don’t know. I hope so, because the owlets are pretty safe in the nest box, but not completely safe. Having a parent on guard duty can only help.

May 4 – Temperatures are reaching the mid- to high-90s in the nest box in the heat of the afternoon. This is above the ambient air temperature. My best guess is that, because the drought killed the nest box tree, there's no foliage to shade the box anymore, so its exterior heats-up in the direct sunlight, with the heat ultimately travelling inward. (I’m still amazed that this old, well established tree, that had doubtless survived other droughts, was killed by the latest one. It could be worse, however; I have a friend who lost more than 2,000 trees to the same drought.) Deep in the heart of Texas there can be great beauty (our wildflowers are doing beautifully this spring), but great hardship, as well.

Otherwise, things are going normally. Both owlets have their eyes open and have begun stretching and even a few wing flapping exercises. No climbing attempts, yet, but I’d bet that that idea is swirling around in their heads somewhere.

By the way, Mme. Owl’s recent habit of sitting in the entryway throughout much of the afternoon has afforded me a photographic opportunity. This is Mme. Owl peering at me from the nest box, across about 100 feet to my house’s (closed) back windows, and some distance past the windows. Given that it was brighter outside than inside, that’s not easy an easy thing to do, but owl eyes are extraordinary organs. Note that her "ear" tufts are raised – this means she was either agitated, or try to camouflage herself, or that she was doing later, because of the former. I didn’t so much as open my back door since about 4 AM, so either she was keeping any eye on me (troublemaker-for-owls that I am), or she’s just keeping an eye on everything, and I was the most interesting thing going on at the time.

Finally, thanks to Nancy C. for the postcard!

May 3 – Life’s been weird, so I’m playing catch-up, and not all that effectively. However it would be fair to say that today was characterized by a warm day that saw Mme. Owl spending much of her afternoon in the entryway, because it’s cooler there, and the view is a lot more interesting than the inside of a box. The night, however, has been cool. With temperatures in the mid-50s, Mme. Owl has had to spend her time brooding the owlets, as they’re still too small to thermoregulate under the circumstances. Doubtless, her instincts make that an unquestionable priority for her, but I suspect that a whole other set of instincts would like the weather to be warm enough that she could go out and hunt. And, as the owlets grow larger, sitting on the family becomes progressively more challenging, which can't be helping her catch-up on her sleep. Fortunately, she seems to need very little.

Odd Fact: Now that I've caught-up on reviewing the nest box imagery, I’ve found that Mme. Owl left the nest box at 4 PM and didn't return until almost exactly an hour later. Was she tired of the heat? Chasing away something threatening, and taking her time to come back? I don’t know, but it’s not behavior I’d expect this early in the rearing process. (Eventually, to encourage the owlets to the leave the nest, Mme. Owl will stop spending her days and nights in there, and she and her mate will even reduce food deliveries to try to entice any reluctant owlets out into the big wide world.)

April 29 – A normal day for recent days, including an Owl Cam’ software crash (or it may have been the video capture hardware that crashed; it’s hard to know).

April 30 – [Preliminary entry, 4:03 PM] - Technical matters aside, for anyone wondering why an owl would stand around with its mouth open, as we're seeing this afternoon, the answer is “gullar fluttering”. What’s happening is that the owl opens its mouth and flutters (rapidly exands and contracts) its throat which draws air into its mouth, expells it, and repeats the process over and over again very quickly. This allows them to loose heat into the air passing through their mouth/throat. Put simply, it’s the bird equivalent of the panting of a dog.

[Preliminary entry, 3 PM-ish] – With luck, the recent spate of owl cam freezes has been resolved. I’ve swapped-in my last spare video capture box, and it seems to be behaving correctly. (But the previous one behaved correctly for a while, too....)

April 29 – A normal day for recent days, including an Owl Cam’ software crash (or it may have been the video capture hardware that crashed; it’s hard to know).

April 28 – Mme. Owl kept a bird’s carcass in the nest today, from which the owlets were fed repeatedly. No other large food deliveries were evident, but that doesn’t mean there weren’t any. Sometimes, Mme. Owl will take a food item from her mate, then leave the nest either to share the prey with her hungry mate, or to cache it somewhere outside the nest where it’ll be safe and easy to retrieve later. Also, the video capture box ceased functioning around 9:20 PM, so I have no data after that. Naturally, it happened on the night I when I had to stay at work well past midnight to perform a scheduled upgrade of the software on one of our production servers. So, normal video capture didn’t resume until sometime after I got home, around 2:30 AM on the 29th.

Things to Know About

If you are enjoying the Eastern Screech Owl Nest Box Cam' this season, please send a picture postcard from where you live. My address is: Chris W. Johnson, P.O. Box 302042, Austin, TX 78703, USA. If you have questions, continue to send email.

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