Three Egg Night

Sometime this afternoon, Mrs. Owl laid her third egg. Though it is hard to tell exactly, it was likely laid between about 12:30 and 1:20, when she sat very still. She spent most of the day incubating the eggs or preening her feathers. So, the eggs are developing, and the young will likely hatch on different days. Mrs. Owl took a shorter evening break than she has in the past, only 15 minutes, so she is getting serious about incubation.

More egg photos

Two Eggs!

Sometime between 10:54 and 11:10pm Mrs. Owl laid her second egg. This is our first view of it.

Heat and a Night Out

Mrs. Owl is in the box again this morning after nearly 12 hours out of the box last night. She was gone from 7:52pm to 7:14am. The first photo shows her returning through the entrance hole. Thus, we didn't observe any feedings at all last night.
Yesterday was quite a hot day (87 degrees), and Mrs. Owl spent the afternoon off the egg, mostly with her wings spread for coolness. She also panted, using a motion called "gular flapping" in which her throat pulses with her mouth open to help cool her down. She spent some time in the entrance hole, looking out into the sun.
We haven't noticed the ants at all in the last day. My guess is that they probably were attracted to any mucus or smell that may have been on the egg when it was freshly laid. Now that it is just a dry egg, they have no more interest, and have gone back to whatever they were doing before the egg was laid. In any event, Mrs. Owl seemed to pay no attention to them when they were there, and doesn't in any way seem irritated.
This morning, she seems like she is settled on the egg, so perhaps she is either beginning ot incubate it, or is perhaps pondering her second egg, which is due today. Typical clutch sizes are 3-4 eggs, but they can number as few as 2, or as many as 6. More experienced owls tend to have larger clutches, probably because they are capable of finding more food.

Snakes and Ants

Mrs. Owl was out all night, from 11:03pm to 6:55am, returning with a gecko in her mouth (first photo). Shortly after, she was delivered a second gecko by her mate (2nd photo).
We've read a bit more on Acrobat ants, and it seems that they are quite compatible with Owls. According to Fred Gehlbach, the world authority on Eastern Screech Owls (he wrote the book on them), Acrobat ants often do live in Eastern Screech Owl nests, and can deter predators. It is a tradeoff, however, as they will eat any cached food.
Gehlbach writes:

Acrobat ants, though, live in occupied boxes and cavities. Their brood (larvae, pupae) is housed in damp nest debris...They sting and spray me but not the owls and bite pieces out of food caches, removing these to their brood, often out of reach of the owls...Such symbiont competition could be severe, if Texas blind snakes did not reduce the numbers of at least some insect competitors, and my limited observations suggest they do....

Texas blind snakes are an earthworm-sized snake that is prey for the owls, but as they are slippery, they sometimes get away in the nest box. In this case, they often set up residence in the nesting material, out of reach of the owls, and feed off insects and larvae in the nesting material.

Gehlbach continues:

But there is a possible tradeoff in the owl-snake-ant symbiotic "triangle." Although the snakes are beneficial in removing ant brood, acrobat ants may protect the owls by attacking potential predators. If ants are indeed displaced by blind snake predation on their brood, the protection disappears. Which is mor important, reducing or eliminating and competition for cached food or cohabitation by the ants and hence their protection? Right now I cannot say, but I have noticed that flammulated and western screech owls are also apparently protected by cavity-cohabiting ants that do not disturb their owlets.

In our nest box, we have observed relatively little cached food during the season. About 3 times per season, something big, like a rodent or bird, will remain in the box for about a day while it is consumed, but most of the rest of the food is consumed within minutes after it is brought in, so the ants would have no effect on it. In Gehlbach's book, I have read accounts of significant food caches of perhaps even more than 1 bird or rat at a time. Our owls seem to subsist mostly on geckos, lizards, cockroaches, and other insects.

1st Egg Laid

Mrs. Owl laid her first egg sometime between 11:15 and 11:40am on March 22nd. She didn't really incubate it much, and spent time standing over it. Eastern Screech Owls generally start incubation with the second egg, which should be laid around the 24th.

Another interesting puzzle we have is that Acrobat Ants seem to have showed up, and are crawling over the egg. We have had Acrobat Ant infestations before, but never so early in the season. Usually we notice them near the end of nesting. And we have never seen them on the egg. While Acrobats don't bite, they can compete with the owls for stored food. So we'll have to keep an eye on this situation to determine whether there is anything we ought to do. So far, it hasn't seemed to bother Mrs. Owl in her dealings with the egg.

FIrst Evening in the Box

Mrs. Owl spent her first evening in the box, looking out the window and watching the world (and Cardinals) go by. She spent the whole day in the box.

Nesting Begins

Mrs. Owl arrived at 3:29am, March 22, with food (probably a gecko... see photo). After eating it, she began rearranging nesting material. Mr. Owl came with a feeding at about 4:00, and about 8 minutes later, she left. She returned at 6:20 and did some nesting and some grooming. She left for a morning outing at 6:46, before finally returning for the day at 7:24  She will likely lay her first egg today or tomorrow. We'll keep a close eye for a shiny round egg under her.

And she isn't alone in the box (see spider). That spider isn't as big as it looks, because it is right up against the camera.

Welcome to the 2011 season.

Second Owl VIsit

We have had our second owl visit this evening from 8:06-8:12pm! We assume it was the female, as the owl spent some time rerranging nesting materials, which we've only ever seen the female do before. Several friends of ours already have occupied boxes, with eggs laid. Our friend Chris Johnson's cam is showing 4 eggs right now. In the past, we have had nesting start as late as March 31st, so there is plenty of time.

Owl Visit

Welcome to the 2011 season. We had not been diligently reviewing the motion capture images, due to some technical challenges. But we noticed that 2 evenings ago (March 10th), we had an owl visit for perhaps a couple of minutes in the evening around 7:39pm!

So, the 2011 season is under way. There have been no visits captured since, so this may have been a male establishing and defending a nest box, or a female checking out potential laying sites. Previous to this, we had just had a few squirrel visits (see second photo, taken March 9th). We had to encourage a squirrel to leave on several occasions by banging on the box with a long stick