Thursday, March 08, 2012

Cage Updates

In a way it was a good thing that Rusty and Iris' first batch of eggs didn't hatch.  This way we have time to make a gazillion updates to the cages that we've been waiting to do.  Yesterday was the day we worked on the breeding cage.

We patched squirrel holes and other gaps on the north side of the cage near the nest, two above the rain roof, and one on the wall near the bath pan.  Hein put steel siding on the ladder leading up to the nest hatch door to prevent climbing critters from getting up there.  I added lots of nesting material to the nest so Rusty can't dig all the way down to China.

Hein installed a dome illuminator near the nest and I removed the hot box from the food tray table.  Since it's kind of warm now, I also put in and filled the bath pan.  While we were in there I also picked up all the gopher remains, pellets and poop.  Whew, it feels good to have all that done!!!!

We watched anxiously for the infrared illuminator to kick in to see what it would look like.  It's marvelous...just like someone put in a light bulb near the nest!  We were also happy to see that Rusty enthusiastically jumped into his role digging in the nest to prepare a new nest bowl.

While in the cage I noticed some chewed walnuts inside the walls near the bath pan.  I assume the squirrels that were in the cage weeks ago did this and have since left them.  But that night I got an answer to the question of what the heck is digging and chewing so loudly on that side of the cage: MICE!  The mice are running in and around the walnut shells, rattling them as the move around.  And they didn't stay put over there either...they had to check out the new nesting material in the nest.  Of course Rusty and Iris ignored them.

It seems we're on the road to renesting.  On Monday I counted all of Rusty and Iris' copulations, for a total of 16!  I don't think they're keeping up that pace every day (I'm not counting), but Rusty sure seems intent on making more fertile eggs yet this year.

Tuesday, March 06, 2012

Removing the Eggs

With Rusty and Iris' eggs more than a week overdue for hatching, I decided to remove the eggs to see if we could figure out what had gone wrong.  I had originally planned to remove the eggs Monday morning after the International Festival of Owls.  But as things worked out, we wound up having our special guests over to our home on Sunday evening, and it seemed too great an opportunity to miss to have Prof. Dr. Michael Wink and Denver Holt present to help evaluate the eggs.  (And to have Tracy Eccles, Pot Plant Owl human, present to witness the event.)

After a fun-filled meal of pizza, beer, wine and lots of laughter, it was time to get down to business.  First I prepared the two gophers for Rusty, Iris, and Alice by cutting them open to remove the liver, stomach, intestines, and bladder, which they don't eat.  I put on my headlamp, went outside to throw out the guts, then took key and food out to feed Rusty and Iris.  I removed the uneaten food, cleaned the food tray, and deposited their fresh supper.

Then I walked around the side of the cage to the ladder that leads up to the peek hole behind Iris' nest.  Thankfully Iris flushed off the eggs when I was at the bottom of the ladder.  I quickly climbed, unlocked the padlock, grabbed one warm egg and tucked it in one pocket, then grabbed the other warm egg and tucked it into my other jacket pocket.  I shut the door, locked the padlock, and hurried back inside.

I handed an egg to Denver and he commented that it wasn't as warm a he would have expected.  I thought they cooled off quickly too.

I tried candling my egg by putting the egg on the end of a vertical toilet paper tube over a flashlight in the dark bathroom.  I couldn't see a thing in the egg.  I tried the other egg--nothing.  Then someone pointed out that I wouldn't see anything if the chicks had developed.  Duh!

Next I weighed the eggs and someone recorded the weights.  Egg #1 was 56.3g and egg #2 was 59.4g (Alice's was 59.3g).

Denver got to be the one to do the dirty work.  Over a paper plate he carefully tapped the egg with a knife around the middle, just like cracking a hard boiled egg.  Then he gently pulled it open.

Inside was a perfectly developed Great Horned Owl chick, complete with fat little toes and an egg tooth. It still had a yolk sac.  It wasn't alive, but it wasn't smelly or decomposed either.  With this knowledge I heaved a sigh of relief--Rusty wasn't shooting blanks!

Egg number two revealed the same, but had a runny pink fluid in with it also.

We removed the yolk sacs, rinsed and weighed the chicks, and put them in jars of alcohol to preserve them.  The yolk sacs and egg shells were put into plastic baggies in the freezer in case they would be needed for further analysis.

We may never figure out what happened to the chicks, but it is probably significant that both didn't hatch.  My suspicion is that they got jostled a few too many times when Iris bolted out of the nest as critters climbed on the cage, since shaking eggs is a method used to prevent them from hatching in some instances.

Iris checked the nest a few times and Rusty checked it a LOT of times.  He eventually dug it all up.  By the next day they were roosting in the sunshine in the flight cage not just side by side, but smooshed up against each other.  Copulations have picked up also, so there is a small chance they will lay more eggs this year.

This isn't necessarily all bad.  Now we will be able to clean the cage out, install the IR illuminators, add more nesting material, fix some holes, and do more predator proofing.  Then if they lay eggs again, things should not only go better, but we should be able to see better.

Let's all hope for more eggs this year!