Even more owl mysteries and the first mating of the season!

December 11, 2009

After an astounding evening on Monday 12/7 (fear not, there will be a post about it), I did not go to the park on Tuesday 12/8. It was pouring rain, cold and generally unpleasant. I returned to the park on Wednesday 12/9 and so did the owl mysteries.

Just as I leaving work, I saw my friend and colleague Timothy Hower leaving as well. I called his name and waved hello. He graciously asked if I wanted a lift to the park and I did not hesitate to accept. With sunset so early these days, every second counts. We got to the owls territory, I thanked Timothy and made my way to The Crossroads Conifers and The Quintet Conifers. No Charles, no Sarah to be found. Even though it was a few minutes after sunset and overcast, it was more than light enough to find them. I looked around The Wooded Area and a little around The Hilly Wooded Area but without success.

I noticed that the southern portion of The Wooded Area had been cleared within the last three days of Bush Honeysuckle, an invasive plant. This work starkly altered the appearance of the portion of woods. While I'm glad that this work was done, I was and am concerned about the timing of the work and its possible impact on the owls. Great Horned Owls as a species and Charles and Sarah as individuals are highly adaptive critters but for this work to occur as mating season arrives is disquieting.

I spent the next hour looking around the core of the owls' territory and heading out west and north hoping to find them but without success. Like the other recent nights when I did not find the owls, I was (and am) at a loss for an explanation of where they had gone and why. Also in-keeping with the other nights of no sightings, I dreamt of owls that night.

Yesterday, Thursday 12/10, was a bright, clear and cold day and I arrived at the owls' territory a few minutes after sunset. I felt confident that the bright conditions would give me more time to find the owls before they went off to hunt. Once again, I could not find them. I thought I heard a hoot or two from far off in The Hilly Wooded Area but it was so vague, distant and inconsistent that I dismissed it. After perusing the nucleus of their territory I went west and north again but from a different point of attack than I had on Wednesday 12/9. It was stimulating to take this different tact but it was no more successful than the previous night.

I then headed northeast, stopping at some locations where I have reacquired the owls both recently and in years past. No such luck this night. Only going south remained, so I went in that direction resolving to conclude my search in The Hilly Wooded Area before heading home. I did not find them on my way to this area and once I arrived there, I only had a glimmer of hope that I would find the owls.

The Hilly Wooded Area is one of the more challenging areas in which to reacquire and observe the owls. It is not the most densely wooded area in the park but the trees are large enough in number and size that there many places for the owls to perch. The large number of trees dump lots of leaves, twigs and branches on the floor making a stealthy approach difficult but not impossible. The frozen ground last night made the leaves extra crunchy and loud. Over the years I have learnt some of their favorite hunting perches in this area and while this helps, it is not a guarantee of success.

I went to a couple of these perches and found no owls but as I came near another perch, I flushed an owl and it flew off past me going north. In the dim light I was pretty sure I saw it pull up and land 80-100 yards from me. Judging by the size of the owl, I decided it was Charles. I thought briefly that it may have been one of the neighboring Barred Owls but I dismissed that thought.

Faint hooting began to waft through The Hilly Wooded Area. Since I was wearing a balaclava and a hat over that, my hearing was limited. I removed my hat and I could hear the hooting more clearly. I walked towards the hooting straining to hear it over the crunching leaves. As I got closer I identified the hooting as Charles' and then I began to hear Sarah hoot in return. In the last week or so, I have seen Charles and Sarah do this post-dusk hooting several times. I've begun to think of these singing sessions as Reunited Duetting or in my sillier moments, as Peaches & Herb Duetting.



I found Sarah hooting in a tree near The Possible Nest Tree a modest distance from where Charles' hoots originated. Moments later, she flew off towards Charles and I heard the distinctive high-pitched call that Charles likely makes when they mate! Although I did not see them mate and while I have heard this call twice outside of the mating season, given the givens I'm sure that they mated! Amazing!!

The only downside that the batteries on the camera with which I shoot video died and I was scrambling to replace them when they mated, so I missed capturing the high-pitched mid-mating call. D'oh!

It was 6:15pm when they mated, over an hour and a half after sunset and one of the latest if not the latest times I have ever observed them mate. This is the earliest in the year I have ever seen them mate. I wonder if the sudden onset of bitterly cold winter weather has had any effect on the timing of mating. In 2006, I first saw them mate for the first time on 12/24, in 2007 on 12/14 and in 2008 on 12/19.

I have been extremely privileged to observe Charles and Sarah mate now 30 times over the past four mating seasons and I hope to continue to add to that figure this year and beyond. It is a privilege not only to have observed such intimate behavior but also because the behavior has been seen relatively few times and only recently described. Mating was first described in the scientific literature in 1998, an especially late date given the fact that Great Horned Owls are the most widespread, commonly found owl in North America. This late description of a key piece of behavior underscores the challenges of observing an animal that is crepuscular and nocturnal, extremely well-camouflaged, and flies silently.

Thrilled at having first found the owls and then observed mating for the first time, I went home with a smile on my face and shared the news with an estatic Wendy.