[Tweeters] Re: Nisqually Great Horned Owls
notcalm at comcast.net
notcalm at comcast.net
Sat Feb 23 00:00:48 PST 2013
I was asked about how much earlier the Great Horned Owls nested at the Nisqually National Wildlife Refuge this year than in the past.
I reviewed my video footage of the Nisqually Great Horned owl nest during Spring, 2011. The two juveniles that year had plumage that was nearly identical on April 4- 6, 2011 as that I and many others recorded this year February 10- 11, 2013, a difference of at least seven weeks.
----- Original Message -----
From: notcalm at comcast.net
To: "Tweeters" <Tweeters at u.washington.edu>
Sent: Wednesday, February 20, 2013 4:06:29 AM
Subject: Nisqually Great Horned Owls
Good news about the two juveniles. I have spent some quality time following and filming the Great Horned Owls at Nisqually for the past five years. This year was unusual for several reasons. The owls nested early, chose a nest site that was a tree with no nearby limbs and the female monitored the nest from across the trail and boardwalk. In the past, the female was usually very close to the young until they fledged. She did not leave the nest site until dark and if the owls were very young, gave them some signal that they should enter the nest cavity before she left for the hunt. When they were older this did not happen. This year, they appeared to be more vulnerable to aerial predators, including a young Bald eagle that landed above them one evening. One of the young owls looked straight up, froze and appeared terrified until the eagle left. Hadn't seen a young owl open it's eyes this widely before. I believe the mother would have taken the eagle out if it would have made the attempt. I have watched Red-tailed hawks, Peregrine and eagles look at the nestlings and fledglings in the past several seasons and all seem to be aware of the risks involved and thought better of it.
Because the nesting site had no nearby limbs, the owls were not able to branch at this nest site. In past years, they have had much practice balancing, limb walking, vigorous flapping and making short flights on and between limbs of the nest tree followed by returning to the safety of the nest hole. I have been fortunate to be present on the evenings the juveniles left their nest trees two of the past five years, but not this year . They fledged by leaving the nest tree after considerable practice at short flights and other skills. This year I believe they walked, and I speculate likely "swam" across the slough to get to the area within the boardwalk oval and climbed the trees. One was seen by many on Sunday, below the boardwalk and before crossing the slough. Likely a post-sunset wet bird. The first was seen across the slough on Monday (great photos posted by someone on Tweeters), I and many others saw both near mom, with both adults vocalizing, Tuesday. So, they are presently both safe and in the trees, within the boardwalk oval. One of the juveniles was day roosting within a few yards of the female- the other about 60 feet away.
Other notes: last week, at least one female duck (sp.) and one coot were being consumed by the juveniles (I was filming one feeding and it held up a lobed coot foot). Cornell BONA lists American Coots as favored prey water fowl species. Apparently, the prey were delivered during darkness or early morning and consumed as need during the day (kind of like Amazon Fresh)- I watched them feeding in the evening on two occasions. They also manipulated the detached wings of the prey. I filmed one of them defecating over the nest- a behavior that one researcher believes ages the juveniles at greater then four weeks. I also filmed one of the juveniles casting a big pellet yesterday.
When I arrived yesterday, a Peregrine was nearby and had just completed a loud conversation with one of the adults. As always, a pleasure to observe this family. It was also nice to be with the people present who enjoyed the experience and the sun. I also enjoyed showing the not yet birders (NYBs- only a matter of time) and their kids close-ups of the owls on my LCD screen- there were a few "wows!".
More information about the Tweeters