Bob et al,
What I have noticed in the past at Grandview Cemetery in Fort Collins is the initiation of Great Horned Owl pair-bonding in late summer. I have not seen it this year, but the pattern in the past has been as follows:
During June and July thru most of August, adults are difficult to find but seem mostly involved with teaching young from the previous spring the ropes. The young birds are vocal (sound more like beginning cello students than large owls), tend to move all around the cemetery, choose different roosting spots, and, thus, the parents tend to move around, also.
Usually in August things change. The status of the kids changes. In the big eyes of their parents, what was yesterday a dependent is today viewed as competition. No doubt pressured by the parents, the young disappear to start their own lives elsewhere.
Usually in late August I notice one parent, presumably the male, start sitting in the huge, champion honeylocust in the southeastern part of the cemetery. This magnificent tree is about 100 yards from the traditional nest site in the crotch of a large American elm in the center of the cemetery.
After a period of weeks extending into September, which may involve some calling by the male at night when I am not present, he is joined by a second bird in the honeylocust. When the second bird shows up, they often sit in disparate parts of the crown. Over several days, if they decide "this is the start of something big", the distance between them lessens and eventually they literally sit shoulder to shoulder. Again, I am not there at night, but I think this period of time involves calling back and forth, and rarely I hear some of this during the daytime. I suspect that sort of thing may what you and Greg have posted about. So, rather than "setting up a territory", I think it is more pair-bonding, with the traditional territory, at least in the case of the cemetery that I'm familiar with, being already established. It's more a case of a long-term lease being extended. Some of the chatter may be discussion of the terms, but I tend to think it is mostly about commitments by the future tenants.
Over the course of autumn into early winter, the birds tend to roost closer and closer to the traditional nest tree. Lots of hooting during this time. Around the turn of the year, the female seems to disappear, the male takes up residence in a big spruce looking down on the nest elm, and then, bingo, some time in late winter (January to early March), she appears in the nest crotch and away the tedium and hard work of nesting progresses.
At least this is how I interpret things in my patch. Certainly there could be other reasons for hooting at any time of year but I would wager what you report involves mate selection. Thanks for your posts, Bob and Greg.
Dave Leatherman
Fort Collins
Sent: Friday, September 21, 2018 8:04 PM
To: cobirds
Subject: [cobirds] Great-horned Owls--started hooting (Denver Co)
You received this message because you are subscribed to the Google Groups "Colorado Birds" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscribe@googlegroups.com.
To post to this group, send email to cobirds@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/1E42527F-288B-44A0-9028-3191BD8324D9%40earthlink.net.
For more options, visit https://groups.google.com/d/optout.
No comments:
Post a Comment