Questions of age have come to my attention from a few readers about the south side female. Yes, she is getting “a little long in the tooth” and according to “Birds of North America,” the peregrine falcon article, female age has a significant effect on all measures of reproductive success: clutch size, fertility, hatchability, brood size, nestling survivability.” What they are saying is that a fourteen year old female will not lay as many eggs as she did in her younger years. Some of her eggs won’t be fertile, some of the fertile eggs won’t hatch.
Onward… Photo by Cleve Nash
I have watched the same female since she arrived at Morro Rock in the summer of 2001 as a subadult. She still carried vertical barring of a juvenile on her chest. I believe her to be 13 to 14 years of age. The article states further that the older they get , there will be fewer eggs produced. This female had her largest clutch last year, four in number. In the wild most peregrine observers believe the average lifespan to be 16 to 20 years. In captivity, 25 or more years. Weakness in an aging peregrine will become evident to other peregrines and a younger one will eventually replace her. We haven’t seen any of these distinct signs. If this season is a failure, it’s not because she didn’t try… twice! I hope we’ll both be here next spring.
Happy trails, Bob
Items:
First: Although we are both in our “golden years,” she hasn’t changed a bit where as I … What happened?
Second: After observing from 4 to 6 hours daily, we haven’t seen any activity around the second nest site since July 2nd. We did see both tiercel and falcon go into the “diving board” nest site, the previous nest site. Now what? It is getting late in the season….
I wanted to inform you about a peregrine nest somewhere in the smokestacks, I have not seen it but a very good friend that lives near them has been watching them. My friend is a docent at the museum and very active so I do believe her if she said it was there. She is Ilene Doering if you know her. Been around Morro Bay for a long time and very active in the natural science. Linda Wedel
Thanks for your observations. We are aware that the north side peregrines use this as a launch site to take pigeons off of the restaurants and docks below. I’ve never know it to be a nest site, since the rock is more suitable and protected. They will nest on open ledges or catwalks like these when nothing more suitable is available. I have talked to the maintenance man who replaces the red lights on the tops of the towers. He’s told me of the many carcasses that littler the catwalk. They like to eat there. This might be mistaken for nesting material. ~Happy trails, Bob
Very informative post, Bob. I hope she (falcon) and you enjoy more golden years before sundown.