Meant to send this out to the whole list-serv. DAL ________________________________ From: DAVID A LEATHERMAN <[email protected]> Sent: Friday, April 3, 2020 8:35 AM To: [email protected] <[email protected]> Subject: Re: [cobirds] Great Horned Owl nest Grandview
Natalie et al, Yes, this year's nest attempt by Great Horned Owls at Grandview Cemetery in Fort Collins failed. I think it happened during the two-day wind-rain-snow event we had March19-20. Based on the female going on the nest February 19th (+ or - one day), I had egg hatch as sometime in the period of Mar19-26. She was in the nest, leaning strangely on the 21st, NOT present on the 22nd or anytime since. There was an owl in the spruce near the nest on the 22nd. At first I chalked this up as the guardian male and an indication the nest was still viable. I now think this might have been the female "in mourning" before leaving the scene altogether. There are lots of scenarios that might have happened here: female got off the eggs because of the weather and they froze; eggs hatched and then the female didn't keep them warm enough; eggs broke prematurely; eggs were infertile; something. Egg hatch is obviously a delicate time in the whole nesting cycle and if this is the same female as has been associated with this nest in the recent past, she just doesn't have the experience or robustness or something to pull off the difficult job of raising young in late winter-early spring. This is the third year in a row this nest has not fledged young. It seems odd to me that the owls keep coming back to this site where they have had bad experiences, including one that could be attributed to the site, not the parents. The site issue was that crotch not being drained and in heavy rain storms it fills up with water. Some of our most serious spring storms come from the north and the configuration of that crotch is wide open in that direction. Snow really packs in there as a consequence. Illustrating the problem with driven rain or snow melt, in 2018 the young had hatched and a 2-inch rain drowned them right underneath the sitting mother. Seems like that sort of traumatic experience would be enough to cause the adults to find a different location the following year. As it is, this situation sort of meets the definition of insanity where the same actions are expected to produce different results. Life in the jungle, I suppose, but hard to watch. Staying on subject, I am now wondering if the Red Crossbill nest nearby has also come to an end. I have stood in that area for many hours of late and not detected either adult bird. The verdict is not final but I am getting worried. The Red-tailed Hawk nest in the southeastern corner is on-going, with the female now sitting in earnest, presumably on her clutch of eggs. No vole running the dry irrigation ditch bank, house mouse venturing out of the crew shop or pump house, Norway rat dumpster diving, fox squirrel or baby desert cottontail in the area is safe. Soon they will add robin fledglings to their menu. A Cooper's Hawk pair usually nests somewhere in the Grandview Cemetery/City Park area. Both have been seen together and hunting individually in recent days. Other birds nesting at present at Grandview Cemetery (GC) include: Eurasian Collared-Dove, Pine Siskin, House Finch, Red-breasted Nuthatch, White-breasted Nuthatch, maybe Bushtit, European Starling. Soon, among the resident species, Blue Jay, American Robin, Downy Woodpecker, Northern Flicker, Mallard and House Sparrow will join the fray. Migrants expected to nest in the GC area include: House Wren, Chipping Sparrow, Lesser Goldfinch, Common Grackle, Chimney Swift, Barn Swallow, Cliff Swallow, Mourning Dove, Broad-tailed Hummingbird. Migrants that rarely nest at GC are Black-chinned Hummingbird, Western Wood-Pewee, , Ruby-crowned Kinglet, Hairy Woodpecker, Brown-headed Cowbird. The "caboose" on this nesting train is American Goldfinch, constrained by having to wait for thistle seed (aka "fluff") with which to construct their nests, usually in ash trees. Of note, City Forestry, in anticipation of emerald ash borer killing many of our ash in the next decade have been "flattening the curve" by proactively removing numbers of city-owned ash and planting other species not prone to this exotic insect sweeping across North America. Dave Leatherman Fort Collins ________________________________ From: [email protected] <[email protected]> on behalf of Natalie <[email protected]> Sent: Thursday, April 2, 2020 4:16 PM To: Colorado Birds <[email protected]> Subject: [cobirds] Great Horned Owl nest Grandview Hi all, Hope you and your families are healthy & doing well. Did the GHO nest at Grandview Cem. fail again this year? I didn't see the female on her nest today. Natalie -- 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 [email protected]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/1728b795-96d8-40a8-9391-99bc2a0e9044%40googlegroups.com<https://groups.google.com/d/msgid/cobirds/1728b795-96d8-40a8-9391-99bc2a0e9044%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/SN4PR0601MB3614543AD6262051C3112BD6C1C70%40SN4PR0601MB3614.namprd06.prod.outlook.com.
