Great monitoring and documentation. Chuck Hundertmark
> On Jul 7, 2018, at 11:56 AM, Jared Del Rosso <[email protected]> wrote: > > > For the better part of a month, Cynthia Madsen, Mary O’Connor, and I have > been dutifully watching a Cordilleran Flycatcher pair apparently nesting > along the Little Dry Creek in Centennial, CO (Arapahoe, approx. 5475’). Our > visits weren’t daily, but they were nearly so, and we’ve been rewarded with > the opportunity to observe the pair’s behavior as the apparent nest went > along. > > > I say apparent because we never found the nest, which we think / thought was > under a bridge over the creek. We inferred from changes in behavior – the > male ceasing to sing regularly, the female remaining out of sight most of the > time, the female reappearing to make food runs, those food runs increasing in > frequency – that nesting was occurring. The timeline of these shifts in > behavior roughly corresponded to the timeline we calculated based on Atlas > data about Cordy nesting. > > > There was definitely a nest, we now know. Today, when I arrived at the > nesting location, I was thrilled to hear some apparent begging calls from > near the bridge. The pair continually visited the location with food. And > then, from some movement near the apparent parents, a fledgling emerged: > cowbird. > > > We’d worried about cowbirds but hoped that the likely location of the nest – > under the bridge – would protect against that. It’s possible that the nest, > in fact, was near but not under the bridge – or that it was under a sort of > “eave” around the bridge. Or it’s just possible that a female cowbird found > the nest under the bridge. > > > A small, not-quite-consolation: the Cordy feeding behavior was interesting > today. Previously, they had been flycatching in a Peachleaf Willow and > downstream from the bridge, out of view. Today, they did much more > flycatching nearer the bridge, where the fledgling cowbird was. Specifically, > I saw several efforts to nab insects from the ground. > > > Here’s the timeline of our observations, keeping in mind we didn’t make daily > visits, nor were our visits always at the same time of day. And some were > relatively brief (20-30 minutes). > > > 5/24 – Male present > > 6/6 – Female arrives > > 6/7 – Female carrying nesting material > > 6/23 (or so) – Male singing slows > > 6/27 – Female carrying food – one run observed; not apparent if female ate or > fed food. > > 6/28 – Female leaving nest more frequently on food runs > > 7/7 – Cowbird fledgling near bridge, fed by Cordy pair (definitely by female, > possibly by male). > > > Not the outcome I was hoping for, but so it goes. > > > - Jared Del Rosso > > Centennial, 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 [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/cobirds/131f3130-727e-45aa-8b1d-ba08117a5dae%40googlegroups.com > > <https://groups.google.com/d/msgid/cobirds/131f3130-727e-45aa-8b1d-ba08117a5dae%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- 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 post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/A643E775-CBBE-4969-90FB-5AC078638F2B%40gmail.com. For more options, visit https://groups.google.com/d/optout.
