A bit of a long story with interesting notes about cordilleran flycatcher nesting behavior.
It starts about 11 years ago when I was re-roofing my home in Teller County and adding overhangs on my front and back porch. The roofer was going to enclose the rafters and I asked him not to. Why? he responded. Well, duh, no self-respecting cordilleran could resist this covered beam as a nest site. Huh - what? was his response. Never mind, just leave it open I said. Well - it took 11 years, but after returning from a weekend away, I was delighted to find a pair of COFLs building a nest on that very beam; this was June 14. The nest appeared to be 70% complete. The main beam runs horizontally and then there are several intersecting joists (is that the correct term) that run perpendicular and at the angle of the roof slant. There are partial (<10%) nests started at 5 different intersections of the main beam and different joists. Apparently trying out different locations until they settled on the one now being built. The birds did their building throughout the day off and on until complete on June 17. Then on June 18, one of the big storms that have been hitting the front range this year blew the nest down. I promptly put it back up, and to my delight the first egg was deposited on June 20! Apart from what the BNA account of COFL states - one egg every day in the morning, this pair laid one egg every 2nd day at mid-day. The former is what I find to be true of many breeding species of this general size, e.g. juncos, chickadees, etc. They did this until the 4th and the final egg was laid on the 26th. But, she started incubating, as usual, on the penultimate (3rd in this case) egg on June 24th. So far so good. This beam/rafter is right in front of a pair of sliding glass doors on our second story loft, and over a deck. She sees us coming and going all the time and I find this species to be quite tolerant of humans around the nest. For example, at Manitou Lake near my house, COFLs have been building nests in the picnic pavilion rafters for as long as I have lived here (21st year) and put up with hoards of noisy kids and picnickers without any apparent issues. In the past 8 or so years, they have also built a nest and fledged young in the little covered hut where the attendant takes money; all while the attendant is there! So, quite tolerant little fellas, to say the least. Well - tolerant of humans - but they will chase just about any bird that gets too close (~ 5 meters) to the nest. According to BNA and other sources, incubation for this species can take 14-16 days measured from start of incubation to hatching. We are now at 24 or 25 days. No hatchlings yet. L So - apparently these eggs will not hatch. Darn - as I know that breeding success or failure helps determine if a species will return in subsequent years and use the same structure. Yesterday, one egg was removed from the nest and placed in the corner of the rafters between the rafters and the nest - but definitely out of the nest. Today, a second egg is in the same location with only two eggs remaining. Obviously, we have a failed nest and the parents (or just the female) recognize something isn't right and are ready to give up; but apparently trying some last ditch odd behavior before calling the game on account of no hatching. Does anyone have any information to add to this odd egg removal behavior? This morning, the male is still defending the territory and calling frequently, but I assume that both will give up on this nest soon and move on. Too bad. I don't want to wait another 11 years! Maybe they will move around to the back covered deck and attempt a re-nesting there! Jeff J Jones ( <mailto:[email protected]> [email protected]) Teller County - 8500' - Montane Woodlands --~--~---------~--~----~------------~-------~--~----~ Colorado County Birding: http://www.coloradocountybirding.com/ You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.as/group/cobirds?hl=en -~----------~----~----~----~------~----~------~--~---
