Bob, In those areas where I bird regularly and/or am conducting breeding bird surveys Western Kingbirds are already quite scarce. There has been a noticeable reduction in this species over the past week or two. I have been birding daily and the last W Kingbird I saw was 2 days ago.
Speaking of the connection of this species with rain (and the bugs it produces), the Fremont County area had a pretty dry spring and early summer. We did get big precipitation in July like many other parts of the state. I had posted earlier on Cobirds that I thought this lack of early precipitation in my area, which northern parts of Colorado were blessed with this year, was related to the fact that Bobolinks and Dickcissels did not nest here this year at all. I might add that though mosquitos have increased noticeably, it has been spotty (lots at the fishing pond where the bats have been gorging on mosquitos that are abundant in the algae infested water that has no inflow or outflow) and mainly since mid-July. You might find the May, 2009 Drought Watch short term map interesting as it shows the entire Arkansas River basin in "moderate drought" while the northern parts of the state had improved to "midrange" status. Then the June, 2009 Drought Watch short term map illustrates the difference in impacts of precipitation between the northern front range (rated very moist) and northeast Colo (rated extremely moist) to the entire Arkansas River basin (rated mid-range) while the rest of the state was rated as moderately moist: http://www.ncdc.noaa.gov/img/climate/research/2009/jun/zin200906_pg.gif SeEtta Moss Canon City http://BirdsAndNature.blogspot.com On Tue, Aug 11, 2009 at 9:12 AM, Robert Righter <[email protected]>wrote: > > HI: > > It has always been curious why the Western Kingbirds leaves Colorado > so abruptly at the end of August, beginning of September, after which > they are quite scarce. One obvious reason is that Colorado’s insect > population rapidly diminishes. Recently its become known that the > Western Kingbird fits a pattern shared by other western songbirds in > that they travel to an area described as the “Mexican monsoon” area > which in this country includes southern New Mexico eastern Arizona. At > this time of year this monsoonal region is rich in insect life where > the kingbird can obtain the necessary protein needed to replace many > of its now year old feathers. What is also interesting is that adults > leave Colorado much earlier than juveniles where by the end of July > beginning of August they have started to move out and by mid August > most of the Western Kingbirds remaining in Colorado are supposedly > juveniles. For more information in this phenomenon see Auk, April 2009. > > This summer Colorado has experienced an unusual amount of moisture, > perhaps even historical amounts, so it will be most interesting to see > come the end of August if Colorado’s Western Kingbird population will > linger longer than usual, assuming the more moisture-insect ratio is > in place or will they instinctively disregard this weather anomaly and > move south anyways. Lets all keep our eyes open after Labor Day and > see how many Western Kingbirds we can tally up. > > Bob Righter > > Denver CO > > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
