[Tweeters] Question About Site Fidelity in Tropical Kingbirds and
other Tyrant Flycatchers
contopus at telus.net
Sat Nov 14 19:00:40 PST 2015
Vincent and Tweeters,
Are you suggesting that the same Tropical Kingbird might return to someplace in Washington 2 years in a row? My response to this is that the chance of this is very close to zero. Of course, there is no way of being certain without marked birds. However, there is no evidence that a Tropical Kingbird has ever survived the winter in Washington, let alone returned for a second year.
My belief is that all the Tropical Kingbirds that show up every fall in coastal WA, OR, and BC are doomed to perish. If you look at all the Tropical Kingbird records for WA in eBird in a bar graph (I just did that), all records fall between the third week of September and first week of December. There are no records later than December 7th. Tropical Kingbirds are entirely, or almost entirely, insectivorous, and there simply are not enough flying insects around after the end of November to sustain them. There is no evidence that any of them go back south; many of them stay for weeks in the same place once they arrive here, and their eventual disappearance, I fear, is always or nearly always due to mortality.
The situation in Florida is vastly different from that in Washington. The winter climate is much warmer, and there are some flying insects all winter in many parts of the state. As you know, several species of flycatcher winter regularly in the state, including Eastern Phoebe, Great Crested Flycatcher, Western Kingbird, and Scissor-tailed Flycatcher, and it’s quite possible that a Tropical Kingbird could survive the winter there.
This is not to say that some vagrant birds may not return to the same location in subsequent winters. The classic case is a Sky Lark— almost certainly from eastern Asia, not from BC-- that was found near Point Reyes, California, and returned to the same area 9 years in a row, despite being thousands of miles out of its normal range. This bird was not marked, but it’s virtually certain that the same bird was involved. There are not dozens of Sky Larks showing up in California every year. There are also quite a few cases of out-of-range birds which have been captured and banded, and recaptured in subsequent years. However, I doubt that any of these are Tropical Kingbirds, or even flycatchers.
The reason, I believe, that Tropical Kingbirds show up year after year at the same localities in WA is that this species has a strong tendency to follow coastlines. There will be sightings every fall in places like Neah Bay, Westport, Ocean Shores, and the Long Beach Peninsula, and maybe even Port Angeles and Dungeness. However, I’m quite certain that these are different birds every time, not the same bird year after year.
Wayne C. Weber
contopus at telus.net
From: tweeters-bounces at mailman1.u.washington.edu [mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Vincent Lucas
Sent: November-14-15 5:03 PM
Subject: [Tweeters] Question About Site Fidelity in Tropical Kingbirds and other Tyrant Flycatchers
I've tried researching site fidelity for TRKIs and other Tyrant Flycatchers on Cornell's __Birds of North America" and other sources. Little is known about this phenomenon I presume. In addition to seeing TRKIs up here in the Olympic Peninsula almost annually, while I used to lead field trips for 8 years to Storm Treatment Area #5 (STA-5) near Lake Okeechobee, FL, when I lived in Naples, a Tropical Kingbird showed up there for several years in a row in late Fall into Winter. One was seen again there today. Yes, it vocalized and was recorded doing so. In BNA, there isn't even a mention of TRKI overwintering or returning to South Florida, yet alone anything about site fidelity. A few Cassin's Kingbirds, Western Kingbirds and Scissor-tailed Flycatchers and sometimes Vermilion Flycatchers are annual in South Florida. Not all birds seen are post-breeding dispersal birds either. I suspect the same is true for TRKIs seen in the Olympic Peninsula and other areas of Washington. Different subspecies than the ones in Florida? I think the whole concept of site fidelity among Tyrant Flycatchers needs to be investigated in depth. Maybe a PHD thesis for some aspiring graduate student in ornithology? Comments welcome.
Port Angeles, WA
vincentlucas5 at gmail.com
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