Re [Tweeters] Early Arriving Migrants and a Plea for Caution

B Boekelheide bboek at olympus.net
Fri Apr 18 14:27:31 PDT 2014


Thanks, Brad, for your post on Tweeters. We deal with too-early reports all the time up here, so every little reminder helps.

One small point about Cassin’s Vireos, however. Over the years we have a distinct pattern here of Cassin’s passing through the north Olympic Peninsula in mid-April, with first sightings around RR Bridge Park along the Dungeness River and a few other local habitats between Apr 10-18. They are singing males, often in the riparian forest where they don't remain to nest, so likely heading further north and singing on the way. When we first heard them, I, too, was a disbeliever, but after repeated sightings there seems to be a pattern. I don’t have the records right at my fingertips right now, but they’ve occurred several years over the last 18 years. I see that Bruce Paige just reported one yesterday, 4/17. The odd thing is that the Cassin’s that nest here seem to be in different areas than where these early birds are singing, so who knows where the early birds end up. Most of the local nesters are in mixed forests in the foothills of the Olympics south of Hwy 101.

Thanks!
Bob Boekelheide
Dungeness


From: Brad Waggoner <wagtail at sounddsl.com>
Subject: [Tweeters] Early Arriving Migrants and a Plea for Caution
Date: April 12, 2014 at 3:49:07 PM PDT
To: tweeters <tweeters at u.washington.edu>

Hello All,

I'm not sure how this will come across, and I really have no intent here on picking on anyone for tweeters post about arriving migrants and breeders. Posts on heard-only birds are especially concerning to those of us that attempt to track records in the state of Washington. Ain't spring wonderful, especially with glorious days like this with returning swallows about, and Common Yellowthroats setting up territory in our local marshes, and Orange-crowned Warbler trilling in shrubby riparian areas. But, there are a number of species, despite such a nice batch of weather, that really do not show until the latter part of the month of April or into May. I would encourage all to take a look at bar graphs in A Birders Guide to Washington, or for those that really are keen on status and distribution here, take a look at Birds of Washington. Take a look at when some species normally arrive, and maybe use it as a reference source for making calls on certain species. Be careful not to interpret rare or casual lines in these graphs as the time they arrive. I find that a bit deceiving and arrivals in those dates need superb documentation.

Specifically, be very careful of flycatchers, especially a few of our empids, pewees, and Olive-sided Flycatchers. Yes, things like Hammond's and Pacific-sloped Flycatchers arrive in late April (early to mid April could use documentation), but Willow Flycatchers do not arrive until mid-May. Pewees and Olive-sided Flycatcher are early May arriving birds, but a few might be found in the waning days of April. Warbling and Cassin's Vireo do not arrive until later in the month despite a few rare or casual marks earlier in April. Red-eyed Vireos, and I will throw in American Redstarts, do not show until mid May. Some of are thrushes are early migrants including the bluebirds, solitaires, and Hermit Thrush, but Veery (a west-side rarity anyway) and Swainson's Thrushes are both May arriving birds. A few Swainson's Thrushes may actually show in the last few days of April, but I can almost guarantee you will get a "whit" vocalization at that time, and not an actual song. They just don't sing until they get strongly territorial until after the first week in May. Warblers such as Nashville, Black-throated Gray, Wilson's and Macs will indeed show quite soon, but Yellow Warbler will not be on the scene until early May. Bright Orange-crowned Warblers in March and April can be the likely source of early reported Yellows. Western Tanagers, Black-headed Grosbeaks, and Lazuli Buntings are late April/first of May arriving birds. And chats too arrive in May. Oh yeah, and nighthawks don't arrive until late May early June.

Thanks and good birding,

Brad Waggoner
Bainbridge Island, Washington


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