DAVE SLAGER ENTERTAINS ABC’ERS April 24, 2018

BE SURE TO SEE UPDATE AT BOTTOM!

Dave Slager at ABC

ABC loved Dave Slager. He was a fount of the kind of info that we want to know and ready to talk on anything we wanted. He is a doctorate student at the U. His areas are research science and ornithology, but he says these are colored by the fact that he is a lifelong birder.

Dave and Slater Museum director Peter Wimberger examine crow specimens

ABC now has the lowdown on the Northwestern Crow vs American Crow question. Picture Dave in a Clean Room wearing a Hazmat suit to make sure nothing sullies his extraction of DNA from antique crow specimens from several museums. Then you’ll know why he was selected to present his paper on the crow question a couple of months ago, results of which should be published soon and will cause a sensation among corvid scholars and birders. We are just the second group after that august gathering to hear his crow results.

Why we are at the epicenter of the Northwestern Crow controversy

Antique specimen DNA studies do not differ much from modern Haplotypes

Dave’s conclusions are that there are definitely two haplotypes that our crows fall into, but that interbreeding occurs at all levels and has been occurring since before “civilization” befell our corner of the continent. But the two types tended toward speciation in prehistoric times, which stopped at some point, and has led now to crows in the northwest breeding together and having various amounts of both signatures.

Some of Dave’s conclusions

Because he has shown two historic types, even though they are evolving away as we read this, he says we should enjoy having Northwestern Crows on our lists while we still can, and he will probably add them to his personal list when he birds Alaska this summer.  In the event of a lump by the AOS checklist committee, he says birders will also gain from many upcoming splits, so don’t mourn the loss.

The Corvid Family Tree

He showed a relationship chart of the Corvids, which was pretty interesting on its own, showing that our Ravens are more closely related to Old World Ravens than to our Crows, and the same for New and Old World Crows. He mentions how poor the western hemisphere is in Corvid species compared to the eastern hemisphere, as well. And the Fish Crow appears to be more closely related to ravens than the crows!

Dave talks about more than just crows.

After discussing some eBird complaints, Dave took some time at the end to talk about sound recording and how exciting that is. He said he can take a photo, and it won’t add much to the body of knowledge since there are so many good photos of any given bird, but a song recording might, since there are many fewer recordings. He was able to take a course from Cornell/Macaulay that really inspired him, and of course eBird is encouraging us to post sound recordings these days. Two of his tips were about amplifying your recordings to an acceptable level, as well as using wav vs mp3 to capture more nuances of birdsong. And try to get recordings of crossbills!  We are still learning many things about the occurrence and distribution of the different call types, and what a challenge they are to record as they fly off into the distance!

Dave had to be dragged away from avid ABC’ers due to his willingness to answer any and all questions, including that he agreed Willets are two separate species, and much more. We’ll definitely be wanting him back at some point!

UPDATE FROM DAVE!  DEC 11, 2018:

Some of you might be interested in reading about our recent UW research on the American Crow / Northwestern Crow hybrid zone, which is currently in the peer review process.

Short version:  Our crows are hybrids!

I posted a summary explanation on Twitter here:
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2Fdlslager%2Fstatus%2F1072353359041085440&data=02%7C01%7C%7Cc0f27135155a475ad62208d65fb9fecb%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636801649774470123&sdata=inD%2B%2BXfVgVF1ZQu2D3EPg7AFKpVtNgzpqwhhu0brklM%3D&reserved=0

For those interested in the nitty gritty, you can read the full
manuscript for free by going to this link and clicking “Download PDF”
<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.biorxiv.org%2Fcontent%2Fearly%2F2018%2F12%2F10%2F491654&amp;data=02%7C01%7C%7Cc0f27135155a475ad62208d65fb9fecb%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636801649774470123&amp;sdata=9u0Ewhc%2FX%2Fts1yFk0zK725U9TCS68E%2Bqsyd1RkQtb4k%3D&amp;reserved=0>.

Happy crow watching,

Dave Slager
Seattle, WA
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