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Quick note:
Dwight Norris on FB points out this 3+ year-old Nature article on the use of eDNA (environmental DNA left behind by species) for locating rare animals:
I believe this is (or has been) used minimally, and unsuccessfully thus far, in searches for IBWO. In any event I suspect it would more likely be a tool for helping confirm the presence of IBWO in a given locale after they have been seen or heard, rather than a tool for finding Ivory-bills in the first place.
A bit of the cautionary note from the piece:
“…the technique is yet to convince some scientists, who say eDNA results aren’t robust enough to be used as the sole basis for making environment-management decisions that can have legal implications for governments and land owners.
“Early studies that used eDNA to pinpoint specific species were criticized because of the potential for improper handling of samples to cause cross-contamination, leading to false-positive results. Scientists using the method are detecting only trace amounts of genetic material, so even minute amounts of contamination from gloves or equipment can taint the results. But proponents of the field say that the recent adoption of rigorous protocols that avoid or detect contamination have largely addressed such issues.”
Chances are by now, fairly 'rigorous protocols' are indeed in place, though there could still be problems of interpretation. I don't know to what degree cost may be a limiting factor in how extensively eDNA is employed? In any event, from my very limited reading the technique has been less successful or used with birds than other animal forms... mammals have even been detected from short-term DNA in air (though this article is inspired by use for a bird).
Here is a Wikipedia article on the subject:
https://en.wikipedia.org/wiki/Environmental_DNA
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ADDENDUM:
Am trying to keep articles not directly pertaining to IBWOs to a minimum here, but this is such a nice story (from Dwight N. again), that I’ll it pass along… about a rehabbed Pileated Woodpecker maintained in a Michigan zoo:
I’ve never given much hope to any notion of possible captive breeding for IBWOs (as done with some other endangered avian species), but this piece is at least interesting. I do wish they said more about the actual habitat and daily routine of this bird, and it will be interesting to see what it’s longevity in captivity is.
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ADDENDUM2 1/29:
A couple more longish postings by Chuck Hunter over on Facebook worth a gander:
https://www.facebook.com/groups/ivorybillnews/posts/1528420804344451/?comment_id=1529215204265011
Sorry for any redundancy of linking to Chuck yet again, but so many of the knowledgeable, thoughtful, objective sources I used to rely on years ago have passed from this arena that he is one of the few left whose views I’m willing to pass along as trustworthy. These posts are mostly historical info, and I always caution about the difficulty of knowing how reliable/valid/relevant such information (based on a small sample of IBWOs) really is for any limited, remnant population still around almost 100 years later, but certainly food for thought.
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ADDENDUM3 1/31:
NPR with a current audio report on the IBWO story (mostly rehash of where we're at):
...the USFWS decision is likely still a couple months away, so don't read too much into the word "imminent" in the story title.
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ADDENDUM4 1/31:
Apologies for all the addenda, but am waiting for more significant news to start a new post. The below again is recent history, old news for all well familiar with it, but definitely of interest for the many new folks entering the IBWO arena. Hat tip once again to Dwight Norris (Facebook) for referencing it, as it comes from one of the most respected, long-term IBWO searchers out there, Paul Sykes (who’s been at this for decades since the 1960s), a nice summary of his searching:
His efforts are of interest in themselves, and his conclusions are important as well, because of his experience and contacts over time. Additionally, years ago he and Steve Holzman spent significant time attempting to deduce the diagnostic features of IBWO scraping and bark scaling (as have many others) only to conclude in the end that we simply don’t know definitively how to separate IBWO work from other work… indeed, if we did, we would surely by now have a clear photo of an Ivory-bill from an automatic camera focused on such work — I’ve long argued that the failure of remote automatic cameras to capture an IBWO (rather than the failure of humans to observe them) is the single most damning evidence against IBWO survival in any given area.
By now, Steve is largely skeptical and pessimistic about IBWO survival… and he’s earned the right to that conclusion from the multifold efforts he put in. With that said, I'm sure no one would be any more excited/ecstatic were definitive proof of the bird's existence to now arise.
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ADDENDUM5 2/4:
Matt Courtman’s next monthly IBWO Zoom meeting is this Monday evening (2/6), again at 8pm EST., details here (free to join):
https://www.facebook.com/events/570295411419641/?ref=newsfeed
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ADDENDUM6 2/5:
Dwight N. has posted five more lengthy entries from Chuck Hunter on Facebook (actually the last one, #5, is an old posting from Bill Pulliam making the same point about IBWO density that Chris Haney emphasizes and makes well more recently in his volume “Woody’s Last Laugh”).
The posts are mostly of a historical nature or commentary (much of it about ‘signs’ of IBWOs, i.e. sounds, dks, kents, flight patterns, behavior etc., but also, in #4, some reference to more recent history since 2005); certainly worth reading for those unfamiliar with much of it. I think #3, with the Reynard information, is the most interesting of the bunch:
#1 https://www.facebook.com/groups/179784035376368/permalink/6156630967691615/
#2 https://www.facebook.com/groups/179784035376368/permalink/6156644977690214/
#3 https://www.facebook.com/groups/179784035376368/permalink/6156661604355218/
#4 https://www.facebook.com/groups/179784035376368/permalink/6156674251020620/
#5 https://www.facebook.com/groups/179784035376368/permalink/6156682907686421/
The historical information is great and (with caution) instructive, but what I'm still hopeful for within the next say 5 weeks is perhaps some more and better publicly-released evidence....
2 comments:
I looked into this, spoke with some experts, and have seen that it's difficult to show if the eDNA is two weeks old, or thirty years old. Thus, for the IB, this is questionable.
yes, that’s part of what I was alluding to in mentioning “problems of interpretation”… though in some circumstances other factors could help indicate the age of a given sample... still eDNA must be used judiciously -- like most IBWO evidence presented these days ;)
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