Monday, November 24, 2008

Quick Question: Birds and Color Vision with Anders Ödeen

The other day I was rewatching the "Signals and Song" episode of The Life of Birds and took special interest in the section about avian eyesight.  David Attenborough, ye giver of knowledge, explained that many birds possess color vision far superior to our own, often allowing birds to see light in the UV spectrum.  The ability to see UV light means that in some cases - examples in the program include Budgerigar and European Starlings - birds appear to each other much different than they appear to us.

This got me thinking, then, about whether or not it matters what colors birders wear in the field.  My winter coat is bright red, and sometimes I wonder whether I'm scaring birds away unnecessarily.  I got in touch with Anders Ödeen, an animal ecologist at Uppsala University in Sweden who has done work with birds' color vision, and asked him about whether or not the color of birders' clothes matters.  Turns out, it probably does.  Here's Anders:

"Birds have a more advanced colour vision system, with one more class of photoreceptor involved in colour vision and a wider spectral sensitivity than humans. The conspicuousness appears to be correlated between vision systems. A colour contrast conspicuous to a human will in most cases also be conspicuous to a bird. For all practical purposes, we can therefore assume that most colours that blend into the background for humans do so also for birds. There are some combinations of foreground and background colours where the difference will be much greater for birds than humans. They will however depend on the specific combination and requires spectrophotometry and retinal modelling to identify. However, human camouflage might differ from the background with respect to ultraviolet reflection, to which we are blind but birds in general, Passerida passerines and psittaciforms in particular, are sensitive. The biggest difference between passerine and raptor colour vision seems to lie in the UV spectral range."

So, just as it would for humans, my bright red winter jacket will make me conspicuous to birds in the field.  It seems obvious, but it really isn't something that had ever crossed my mind before.  Looks like someone is going to have to put "camouflage coat" in his Christmas list...

Tuesday, November 18, 2008

How Many Field Guides Do You Own?

I began birding when I pulled an old copy of Peterson's off a shelf at a used bookstore in Fort Wayne, Indiana.  I flipped through the book and noticed that someone (whom I later deduced to be an old woman in Florida) had written the date and location of each sighting next to the bird's picture in the book.  "What a cool idea!"  I thought.  I bought the book, crossed off that old woman's chickenscratches and began watching the skies. 

Just a few years later, my collection of field guides has grown by leaps and bounds.  I purchase new ones every year to keep year lists in, and I try to obtain as many exotic ones as possible.  My bookshelf currently includes:

1 copy of The Sibley Guide to Birds  (This is the book I keep my life list in.  I mean, it's just the best.  Best pictures, most detail.)  

2 copies of The Sibley Field Guide to Birds of Western North America (Both given as gifts before I moved to Colorado)

2 copies of National Geographic Field Guide to the Birds of North America (Where I kept my 2007 and my current 2008 year list.  I like the NG because it has a lot more rarities than Peterson or Sibley.  However, it lacks Sibley's detail.)

3 copies of Peterson's A Field Guide to the Birds of Eastern and Central North America (My original copy is gone.  I kept my 2004, 2005 and 2006 year lists in this guide.  I like it, but some of the art is dark or tough to see.  I haven't looked much at the new, large edition.

1 copy of A Field Guide to the Birds of East and Central Africa (JG Williams, 1964 ed.) (old, worn copy given to me by Uncle Mike)

1 copy of The Book of Indian Birds (Salim Ali, 1979 ed.) (Another cool old guide given by Uncle Mike)

1 copy of Stokes Field Guide to Birds, Western Region (1996) (my only guide using photos.  Not a huge fan)

1 copy of Birds of Ecuador (Awesome book.  I bought it before my trip to Ecuador's west coast [which is probably the least birdy part of the whole country...].  I had an incredible time leafing through this book and scrambling to identify the birds I would see.)

1 copy of Peterson's Gulls of the Americas (My most recent purchase.  I really love the idea of a Gulls guide, but I have to say I'm a little disappointed in this book.  A lot of the photos are very old, there is no index at the beginning, the birds aren't separated clearly, and the inclusion of South American gulls is confusing.  I understand that it's not meant for use in the field, but it's still tough to use at home.  It's OK, but there is a lot of room for improvement in a Gulls guide.)

1 copy of The Shorebird Guide  (This is what the Peterson Gulls guide should be.  The Shorebird Guide is incredible: beautiful, easy to use, lots of rarities.)

1 copy of National Geographic's Water, Prey and Game Birds of North America and Song and Garden Birds of North America (1964) (A box set of two companion volumes given to me by my grandfather.  At the back of both books are birdsong recordings which can be played on a record player!)

Those are all the bird guides I've acquired so far.  I'm looking forward to being an old man with an entire bookcase dedicated to different bird guides from around the world and from different eras.  

How many do YOU have?

Sunday, November 9, 2008

The Birdist: "As Refuted By David Sibley!"

Master birder/fieldguidist/artist David Sibley has recently picked up the discussion of "how many rare birds to we miss?" on his personal blog, Sibley Guides Notebook.  Since I had interviewed John of A DC Birding Blog about that very topic back in March, I left a comment with the link in Sibley's comments.  On Thursday Mr. Sibley posted his own answer to the "how many do we miss?" question, suggesting that the number is somewhere around 3 to 10 percent.

And you know what?  He's right.  What made me think so?  It wasn't that blog post, but it was an example Mr. Sibley used: the search for the European Golden-plover.  

Mr. Sibley began the discussion of finding rare birds by linking to a video of a moonwalking bear.  Well, the search for the EUGP in Scarborough Marsh was pretty much exactly like the classic sniper training scene (careful, there's a swear word in there) from A Clear and Present Danger: a bunch of guys with binoculars staring into a field, failing to locate something they know is there.  

Standing at Seavey's Landing that morning, I realized how truly difficult it is to find an extralimital bird.  Here, completely surrounding this one square mile of marsh, were probably 50 of the best birders in New England, all with their scopes trained.  For hours.  No bird.  

If 50 experts with scopes can't find one little bird in a field, what chance does one expert have?  What about one non-expert?  What is the EUGP had landed in any of the many less-birded or less-accessible areas of Scarborough Marsh?  The odds become miniscule.  I mean, there are only a handful of birders in Maine good enough to suspect that the bird was anything but an American Golden-plover (I'm not one of them, but thank goodness that Robby Lambert is), and that's if they were lucky enough to get a good look at it to start with.  

Secondly, I came to a separate realization about finding rare birds while looking for the EUGP.  After hours of sitting on the outskirts of the marsh, waiting fruitlessly for the bird to appear, some Mass. birders and I decided to start walking through the marsh, hoping to locate the bird closer to where it had been last seen.  During our walk we repeatedly kicked up birds that no one else had been seeing, including American Bittern, Snipe and Pectoral Sandpipers.  All these birds, like the EUGP, were hunkered down in the grass, unseen by the mighty 50 and their powerful scopes.

Scarborough Marsh is probably the most heavily birded area in Maine (except for maybe Evergreen Cemetery in early May), and yet it took a mighty effort to refind a single extralimital bird there.  Mr. Sibley is right, the actual find-rate for extralimital birds must be much less than my estimate of 1/3.  Well, unless you've got Robby Lambert on your side...

Friday, November 7, 2008

The Onion is Funny

Check out this article from The Onion about the lack of gratitude Peregrine Falcons have been showing since their removal from the Endangered Species list.  Also includes a Maine shoutout!

However, since there's no one else in the world to criticize and correct tiny, passing minutiae regarding the representation of birds in the media, I'll say this:  the sentence in the article reads "hunting prey off the coast of Maine as though it were 'master of the fucking skies.'"  Peregrines hunt near the coast, sure, but aren't a bird you'd find hunting off the coast.  OK?  That's enough.

Sunday, November 2, 2008

Birds at Large VI: Mark Trail

The other day I broke down and bought the Peterson Gulls of the Americas book (review to come later, probably).  I've looked through the thing a ton of times since it arrived, and darn if I can't find either of the two gull species that appear in the above Mark Trail strip.  

I mean, let's think about it.  It looks like the two birds on the left of the second cell (the detailed ones, not the faraway ones above the people) appear to be the same: white-headed gull, no black on the wingtips, unmarked bill.  What could that be?  The lack of color on the wingtips could indicate an adult Iceland Gull or Glaucous Gull, but both of those species have bright red gonys spots.  

As for the rightmost gull, the one with the black head (or, as Peterson puts it, the "masked" bird), the combination of black head, black bill and unmarked wingtips leaves an adult Little Gull as the only possibility.  

So Mark Trail has apparently found himself on a pier with two aberrant-billed white-winged gulls and an unusually large Little Gull.  Holy Moses, Mark!  Alert someone!  Ditch that boring chick and put something out to the listserv!  If you want to protect natural resources for future generations, you better start with this magical, rare-gull attracting pier!

Much more probable is my assumption that Jack Elrod just drew generic gulls thinking that no one would notice.  Well, guess what, I noticed.   Mr. Elrod, I implore you, as this nation's preeminent naturalist/cartoonist you have a duty to present your drawings with the highest of accuracy!  How are kids going to know to value our national resources when they're presented inaccurately?  

I mean, how hard is it to stick a little gonys spot on there?  

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