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...

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 Peterson's A Field Guide to Western Birds 

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?

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...

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.

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?  

Interview with Dr. Keith Arnold, founder of the Texas Bird Records Committee

Records Committees are those bodies of expert birders who examine unusual bird sightings from within their state to determine their validity and accuracy.  As a regular birder, I have a tendency to romanticize such proceedings.  What power!  Are the Committee members sitting around a big round table like the Knights of Camelot?  Do they spend late nights in the backrooms of nightclubs, smoking cigars and politicking about Canada Geese subspecies?  

It's an extremely interesting subject, and I am very thankful that Dr. Keith Arnold has agreed to help me clear up my imagination.  Aside from being one of America's most respected ornithologists, Dr. Arnold is an author, a Professor Emeritus at Texas A&M and a founder of the Texas Bird Records Committee.

I'm grateful (and honored) that Dr. Arnold was able to take the time to help me clear up some of my misconceptions about Record Committees, and give me a glimpse of what actually goes on behind those closed doors:

Birdist: What was the impetus for the creation of the Texas Bird Records Committee?

Keith Arnold: Birders have a problem with rare birds and acceptance by the scientific community. Our committee started [in 1972] when George Newman, then president of the Texas Ornithological Society [and also my graduate student] asked me to form a committee to examine such records and to develop a state checklist for all birds. I did so initially by recruiting a well-known birder from each of the 8 T.O.S. regions.

What exactly were the problems? A lack of uniformity in terms of what birds were countable? A lack of knowledge of what existed, or what was common or uncommon, in Texas?

KA: Where to start?
1. The reputation of the birder for "finding" rarities...usually not "re-found" by others...
2. Species easily confused...
3. Need for documentation, even written details, but photos, recordings, etc., preferred...
4. Where are records available...
5. How does one evaluate a record that appears simply as a name in a printed account such as in American Birds or its predecessor or successor...

Given a bit of time, I'm sure that I can add to this list, but it should give you an idea as to what the birding and scientific communities face.

So you sat down with your 8 T.O.S. birders and began examining records. Because these pre-TBRC birders didn't realize that they needed a certain amount of proof for a sighting (because the TBRC didn't exist yet) did you find yourself disallowing a large number of sightings?

I imagine there must have been some controversy, or at least heated discussions, among the members of the committee and with local birders, do you remember any specific incidents?

KA: After the formation of the committee, we only considered records that were submitted to us by birders. After Greg Lasley joined the committee in the 1980s, he began to dig into the birding literature for rarities. He and Chuck Sexton complied a list of "review species", based on less than 4 records a year over a ten-year period. The committee adopted that list as its staring point, although it has been modified -- birds added or deleted and, in some cases added again; at least one committee member didn't think that we should remove ANY species because of a loss of information.

And yes, we had some "differences of opinion" with some birders, some to the extent that they refused to submit details on any rarity they encountered. Along those lines, we have a number of birders who will not submit details on a species that occurs almost every year, but does not meet the criteria for removal, simply because they know that they can find the bird in Texas almost any year. The parrots and parakeets have been a problem in that we now have sustaining populations, but the origin is in doubt; one of our former members [I think he is now back on the committee] took it upon himself to survey for breeding birds of the Red-crowned Parrot and Green Parakeet and we added these species to the Texas list, based on his findings.

While I'm sure I could dredge up some controversial records, I don't think it would do the birding public any good to do so. As stated above, we have enough difficulty in gathering details on rarities, even though dozens of birders saw [and many photographed] that particular bird. I will give you one example in which I was directly involved. I refused to accept [vote for] records of Lesser Black-backed Gull for a number of years because the only species considered in those reporting was the Greater Black-backed Gull: I wanted the committee [and birders] to consider other "black-backed" gulls. Since that time, mostly in the 1970s, the birding community has become more adept at IDing gulls and we have since added Western, Slaty-backed and Kelp and possibly Yellow-legged -- all dark-backed gulls. I continue to struggle with Iceland and Thayer's Gulls.

How are Committee members chosen and how long do they stay on?

KA: Current committee members suggest names for open positions; if more are nominated that the number of positions - usually two, then those receiving the most votes at the annual meeting will be elected. We have two members rotating "off" each year, with each serving a 3-year term, and eligible for a second term if so desired. The committee chair and the academician [the position I hold] are elected each year, usually without opposition, and have no limit to the number of terms that person can serve.

How is a sighting presented to the committee? Is it like a courtroom, where a birder or a committee member presents the information and pleads his case, or does someone in charge present each case and opens it to discussion?

KA: The TBRC has a form on the T.O.S. web site that anyone reporting a Review Species can use; we occasionally get information in a less structured way, however. We ask that all relevant photographic materials be submitted: today, that usually means digital images sent as e-mail attachments. The record [usually one of at least six] is then sent out to the committee members via an e-mail, with access to them on a web-site. 

A record that receives no more than a single nay is accepted on the 1st round; those that receive 2 or more nay votes, but at least 5 yea votes are sent as a 2nd round, with copies of votes and comments of all committee members; this may be repeated in a 3rd round with the same criteria. If the record still has at least 2 nays and 5 yeas, it goes to a fourth round for discussion and a final vote at the annual meeting; we try to hold an actual "in person" meeting and, because of the size of the state, not all members may be present. A few years ago, we modified the bylaws to permit electronic or tele-conference meetings. That came into play this year as the annual meeting was scheduled for the day Hurricane Ike hit Texas!

We don't say that we "reject" a record, but that it is a "non-accepted" record; any record can be recall for the committee if additional evidence comes forth and such a recall is usually initiated by a TBRC member.

What effect did the advent of records committees have on birding?

KA: Has this affected birding in Texas? Without doubt. We have some birders who, having submitted a "non-accepted" record, simply will not submit another record. That is unfortunate, not just for that person, but also for Texas birding. On the other hand, many Texas birders have begun to write better field notes [or begin to keep field notes], carry a camera with them and some, even a recorder, since in some cases, vocalizations are better evidence than photos. I also think that having the TBRC and a Review Species list has sharpened the skills of a number of Texas birders, as they come to understand the difficulties in identifying certain species complexes. ø

Quick Question: Birds and Apple Trees with Nancy Coverstone

My mom has some apple trees on her property. Each autumn the apples fall to the ground and my mom (or me, if I can be wrangled into it) rakes them up so we can mow under the trees.

I was thinking, though, wouldn't these apples be better for birds if they are laying on the ground all delicious and eat-able? I've seen Robins eating my mom's fallen apples, but would other birds eat them as well? Would leaving them on the ground mean that I won't asked to mow?!

I did a little research and turned up this informational page produced by the University of Maine Cooperative Extension. I wanted to know more, so I emailed Nancy Coverstone, the Extension Educator at the UMaine Cooperative Extension, with my problem. She gave a great response, including some thoughts on how birds will benefit not just from eating the apples themselves but from eating the things that eat (or grow on) the apples. Many thanks for Nancy for her thoughtful response. Here's the interaction:

Birdist: My mom has three apple trees on her property. Traditionally, my family has raked up the fallen apples in autumn and put them in a pile in an out-of-the-way part of the property. I want to start thinking about other strategies in order to maximize benefit to birds. However, I also have to take into consideration more domestic considerations, like mowing. As far as I can tell, here are my options: a) continue to rake and pile fallen apples, b) let apples fall and leave them there all winter, don't mow under the trees, and c) something in between. What do you think of these options? Which will be best for birds?

Nancy Coverstone: I’m assuming the fruits are not persistent (staying on the tree, and above the snow line, into the winter.) Persistent fruit, whether apples or other kinds, are particularly beneficial for resident bird species, because the fruits are not buried under the snow and are available during winter, and are made palatable by the freezing and thawing that takes place.

The trees you have, both while the apples are still on the tree and when they’ve fallen to the ground, are eaten by many birds, mammals and insects.

Once the apples have fallen, I don’t think it matters that they remain under the trees. It makes sense to mow under the trees, so that other vegetation does not compete with the apples trees and also that the apples as they rot attract wasps in the fall and some butterflies too. It’s great to have a fall food source for wasps and other insects, but conflict does arise if you are mowing.

So – raking up the windfalls is fine to do. I would, however, put them in an out of the way place, in the sun and spread out, rather than in a pile. I would also locate this “apple spread” near some shrubs where birds can perch, before they might move to the ground to eat or peck at the apples. Being in the sun is beneficial for butterflies, bees and the other insects that might feed on the rotting fruit, because they need the warmth of the sun on them to be active.

Whenever I think of what might benefit birds, I also consider what benefits other forms of life, because usually what’s good for one is good for others. An example is that during the winter, chickadees may eat the larvae of wasps who fed on the rotting apples. See what I mean?

Also, the cover and nesting opportunities provided for some bird species is not affected by your management of the fallen apples.

Just some thoughts.

Since you found the fact sheet on apple trees and wildlife, I assume you’ve found the other Habitats fact sheets on UMaine Extension’s publication site. Check out some of the books now on offer through this site – under Yard and Garden and Natural Resources especially.

http://extensionpubs.umext.maine.edu ø


Also,
I and the Bird Number Eighty-Six now up at The Drinking Bird