tag:blogger.com,1999:blog-87232698829192066122011-08-16T23:11:37.475-04:00Field identification and related studies of birds and treesDavid Sibleynoreply@blogger.comBlogger761100tag:blogger.com,1999:blog-8723269882919206612.post-35192347012862913262009-11-06T12:20:00.000-05:002009-11-06T12:20:38.091-05:00

This blog has been moved to a new and improved blog and website at sibleyguides.com. Thanks for your support! Comments here are closed. All future posts will be at the new site, and all of the old posts and comments from this blog have been transferred there as well.

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-17000057217955244702009-10-20T14:25:00.001-04:002009-10-20T14:27:13.618-04:00

Determining the age of a goose can be helpful for identification, and can also reveal some interesting behavioral and ecological information by enabling you to sort out family groups and subflocks. Given good views it's not hard to distinguish Canada Geese that are still in juvenal plumage from those that are in adult plumage. By October many immatures (hatched in the summer a few months earlier)

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-1920160089240366652009-10-19T10:55:00.000-04:002009-10-19T10:55:42.769-04:00

Have you seen any Field Plovers lately? Blue Nutcrackers? Day Owls? These are all alternate common names of North American birds. Richard Banks has assembled a complete list of outdated English names of North American birds along with the current official names for those species, and it makes a great resource to find out what early authors meant, as well as just fun browsing. You can read it at

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-660638663547476972009-10-14T16:55:00.002-04:002009-10-16T15:33:27.847-04:00

updated 16 Oct 2009 Here are page-by-page corrections and changes for the Sibley Guide to Trees. This listing will be updated periodically as issues come to my attention. Please feel free to leave comments or send me an email if you notice anything that is not listed here. p 3 - California Torreya, the common and scientific names should be justified left p 28 - Red Pine needs a new name to

David Sibleynoreply@blogger.com5tag:blogger.com,1999:blog-8723269882919206612.post-89648783713783746682009-10-03T09:25:00.002-04:002009-10-07T11:48:12.436-04:00

In the past, tree identification guides have emphasized the presence of opposite leaves as one of the most important field marks. In the Sibley Guide to Trees I used a more holistic approach, like modern bird identification, giving equal weight to all parts of the tree. A tree might catch your attention because of its flowers, twigs, bark, fruit, etc., and I don’t think it’s helpful if the field

David Sibleynoreply@blogger.com6tag:blogger.com,1999:blog-8723269882919206612.post-58064117435269444722009-10-01T15:07:00.000-04:002009-10-01T15:07:06.979-04:00

One of my regular birding spots is a small farm field near my house in Concord, Massachusetts. I can walk around the entire place in about 20 minutes, but I usually take about two hours and get in some good sparrow-study. The clump of taller vegetation shown here is always a good spot to study birds that come up out of the grass and weeds and perch a little more conspicuously, so I usually spend

David Sibleynoreply@blogger.com3tag:blogger.com,1999:blog-8723269882919206612.post-37260005653711947622009-09-23T09:27:00.003-04:002009-10-01T11:10:29.893-04:00

Reader Sherman Dunnam sent me a note about an error in the introduction to maples on page 332. The third paragraph begins "All maples have palmately compound leaves..." This should instead say "Nearly all maples have palmately lobed leaves..." And could go on to elaborate that a few species have the leaves so deeply lobed that they are compound, and Boxelder is unique among the maples in having

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-27494515517523630922009-09-23T09:20:00.003-04:002009-09-23T09:27:10.753-04:00

I have spent the last seven years working intensively on my new Guide to Trees, but of course a few misstatements and errors somehow managed to creep in. I'm always interested in learning more, correcting my mistakes, and passing along to you - the reader - newer, better, more accurate information.So if you notice any errors, or anything that seems to be missing or misleading, please don't

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-84173516305329848192009-09-22T21:42:00.004-04:002009-09-22T21:55:01.754-04:00

Two events related to The Sibley Guide to Trees: It is the featured product today on the Daily Grommet website. I’ll be checking in periodically, responding to comments and answering questions through noon tomorrow (Wednesday Sep 23rd) . And “The Art of Identification” - a show of my artwork and field sketches at the Massachusetts Audubon Society’s Visual Arts Center in Canton, MA, will be

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-52810667720121028812009-09-10T22:13:00.002-04:002009-09-10T22:13:00.189-04:00

After seven years of work, my new Guide to Trees goes on sale officially on September 15th (but those who live near Philadelphia can get it as early as Saturday the 12th when I'm there for book-signings). I'll be traveling quite a bit this fall to book-signings across the US and Canada, doing a variety of publicity-related things, and adding tree identification to the topics I cover here on this

David Sibleynoreply@blogger.com5tag:blogger.com,1999:blog-8723269882919206612.post-77501570765829345092009-07-09T22:15:00.009-04:002009-07-10T13:04:42.550-04:00

After listening carefully to Pine Siskins this year to pick out the calls of other species (see my earlier post) I have run across several other mimics. In early June in Arlington, Massachusetts I heard a remarkable American Goldfinch song that incorporated several phrases of a Song Sparrow song along with Northern Flicker and I suspect other species were being copied but I couldn't pick them out

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-77411803727667705342009-06-24T14:43:00.003-04:002009-06-24T15:29:08.061-04:00

The most recent research by Dr. Daniel Klem, who has been studying the problem of bird/window collisions since the 1990s, has just been published in the June 2009 Wilson Bulletin. It is available, along with lots of other bird/window resources, at his website here. Klem tested the effectiveness of various window treatments confirming, for example, that single decals on a window are not effective

David Sibleynoreply@blogger.com10tag:blogger.com,1999:blog-8723269882919206612.post-13540548298066599282009-05-14T06:48:00.002-04:002009-05-14T07:03:34.660-04:00

In early March 2009 it was my pleasure to spend a few days in California at the San Diego Bird Festival. On my first morning in San Diego I headed straight out to the Tijuana River National Estuarine Research Reserve hoping to spend a few hours studying Savannah Sparrows (who wouldn't, right?). I had seen some Belding's Savannah Sparrows in March 2008 in Orange County, California, and realized

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-74721681937641954942009-05-13T13:42:00.004-04:002009-07-10T08:30:17.714-04:00

[10 July 2009 - update added at end]In July 1990 I spent several weeks birding in west-central British Columbia, where Pine Siskins were one of the most conspicuous birds, and I became convinced that Pine Siskins were copying the sounds of other species of birds and incorporating these sounds into their songs. I was able to identify American Robin (squeal call), Evening Grosbeak (“krrr” call),

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-34652893179796703042008-11-24T22:13:00.009-05:002009-03-13T11:02:19.190-04:00

Coincidentally, just days after my last post about the two White-fronted Geese in Concord, two White-fronted Geese showed up in Amherst, Massachusetts (about 60 miles west of Concord, but not the same birds) that appear to be one Greenland and one North American type. James Smith has some discussion and really nice photos on his blog, and he's allowed me to post some of the photos here. Two

David Sibleynoreply@blogger.com5tag:blogger.com,1999:blog-8723269882919206612.post-47334239436668101482008-11-21T14:21:00.000-05:002008-11-21T14:24:01.976-05:00

The Greenland Greater White-fronted Goose (Anser frontalis flavirostris) is known to be a rare visitor to northeastern North America, but I have never been satisfied with a reliable, objective way of distinguishing it from the North American subspecies of Greater White-fronted Goose, also a rare visitor to the northeast.Bill color is the most frequently-mentioned field mark – supposedly orange on

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-55842156509156079402008-11-19T05:47:00.006-05:002008-11-21T14:20:54.859-05:00

Stunning news from Bosque del Apache NWR in New Mexico: a female Sungrebe was photographed there on 13 November 2008, those photos here. It was correctly identified on 17 November from the photos, then refound and photographed more on 18 November. This is not only a new species for North America, but a whole new family.A map of the species' whole range can be seen here at InfoNatura (scroll down

David Sibleynoreply@blogger.com9tag:blogger.com,1999:blog-8723269882919206612.post-51181427955761347562008-11-17T10:07:00.008-05:002008-11-18T08:03:42.710-05:00

The primary challenge of distinguishing Canada from Cackling Goose centers on the intermediate-sized 'Lesser' Canada Goose, B. c. parvipes, which reportedly nests across the boreal forest regions of western Canada and interior Alaska (more details on my website here). I've seen a few birds that I thought were 'Lesser' in the northeast over the years, most convincingly one at Brigantine NWR in NJ

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-27105114002402637612008-11-15T06:14:00.006-05:002008-11-19T15:17:07.798-05:00

Yesterday morning I 'found' Canada's first Lucy's Warbler... in my inbox. After reading my recent posts about rare birds, Cathy Mountain (whose redpoll photos were featured here last winter) sent me a series of pictures of a warbler that had been in her yard in Fort McMurray, northern Alberta, from November 8-10, 2008. After rejecting the possibility of a drab Yellow Warbler, she thought it might

David Sibleynoreply@blogger.com10tag:blogger.com,1999:blog-8723269882919206612.post-72669435376336819142008-11-06T10:05:00.004-05:002008-11-06T11:49:42.691-05:00

My last post "How many rare birds do we miss?", was simply getting at the idea that we can miss something glaringly obvious if we are not looking for it. A popular psychology quote goes "I wouldn't have seen it if I hadn't believed it". In the case of the moon-walking bear, since I wasn't looking for it, I didn't see it. In the comments a reader pointed to a discussion on his own blog "The

David Sibleynoreply@blogger.com13tag:blogger.com,1999:blog-8723269882919206612.post-70385710037687544242008-10-21T06:46:00.003-04:002008-11-19T15:17:07.799-05:00

As birders we often talk about the problem of common birds being misidentified as rare ones. The counterpoint, but probably more frequent, is that rare birds are simply overlooked. Here's a link to a fantastic "Awareness Test" on YouTube. Give it a try, it only takes a minute. The relevance of this test to bird identification should be obvious, so now you can just imagine all the rare birds you

David Sibleynoreply@blogger.com9tag:blogger.com,1999:blog-8723269882919206612.post-76106518950792299932008-05-06T09:29:00.001-04:002008-05-06T11:38:59.631-04:00

Upcoming events: I'll be out on a fossil-fuel-free big day this coming weekend, bicycling around Concord, Massachusetts (hoping for 100 species) and I'll try to post a report about that next week. You can sponsor me through Bird Studies Canada, or through Malkolm Boothroyd's Bird Day Challenge.-----------------========-----------------The Blog: When I started this blog last August I didn't have

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-20024468621251395382008-04-10T09:32:00.003-04:002008-04-10T09:45:26.283-04:00

Prompted by some good discussion I've read on TexBirds and elsewhere: I want to stress the point that the danger to birds is not so much the height of the wall, but more the wide swath of habitat that would be cleared for the wall and service roads. Chachalacas, Pygmy Owls, Green Jays, etc will fly over a wall, but they're less likely to cross 100 yards of barren gravel. This project might as

David Sibleynoreply@blogger.com8tag:blogger.com,1999:blog-8723269882919206612.post-71350989153912046092008-04-07T11:38:00.009-04:002008-04-08T14:48:20.816-04:00

Revised 8 Apr 2008 -Do something: Write or call Congress. See the No Texas Border Wall campaign and their suggestions for action with several petitions to sign and instructions for contacting government officials. Defenders of Wildlife has a handy form here for writing to your representative.---------------------------The proposed border wall (1) from Texas to California has been hotly debated,

David Sibleynoreply@blogger.com3tag:blogger.com,1999:blog-8723269882919206612.post-88473161113846386002008-04-02T11:29:00.005-04:002008-04-02T11:59:59.996-04:00

Here's an example of one of the countless thousands of questions that are still out there waiting to be answered about North American birds. I went to Texas in February (for the opening of the fantastic new Clif Moss Nature Education Center of the Corpus Christi Public Library) and I had a chance to see some Wild Turkeys nearby. As expected they had whiter tips on all the body feathers than

David Sibleynoreply@blogger.com6tag:blogger.com,1999:blog-8723269882919206612.post-47657096542977846312008-03-28T09:15:00.008-04:002008-03-28T10:39:16.956-04:00

One of the enduring mysteries of North American ornithology involves several species which were painted by Audubon in the early 1800s but never seen again. The most striking and appealing of these birds is the Carbonated Swamp-Warbler, and since the painting was published ornithologists have debated whether this could be a rare and now-extinct species, a hybrid, or merely a fantasy created by

David Sibleynoreply@blogger.com11tag:blogger.com,1999:blog-8723269882919206612.post-82993741185229960652008-03-26T12:01:00.004-04:002008-03-26T12:13:59.523-04:00

Great news: New Jersey's governor Corzine yesterday signed into law a moratorium on the harvest of Horseshoe Crabs in that state (press release here). This is great news for Red Knots - politicians have finally recognized the dire situation and put the needs of a species ahead of the seasonal income of a few fishermen. This moratorium protects the knot's primary food source during spring

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-89935689846722391072008-03-11T09:00:00.009-04:002008-03-12T06:27:21.287-04:00

Maybe I should change the name of this blog to "All about Redpolls", but I've received a few photos that I wanted to pass along, making the point that "Greater" Common Redpoll is not just an eastern specialty. The AOU checklist and the BNA account report that this subspecies winters regularly from Labrador west to Manitoba, and has been recorded from Michigan, Illinois, Indiana, and Ohio, as well

David Sibleynoreply@blogger.com8tag:blogger.com,1999:blog-8723269882919206612.post-33067502407061345472008-03-10T09:20:00.004-04:002008-03-11T10:19:15.963-04:00

A new photo by Dan Berard shows what looks like an intermediate large redpoll, and should be added to the discussion in my previous post.photo copyright Dan Berard, used by permission - 7 Mar 2008, Millbury, MADan says both of these birds were about the same size and both were larger than the other redpolls with them. This is interesting on its own because the paler bird looks larger in this

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-4541349459424480032008-03-07T09:26:00.001-05:002008-03-11T10:06:01.565-04:00

Maybe we are just more aware and looking harder for "Greater" Common Redpolls (Carduelis flammea rostrata) this winter in Massachusetts, or maybe it's really an exceptional winter, but there is no doubt that they have come south in significant numbers. I have seen them on a couple of visits to Dan Berard's feeders in Millbury, MA, where he has been studying redpolls almost daily since December.

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-18664898289343572312008-03-05T09:21:00.004-05:002008-03-04T10:51:17.073-05:00

The decline of Red Knots from 1982 to 2006:data from Niles et al. 2007. Status of the Red Knot (Calidris canutus rufa) in the Western Hemisphere. USFWS report.The Red Knot and Horseshoe Crab story has been in the news in the last several weeks, with a major PBS documentary "Crash: A Tale of Two Species", and the New Jersey Marine Fisheries Council's ludicrous decision to reopen a limited harvest

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-91131656887337669052008-03-03T18:18:00.005-05:002008-03-03T18:58:38.113-05:00

Taking a break from redpoll identification: I've written an essay about the challenges faced by migrating birds, which appears in this month's Green issue of Delta's Sky magazine. You can read it here.

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-14877036623223500172008-03-03T06:38:00.007-05:002008-03-13T06:40:52.456-04:00

In considering the true status and distribution of Hoary Redpoll, I realized that I had overlooked one significant source of information - the Christmas Bird Count results. While Common Redpoll nests throughout the boreal forests across the continent, Hoary is virtually unknown as a breeder east of Hudson Bay (ignoring the "Hornemann's" Hoaries in Greenland and Baffin Island). Therefore the

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-81957742329717566212008-02-19T14:31:00.003-05:002008-02-26T16:19:45.584-05:00

[Major updates 25 Feb 2008, adding new information about the introduced Siberian populations]You might think that the words "intriguing" and "House Sparrow sightings" are mutually exclusive, but here's a case where they go together! In October 2007 a flock of five House Sparrows showed up in the coastal village of Shishmaref in northwest Alaska. They were found and photographed by science teacher

David Sibleynoreply@blogger.com7tag:blogger.com,1999:blog-8723269882919206612.post-76448532925220982212008-02-13T20:08:00.000-05:002008-02-14T10:16:09.240-05:00

The question of age variation has come up repeatedly in redpoll discussions, so I finally tried to find an answer to the question of just how important age-related variation in plumage might be. And based on published studies the answer is ... not very important.Seutin et al. (1992) studied redpolls at Churchill, Manitoba using a character index, and found only one statistically significant

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-89713425416768977992008-02-11T17:55:00.000-05:002008-02-12T11:32:05.118-05:00

[edited 12 Feb 2008]From Texas comes the remarkable news of the discovery of an apparent White-crested Elaenia (Elaenia albiceps) found by Dan and Honey Jones on 9 Feb 2008. Photos, sound recordings, and ID discussion can be found at Martin Reid's website and some great photos at Erik Breden's website. The bird was found at the Sheepshead Woodlot sanctuary (preserved by the Valley Land Fund) on

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-39929431378355900122008-01-31T12:08:00.000-05:002008-02-11T17:54:44.862-05:00

Feb 24 - I'll be speaking at the Northwest Branch of the Corpus Christi Public Library on February 24th at 4 PM to help celebrate the opening of their new Clif Moss Nature Education Center. Some details here. And if you're in the area that weekend check out the Celebration of Whooping Cranes in nearby Port Aransas.March 21 - I'll be in Irvine, CA for the Annual Dinner of the Sea and Sage Audubon

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-85454861440453279052008-01-14T07:24:00.000-05:002008-01-14T07:48:19.060-05:00

Redpoll identification is challenging because Hoary and Common Redpoll seem to show an unbroken continuum of variation from pale to dark, and there are no fully reliable differences. So birders have to rely on a subjective assessment of overall color and struggle to define the threshold for confident identification. Virtually all birders see redpolls only in the winter, where identification is

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-51286431547514050022008-01-08T10:46:00.000-05:002008-01-08T11:11:48.754-05:00

I'm reposting here some comments I just sent to ID-Frontiers, about a pale redpoll in Illinois and another in Massachusetts:The comment under these photos on the ILBIRDS forum giving the bird an index score between 11 and 12 is, I would say, overly generous. The undertail coverts that we can see (not much) seem to show a small dark streak on one of the smaller undertail coverts coming up

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-81945884058503762802008-01-07T08:32:00.000-05:002008-01-07T12:52:38.496-05:00

Just a quick update on my window-collisions research:I've heard from several more people who have tried the highlighter with pretty good success.Continuing my own experiments here I've had over a month of 100% success with an array of monofilament stretched between two wooden boards outside the window. The monofilament is suspended a couple of inches in front of the window in vertical lines about

David Sibleynoreply@blogger.com3tag:blogger.com,1999:blog-8723269882919206612.post-20845811832338700542008-01-05T22:30:00.001-05:002008-01-14T07:43:21.441-05:00

[edited 12 and 14 Jan, 2008, adding comments about the index]I've been thinking about redpolls more, and had another, more careful, look at Troy's 1985 paper, which is filled with interesting observations and some serious "food for thought".First of all, Troy identified redpoll specimens using a character index, which is a well-established method of objectively sorting out variation when there

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-3391273634942578232008-01-03T07:06:00.000-05:002008-01-05T15:46:47.330-05:00

I have had two inquiries about Tropical Parula in the last 24 hours, prompted by a bird currently in Austin, Texas. You can check out that bird in photos by Andy Balinsky and photos and some background by Martin Reid. It has the throat pattern and extensively yellow underparts of Tropical Parula, but the pale eye-crescents and the extensively green crown of Northern.In The Sibley Guide to Birds I

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-48305518600389638292008-01-02T10:44:00.001-05:002008-01-05T15:47:22.878-05:00

On the MOU website: a Hoary photo Here from Minnesota (where Hoary is expected and the threshold is low) of a pale Hoary-type with a relatively long billSome other recent Hoary photos from Michigan - scroll left and right to see about 5 shotsFrom Ontario this photo and the two following show a very small-billed Hoary

David Sibleynoreply@blogger.com3tag:blogger.com,1999:blog-8723269882919206612.post-90618964892925783112008-01-02T06:58:00.000-05:002008-01-05T15:48:26.998-05:00

More thoughts on redpolls after yesterday's post, prompted by my own nagging doubts and a query from Nick Anich: In all of this redpoll ID discussion, I think people ask the general question "How can I identify a Hoary?" when what they mean is the more specific question "Just how pale/small-billed/unstreaked does a redpoll have to be before I can feel good about calling it a Hoary?"I don't have

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-69145390221905674402008-01-01T14:46:00.001-05:002008-01-05T15:48:26.998-05:00

[Edited 2 Jan to add a hint of uncertainty to the identifications]Over the holidays I was able to spend a few days at my parents' house in upstate New York, and enjoyed the redpolls that were visiting the bird feeder. I saw one clear-cut Hoary and at least two other Hoary-type Redpolls, and at least one "Greater" Common Redpoll among the flocks of regular Commons. There were up to about 60

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-24154077197896692332008-01-01T08:00:00.000-05:002008-01-05T15:48:26.999-05:00

After my previous posts on redpolls here and here, I've had a chance to skim some of the redpoll literature, and it confirms that these are two very similar species (gasp! really?). Two papers in particular by Seutin et al (1992, 1993) offer some interesting observations. They conclude that it is possible to classify specimens into either a small-billed pale population or a large-billed dark

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-66267292445635388542007-12-31T16:45:00.000-05:002008-01-02T10:14:21.813-05:00

Slaty-backed Gull in Gloucester, MA on 23 December 2007 - Photo by Phil BrownPart 1:On 6 December 2007 at about 8PM, in the midst of an intense winter storm, a resident of Lilllooet, BC heard a thump on their front door. Thinking the dog wanted to come in, they opened the door to find a strange bird lying on the front porch. It later died despite their best efforts, and it turns out to be a

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-25555539468399817142007-12-06T21:14:00.000-05:002007-12-10T06:08:58.942-05:00

I was in Washington DC recently and signed some calendars at my cousin's flower shop in Mount Airy, Maryland. So if you've been thinking about getting a calendar and you'd like one that I've signed, you can order them here.And my new Birder's World column about identifying songbirds by flocking habits is now available online here.

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-77694086371155955482007-12-06T09:49:00.000-05:002007-12-06T11:02:16.051-05:00

Our perspective and the assumptions and decisions that are triggered by that point-of-view, strongly influence how we perceive the world around us. In short, what we see often depends on how we look at it.This classic drawing looks like a frog sitting on the edge of a pond...but rotate it ninety degrees and it turns into a horse's head!This horse/frog drawing comes from a generic internet source

David Sibleynoreply@blogger.com6tag:blogger.com,1999:blog-8723269882919206612.post-75537756736057182732007-12-04T21:23:00.000-05:002008-01-05T15:48:26.999-05:00

If identifying Hoary Redpoll is not enough of a challenge for you, maybe you'd like to look for subspecies of Hoary and Common Redpolls?First, check out this map from the Canadian Atlas of Bird Banding.This shows selected western band recoveries of Common Redpolls, and the obvious suggestion is that some of the Common Redpolls being seen in the east right now might be coming from Alaska! Troy (

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-37592770699382131812007-12-01T14:30:00.000-05:002008-01-05T15:48:26.999-05:00

Some updates 4 and 6 December -check out Jochen's comments and blog post here With the predicted superflight of finches beginning to develop (1st ever Common Redpoll in New Mexico last week) more and more questions are coming up about finch identification.RedpollsHoary Redpoll, although always less numerous than Common south of the Arctic, is probably more numerous than reports indicate.

David Sibleynoreply@blogger.com4tag:blogger.com,1999:blog-8723269882919206612.post-16257152624682341442007-11-20T13:16:00.000-05:002007-12-06T11:04:30.309-05:00

After a week of pretty good success on the windows, today was cold with light snow, and the bird feeder was very active. I realized last week that one of many variables I need to consider when I record bird-strikes-per-hour is bird activity, but I haven't tried to record that yet other than excluding long periods when no birds were present. Obviously, if there are few birds visiting, there are

David Sibleynoreply@blogger.com9tag:blogger.com,1999:blog-8723269882919206612.post-1559996808531333312007-11-15T14:50:00.000-05:002007-12-06T11:03:38.249-05:00

Update 16 November - There are a couple of points I think I should clarify. First - and I guess this may be clear already - I'm still not convinced this will work, or how well it will work, and it will probably work in some situations better than others, and never be 100% effective since the hard glass surface is still exposed. If you try it please let me know how it works, good or bad.I should

David Sibleynoreply@blogger.com42tag:blogger.com,1999:blog-8723269882919206612.post-24783601135238310002007-11-15T09:53:00.001-05:002007-11-15T13:11:25.700-05:00

I'm pleased to join my friends Kenn Kaufmann, Pete Dunne and others as a contributor to Birder's World magazine, and editor Chuck Hagner promises that I will "reveal the real secrets" of bird identification. I don't know if everyone's really ready for that, but each of my columns will be a short illustrated discussion of bird identification challenges from a more general perspective. The first

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-76558046313310754532007-11-14T11:40:00.000-05:002007-11-15T05:22:25.594-05:00

The latest Siberian highlight was California's first Eurasian Kestrel banded in Marin Co. CA on 23 October 2007 but not seen again (photos here). About 10 North American Records.Otherwise, in addition to what I listed previously, a Dusky Warbler and four Eastern Yellow Wagtails in CA, and a Rustic Bunting in BC are the only Siberian birds that I've heard of that seemed to find their way down from

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-18175066096003655602007-11-14T11:38:00.000-05:002007-11-14T11:45:21.865-05:00

Six original plates from the Sibley Guide to Birds will be exhibited at the Cahoon Museum of American Art in Cotuit, MA now through December 31, 2007 as part of their show "In Fine Feather: Excellence in Contemporary Bird Carving and Avian Art"

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-82554886499035815942007-11-05T10:57:00.000-05:002007-11-13T12:29:33.818-05:00

Great White Heron Ardea herodias occidentalisupdated 13 Nov 2007, thanks to all those who have commented publicly and privately. I've backed off a bit from my criticism of the TBRC decision, the more I learn the less clear-cut this seems, although I still think it's at least a good subspecies. Shaibal Mitra sent me a copy of a paper he and John Fritz published in the Kingbird a few years ago,

David Sibleynoreply@blogger.com6tag:blogger.com,1999:blog-8723269882919206612.post-14958175232521436862007-11-05T10:30:00.000-05:002007-11-05T10:53:59.285-05:00

Responding to some recent questions:A couple of readers have asked about any plans for an updated version of my bird guides. This is something I'm always planning for and I look forward to compiling all the new things I'm learning into a new edition in the future. But there are no plans at present to create an updated version of the bird guide. Whether that will happen in two years, five years,

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-22065750815316998342007-10-31T10:27:00.000-04:002007-11-15T10:39:54.551-05:00

Green-breasted Mango Anthracothorax prevostiiThis species is not included in the Sibley Guide to Birds because at the time that I was planning the book there were only two records north of Mexico. By the time I had finished the book there were 7 records (enough to warrant inclusion, if only I had known sooner!). Records have continued to increase with the total as of today up to at least 16 in

David Sibleynoreply@blogger.com10tag:blogger.com,1999:blog-8723269882919206612.post-84269845472219120682007-10-30T10:15:00.001-04:002007-11-03T07:14:57.081-04:00

In late August 1982 I walked into the weedy fields at the South Cape May Meadows in search of rare birds. Among many species that I had in mind as possible "prizes" that day was Loggerhead Shrike and, lo and behold, a scan of the bushes ahead revealed a small, white-breasted, dark-masked bird perched conspicuously on top of a slender post - a Loggerhead Shrike!I looked for a couple of seconds and

David Sibleynoreply@blogger.com15tag:blogger.com,1999:blog-8723269882919206612.post-57921723119223742502007-10-23T09:17:00.000-04:002007-11-05T15:25:41.878-05:00

In August 2007 the US Fish and Wildlife Service published the Draft Ivory-billed Woodpecker Recovery Plan and invited public comments (the deadline was 22 Oct 2007). I'm posting a slightly edited version of my recently-submitted comments here. Although I'm critical of many aspects of the claimed rediscovery, and some may reject my views outright, I think raising these issues is in the best

David Sibleynoreply@blogger.com16tag:blogger.com,1999:blog-8723269882919206612.post-45148739761404439982007-10-13T09:03:00.000-04:002007-10-13T11:56:38.320-04:00

The enigmatic and charismatic Spoon-billed Sandpiper may be headed for extinction according to a Bird Life International report. The population estimate, never more than a few thousand pairs, has recently plummeted to only 200 to 300 breeding pairs.The reasons for these losses are complex, involving changes to habitat during migration and loss of breeding areas. What is clear is that nest

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-69970643185614719862007-10-13T08:58:00.000-04:002007-10-13T09:03:03.796-04:00

A fascinating story of two flamingos, one from the Yucatan that provides a very rare undisputed US record of a wild bird, and another from the Old World (via a Kansas zoo) that shows how widely an escaped bird can wander.Details and a great comparison photo are on the Louisiana Ornithological Society website

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-31219188753936832872007-10-04T09:14:00.000-04:002008-02-07T12:25:34.449-05:00

In my previous post about Siberian birds I made a tenuous connection between an above-average season for vagrants in the Bering Sea and a few vagrants farther south and east. Updates from Gambell by Paul Lehman show a continued surge of Siberian birds, highlighted by North America's first Sedge Warbler, and even more of the species recorded earlier in the fall (e.g. a final season's total of ten

David Sibleynoreply@blogger.com1tag:blogger.com,1999:blog-8723269882919206612.post-14519305981149491122007-09-27T09:40:00.001-04:002007-09-27T13:51:30.790-04:00

An Op-Ed in today's New York Times by Vaclav Havel makes reference to the larger issues of consumption and the environment. He minimizes the debate over climate change, saying that whether it is primarily human-caused or not action is important, and there are other equally serious anthropogenic issues which are simply Nature's response to the species known as humans. In today's euphemistic

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-1599074789937164082007-09-22T15:45:00.000-04:002007-09-24T09:15:43.753-04:00

Update 24 Sep 2007: Seen on the 22nd was Gambell's 3rd Siberian Accentor, 4th Dusky Warbler, and 6th Little Bunting of the season; while St Paul, Pribilofs turned up their 2nd Siberian Accentor and first Pechora Pipit of the season. And the big news, adding some weight to my tenuous connection - a Common Rosefinch at Southeast Farallon Island, California - the first ever in North America away

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-92181767129514325312007-09-18T08:01:00.001-04:002007-09-18T08:16:07.339-04:00

Here's a neat tool from American Public Radio - an educational game that calculates your global ecological footprint.Overconsumption is at the core of virtually all environmental problems, and most of that consumption is stuff that we don't even think about. Especially in the fast-paced world of the US middle class, we do things the way we always have. There isn't time to think about each action

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-29077230892722645782007-09-17T09:45:00.001-04:002007-09-17T13:38:02.400-04:00

I've thought more about the "square-peg-in-round-hole" analogy in my previous post, and made a few simple drawings to expand that analogy. In many ways, bird identification is like a matching game. The observed bird (here in black) must be identified by matching it to illustrations in a diagnostic key (the gray shapes here).This is pretty straightforward, and you should have little trouble

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-41296736700286143962007-09-15T07:30:00.000-04:002007-09-17T11:13:14.939-04:00

Last week I had the pleasure of spending four days birding at Barrow, Alaska, working on an eider identification project with the US Fish and Wildlife Service. While there I was able to study hundreds of Greater White-fronted Geese that were grazing on the tundra - surprisingly numerous and surprisingly approachable. I'll write a separate note about variation in the geese - size, bill color (pink

David Sibleynoreply@blogger.com2tag:blogger.com,1999:blog-8723269882919206612.post-41916815634045717312007-09-05T08:47:00.001-04:002007-09-05T11:29:01.848-04:00

Another note from the comments under Sandwich Tern by Joseph Kennedy on 4 September, this deserves a separate discussion (Thanks, Joseph). He writes:I have received a note Stu Wilson concerning the black tern pictures posted from the same date. I guess that I should check feet on the rest of my tern pictures. According to Sibley, young black terns should have light colored legs as would adult

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-70353464405017497042007-09-05T08:29:00.001-04:002007-09-05T11:29:35.958-04:00

In an interesting 4 September comment under the Sandwich Tern bill color discussion, Joseph Kennedy presents a photo of a juvenile Royal Tern with partly yellow-orange legs. Compared to one of his photos of juvenile Sandwich with yellow legs, the Royal appears to have brighter leg color. Presumably that is variable, but it would be interesting to compare a larger sample. I remember seeing a

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-60816755573883414542007-09-05T07:27:00.000-04:002007-09-05T11:26:12.166-04:00

On Thursday, 27 Sep 2007, I'll be in New Haven, Connecticut lecturing at Yale's Peabody Museum (where I spent many afternoons as a teenager in the 1970s) as part of their John H. Ostrom program series. Details here (click on September and scroll down)On 19-21 Oct 2007 I travel to Oklahoma to speak and lead a couple of field trips at the University of Oklahoma Biological Station's Friends weekend

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-57957777718870784202007-08-30T18:59:00.000-04:002008-02-07T12:17:46.462-05:00

An eventful few weeks for bird records in North America:The long-anticipated first nesting record of Lesser Black-backed Gull in North America (even though it hybridized with a Herring Gull) - on Appledore Island, Maine.Green Violetear reaches Maine - the farthest northeast record to date. 19 Aug 2007 on Mount Desert Island; photo hereFirst Fan-tailed Warbler in Texas, in Pine Canyon, Big Bend NP

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-37735414415683722612007-08-29T21:42:00.001-04:002008-01-07T12:54:41.867-05:00

Size judgment is one of the constant quandaries of bird identification - critically important but fraught with error. In a recent online discussion about these photos of sandpipers in flight, I was intrigued by the question of how I, and others, "just knew" that these birds were too small to be Knot or Pectoral and must be Least or Semipalmated. There are no reference points in the picture, so

David Sibleynoreply@blogger.com3tag:blogger.com,1999:blog-8723269882919206612.post-86169066101138679322007-08-23T10:44:00.000-04:002007-09-05T11:30:27.079-04:00

Several recent Massachusetts reports of Olive-sided Flycatchers seem to have used the presence of white patches on the sides of the back to age the birds as juveniles. This is incorrect and unfortunately the source of the error seems to be an ambiguous entry in the Sibley Guide - sorry.Both adults and juveniles can show the white patches, it has nothing to do with age, the patches appear and

David Sibleynoreply@blogger.com0tag:blogger.com,1999:blog-8723269882919206612.post-79453728879373360492007-08-23T10:26:00.001-04:002008-09-27T07:48:26.688-04:00

-- updated Sep 27, 2008This photo by Greg Lavaty of Texas, generated a lot of discussion on the Texas Birds listserv recently, and brings up some interesting points and questions.First, this is definitely a juvenile Sandwich Tern, and the bill color is pretty typical of a recently fledged bird. Here are some photos of similar birds in Texas by Martin Reid. Few birders have the opportunity to see

David Sibleynoreply@blogger.com3