David Sibley – Page 27 – Sibley Guides

Distinguishing female Barrow’s and Common Goldeneyes

January 21, 2010 / David Sibley / 4 Comments

minor updates 2 Mar 2010 Identifying female goldeneyes is extremely challenging. Differences are subtle, subjective, and inconsistent, but experienced observers still build up a “template” of expected impressions that allow them to identify the species with confidence. Describing these differences, and identifying individual birds from photos, can be very challenging because the process of identification […]

Distinguishing female Barrow’s and Common Goldeneyes Read More »

New page on Tree references

January 19, 2010 / David Sibley / 1 Comment

I’ve just posted a new page that lists some of my most-frequently-used online references about trees. You can find it here, and it is also linked on the Tree Info page.

New page on Tree references Read More »

Identification of (hybrid?) female Goldeneyes

January 13, 2010 / David Sibley / 8 Comments

Distinguishing Common and Barrow’s Goldeneyes is always a challenge, and particularly so when the bird is a female. One of the most conspicuous and easily judged differences is bill color – Common Goldeneye has a black bill with a small yellowish patch at the tip, while Barrow’s has the bill almost entirely orange-yellow. This works

Identification of (hybrid?) female Goldeneyes Read More »

My painting process – gouache

January 13, 2010 / David Sibley / 11 Comments

In 2004 I was working on a small painting of a flying Ferruginous Hawk, and I scanned the work at several stages to show the progression from pencil sketch to finished painting. I created an annotated slideshow from those scans for my 2009-10 exhibit at the Mass Audubon Museum of American Bird Art. Now the

My painting process – gouache Read More »

Updates

January 12, 2010 / David Sibley / Leave a Comment

I’m back to the website after a long holiday break, and I have a few things I’ll be posting over the next two weeks. For now, important news to report is that my seminar at the Yale School of Forestry has been postponed. Originally scheduled for Jan 20th, it will hopefully be rescheduled for the

Updates Read More »

Kingbirds, nightjars, and the perception of bird sounds

December 10, 2009 / David Sibley / 4 Comments

In a recent post on his excellent blog Earbirding, Nathan Pieplow points out an issue with the voice description of Buff-collared Nightjar in the Sibley Guide to Birds, which says: Song of rapid, sharp, dry chips in crescendoing series tup to to tu tu ti ti trridip accelerating and rising to flourish at end; pattern similar to

Kingbirds, nightjars, and the perception of bird sounds Read More »

Variation in immature Ring-billed Gulls

December 1, 2009 / David Sibley / 6 Comments

On October 9th, 2005 I was enjoying the view at First Encounter Beach in Eastham, Massachusetts and watching a small flight of seabirds. A flock of gulls began to gather on the beach close to my car and I found myself more and more engrossed in the plumage variation of Ring-billed Gulls. This first photo

Variation in immature Ring-billed Gulls Read More »

Variation in shape of Hickory nuts

November 30, 2009 / David Sibley / 4 Comments

Thanks to an email from Ray Telfair I’ve taken a closer look at the illustrations and descriptions of hickory nuts on pages 143 to 149 in the Guide to Trees. I used the terms “angled” and “ribbed” interchangeably, and illustrations such as Pignut Hickory p 145 appear “angled”, which is confusing and incorrect, so I’ll try to

Variation in shape of Hickory nuts Read More »

Variation in fall color: Red Maple

November 24, 2009 / David Sibley / 19 Comments

Watching the changing colors of fall leaves is always interesting, and even more so when you recognize the species of trees and begin to understand some of the finer points of variation in color. In these four photographs of Red Maple, all taken within a few days in Massachusetts and New Hampshire, I’ll describe a

Variation in fall color: Red Maple Read More »

Variation in Ruffed Grouse tail patterns

November 12, 2009 / David Sibley / 1 Comment

Since The Sibley Guide to Birds was published in 2000 I’ve received several comments and questions about the fact that I illustrated the displaying male Ruffed Grouse with a broken tail band (not a solid dark band continuing across the two central tail feathers). Readers note that males are supposed to have complete dark tail bands, while

Variation in Ruffed Grouse tail patterns Read More »