Last week I brought into question the accuracy of some of the illustrations in the Sibley Guide To Birds. David Sibley has responded. His response was as a comment to the original post but that was several days ago and I doubt that most of those who were interested in what he might say about it would ever go back to see his comment so I decided to address the matter once again this morning.
1/2000, f/9, ISO 640, Canon 7D Mark II, Canon EF500mm f/4L IS II USM +1.4 tc, not baited, set up or called in
My concern in the original post (which can be seen here) was the color discrepancy I thought I saw between Sibley’s Western Kingbird illustrations and some I photographed about two weeks ago in northern Utah. Sibley’s illustrations show the colors of adult and juvenile to be “very similar” (almost identical to my eye) but the birds I photographed had significant, even major, color differences. In this image of those birds two juveniles on the right are begging for food from the adult on the left.
Friend and regular contributor to Feathered Photography Dick Harlow brought my concern (and my blog post) to the attention of David Sibley and yesterday Sibley responded with the following comment:
“Thanks to Ron for posting some great photos and starting this discussion, and to Dick for alerting me to it. There is certainly a very clear difference between these two birds, and I did not do a very good job of capturing those differences in the guide. I wasn’t trying to show the difference between a very worn adult and a fresh juvenile, but still, there are things that could be improved.
A lot of the difference in these two individuals in the photo is simply the age of the feathers, as others have already pointed out – brand new on the juvenile and almost a year old on the adult. In general among songbirds it is very easy to determine age this time of year, because the feather condition of adults and juveniles is so different. By November when the adult has molted to new feathers it will look a lot “cleaner” and more like the juvenile. It is also likely that juveniles are variable, with some very pale and others closer to adults.
Deciding what to show in the guide is always a balancing act. I usually opt for the “average” rather than the extreme, and try to avoid showing rare variants or differences that are only visible some of the time (unless these involve real ID pitfalls, and in that case I illustrate the typical bird as well as the variant). Because the illustrations contain so much more information than could ever be in the text, it is unavoidable that readers will search the images for details, and even the slightest (sometimes unintentional) difference between illustrations might be picked out as a potential field mark. In the case of the Western Kingbird illustrations, I opted to make the adult and juvenile very similar, because they are really hard to tell apart except when you see a worn adult with a fledgling (as in Ron’s photos), and I was also concerned about how they would compare with Cassin’s Kingbird and other species.
Nevertheless, I have some ideas now about how to represent these ages better in future revisions of the guide. It might involve adding a third perched illustration to show three ages: juvenile, fresh-plumaged adult, and worn adult. But that might require doing the same for all of the kingbirds…
Thanks, again, for bringing this up; learning is what this hobby is all about.”
I was fascinated to learn some of the things that go through David’s mind as he decides how to best represent the physical attributes of a species in his illustrations. It must be a daunting task to attempt to illustrate the many plumage changes that occur in a bird species over time with just a few illustrations.
I thought his response was clear evidence that David Sibley is a class act.
Ron
❤️ Excellent response… I too have searched and searched my guides wondering about what I am looking at…
Wow! I certainly do agree with you that he is certainly a “class act”. Eloquent, astute and tactful as well, Very impressive!
Charlotte
WOW! Ron and David Sibley in the same post….does it get any better? Between your photos and his insight, I’m overwhelmed. In my opinion (for what it’s worth) the two best in their fields. Thank you, once again Ron. A big thank you to Dick Harlow also.
Class act meets class act.
And I agree with Dick Harlow. I hope he becomes a regular.
I was very glad to see this response. It took me a while, but I’ve come to use Sibley’s guide as my go-to reference for birds. This gives me a lot more confidence in it. I like knowing that the author is a well-balanced and thoughtful person.
I will now DEFINITELTLY want to get a Sibley book…the problem is WHICH one…The integrity, honesty and thoroghness of his answer, is Dudleyesque and Liguoriesque enough to impress the daylights out of me! As for the photo, facts aside, It is gorgeous! The light, balance and composition, the subtlety of the colors, the punch of orangey-gold in the baby’s beak, the implied action, the contrasting texture of the weathered wood…just plain beautiful!!! Kudos to all!!!
“I will now DEFINITELTLY want to get a Sibley book…the problem is WHICH one”
Patty, I’d suggest the Sibley Guide To Birds, 2nd edition. Be sure to get the latest printing – the first one used light gray print that is very difficult to read unless you have good eyesight. That has been addressed in the latest printing with black print.
Thanks…will do….
What a classy response. If bird guides included all the variations, can you imagine how much heavier they’d be to lug about? I seem to be the designated book hauler on our Audubon bird walks, and by the end of the three to four hour walk, I wish it was half as thick.
VERY CLASSY, both of you !
….all THREE of you…
Good job Ron and Dick! Nice response from David Sibley too.
When honest and superior souls meet this is the result PURE JOY and ENLIGHTENMENT.
Thank you all.
Well done Ron!
Thank you, Christine.
Absolutely fantastic explanation by David Sibley. Hats off to his patience and concern. I can imagine how difficult it is to represent all the variations.
Thank you Ron, Dick Harlow, and David Sibley.
Thanks, Prathap, although David and Dick deserve most of the credit. I’m largely just a reporter here.
Ron, I have to admit I’m impressed as well. He gave an excellent response and the transparency and honesty of his answer put him on an elevated plain in my mind. I hope he becomes a frequent reader and contributor of your blog.
“the transparency and honesty of his answer put him on an elevated plain in my mind”
Well said, Dick. I agree.
I’m impressed by his thorough answer!
As was I, Arwen.