Utah Birders | Birding Blog, Utah Birds, Utah Birding, Utah Bird ID: Ageing Adult Red-tails by Tail Bands?

Originally posted @ http://jerryliguori.blogspot.com

I've received several emails asking me whether Western Red-tailed Hawks in their first adult plumage have multiple tail bands, whereas older adults have unbanded tails. I asked where that notion came from? It turns out it's published in the 2008 Pyle guide. I wish it were that easy, but the truth is that tail patterns of adult Red-tails of every age vary from being completely banded to unbanded. Before we look at examples of this, let’s dissect the issue. First, I'm curious how this was determined? What specimens or live birds were reviewed? There are millions of Red-tails out there, so a very large sample size from a broad geographic range is required to make such a statement. Is this proposed tail pattern true for dark and light-morph birds? How about males and females? Why were the other races/types of Red-tail that show tail bands not treated or commented on? Also, can we review the study birds to fact-check the identifications to race, or was that assumed? These type of questions should be posed for any study. The statement about tail bands just seems arbitrary and poorly researched. If there’s one thing I’ve learned, it's to question things you read or hear until fact-checked, as there are inaccuracies in literature that have been propagated over the years, even in texts written by the 'top experts.' It is impossible to reach the entire birding community to fix a mistake once it's published. Everyone makes mistakes, but I find it irresponsible when authors publish theories and assumptions as fact that results in misinformation ingested by the birding community and thereafter very difficult to purge. Have you ever discussed an ID with someone where you had facts to support your stance, but their stance was "so-and-so said so?" I hope the younger generation of birders gets on-board with taking the time to research things properly and publish only what is supported with real data and verifiable examples.

I think it's the responsibility of all birders to share information if it corrects an error. However, it's also requisite to be absolute before attempting to challenge literature. A friend sent me a few excerpts from the Red-tailed Hawk section of the Pyle Guide and I was horrified at the misinformation in there -- to see so numerous mistakes in one species account is alarming! If one of North America’s commonest birds is poorly treated, I cringe to think of the validity of the other species accounts.

Here's one I wasn't even aware was in the Pyle guide:
http://jerryliguori.blogspot.com/2013/07/wing-molt-in-raptors.html.

I will address the inaccuracies in Red-tailed Hawk section in various blog posts since there is not enough room here to do it, as well as problems with other raptor species throughout Pyle's Guide so birders are aware of them. Hawk banders especially need to use caution since they are responsible for the data they submit to the BBL. If you smell a rat, "Unknown" for age/sex is proper and always acceptable.

Check out these Red-tails in their first adult plumage (labeled 2nd-year) that lack multiple tail bands, and various others at least one year older (labeled After-2nd-year) with obvious tail bands…and thanks for reading. By the way, if you want to age Red-tailed Hawks correctly, note either retained juvenile feathers (preferably flight feathers) for SY/TY, or 2 generations of adult feathers for ASY/ATY. Sometimes it is possible to age buteos as 3rd or 4th-year in fall, but that is difficult without extensive practice, and sometimes inaccurate in certain cases. Eye color can be helpful as a hint (and does match up well on the birds below), but NEVER takes the place of flight feather ages. And remember, NEVER age adult Red-tailed Hawks based on presence/absence of tail bands!