Edited 4/4/12 to add: I got a note from the biologist associated with this study, who gave me some background on the hawk pictured here. It’s a juvenile female who was tagged last August 2011 at SeaTac Airport. She — along with the other hawks who are trapped and tagged — was taken up to Skagit County where the habitat can support many Red-tailed Hawks and other raptors (lots of voles and other food sources, as well as open spaces). The photo I sent was the first report they’ve had of this hawk since they tagged her. And, apparently, another juvenile Red-tail tagged within days of her (Right, blue, #34) is also hanging out at this location … in case you happen to be there with your camera or scope.
I ask this question because every time I see a bird marked with patagial tags on one or both wings, I can’t help but be struck by how large they often are in proportion to the bird’s natural wing. I photographed this Red-tailed Hawk a few days ago at Seattle’s Union Bay Natural Area. I believe the hawk pictured is part of a SeaTac Airport relocation study, where raptors are trapped and moved as a measure to reduce avian aircraft strikes.
The wing tag pictured on this hawk doesn’t seem at all invasive compared to the huge, orange, double patagial tags on this Great Egret, captured on digital by a Flickr photographer. Click here for that image.
I’m not a biologist, so I make these comments without knowing the full benefit of each study in question. And, I understand why patagial tags are used — for easy visibility and tracking. It was impossible for me to miss this hawk’s blue tag, and thus easy for me to report the bird. (Of course, I was able to do the same recently with a crow who had color-coded leg bands and no wing tags.) I’ve also read that in some cases, such as with Turkey Vultures, leg bands are not practical or healthy because of the way vultures cool themselves by defecating on their own legs.
In other cases, however, I found abstracts which suggest that in some species, patagial tags do affect the behavior and well-being of the marked birds who spend more time preening because of the patagial tags. And this, in turn, affects how much time they devote to other important activities. A few study abstracts I came upon documented the negative effects of wing tags on Ruddy Ducks, Common Eiders, Adelie Penguins (flipper tags), and Carnaby’s Cockatoos. I found one documented case of a White Pelican that died because of tag entanglement, and I’ve heard a few anecdotal accounts from people who’ve seen tags that seemed to cause distraction and preening in the birds they observed.
Personally, I find it difficult to look at a marking that so drastically alters the appearance of a bird, as in the case of this Great Egret I mentioned earlier. The crude, anti-collision orange markers on the egret seem obscene in any context — and the photographer who captured that image suggests the same. In terms of visibility, even if patagial markers are needed for critical studies, it seems the tags could be a fraction of the size worn by the hawk I photographed — and still be easily visible with binoculars, a scope or a telephoto lens. Actually, even a point-and-shoot with a reasonable zoom could focus in on a tag not nearly this large.
How do you feel when you come upon birds with large single or double wing tags? Does it bother you at all, or do you feel the benefits outweigh the negatives?