The Benefits of Photography for Mapping Avian Movements
by Bryce W. Robinson
Above is a photo of an immature light morph Swainson’s Hawk that I took on the 7th of September, 2013 at the Goshutes Raptor Migration Sight in eastern Nevada. Notice the red band on the birds left leg. I’ve cropped the image a great deal, but below I’ve enlarged the section of the image to show the band in greater detail. At this resolution, the image becomes pixelated, which is unfortunate.
I contacted the BBL in hopes of tracking down someone that might recognize the band. I am so very grateful for their organization, as they quickly sent out emails asking those they have permitted for color banding SWHA. Within a day or two, I had a hit.
A man name Chris Briggs contacted me and gave his firm assurance that this bird was a bird he had banded earlier this year as a nestling. He mentioned his use of special characters such as the obvious < symbol on this birds color band. He thought that the other character on the right was either an 8 or a 9. One cannot be too certain, but he did assure me that the band was certainly his.
As the birds age was apparent from its plumage, I was really interested in where the bird originated. Chris informed me that this bird was banded as a nestling near Macdoel, California, a town near the northern border just south of Klamath Falls, OR. He sent me the photo below.
Photo courtesy of Chris Vennum
How exciting! It is nearly certain that this bird is the same bird as the bird I photographed in Nevada. I am so thankful that the organization exists such that a photographer can capture a photo of a bird with a band, and if the band is legible, can track that very same bird to the place that it was banded, without ever trapping the bird. The invasiveness of trapping hawks is curbed with the advent of the camera! Revolutionary….
Well, my question is then why are we as raptor researchers, or ornithologists as a whole not employing this technique more often? Some may state the added detriment of more bands is not worth while, and I do not discount this contention. However, how much more detrimental will one color band be to an already banded raptor? It is a discussion worth having, because with the amount of folks armed with cameras today, we could find ourselves with a lot more re-sight records, and a better understanding of spatial ecology in particular species.
I’d like to include another recent instance for emphasis. A few months ago, my friend and obscenely talented photographer Ron Dudley photographed a young Prairie Falcon in Montana. It happened to have a color band, and he was able to track down where the bird was banded. As it happened, his bird was also from California. You can read the story in detail on his blog.
How peculiar, this bird that fledged from its nest, and for whatever reason did not disperse directly south, but in a somewhat north east direction. North east enough that it passed by the Goshutes in early September on its way south. In my own personal study, I’ve learned that this non southward directionality of post fledging dispersal is something many people tracking birds of prey are seeing. The old north to south paradigm is becoming a bit more complicated than initially thought, and young birds seen traveling south on their fall migration, aren’t necessarily birds fledged from the north.
ornithologi.com 
So cool that you were able to figure out where that bird had come from! I think it would super interesting if we could map out these birds where-abouts better!
I feel the same way. Perhaps with the new information age, more cameras and birders, and more color tagged birds, we might be able to start piecing together more precise species specific temporal and spatial movement patterns without having to conduct high cost and highly invasive techniques such as telemetry, or even recapture!
Hi Bryce, as always, I love your photos, writing, and thought process. Allow me to raise a few issues as I see them on this topic. First, if everyone was using color bands, we would quickly reach a saturation point where you wouldn’t easily be able to find out where a red band came from without recapture to read the band (i.e., lots of people would be using red bands on SWHAs, rather than just one or a few people). Second and more importantly, sighting of color bands, like all band “encounters”, is biased by where people are likely to trap or spot raptors. How would we learn about raptors that took routes or died in places where no trappers or photographers were present? Color bands are one of many tools we can utilize to help us understand movement ecology and I applaud your desire to think about less invasive ways to study raptors. However, I don’t think we will be able to get around GPS tracking in some form to fully answer some critical research questions. Also, I think it is important to think about costs to the birds in a slightly different manner. Which is more impacting: trapping ~1,000 birds of a particular species to put small bands on them in the hopes of receiving ~35 returns total, or putting 45-gram GPS transmitters on 35 birds for tens of thousands of GPS points and detailed information on habitat use, survival, etc.? Just some thoughts to consider. Best, Steve
Thanks for your comments Steve. I believe I’m on the same page as you. I wasn’t bemoaning the use of PTT’s or any other forms of tracking. And I absolutely feel that the benefits of color bands are only supplemental, not to replace any other technique. My point was to enhance the process of banding by adding color bands to the equation, raising the chance for relocations.
Your point about over-saturation is important. I believe there are ways to get around those, as they do in shorebirds with color combinations. This complicates the process of re-sighting though.
I love that you took the time to comment. I think that this conversation is worth having, and it was nice to have some things brought forward that I hadn’t considered.
How very exciting, Bryce! (I do know that feeling). I’ve found the conversation here interesting as I have mixed feelings about banding and GPS tracking units on raptors (truly mixed, as I see both the benefits and perhaps some of the down-sides) so the comments have been enlightening.
Glad you enjoy the discussion Ron. That is just what I’d like to facilitate, a conversation.
I liked your post so much that I was inspired to go back through all my raptor photos to check for bands. No luck,but I will be checking from now on.
Another benefit of the amazing good DSLR long lenses is that we can see bird deformities from afar and pass those photos on to experts for study. Last Spring I took photos of an immature bald eagle with a lower beak deformity – one I would have never seen without my camera and post processing software. I sent the photos on to raptor experts.
Thank you for your insights.
I agree with your addition to the benefits of the “good” DSLR lens. In regards to birds with deformities, it is a great way to record instances that can be used for education. I know Ron Dudley has captured photos of raptors with bill deformities, and has sent them along to experts as well. He also shared his photos on his blog, and discussed the issue of bill deformities and other causes of toxins in the environment. What a great platform for education. Sorry your in depth review didn’t provide any re-sights. Perhaps in the future you will have some good fortune. I’ll keep my fingers crossed for you. Thank you for the comment.
Re. the north/south paradigm: Do you recall the two juvenile Red-tails adorned with federal leg bands we caught in the Goshutes last year during the migration? They were moving south as NA raptors do in the fall, and we assumed them to be from nests to the north of us. It was a bit surprising to learn that both fledged from nests far to the south of Goshute. One was from southwest of Las Vegas, and one from coastal southern California. I think post fledging dispersal (or wandering for us non biologists) and migration are two different interrelated animals and probably a lot more complex than straight lines on a map. How those movements are ethically and efficiently tracked is an interesting discussion.
I do remember Mike, but I am careful to publish anything public about those birds because I know who is conducting the study, and I believe he hasn’t published yet, so it is in essence his information to disseminate. However, there are published papers of post fledgling dispersal in an extreme northward fashion. They are the supports to my statement that I’ve learned that first year birds headed south weren’t necessarily from nests to the north. Tracking these birds properly is an interesting discussion, and I’m very grateful people are taking the time to share their ideas on the matter. Thanks for the comment Mike!
Given the endangered status of bald eagles for years, their movements after fledging (often from a hack site in a state far removed from their actual nest) were well studied. Of course, bald eagles don’t have the fairly rigid North America-to-Argentina migratory habit of Swainson’s, as they tend to move around and congregate during the winter wherever there is a good food source. But it was still interesting to chart the apparently formless wanderings of these youngsters. During the 5 pre-adult years, before they returned to their ‘natal’ area to breed, they go east, west, north, and south without a whole lot of apparent reason. I’m wondering if other juvenile raptors might not do some of the same thing in their first year or two, before claiming a breeding territory.
Louise, I’m wondering the same thing, and I think there is some evidence coming forth to support that assumption already. I also think we will start hearing more of these color banded birds “captured” in photographs, and will start to build an even more detailed record of post fledgling movements. How exciting! Thanks for the comment!
Pretty crazy! We caught a glimpse of a couple peregrines at Spindletop Farm in Lexington, KY with color bands. With the help of some state biologists, we were able to determine which individual it was and how far it traveled! They were stoked!
http://thekentuckynatureblog.blogspot.com/2013/02/january-22-nd-one-of-coldest-days-of.html?m=1
Great to hear John. Just the instance to support my idea that color bands can be used by the public to help enhance the probability of re-sights. Great work with the PEFA!