Readers’ wildlife photos

Reader Tom Carrolan, a raptor expert, has sent some photos of those birds. His captions are indented, and he notes, “All images are mine from many decades of imaging this species in migration and on wintering grounds in US and Canada.” Tom’s website is HawksArtScience.

Spring hawk migration is underway and Rough-legged Hawks (Buteo lagopus) are early-in-the-season migrants to the Arctic. Roughlegs, Snowy Owls and Gyrfalcons are our three arctic raptors. They are called “rough legged” as the legs are feathered all the way down to the talons.

I’ve been looking at Roughlegs in migration and on their wintering grounds since the late 60s. They come in two color morphs, known as light and dark. There are old birders and old field guides that refer to the plumage diffs are phases, but this is not a phase they are going through. Here’s an assortment of the two morphs, in both adult and immature birds. And because their Arctic “growing season” is short, we also see incomplete and arrested molt in this species.
This shows a light and dark Roughleg. Both have incomplete molt and are likely second-year birds. Left: while P10 (outermost primary) is black/new, P9 is a retained light juvenile feather, and P8 had started to emerge and is now arrested. Also, all secondaries have molted to adult-like state. On the right, we can see longer black-tipped secondaries, but also pale unmolted juvenile feathers. In both birds, only the talons are showing.
The most common Roughleg sightings are of juvenile birds. Light iris coloration is a juvenile feature. As in all Buteo species, the young birds have a pale trailing edge to the flight feathers. This first light juvenile shows classic dark carpal patches at the wrist.
This is a dark juvenile.
This juvenile was imaged in mid-March and shows a typical darkening of the iris from yellow to brown.

Light adult male. A dark bib, and losing the bellyband. Dark iris.
 Adult female. Dark bellyband with upper breast markings and dark iris.
Perched juveniles with pale irises and unbanded tails.
 This bird shows the upper wing pale panels that are diagnostic for first-year birds, and in this case a young adult (likely a second-year Roughleg) with an adult tail type and dark banding on the secondaries.

7 Comments

  1. Christopher
    Posted March 27, 2018 at 8:18 am | Permalink

    It’s great to see some different raptors, however, these photos of the same species show how different they can appear, and why I have so much trouble identifying raptors! I need a good series of shots of all the different morphs of all the local species side by side to study until I get a good grasp of the differences.

  2. Liz
    Posted March 27, 2018 at 9:52 am | Permalink

    Love the notes on the different iris colors. Wonderful.

  3. Posted March 27, 2018 at 9:54 am | Permalink

    Interesting series of photos!

  4. Mark Sturtevant
    Posted March 27, 2018 at 11:31 am | Permalink

    Very detailed pictures and descriptions. I really enjoyed them. It was especially interesting to learn about how the feathers & eyes change with age, so one can gauge the age of these birds.

    • Glenda Palmer
      Posted March 27, 2018 at 12:28 pm | Permalink

      +1

  5. Posted March 27, 2018 at 7:16 pm | Permalink

    Absolutely beautiful. They look great!

  6. Mark R.
    Posted March 27, 2018 at 7:43 pm | Permalink

    Thanks for the learnings and nice raptor pics. Rough-legged…good to know.


%d bloggers like this: