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Tag: bird

Notes on Gyrfalcon Molt

by Bryce W. Robinson

Adult Male Gyrfalcon - Falco rusticolus

Photo 1. Adult Male Gyrfalcon – Falco rusticolus

I like to pay attention to molt in birds. There are many aspects of a birds life history that can be reflected by their strategy for feather replacement. A great example is something I’ve been watching with the nesting Gyrfalcons I’ve been working with lately.

Last summer, I noticed something about the molt between male and female Gyrfalcons. While I was entering nests to install cameras in the early nesting period (mostly during incubation), I noticed that males were behind females in their molt progression. Following my initial observation, I started paying closer attention to each bird. I continue to take notes on this, and wanted to share the molt of a pair from a nest I visited recently.

Adult Female Gyrfalcon - Falco rusticolus

Photo 2. Adult Female Gyrfalcon – Falco rusticolus

You can see that the male (photo 1) has just dropped his fifth primary. Falcons generally begin their primary molt at P 4&5 and progress in two directions. The female (photo 2) has dropped her third, fourth, fifth, and sixth primaries. You can see P 4&5 are growing in already.

This illustrates a few simple things in the life of a Gyrfalcon. One, that energetics govern the ability to molt. Two, that male and female Gyrfalcons have different energetic roles and energy budgets during incubation and early brood rearing. They have different roles in the process. These are illustrated by the fact that they differ in the progression of their molt.

Later, the rates even out as both adults need to provision for their growing brood. I hope to get photos of this pair on my next visit to the nest in a few weeks.

Long-billed Curlew Flight Display

by Bryce W. Robinson

The Long-billed Curlew has a bizarre courtship flight display, not unlike many other members of the family Scolopacidae. The male flies tirelessly in broad undulating circles, broadcasting a mournful whine into the sagebrush strewn hills. Having always been enamored by the spectacle, I made it a goal and was extremely pleased to capture the display on video.

If you haven’t heard of the Intermountain Bird Observatory’s Long-billed Curlew Project, I’d like to use the above video to make an introduction. Long-billed Curlews are facing threats in the west, on multiple levels. For many years now the impacts of landscape change have added stress to nesting curlews. Habitat loss from development, degradation from grazing, ATV recreation, etc. are all causing added stress to the birds ability to reproduce. On top of that, IBO has found that there is an issue with folks shooting curlews. What reasons there could be for shooting a curlew escape me, but it is an issue nonetheless and one that IBO attempts to overcome through education and outreach.

On top of these issues, these birds are facing threats off their breeding grounds as well. Contaminants on the wintering grounds add yet another stress to these birds. IBO has deployed satellite telemetry units on a handful of birds to fully understand their year round distribution and where particular populations may face threats.

Stephanie Coates, an all-star of bird biology, recently started her pursuit of a master’s degree in biology at Boise State University. She is working with IBO on their curlew project, and has started a website to chronicle her work and the work of the field crew. Follow along and check out live viewing of curlew movements via satellite imagery, great photos from the field crews, and more.

Visit curlewcrew.com

Singing Sagebrush Sparrow

by Bryce W. Robinson


I took this clip the other day in the Sagebrush strewn landscape of southwestern Idaho. I recorded the video by digiscoping using my ZEISS Diascope 65 T* FL. Normally, Sagebrush Sparrows are busy singers and will generally tolerate you in the area so long as you don’t pay them too much attention. But for whatever reason, no matter how far I was the sparrows on this morning were extra timid. On top of that, the wind wasn’t helping. Due to the wind and the distance from the bird, you can’t really hear the singing. To add one more difficulty to getting the song recorded, there was a lone bull nearby that was constantly growling. I didn’t know bulls growl… So, there is room for improvement for recording video of a singing Sagebrush Sparrow.

Anyway, I’m still pleased with the outcome. I do think I need an external, directional microphone for recording singing birds. Digiscoping really caters to sparrows and other passerines that are more flighty, but it doesn’t capture the song well. Still, It’s really nice to have quality glass to help with the effort. I’m really excited to apply the technique to some of Alaska’s more timid birds this summer, such as the singing Arctic Warbler and displaying Bluethroat.

Gyrfalcon T-shirts

by Bryce W. Robinson

2015-04-07 00.00.00

We have Gyrfalcon T-shirts for sale on the ornithologi`art shop until April 20th. Click the photo or follow the shop link for pricing, sizes, and color options. Represent the Gyrfalcon project and get a shirt!

GYRF