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Tag: video

May 20, 2016

Lesser Yellowlegs Casts Pellet

by Bryce W. Robinson

 

I’m currently working in the Alaskan boreal forest outside of Anchorage. The focus of the work is on boreal wetland species such as Lesser and Greater Yellowlegs, Solitary Sandpiper, Short-billed Dowitcher, Olive-sided Flycatcher, and Rusty Blackbird to name a few. The time I’ve spent in the field has been rewarding on many levels, mostly because I’ve never worked in this system and I’m exposed to behaviors I’ve never seen.

Today I was in a canoe on my way to find some Rusty Blackbird nests. While slowly making my way, watching what I passed, I noticed a Lesser Yellowlegs perched on a log in the water. At the shoreline, I got out of the canoe and crept on the yellowlegs, laying down and turning on my camera. I’ve never had the chance to get great yellowlegs photos, so I took the opportunity. Meanwhile I recognized the opportunity to take some video, and as I switched over and began recording the yellowlegs expelled a pellet. This video alone, though it could be better quality, is worth an entire summer spent in the boreal. These seldom seen instances that speak to the life histories of birdlife are what I value.

Owls and raptors often get the attention when speaking about pellets in birds. In fact, many people don’t realize that most birds expel pellets. As recently as 1979, many species weren’t known to expel pellets (Below 1979). Now we understand that most species that consume insects and vertebrates cast pellets to reject indigestible material.

More description of the excellent boreal birdlife to come. I’m in heaven.

Referenced literature:

Below, T. H. 1979. First Reports of Pellet Ejection in 11 Species. Wilson Bulletin 91(4) pp. 626-628

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April 27, 2016

Singing House Wren on the Boise River

by Bryce W. Robinson

 

I recorded a singing House Wren (Troglodytes aedon) today while banding birds along the Boise River with the Intermountain Bird Observatory (note the bird is banded!).

Although spring migration hasn’t hit in its entirety at this site, the House Wrens seem to have arrived in full. There are at least three different individual males singing in the area, and I’ve noticed an additional four individuals in the area as well. The House Wren population at this site seems to be healthy.

Unfortunately the video I recorded does not capture the song of the House Wren. I wasn’t too far from the wren, but I believe the inability of the phone to capture the song is related to the masking of other noises in the environment (and the iPhone’s lack of a directional mic). First and foremost it was a windy day, which I believe is the main contributor to the masking. On top of the wind was the noise of the busy highway, the noise of the Boise River, and nearby construction (all large bandwidth, but mostly low frequency). With both natural and anthropogenic noise, I wonder how House Wren territory distributions differ between an area like this and a relatively noiseless area such as a remote forest location away from a river.

HOWR

House Wren (Troglodytes aedon) banded at the Intermountain Bird Observatory’s Boise River site on the east end of Boise, Idaho.

Despite the heightened noise, the wrens in this area seem to be thick and continuing with life as they would. A study may enlighten us on the human noise impacts coupled with natural noise (rivers, etc.) on bird territory distributions like in this case, but if I were to hedge a bet I’d say the House Wren is one species that seems to weather the added impacts of humanity enough to maintain a regular and healthy population within human disturbance areas.

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January 21, 2016

Black Rosy-Finch Use Cliff Swallow Nests to Roost

by Bryce W. Robinson

 

East of Boise, Idaho, on a cliffside along the Boise River is a conglomerate cliffside of volcanic rock. On this cliffside is a group Cliff Swallow (Petrochelidon pyrrhonota) nests. The Cliff Swallow is migratory, so during the winter months the Cliff Swallow does not occupy these nests.

In winter, the mud cavity nest sites are utilized by other bird species as roost sites. Interesting, to me, is that wintering Rosy-Finch species use these nest sites as well. I finally succeeded in capturing a video clip of a Black Rosy-Finch (Leucosticte atrata) entering a mud cavity to roost for the evening.

The composition of the flocks at this particular site are also of interest. Take a look at the eBird checklist of the time I spent filming this small flock. Most were Black Rosy-Finch, the next most numerous were “Hepburn’s” which are a coastal breeding subspecies of Gray-crowned Rosy-Finch, and there was only one “tephrocotis” Gray-crowned Rosy-Finch, the interior subspecies.

http://ebird.org/ebird/view/checklist?subID=S27027048

The regularity of this Cliff Swallow – Rosy-Finch relationship is of interest to me. I have read accounts of the behavior in California and Washington, but these accounts are few. I do not know of other areas that these birds currently use Cliff Swallow nests, but I will be searching for them and would appreciate any information from other’s observations.

Wintering ecology, what a fascinating faction of bird study.

 

 

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Video | January 5, 2016

American x Eurasian Wigeon Hybrid

by Bryce W. Robinson

 

The phenotypic expression that results from hybridization is fascinating, especially in colorful birds such as the male ducks. One duck hybridization I enjoy is the American x Eurasian Wigeon. The subtle combination between the traits of the two species is pleasing to the eye, but also presents a fun and satisfying ID challenge.

I found a drake American x Eurasian Wigeon the other day in a large group of American Wigeon feeding on a grass field at a large sports park in Boise, ID. The winter group that frequents this field every year generally holds a drake Eurasian Wigeon. This year no Eurasian, but a hybrid.

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Note the retention of the American Wigeon head pattern. The Eurasian has a beautiful red-orange head with a golden fore-crown. The neck and auriculars do not differ in color than the superciliary and hind-neck as in the American. This hybrid holds the American pattern, but with strong Eurasian coloring throughout the head. The other most obvious quality on this bird is the gray flanks unlike the American Wigeon which have rufous flanks. Thus, the combination of American head pattern with reddish hints and the gray flanks are enough to confidently call this bird an American x Eurasian Hybrid.

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Eurasian Wigeon sure show up regularly each winter in N. America. I’d love to know if the regularity of Eurasian in N. America mirrors the regularity of American in Asia. It’s fun to wonder, but with the growing popularity of eBird, answering these types of questions are beginning to seem more and more possible.

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