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Tag: innoko

Great Gray Owl Fledglings

by Bryce W. Robinson

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Another highlight from my recent time spent on the Innoko National Wildlife Refuge was happening upon three Great Gray Owl (Strix nebulosa) owlets that had “branched”.

In fact, these birds had hatched in a nest that was nothing more than the top of a birch snag, so far as I could tell. There were no nest structures in the area, only a plenty of broken tree snags about 5 meters tall. I believe that once they were too big to fit, the owlets fledged. Each bird was on a partly fallen truck leaning diagonally, a ramp for them to climb from the ground to relative safety from ground predators.

The first bird my friend Nick and I found sat staring at us, but with only one eye open. It appears from the photo that a Moose Fly (Tabanidae sp.) was biting its eyelid. I became very familiar with these flies during my time in the area, and felt for the poor young owlet.   The flies have pinchers on their mouth that they use to break skin, and from my experience with them it seems they do this to draw the blood and then feed. At least mosquitoes are mostly painless during their blood draws…

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We first heard the owlets begging calls while conducting a point count a few hundred meters away, but by the time we found them they had quieted down and stood extremely still, staring at us. Without a doubt we were the first humans these birds had seen. The Innoko is a very remote place, as we never saw a single person during our five-day stay in the area despite covering a distance of over 200 river miles round trip.

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I was enamored. I’ve seen very few Great Gray Owls in my life, and seeing birds at this age was a first. It has always been something I’ve wanted to see, so it was a dream realized. After getting our fill of the owlets, we began searching for an adult. We soon found a large ghost-like owl, the adult Strix nebulosa, 50 meters from the owlets. In my experience with Great Gray Owls, they’ve been extremely tame birds that tolerate your intrusion and lend themselves to photography. This birds was not tame, and unfortunately flew into the forest as we drew near. I wasn’t able to get any photos, but I managed to watch through my binoculars for a bit.

I captured a short clip of one of the nestlings (below). It’s a rather uneventful short clip, but it adequately describes the experience and the owlets tactful poise as it remained motionless as it kept eyes on Nick while I took video.

 

Here it is in full, the media from my first encounter of a Great Gray Owl family in the remote Alaskan wilderness.

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Harlan’s Red-tailed Hawk on the Breeding Grounds in Alaska

by Bryce W. Robinson

This post details my encounters and notes of Harlan’s Red-tailed Hawks in Alaska during the early summer of 2016. The post is separated into two parts, individuals I encountered while conducting the Alaska Land Bird Monitoring Survey in the remote western interior, and individuals I’ve encountered in the Anchorage area.

From the Innoko National Wildlife Refuge:

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Photo 1. Adult male light morph “Harlan’s” Red-tailed Hawk (Buteo jamaicensis harlani). Innoko National Wildlife Refuge, Alaska. Photo copyright Bryce W. Robinson.

I just returned to Anchorage from two weeks of bird surveys in the interior of Alaska, conducting the Alaska Landlord Monitoring Survey for the Boreal Partners in Flight. These surveys entailed travel to three remote national wildlife refuges; Innoko NWR, Nowitna NWR, and Koyukuk NWR. The aim of myself and my friend Nick Hajdukovich was to conduct point counts on refuge land. Our travel consisted of float plane transport to each refuge. Once in the Innoko, we logged 200 miles of river travel on the Innoko River to and from our two survey plots, which provided me with great exposure to untouched Alaskan wilderness. Along the way I happened upon a few individuals of perhaps my favorite bird taxon, the harlani subspecies of the Red-tailed Hawk.

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Photo 2. Innoko River, Innoko NWR, Alaska. June 2016. Image copyright Bryce W. Robinson.

The first birds I encountered on the Innoko River happened to be a nesting pair. Their nest was situated on a partially fallen White Spruce that extended over the open river. As we approached the nest we cut the motor and drifted directly beneath the brooding female. At 200 m from the nest a light morph bird, the male, took flight from a nearby tree and began vocalizing and stooping on our boat (Photo 1, 3). As we floated by, I took the opportunity to document the situation.

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Photo 3. Adult male light morph “Harlan’s” Red-tailed Hawk (Buteo jamaicensis harlani). Innoko NWR, Alaska. June 2016. Photo copyright Bryce W. Robinson.

It was excellent to observe the defensive behavior. Equally excellent was the light morph plumage of the male, and his silver/white tail with hints of red near the tip (Photo 3). As we passed the dark morph female on the nest (Photo 4), we could see her heavily banded tail, dark and red throughout (Photo 5). The variability in tail pattern in these birds interests me greatly, and it was excellent to see this dark bird with a near wholly red tail.

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Photo 4. Adult female “Harlan’s” Red-tailed Hawk with nestling. Innoko NWR, Alaska. June 2016. Image copyright Bryce W. Robinson.

The female was sitting in the nest, along with one nestling which appeared to be around 15-20 days old. The nestling was panting in the intense Alaskan sun. The temperature was a balmy 70 degrees Fahrenheit, very warm for Alaska. We drifted on, got our fill of photos and satisfying looks, started up the 5 HP motor, and continued our trip.

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Photo 5. Female dark morph “Harlan’s” Red-tailed Hawk (Buteo jamaicensis harlani). Note the near wholly red tail. Innoko NWR, Alaska. June 2016. Photo copyright Bryce W. Robinson.

Throughout our trip we saw a few other adults, all dark morphs that one would consider “typical” harlan’s with whitish and silver tails, white streaked bibs, etc. The birds were uncooperative for photography, except for two individuals that happened to be my most sought after group of this taxon, second year birds midway through their pre-basic molt (Photo 6). I included a photo of one of the individuals, as they were quite similar in appearance and at the same stage in their molt.

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Photo 6. Second-year “Harlan’s” Red-tailed Hawk (Buteo jamaicensis harlani) midway through pre-basic molt. Innoko NWR, Alaska. June 2016. Photo copyright Bryce W. Robinson.

The degree of molt which these young birds undergoing is worth noting, as compared to all adults that I’ve seen. All adults, presumably breeding, are limited in the extent of their feather replacement. The two Second-year birds that I’ve photographed are molting heavily, as you can see in photo 6. This speaks to the energetic requirements of both molt and the reproductive effort, and the trade-off in allotment between both, something of which I’ve noted before in Gyrfalcons (find it HERE).

Overall the time spent in the western interior was grossly fruitful in my exposure to Harlan’s alone.

From the Anchorage area:

Something interesting is happening in Anchorage. Although I’ve seen plenty of birds in the region that fit what we call the “typical” Harlan’s (Dark morph, light bib, silver or white tail, mottled flight feathers, etc.), I’ve found two individuals, a pair, that are worth documenting. It’s important to note that I’ve been working in a fairly restricted area on the U.S. Air Force base at the north end of the city. I haven’t been able to cover much area throughout the valley, but much of my assumptions about other Red-tailed Hawk in this region come from observations at Gunsight Mountain Hawkwatch.

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Photo 7. Adult light morph “Harlan’s” Red-tailed Hawk (Buteo jamaicensis harlani), showing traits suggestive of B. j. abieticola. Anchorage, Alaska. June 2016. Image copyright Bryce W. Robinson.

The first bird is a light morph female that my friend Laura showed me (Photo 7.). Although it has qualities typical for Harlan’s such as a mottled tail with silver and white tones amidst red, and globular belly markings, it also possesses traits reminiscent of other subspecies such as B. j. abieticola (Northern). Most notable is the barring throughout the wing lining, and on the belly. Also notable is the regular and distinct barring in the flight feathers. The question arises whether this bird’s phenotype is an infrequent but regular occurrence in the harlani population, or a result of integradation somewhere in its recent lineage? Although the area is an intergrade zone for many other species, I’m fully comfortable saying that I don’t know, nor do I want to suggest one over the other.  The most exciting part is not knowing, and realizing there is a frontier to explore in our understanding of this species.

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Adult dark morph Red-tailed Hawk (Buteo jamaicensis). Subspecies unknown, but this bird resembles what we would expect of a dark morph abieticola, if these exist.  Anchorage, Alaska. June 2016. Image copyright Bryce W. Robinson.

The second interesting bird from the area is perhaps more exciting (Photo 8). It shows no indication that it belongs to the subspecies harlani. It resembles a dark morph calurus, with some unique contrasting qualities to the auxiliaries and undertail. I’m not sure what subspecies this bird is, but if I were to guess I’d say this bird fits with the Northern population (abieticola), suggesting that this subspecies is polymorphic. Regardless, This bird along with observations at Gunshight Mountain hawk watch support that the Anchorage area and Matsu Valley are an intergrade zone, as is the case with many other species. I think there remains much to learn about the biogeography of Red-tailed Hawks, especially as it pertains to this small area of Alaska.