Monday, November 3, 2014

In Search of the Bristle-thighed Curlew

 Alaska 2014 continued:

The big push for day three of the birding tour in Alaska was to search for the Bristle-thighed Curlew. This was one of the birds highest on our list, as it is a species that does not migrate through the United States, and therefore can only be seen in Alaska. The curlew only breeds on inland tundra along the Yukon River and the central Seward Peninsula, which is where we headed. The species' wintering grounds are on islands in the South Pacific. While not listed as threatened or endangered, it is a species of special concern as there are only about 10,000 of them.

We pulled off the Kourgarok Road near mile marker 72 around 11:00 am. I was hungry but Bill wanted to wait until after our hike to eat. I knew I couldn't wait that long so I snagged a banana and granola bar. Those of us who were headed up the hill found semi-private places to relieve ourselves, then gathered up our gear and began to trudge up the hillside.

The hike wasn't bad at first but the walking conditions quickly deteriorated. The tundra here was made up of clumps of grasses and forbs surrounded by muddy, wet depressions. Each step had to be tested for stability. Most people fell down, a couple more than once. You could not walk and look around at the same time, so we'd take several steps then pause to look and listen. It took forever to get up the hill. I was afraid I was overdressed, since I had my down coat on, but it was windy and chilly enough to keep me comfortable. It snowed on us a bit too, but it was short lived.

We all got excited when we spotted a tall, long-billed bird perched on a hummock near the curve of a small ridge, but Bill quickly determined it was a Wimbrel, and not our curlew. The two birds are remarkably similar, but Bill was confident this was not our quarry. I took some images anyway as this was a bird I'd only seen once before.

A Wimbrel stands atop a hummock on a high tundra ridge.

The Wimbrel apparently felt some discomfort at our presence and flew a short distance away. After going through my photos I could also confirm this was not a curlew. One of the best ways to ID the Bristle-thighed curlew is that it has a pale, buffy rump, which this bird clearly lacked.

Image showing lack of light rump patch, confirming it is not the curlew.

We trudged along the hillside for quite some time with no luck. Our group fractured and several of us fell behind or wandered off, myself included. I was fascinated by the plants growing on the tundra, and surprised by the amount of water that was held on the hillside by the hummocks.

After nearly an hour and a half we abandoned our search and started to trudge back down the hill. But then one of our group pointed out two birds on the ground, and we all grabbed our binoculars for a look. Shortly after that, one of them took to the air and began singing--at that moment, we knew we had our bird. The song of the Bristle-thighed Curlew is very distinctive, and Bill had played it for us, describing it as sounding like a short-wave radio. Have a listen here:

At first the bird was little more than a speck on the horizon. But to my great delight, he banked and flew almost directly towards us.

A Bristle-thighed Curlew flies above the tundra.

Within moments the curlew was nearly directly above me.

The curlew flew in close, giving us great looks.

Then the curlew let us know exactly what he thought about our presence on his hillside.

Cries of "Look out, Bob!" rang out across the tundra as the curlew launched an assault. He missed.

The curlew continued past, then banked and flew by again, a little lower, giving us a clear view of his buffy rump.

The curlew shows us its buffy rump.

The bird eventually landed some way off, nearer to the rest of the group. Stunning how well the bird blends into the tundra.

Amazing camouflage.

He took to the air again after a few minutes, and we decided it was time to move away. It was not our intention to be that close and we didn't want to cause the birds any more stress.

As we began to move down the hill, Bill gave out a little yelp. Looking down he discovered that he had very nearly stepped on the bird's nest. Now, before you worry too much, keep in mind that these eggs were not yet being incubated. The Bristle-thighed Curlew lays a clutch of four eggs, and birds who hatch precocial chicks (ones that are hatched at an advanced state and are able to move around and fend for themselves) don't begin incubation until all the eggs have been laid. At that point the female will not leave the nest, no matter the threat. We hurried over for a quick look, and I took a few pics with my long lens, so as to not get too close to the nest, then we quickly moved away.

Bristle-thighed Curlew eggs, laid in a shallow depression among the lichens and moss on the tundra.

Thrilled with having seen and heard the bird and seen its nest, we stumbled, tripped and rolled down the hill back to the van, where we devoured our lunch and showed off the pics to the handful of people who had opted out of the difficult trek. Those few hours up on the high tundra is something I will never forget. And Bill was kind enough to say that mine were the best shots of that bird he had seen anyone on his tours take.

Next: the rest of the birds from day three.

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