16 April, 2012

Sleeping in the Clouds

We got the coordinates for Felipe this morning about 0730 and fortunately (by luck or intuition, not sure which) he was only a short distance north of us roosting in a canyon. It was just getting light at 0800 and it took us an hour to drive up the coast and find our way into Quebrada Honda, a drainage coming down from the foothills above the coast.

                             The Road Down Into the Quebrada

His site was located about 5 miles up but he had migrated out by the time we got there at 0900 (no VHF signal). We must have just missed him.

It was quite calm in the canyon but all of ridgetops were covered in dense coastal fog. So he had to have been sleeping in the clouds last night, probably not much different than sleeping in the fog at Putu.

            Felipes Roosting Ridge to the Right Covered in Coastal Fog

I hiked up the valley about a mile and got within about a quater mile of his site but as you can see it was impossible to see much.

This is a an arid valley supporting lots of cactus and other dry country plants typical of the coastal Atacama. They are nourished here primarily by the fog.

                 Typical Cactus in the Valley

I also found a variety of lichens which I did not expect but in retrospect made perfect sense.

                                   Lichen Species

The valley was alive with birds, mostly passerine types living well down in the scrubby vegetation. They included Chilean Mockingbirds, Common Duica Finch,  Rufous-collared Sparrows, California Quail and a Green-backed Firecrown.

We saw few birds flying out in the open sky, so hunting here cannot be easy. There is so much cover and it is easily accessible. We only saw one dove but many Chilean Swallows high in the air.

It makes me wonder where peregrines hunt on migration. Is it just in the morning and evening after their long daily flights? I think it just as likely that they hunt opportunistically throughout their day, taking advantage of any easy prey that happens to fly by.

It makes sense that they are hunting constantly, unless they take good-sized prey early in the day and start off with a full crop.

The fog lifted by 1000.  We could see that it really did not extend inland very far from the coast.

Over the years, I have often noticed that our tagged adults will often migrate well back from the coastline, i.e. at some distance inland. I am wondering if they fly along this fog line, keeping to the sunny side to both see where they are going and hunt prey as well. Flying through this coastal fog could be fatal to a bird traveling through rugged terrain at 50 mph.

          Felipes Roosting Ridge on the Upper Right After the Fog Lifted

It could just as easily be that peregrines simply fly up high enough to rise above the fog entirely.

After remaining below his roosting ridge for an hour, we headed north in anticipation of Felipes next location. This afternoon, we got a satellite call from Don who told us that Felipe had already flown well north so we are now trying to catch up as usual. We are happy to learn that he is back on the coast so we might have a chance to get to his roost if there is road access.

1945-Sitting here in Caldera wating for a call but I am worried. There has been a STRONG south wind blowing today and I think he may have really blown past us in this perfect wind for migrating.

Is this south wind typical for this time of year? If so, what a turbo boost for a migrant peregrine.

We are finding that our main probelm is getting the location data from his 4 PM signal in time. It is now well past dark and we really have no idea where to stay tonight. Should we drive north in the dark for an hour? Should we stay at a hotel with an Internet connection to see how to get to him early in the morning? We are learning.....

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