|Resting on a small trail my crewmate and I carved through an arrowweed stand (Photo by Brandon Breen)|
During this first tour, the crew spent several nights camping at Fishers Landing on Martinez Lake. The campground itself was nothing to write home about, but the birding in the area was pretty good. One thing we noticed at our campsite was that streams of hundreds of Tree Swallows would pass overhead each evening. This was no surprise to any of us who had spent a spring along the Colorado River before, as migrating streams of swallows are a common sight out here. One evening, though, we went up to an overlook point to scan the lake and we were impressed by the number of swallows streaming over the water, swirling over the marsh, and gathering in flocks high over the lake. Eventually, all the swallows gained elevation and streamed into the masses high in the sky. Numbers increased rapidly, from a few thousand to more than 20,000 as we stood and watched, estimating numbers repeatedly. The ball of swallows moved through the sky with the liquidity of smoke, merging and splitting, climbing and shifting as the light dimmed. Eventually, a few hundred birds broke off from the flock, diving almost straight down toward the marsh before breaking at the last moment and settling into the cattails, preparing to roost for the night. As more and more birds joined in the plummet to the marsh, they appeared as whirling vortices to the naked eye, like twisting pillars of smoke. Soon the clouds of swallows had drained to nothing, and as darkness fell, and two Black Rails began calling from the marsh, we headed back to the campsite.
The next night, having heard from us the spectacle we'd seen, most of the crew took the walk to the viewpoint. The swallows were out again, streaming over the water and building in flocks over the marsh. Eventually the flock built to an estimated 50,000 birds, more than twice the size of the previous evening's flock, and twice as spectacular!
|The swallows' marsh|
|The crew enjoying the swallows (Both photos above by Brandon Breen)|
|Watching the swallows spiraling down to roost|