Friday, April 12, 2013

That's Hard to Swallow

Recently I was scouring the eastern reaches of Tempe Town lake, along the McClintock Bridge, for Clark's Grebe and Common Loon. This isn't the best place to look for these birds, but the better-viewing pedestrian bride farther west limits your photographic range, and the McClintock bridge presents the rarer possibility of better photos. At any rate, the waterfowl were a no-shows anyway, but there was something very intriguing going on along the northern shore. 

Hundreds of Cliff Swallows were creating a commotion, a disturbance in the force, amidst the putrid muck on the water's edge. I hate to admit it, but it took me a minute to figure out why this big rotating system of birds touching down and lifting off after apparently getting a drink was necessary. 
Surely, ariel aces like them could swoop to drink cleaner water away from the stagnant muck?

Of course, the stagnant muck was the whole point. They were gathering material for their nests, impressive adobe things they build on the underside of bridges, cliffs, and any other shady overhangs that meet their territorial requirements. At some of the larger, more accommodating locations, these gregarious birds will nest in groups several hundred strong. 

The way they'd touch down and keep their wings raised, even while fluttering and collecting goop, reminded me of butterflies, but the way they flew certainly did not. 

 There seemed to be various levels of completion among the little gourds, and various levels of work ethic too. Some Swallows were more casual than others, at least in the building process. The concentrated activity also generated lots of bird droppings, and these were happily gobbled up by the insouciant Carp down below, the ultimate unscrupulous fish.

Despite there being plenty of muddy shoreline, even shaded shoreline, the mass of birds seemed interested in gathering from only one relatively small patch. As such, they had to harvest in shifts, and there was a constant revolving motion around the little mud farm. 

The grounded birds take a mouthful and lift off; new birds take their place and begin to gather.

They then bring the mud up to their nest, sometimes to construct of their own design and energy, and other times to merely drop off the raw materials for a waiting mate in the semi-finished structure. This dynamic was very curious.
Presumably all the birds building nests already had mates? Were some building homes with an eye for snagging a mate with their bodacious pad? Were some Swallow families just having two working parents? Interesting stuff...

At any rate, this high-stress, fast-paced cycle was more fun to observe and photograph than distant, blurry waterfowl. Even though I still have no photos of Loon species, this was a pretty good way to wind down the afternoon. Good riddance to those Loons. 
For these nest-builders, the big rule is, Don't Swallow!