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!


  1. Awesome write! Plus excellent photos of the birds in action. This is an incredible find. Great captures!

    1. Cheers Chris thanks. I thad a Salton Sea-esque smell.

  2. How were you telling the individuals apart? That one was lazy and the next was industrious? eh?

    They can carry mud from 20 ft. to 1/2 mile. The make selects the site, then both the male and female cooperate in nest construction. They can construct at a rate of ~1.5 inches/daily. They work for about two hours, generally starting 1-2 hours after sunrise, then take significant breaks (30 minutes to a couple of days). One nest takes about 900-1200 trips.

    I think my favorite part is that when one mate arrives at the nest, there is a soft chirp in greeting, but when one departs, the chirp is harsh.

    1. Well, if you're SUCH an expert worthy birder, where is your Cliff Swallow post??????????

    2. I've never seen a cliff swallow in my life. I just went and read the primary literature because I thought it would be nice and helpful to answer some of the questions you posed.

      I'm probably about to be the least competent birder to ever lead a bird walk.... in less than two hours. Whee! Nothing like cramming.

    3. That's of you.

      Thanks for the specifics on the info. I still stand by my observation that some Swallow are lazier than others. As a prime example of humanoid laziness, I can spot my own kind.

    4. We'll try replying again....

      It really was. I took a break from reading primary literature to read primary literature on a different topic. It was a very good read. I think that the early literature is generally easier to read than the papers published today.

      May I share one more tidbit with you? (Well I suppose I can, since you can't say no, although the site did reject my credentials. The way the authors identified individual birds was to mark them with paint from water pistols.

    5. That is very interesting. I could certainly volunteer for something like that. Hitting those guys...that's a marksmanship challenge for sure.

    6. I thought you might appreciate it.

  3. Laurence, I've had the same thought about the swallows when they are gathering mud, those wings stay in motion and they do look like butterflies. Wonderful images of this activity!

    1. Thanks Mia. Sometimes we all have to get down and dirty.