Dennis:
>I assume some of us might not have thought about the consequences of making
>a mud nest. You can only breed somewhere there are mud puddles, and this
>surely must affect where Barn and Cliff swallows nest.

Certainly in dry eastern Oregon. The relative scarcity of good mud
puddles in much of the cliff swallow's range might've been one of
the factors that has led them to adopt mass-mudding (mudding of
the masses?), rather than the more solitary mudding style of the
barn swallow.

Around Malheur, you'll see an entire building's colony make use
of one little puddle which has formed in a tire-created depression
nearby.

The barn swallows tend to nest along the canals, where there's a lot
more mud - though the total overhang of the small road bridges, under
which they nest, is probably the real attractant.

What was the distribution of barn swallows in areas like the Great
Basin before we arrived to build bridges and carports and front
porches?

>And, by the way, if you want to check about the life and times of Cliff
>Swallows, check the recent Birds of North America account, perhaps
>available at Flora & Fauna Books.

There was a good article a few years ago in Natural History magazine,
outlining the intense egg-removal, egg-dumping, neighbor-humping (sorry,
couldn't resist the rhyme) activities going on in these sweet-looking,
benign-appearing colonies.

- Don Baccus, Portland OR <donb at rational.com>
Nature photos, on-line guides, at http:://www.xxxpdx.com/~dhogaza