The darker side of pronghorn life: sibling rivalry in the womb

One pronghorn embryo piercing another

On Mother's Day, Montana Public Radio aired my field note on siblicide among pronghorn embryos in utero, and I was on the Rocky Mountain front near Choteau, watching a pronghorn that had just given birth to one fawn.

The umbilical chord was still dangling from both, and we watched for over an hour as the fawn struggled to stand and suckle for the first time.

The mother seemed quite uneasy about all the traffic on Bellview Rd and after lying down and getting back up several times, led her first fawn away from the road, probably to find a more private spot to deliver number two. We left her in peace so didn't watch the second little horror arrive.

The very next day, on the same road, we saw a female pronghorn with two young fawns.

A week later, on the National Bison Range, the pronghorn there are no newborn pronghorn in sight, as their mothers have probably hidden them among the brilliant yellow arrowleaf balsamroot.

Yearling and adult female pronghorn among the arrowleaf balsamroot

Why do races look different?

These are illustrations for a book proposal, showing the differences between European and North American barn swallows. Female European swallows prefer males with longer tail streamers, and have selected for males with streamers that are longer than is aerodynamically optimal. In contrast, North American female swallows don't care much for long tails, but prefer their males bright orange below. As a result, American barn swallow males have shorter tails but brighter bellies than their European counterparts. In the Descent of Man, Darwin first proposed this idea of the arbitrariness of female mating preferences as an explanation for most of the racial variation within humans.

On birds on air: http://mtpr.org/post/singing-snow

A Natural History Note I wrote for Montana Public Radio: http://mtpr.org/post/singing-snow

Some views from cross-country skiing near Missoula this winter:

Top of Crazy Canyon Road between Mt Sentinel and University Mountain

Dog road at Lolo Pass

Ellie at the base of Blue Mountain

Base of Blue Mountain