These bighorn ewes seen in canyonlands of southeast Oregon this spring were all bunched up. Wonder why? Biologists say ewes congregate during the lambing season as a defensive mechanism. It’s called predator swamping. The idea is that in a big group you have a lower chance of you or your offspring being the one that gets taken by a predator. If an ewe and lamb were on their own, the chances of getting taken by a predator increases. Predator swamping also is the reason that the timing of lamb births is synchronized; it reduces the chance of the predators being effective at taking the young lambs over a longer period of time, according to wildlife biologists. PETE ZIMOWSKY — pzimowsky@idahostatesman.com Buy Photo