The relationships of antelope siblings at home on the range may teach researchers more about the behavior of human children at home in the suburbs.
Firstborn children are more likely to be famous and score better on national achievement tests. Pronghorn antelope fawns don't take exams or make talk-show appearances, but the early-born among them tend to be dominant.University of Idaho zoology professor John Byers has spent the past nine summers studying antelope at the National Bison Range in the shadow of western Montana's spectacular Mission Mountains.
Dominance among fawns, particularly females, is decided by birth order and that social position usually carries on to the next generation, Byers said.
In other words, the meek don't inherit the earth among antelope.
"It's the first study that shows natural variation in early experience has a lifetime effect," Byers said.
His research shows that fawns born early in the four-week birthing season are usually the most mature, the biggest and the strongest when they come out of hiding and join the group.
"The fawns start contesting for dominance," Byers said. "They push each other around a lot."
The littlest, youngest fawns - the ones usually bullied around the range - become more subordinate in the social group and sometimes loners.
"They are more likely to be found on the periphery of groups or alone," Byers said. "Their personalities are set by early experience."
When they grow up, it's like mother, like daughter. Subordinate or later-born does tend to have subordinate fawns, Byers said.
"When their fawns get into tussles with other fawns, they can't intervene as much. Dominant mothers occasionally step in," Byers said.
When it comes to the mating game, male antelope show no preference for females based on either sex's birth order.
"The males mate with anything standing still," Byers said. "The males aren't choosy at all."