Dominance Hierarchy

So this has been observed among a particular species of deer, red deer. These deer live together in groups, with males and females forming separate groups for most of the year, but during the mating season, the mature males compete against each other for the attention of females. The male deer challenge their rivals by making a particular sound as they walk side by side, assessing the size of horn like structures on their heads called antlers, since antlers are the main weapon they use for fighting the males with smaller antlers usually won't fight male deer with larger antlers. They back down instead and let the large antlered males have their way. So the male deer kind of organize themselves according to antler size, and in this way, the males with the largest antlers are able to have their choice. But here's the thing, once a year, around the end of winter, the male deer lose their antlers. They fall off, and can take a while to grow back. But the deer don't all lose their antlers at the same time. Each deer loses its antlers at a slightly different time. So. For a while, some deer have antlers and some don't, and when a male deer loses his antlers, the female deer do not show as much interest in him. At the same time, the male deer that haven't lost their antlers yet, that still have them, will have a higher status and become more appealing to the female deer.