Although I cannot imagine how researchers were able to ascertain this information, male burying beetles that mate more frequently than average are likely more insecure about their social status. This insecurity is rooted in the relative differences in body size among male burying beetles.
When a male burying beetle wants to mate with a female beetle, the male will select an animal carcass, most often a rodent. The male beetle will then proceed to allow the stench of the dead animal’s carcass stink up its environment. The male beetle hopes that the dead animal’s pheromones will attract a female. Unfortunately, the carcass smell often lures a male beetle into the other male beetle’s environment.
Once the two males find themselves in a shared environment, hostilities arise. It is the smaller, and therefore, the more insecure male beetle, that will become overtly aggressive towards the larger male. Also, the smaller beetle experiences a greater threat to his chance at reproduction since a larger male is now a potential competitor. Given the presence of a superior male beetle-suitor, the smaller, and more insecure beetle, will rush to reproduce with the nearest female before the larger male has a chance to. Therefore, it is the smaller sized, and naturally, more socially insecure male beetle that indulges in a greater frequency of reproductive acts in an effort to reproduce quickly.
Do you think that the smaller the body size of any animal, the more likely that animal is to indulge in defensive behavior towards larger competitors? Do you think beetles with small body sizes experience a greater pressure to reproduce?