Forest-dwelling live in deciduous and tropical forests. With their large body-size, wild cattle have few natural predators aside from humans. Still they are often prey to crocodiles, big cats, spotted hyenas, dholes, and wolves. It is often the young and the weak that are commonly selected by these predators. Behavior and reproduction Wild cattle are very social animals, which they accumulate into large herds, with some individual sizes that can go into the hundreds. Usually these herds consisted of females and their young, although in some species there are occasionally bachelor males among them. Generally the larger and more experienced males tend to be solitary, though in the breeding season mixed-herds occur. There is a strict hierarchy among males based on size dominance. All species of bovin are polyandrous. During the rutting period males engage in ramming against each other in order to obtain the breeding rights for females as well as territory. The gestation period occurs once the female has been inseminated from the male successfully. In most species it lasts approximately nine to ten months. They only give birth to a single calf. Once the young are born, they won't wean until they are around six to 10 months depending on the species. Females of most species sexually mature by four years while for males it is seven years. Genetics and hybridization The chromosome number varies by species, and sometimes even by subspecies, which warrants further research for taxonomic purposes. The ancestral Y chromosome was probably a small acrocentric, but evolved into several distinct characteristics. The subtribe Bubalina have the acquisition of X-specific repetitive DNA sequence on their Y chromosomes; Bos has derivative metacentric Y chromosomes, and share the presence of shared derivative submetacentric X chromosomes with Bison. Below is a listing of the diploid number 2n of selected species as follows: Saola: 2n = 50 Forest buffalo: 2n = 54 Cape buffalo: 2n = 52 Lowland anoa: 2n = 48 Water buffalo: 2n = 48 Gaur: 2n = 58 Banteng: 2n = 60 Yak: 2n = 60 European bison: 2n = 60 American bison: 2n = 60 Cattle: 2n = 60 Bovin hybridization is most common in the subtribe Bovina, the most well known of these is the beefalo (a cross between cattle and American bison). Most of these hybrids are deliberate from humans wanting to improve the quality of various cattle breeds (in particular for beef