Current data on the reproduction of Four-horned Antelope Tetracerus quadricornis in zoological parks

Abstract

The Four-horned Antelope Tetracerus quadricornis is currently facing numerous dangers throughout its natural range. The major threats include human overpopulation, deforestation, and degradation of its habitat. It is classified as Vulnerable on the IUCN Red List. Now, this species is rare or even absent in most zoos. Given the threats encountered by this species in the wild, its reproduction was analyzed from animal data obtained in European and Indian zoological parks during 39 consecutive years from 1977 to 2016. There was an average of 1.42 new-borns per litter. Twins were more numerous than singletons. Sexual maturity in females did not occur before 18-36 months of age. Most females, however, reproduced for the first time much later, on average at 6-7 years of age and more than half of females produced only one litter. In females that raised their young, new fertilization generally took place 101 days after the preceding birthing. In Indian zoos, where temperatures vary little between seasons, births were numerous in September-February, especially in September-November when rainfall decreases, contrary to deaths that occurred predominantly in June-August during peak rainfall. In European zoos, most litters occurred in December-February. Thus, Four-horned Antelopes maintain part of the birth season of their native countries, despite unfavourable local climate conditions. Deaths of individuals also occurred mainly in December-February in European parks, i.e., during the coldest season. Globally, more males than females died during the first month of life as in other species, but not so after that age. On the whole, there is a low reproductive success in populations of the Four-horned Antelope under managed care compared to other ruminant species. This could partly be due to husbandry and management procedures of individuals in these parks. This raises the question of the possibility of reintroducing individuals into the wild from ex situ livestock.