The Eld's deer is mainly active at night. Males and females lead solitary lives, and it is only during the mating season that herds of several dozen individuals form. The males then fight each other, and the winner mates with the females in his harem. As soon as the fawn is born, the mother hides it in tall grass.

There are three subspecies of Eld's deer: the thamin, the Siamese Eld's deer, both of which are represented at the Réserve zoologique de la Haute-Touche, and the very rare Rucervus eldii eldii from India. The nickname "lyre deer" comes from the distinctive shape of its antlers, which curve backwards and then forwards, resembling the musical instrument.

The male, darker than the female, has longer and thicker hair under the neck.

The Eld deer is threatened by hunting, wars and the loss of its habitat to agriculture and livestock farming. It is also susceptible to diseases carried by domestic animals.

Of the three subspecies of Eld's deer, the Thamin has the largest population in the wild, with around 2,000 individuals (compared to 150 Siamese Eld's deer and 150 Cervus e. eldii). In the early 2000s, there were 1,000 in captivity (mainly Thamin). Thanks to breeding programmes, this small population in zoos represents one of the best chances for the survival of this deer.

The Réserve zoologique de la Haute-Touche is the only park outside Asia to feature the siamensis subspecies. After being declared extinct in the wild, a small population of just 150 individuals was rediscovered, surviving only in certain enclaves of its former range (Laos, Cambodia and Vietnam). In order to increase the genetic variability of this captive population (and therefore its chances of survival), it is necessary to allow reproduction between Asian and European individuals. With this in mind, the team at Haute-Touche Park is working with Bangkok Zoo to collect semen from Thai males. Back in France, this sperm is frozen in liquid nitrogen. Some of our females will be inseminated and will give birth to young with a richer genetic heritage.