Helpful Hormones & Hormonal Elephants

Endocrinology is the study of hormones. Our endocrine lab helps to support breeding programmes through an endocrine diagnostic service and research, both in the zoo and with other conservation partners.

We measure hormones in our animals non-invasively by sampling faeces, urine or saliva.

From the samples we can tell:

• When an animal enters puberty
• When the breeding season occurs
• If an animal is reproductively healthy (cycling regularly)
• The best time to introduce males to females
• If an animal is pregnant and when they are likely to give birth
• Whether a contraception method is successful
• How an animal is responding/adapting to its environment

Knowing these things helps to enhance the well-being and reproductive success of threatened species, both in zoos and in the wild.

Here at the zoo we routinely monitor our Black Rhinos, Asian Elephants and Okapi.

 Elephants - Chester Zoo

Hormonal Elephants

At the zoo, we regularly monitor the hormone concentrations in the faeces (poo) of our female Asian Elephants.

This is a vital tool for managing reproduction in our herd. This routine monitoring allows us to predict when the females are going to be in season and when we can introduce our male for mating.

It can also help to find out when a female is pregnant and when the baby is due. The keepers collect a faecal sample twice a week and deliver it to the on-site lab, which returns the results within 24 hours.

Hormone levels - Chester Zoo

See how during normal cycling the hormone concentration levels rise and fall during the cycle, but when pregnant the hormone concentration levels stay consistently high right up until the elephant is just about to give birth.