Keepers at Paignton Zoo in Devon are using a Moore & Wright calipers supplied by Bowers Group (www.bowers.co.uk) to measure the growth and development of a spider tortoise, which hatched in April.

The width of the tortoise’s shell is a good indicator of its healthy growth, and a method was needed to take very precise measurements in a minimally invasive way.

The Moore & Wright Plastic Dial Calipers have an accuracy of ±0.1mm and are made from glass-reinforced nylon.

Senior keeper Katy Upton said: “The calipers give us very precise measurements — essential for monitoring the growth and development of such a small animal. They give us nice accurate results every time.”

The spider tortoise — named after the pattern on its shell — is found in Madagascar, but it is on the brink of extinction.

The adults are only around 6in long, and they are thought to live for up to 70 years, but little is known about their life-cycle.

Paignton Zoo is home to four adults — two males and two females — ranging in age from 11 to 22. Experienced keeper Andy Meek devised a husbandry protocol for the tortoises based on field data and the experiences of other collections.

He managed to mimic the seasonal changes that the adult animals would experience in the wild, including fluctuations in their diet, as well as spraying them with water to simulate rainfall.