All the animals at Whipsnade Zoo in Bedfordshire, from little lemurs to enormous elephants, are being weighed and measured in an annual survey.
It's a huge task for keepers as they began the task of cataloguing each one of its 2,500 animals. The heights and weights of 200 species are being recorded.
Click below to watch a report by ITV News Anglia's Claire McGlasson
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Any early rain should clear, leaving a dry morning. Some brighter spells could develop and it will be feeling very mild. Highs of 16 deg C.
Teams searching for the missing RAF serviceman Corrie McKeague have admitted they're running out of logical places to look for him.
Cloud will thicken this evening but most places will remain dry. However some rain will creep in early Monday morning. Lows of 8 deg C.