Braving sub-zero temperatures, the dedicated team at ZSL London Zoo has embarked on its crucial annual animal census, counting every single resident from the tiniest ant to the mightiest gorilla.
A Chilly but Vital Task for Global Conservation
As snow fell on the capital and thermometers plunged to -4°C, zookeepers armed with clipboards began their meticulous task at 7am on Tuesday. This stocktake is not just a bureaucratic exercise; it is a mandatory licensing requirement that provides essential data for international conservation breeding programmes. Dan Simmonds, head keeper at the zoo, emphasised its significance, especially as the Zoological Society of London (ZSL) celebrates its 200th anniversary this year.
"We've been counting animals at London Zoo for 200 years. It's a really important day [and] it's also a great day for visitors to be able to watch as well," Simmonds said. He noted the contrast between the shivering keepers and animals like the capybaras, who were cosy in their heated enclosure.
Conservation Success Stories Amid the Count
The headcount revealed several heartening successes for species preservation. Keepers recorded 75 Humboldt penguins, including 16 chicks hatched in 2025. This is a boost for the vulnerable species, whose wild numbers in Chile and Peru are in decline.
Further cause for celebration came with the addition of eight Socorro dove chicks, also hatched last year, marking a milestone in bringing this bird back from the brink of extinction. Perhaps most notably, the population of critically endangered Darwin's frogs increased by eight in 2025. These unique EDGE (Evolutionarily Distinct and Globally Endangered) frogs are part of an international project to save them from a devastating fungal disease.
From Lions to Leafcutters: The Scale of the Operation
With over 8,000 animals to account for, the scale of the operation is immense. The count encompasses every mammal, bird, reptile, and invertebrate in the zoo's care. Highlights from the day included:
- Carefully counting the zoo's four impressive Asiatic lions, a species with only several hundred left in the wild.
- Tallying Humboldt penguins as they swam underwater.
- Examining tiny but important residents like Seychelles millipedes and leafcutter ants.
- Registering the zoo's two new capybara residents.
By the end of the day, all data was logged into an international database shared with conservation zoos worldwide, ensuring the information contributes to protecting species on a global scale.
