Critter count: London Zoo begins annual animal census

Before you go, we thought you'd like these...

23 PHOTOS
NTP: London Zoo's annual animal census
See Gallery
Critter count: London Zoo begins annual animal census
Humboldt Penguins swim in their pool during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals. (AP Photo/Alastair Grant)
Keeper Colette Gibbings looks at a tank full of Moon jellyfish during the annual stocktake press preview at London Zoo in Regents Park in London, Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals. (AP Photo/Alastair Grant)
Humboldt Penguins swim in their pool during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals. (AP Photo/Alastair Grant)
Keeper Colette Gibbings looks at a tank full of Moon jellyfish during the annual stocktake press preview at London Zoo in Regents Park in London, Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals. (AP Photo/Alastair Grant)
Rikki the sole Rockhopper penguin gets his fish as Humboldt penguins queue behind him during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
Keeper Luke Harding holds a female Jackson's Chameleon during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals(AP Photo/Alastair Grant)
A television camera man moves back as a llama investigates his lens during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
A Mexican redknee tarantula spider stays still on their keeper's hand during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
Keeper Veronica Heldt moves her counting clip board as Meerkats look for food around her, during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
Keeper Veronica Heldt moves her counting clip board as Meerkats look for food around her during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
A ring-tailed lemur looks round during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
Humboldt Penguins swim in their pool during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals. (AP Photo/Alastair Grant)
A ring-tailed lemur looks round during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programs for endangered animals.(AP Photo/Alastair Grant)
Humboldt Penguins swim in their pool as a keeper looks on through a spherical window during the annual stocktake press preview at London Zoo in Regents Park in London Monday, Jan. 4, 2016. A requirement of ZSL London Zooâs license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where itâs used to manage the worldwide breeding programmes for endangered animals. (AP Photo/Alastair Grant)
LONDON, ENGLAND - JANUARY 04: Zookeeper Veronica Heldt poses for a photograph as she counts meerkats during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
LONDON, ENGLAND - JANUARY 04: A zookeeper poses for a photograph as she counts penguins in their pool during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
LONDON, ENGLAND - JANUARY 04: Jessica Jones handles a clipboard as she poses for a photograph with a llama during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
LONDON, ENGLAND - JANUARY 04: A Jackson's chameleon climbs on a clipboard as it handled by a zookeeper during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
LONDON, ENGLAND - JANUARY 04: A curious llama looks into a camera lens during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
LONDON, ENGLAND - JANUARY 04: Jessica Jones handles a clipboard as she poses for a photograph with a llama during the annual stocktake of animals at ZSL London Zoo on January 4, 2016 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Carl Court/Getty Images)
A zoo keeper poses with a Jackson's Chameleon during the annual stocktake photocall at London Zoo in central London on January 4, 2016. The compulsory annual count is required as part of the zoo's licence. AFP PHOTO / BEN STANSALL / AFP / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A zoo keeper poses with South American camelids, an alpaca (L) and a llama (R) during the annual stocktake photocall at London Zoo in central London on January 4, 2016. The compulsory annual count is required as part of the zoo's licence. AFP PHOTO / BEN STANSALL / AFP / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION

LONDON (AP) — Animals stood up to be counted — or in some cases swam, crawled or flew — as London Zoo began its annual census.

Zookeepers with cameras, calculators and clipboards counted critters Monday, the start of a weeklong campaign to record every resident mammal, bird, fish, invertebrate, reptile and amphibian.

See photos of the animals at the zoo's annual weigh-in:

14 PHOTOS
Britain Zoo animals annual weigh-in
See Gallery
Critter count: London Zoo begins annual animal census
Dirk, a Galapagos giant tortoise who weighed in 160 kilograms (353 pounds) has his head measured by keeper Sebastian Grant at London Zoo, in London, Wednesday, Aug. 26, 2015. The Zoo held it's annual weigh-in where the vital statistics of animals were taken in an aid for keepers to detect pregnancies and check the animals general wellbeing. (AP Photo/Alastair Grant)
Humboldt Penguins are led to the weighing scales with a feed of anchovies to encourage them at London Zoo, in London, Wednesday, Aug. 26, 2015. The Zoo held it's annual weigh-in where the vital statistics of animals were taken in an aid for keepers to detect pregnancies and check the animals general wellbeing. (AP Photo/Alastair Grant)
A young penguin is weighed during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
An Eagle Owl is weighed during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
An Iberian Midwife Toad is weighed during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A zookeeper poses for pictures as she counts penguins during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A zookeeper holds an Eagle Owl during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A young penguin is weighed during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A zookeeper measures a Galapagos Giant Tortoise during a photocall at London Zoo on August 26, 2015, to promote the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
An Emperor Tamarin looks up at its keeper looking for food as it stands on a pair of scales at London Zoo, in London, Wednesday, Aug. 26, 2015. The Zoo held it's annual weigh-in where the vital statistics of animals were taken in an aid for keepers to detect pregnancies and check the animals general wellbeing. (AP Photo/Alastair Grant)
An Iberian midwife toad sits in the hand of a keeper wearing blue gloves at London Zoo, in London, Wednesday, Aug. 26, 2015. The Zoo held it's annual weigh-in where the vital statistics of animals were taken in an aid for keepers to detect pregnancies and check the animals general wellbeing. (AP Photo/Alastair Grant)
Max, an Eagle Owl settles down after being weighed at London Zoo, in London, Wednesday, Aug. 26, 2015. The Zoo held it's annual weigh-in where the vital statistics of animals were taken in an aid for keepers to detect pregnancies and check the animals general wellbeing.(AP Photo/Alastair Grant)
A penguin is pictured during a photocall at London Zoo on August 26, 2015, during the zoo's annual weigh-in event. With more than 17,000 animals to weigh, the exercise is carried out on a regular basis by zookeepers as a way of keeping track of every animals health and wellbeing. AFP PHOTO / BEN STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION

The zoo is home to 17,500 animals of more than 750 species, from silverback gorillas to tiny leaf-cutter ants. New arrivals in the past year include a baby Western lowland gorilla and a litter of African hunting dog pups.

Ants and other extremely tiny creatures are counted in colonies, but all others are recorded individually.

The annual stock-taking is required under the license terms of British zoos. The data is used for zoo management and international breeding programs for endangered animals.

London Zoo Begins Animal Census
More from AOL.com:
Britain denounces ISIS video showing 'spies' shot
New York governor orders homeless off streets in freezing weather
2 men dead, 2 missing after Wisconsin canoe accident
Read Full Story

People are Reading