Excited staff at Colchester Zoo are celebrating the arrival of two rare Amur leopard cubs.

East Anglian Daily Times: Esra, mother of the new Amur leopard cubs at Colchester Zoo. Picture: BARBARA MEYEREsra, mother of the new Amur leopard cubs at Colchester Zoo. Picture: BARBARA MEYER (Image: Barbara Meyer)

This is the first time the zoo has bred Amur leopards, which are critically endangered, and the adorable pair are the first litter for mum Esra and dad Crispin.

The zoo said via Facebook: "Keepers will be monitoring the cubs closely via CCTV, but so far Esra is being very attentive and gentle with the cubs, who are both looking well.

East Anglian Daily Times: Crispin the Amur leopard, father of the new cubs at Colchester Zoo. Picture: BARBARA MEYERCrispin the Amur leopard, father of the new cubs at Colchester Zoo. Picture: BARBARA MEYER (Image: Barbara Meyer)

"It will be a number of weeks until they are big and strong enough to begin emerging from their den and this will also be determined by Esra."

It takes around two weeks for leopard cubs' eyes to open and four weeks until they become more stable on their feet.

READ MORE: Two fluffy panda cubs are born at Colchester ZooBoth parent leopards were born in 2016. Dad Crispin arrived at the zoo in April last year from the Czech Republic, and mum Esra arrived in May from Belgium, with hopes of breeding them together - which have now proved successful.

As Amur leopards are solitary cats, only pairing during breeding season, the animal care team have been introducing Crispin and Esra to one another when Esra shows signs that she is in season.

When the keepers mixed the pair, it was apparent they enjoyed each other's company during this time and the bond has grown between them since their arrival.

Amur leopards originate from the Russian Far East and north-east China, living in temperate forests. These big cats face a number of threats in the wild, as they are affected by illegal wildlife trade, climate change, habitat loss and deforestation, so this birth is very important for the species.

Other new arrivals at Colchester Zoo recently include three Amur tiger cubs, born in June, and two red panda cubs, who were born in July.

READ MORE: Adorable tiger cub trio are named - and go exploring