London Zoo lion inbreeding causing 'high levels of cub deaths', finds report

Report found 39 of 57 cubs born between 2007 and 2009 died within four months of birth

Asian lions, like those pictured in the wild in Sasan Gir, Gujarat, were brought to Europe in the 1990s – but the gene pool is very limited (ZSL)

London Zoo’s lion population could be “compromised” by decades of inbreeding resulting in high levels of cub mortality, a new report has found.

The lions at the world famous zoo are descended from nine “founders” brought to Europe from India in the 1990s, as part of the European Endangered Species Programme (EEP).

London Zoo received two pairs, Zürich Zoologischer Garten took one pair, and Helsinki Zoo received one male and two females.

The programme was established to manage a captive population of the threatened Asian lions within European zoos.

But researchers have warned a lack of diversity in the mating pool is causing high levels of stillbirths and infant mortality, risking the species’ existence in Europe.

The report in the journal of Mammalian Biology found 39 of 57 lion cubs born between 2007 and 2009 died within four months of birth.

As many as 35 of the cubs died within 20 days, three died within two months and one was put down at four months old.

The authors also found over 50 per cent of the total historical captive population died within 30 days of birth.

“The ‘European Studbook for the Asian Lion’ shows that the EEP founder population contains individuals from matings of full and half siblings, including all female founders,” the authors wrote in October 2017.

They also issued an urgent warning to introduce new genotypes from India to combat the problem.

“The future of the Asian lion EEP is compromised by lack of genetic variation and high levels of inbreeding, which can only be alleviated by importing further individuals with different genotypes from India,” the authors wrote.

A separate report, published in January 2017, found 270 of 392 animals died between 2000 and 2014, 80 per cent of which were under one year old. Cause of death was obtained for 133 animals, and congenital defects were to blame for 9 per cent of the fatalities.

Malcolm Fitzpatrick, curator of Mammals for ZSL, said: “We welcome this study and the advancements in science that will assist in the conservation breeding of Asiatic lions and other endangered species in zoos throughout Europe and India, and which may also assist with management of isolated populations in the wild that themselves have limited genetic variability.

“By taking a holistic approach that combines conservation breeding of Asiatic lions with collaborative work alongside local partners to train wildlife rangers, promote local understanding and encourage the latest wildlife healthcare practices on the ground in India, we’re confident ZSL is doing its bit to encourage the ongoing recovery of these magnificent animals in their remaining stronghold.”