Threatened Black-Footed Cats Face Alarming Inbreeding and Disease Risk Due to Habitat Fragmentation

Black-footed cats (Felis nigripes), already a threatened species, are now facing an alarming increase in inbreeding, which poses a significant risk of a rare and deadly disease. These tiny but deadly felines, native to Africa and known for their nocturnal desert lifestyle, are among the deadliest cats on Earth when it comes to kill rates.

Unfortunately, their survival is increasingly threatened by habitat loss and human persecution, often mistaken for jackals. As a result, they are listed as "vulnerable" on the International Union for Conservation of Nature Red List of Threatened Species. A recently published study in the journal PNAS, dated January 2, 2024, reveals that black-footed cats may be experiencing genetic isolation and inbreeding.

Scientists conducted genome sequencing on ten black-footed cats and combined this data with previously available genomic information. Their analysis uncovered evidence of recent inbreeding events, possibly exacerbated by habitat fragmentation caused by projects like roads or farms. Such fragmentation disrupts natural habitats and separates potential breeding partners within the population.

What makes this inbreeding particularly concerning is its link to a higher susceptibility to amyloidosis, a rare disease responsible for approximately 70% of deaths among captive black-footed cats. Amyloidosis leads to protein build-up in vital organs, including the kidneys, and can be fatal. In addition to kidney failure, inflammation resulting from amyloidosis can affect the cats' auditory canals, which are especially sensitive due to the bony structures taking up 25% of their skull.

The study also identified two potentially harmful gene variants associated with amyloidosis development in black-footed cats. Inbreeding increases the likelihood of offspring inheriting these same gene variants from both parents due to decreased genetic diversity in the population. Many harmful mutations are recessive, meaning they only manifest if both parents carry them, posing a higher risk if the parents are related.

Researchers described the levels of inbreeding among black-footed cats as "alarming" and attributed this phenomenon to "severe genetic isolation" stemming from habitat fragmentation.

Nadine Lamberski, chief conservationist at San Diego Zoo, emphasized the importance of further research on the conservation risks faced by small feline species. She noted the limited attention and funding allocated to these species compared to larger carnivores like cheetahs, lions, and tigers.

While she acknowledged that the study's sample size might not fully capture the extent of the issue, Lamberski highlighted the possibility that inbreeding and reduced genetic diversity have become more prominent risks as black-footed cat populations have declined over time. Small carnivores play unique roles in ecosystems, making their conservation a critical aspect of overall biodiversity preservation.