How many feral cats in Australia

National feral cat population estimate

  • Feral cats in the bush – 1.4 million after continent-wide droughts and 5.6 million after extensive wet periods
  • Feral cats in urban areas – 0.7 million
  • The overall estimate of Australia’s feral cat population (in natural and highly modified environments) – Between 2.1 and 6.3 million
  • In just over 200 years, feral cats have colonised all of mainland Australia and most of its large islands

Source: Legge, S. et al. (2017). Enumerating a continental-scale threat: How many feral cats are in Australia? Biological Conservation, Vol. 206, pp.293-303

 

Cat origins

Domestic cats are descended from the African wildcat Felis lybica. They were domesticated in Egypt and the Middle East around 4000 years ago, and have since been extensively moved around the world by people. They now occur on all continents except Antarctica, and on many of the world’s islands.

The domestic cat’s scientific name is Felis catus. There have been many categorisations for domesticcats, relating to their lifestyle, or the extent to which they are socialised, owned and cared for. However, the simplest categorisation is ‘pet cat’  for cats that live  in  a  household and are owned and cared for by people and ‘feral cat’ for everything else. Feral cats can live in  our towns and cities as well as in  remote areas of  the  Australian bush. Feral cats and pet cats are exactly the same species.

Image by Joanne Heathcote

Cats in Australia

Domestic cats were introduced to Australia with the First Fleet in 1788, with many subsequent introductions around the mainland and to many Australian islands. Cats spread rapidly across Australia: historical records and genetic analyses show that cats colonised the entire continent (7.7 million km2) within 70 years.

Cats now occur in all habitats, from alpine areas in south-eastern

Australia to the arid deserts of central Australia. They cover more of Australia and occupy more habitats than all other introduced mammals, such as foxes and rabbits. Cats also occur on nearly 100 Australian islands, including most of the largest islands. They are present on over 92% of Australia’s combined island area.

We estimate that the cat-free area in Australia comprises only around 8000 km2 – about 0.1% of the Australian land mass. These cat- free areas are (small) havens for the many threatened species for

which cats (and foxes) are the main cause of decline and endangerment. These havens are either islands or purposefully designed and established fenced areas on the mainland.

Islands

Cats never made it to some Australian islands, and cat populations that managed to establish on 25 islands were later eradicated. Over 590 islands (covering 5,539 km2) are known to be cat-free; the real number is probably much higher but most of these potentially cat-free islands are small, and would not add much in terms of total island area.

Fenced exclosures

Over recent decades, cats have also been eliminated from 28 fenced exclosures (covering 594 km2) on the Australian mainland, established for the protection of predator-susceptible threatened mammal species.

How many cats are there in Australia?

There are 3.8 million pet cats in Australia.

The feral cat population in our towns and cities is estimated at 0.7 million, but it could be as high as 2.5 million. Towns and cities support a high density of feral cats, including cat ‘colonies’ at sites such as rubbish tips and skips, or intensive farms that offer abundant food sources.

Based on extrapolation and modelling from studies which have estimated cat densities at about 100 locations spaced across Australia, the feral cat population in the bush is estimated at 2.1 million, but fluctuates between 1.4 million in dry-average years to 5.6 million after widespread and extensive rainfall events across arid Australia. These rainfall events cause rapid increases in prey populations (including native rodents), and the cat population increases quickly in response to the resource boom. The average density of feral cats in the bush across the mainland is 0.27 cats/km2, with that average fluctuating between 0.2 and 0.7 cats/km2 depending on patterns of widespread rainfall.

The density of feral cats is higher on islands, especially smaller islands, which often have abundant  food  resources for cats, including seabird colonies.

 

How to reference this page:

Centre for Invasive Species Solutions (2023) How many feral cats in Australia. PestSmart website. https://pestsmart.org.au/toolkit-resource/feral-cats-in-australia-2 accessed 08-10-2024