Cat population part two

The Southampton cat population study led to a major rethink about tackling the problem of the number of cats coming into rescue. 

I can remember the first wave of projects, about seven years ago, when branches tried to adopt a scientific approach, based on the study's figures for the percentage of neutered cats needed for the population to be in balance. Ideally, this involved selecting areas which experience had shown were a frequent source of incoming cats; surveying local cat owners to find the percentage of un-neutered females and following up with a campaign to offer vouchers for spay/neuter in areas where the percentage of un-neutered cats was higher than needed to produce just enough kittens to replace cats dying from natural causes. 

This sounded wonderful, but in practice was so labour-intensive that hardly anyone actually managed to follow the whole protocol.

The second wave was less scientifically ambitious and just involved the branch identifying areas tending to generate incoming cats and targeting offers of neutering vouchers to those areas. 

The third wave evolved into the current series of Community Animal Action Weeks, which have been so successful and useful on many fronts, not just cat numbers, that they are probably the final, optimised version. 

The aim of Community Animal Action Week is to help pet owners by providing free animal care advice and discounted microchipping. Neutering vouchers will also be provided.

Local RSPCA officers will team up with dog wardens and police community support officers to visit as many homes in the selected areas as possible. The service is free, but anyone receiving help is welcome to make a small donation towards the charity's costs.

An additional bonus of the Animal Action Weeks is the way they give Inspectors, ACOs and volunteers a unique chance to work together as a team on something positive, rather than continual "fire-fighting" and to get away from the "us and them" view of the general public. Several people I know who participated commented that, even on supposedly "sink" estates, the vast majority of pet owners want to do the right thing and do look after their animals.

Cat population

Two interesting science articles about regulation of the domestic cat population size, tip Saving Pets.

"Each cat-owning household kept 1.3 cats on average, with the majority keeping one (75.8% households) or two (18.7%). For the 260 cats, the mean age was 7.1 years, the median 6 years, with a range of 3 months to 22 years. There were significantly more female (143; 55%) than male cats (117; 45%). Only seven cats (2.7%) were sexually entire, and these were all ≤6 years. Crossbred cats outnumbered pedigree cats by a ratio of 3.3:1." (Demographics and husbandry of pet cats living in Sydney, Australia: results of cross-sectional survey of pet ownership doi:10.1016/j.jfms.2008.06.010 )

"Recently, neutering of domestic cats has been encouraged by veterinary surgeons and rescue organisations as a means of population control for both the pet and feral populations. This is likely to have profound effects on cat population dynamics (and population genetics). In an attempt to quantify this, we have carried out population studies, by means of door-to-door surveys in Southampton and the surrounding area. The aims were to quantify levels of neutering, and investigate the recent reproductive status of the cat population.

The most comprehensive of these surveys was carried out in a 50 ha area in the Shirley area of Southampton (UK). Householders were interviewed from 949 (80.8%) of the 1175 residences in the area. This revealed a population of 315 cats, of which 21 were pedigrees (and were excluded from further analysis) and 294 were mongrels. Overall neutering rates were very high: 96.8% of adult males and 98.7% of adult females were neutered. The oldest cats in the survey had been born 18 years previously, so it was possible to examine trends in neutering over this time period. However, many females were allowed to reproduce before being neutered, so a more informative analysis came from relating lifetime fecundity (mediated by neutering) to year of birth. Mean lifetime fecundity could be calculated for each cohort where all the females had ultimately been neutered. The regression (Fig. 1) shows a dramatic decline in the mean number of litters born per female, from over 0.6 in 1978 to 0.12 in 1991–1992. With a measured median litter size of 4, 0.5 litters/female are needed to keep the population size constant; increasing neutering has meant that the cats in the Shirley survey area fell below this level of fecundity in the early 1980s. In 1994, owned cats in the area could only produce sufficient kittens to maintain the population at approximately 25% of its present level."

(Feral cats: their role in the population dynamics of Felis catus doi:10.1016/S0168-1591(99)00086-6)

So, a combination of education and help with costs where needed can prevent pet over-population and the need to put down healthy animals.