Whilst our native wildcats are not doing well at the moment our native cats are running wild. Domestic cats are currently the UK’s top predator, killing around 275 million animals every year. It seems you can take the cat out of the wild but not vice versa.
Currently the UK has around 8 million pet cats, whether you love them or hate them there is no denying that they do their fair share of killing. But is this killing doing any damage to the wildlife?
Generally the direct predation is not too damaging and the consensus is that cats will not damage healthy populations of animals. However, it is believed that they may be doing damage to the rarer species in the UK, species already under threat that are struggling to bounce back. It is thought, in terms of bird life, that cats primarily take house sparrows, blue tits, blackbirds and starlings. Now of those four, the sparrows and the starlings are not doing particularly well. Although there are around 5 million sparrows the population has declined by around 70% in the past 30 years. Likewise the starling has declined dramatically and now there are only around 800,000. Now we certainly can’t blame this solely on cats. If you break it down cats actually take around four times as many mammals as birds, 200 million versus 50 million. That being said direct predation is still a factor in the decline.
However cats alsohave indirect effects on birds which cannot be easily quantified.
Studies have shown that the presence of a cat near nesting birds causes them to panic, make alarm calls and show defensive behaviours. This was expected but it was found that during this time that food delivery by parent birds to the nest was reduced by just over one third. This in turn affects the survival rate of the chicks, though it is hard to say by how much. Furthermore, one quarter of birds that displayed defensive behaviour were found to have had their nests predated upon in less than 24 hours after seeing a cat. This is thought to be due to crows and magpies hearing the alarm calls and working out that there was a nest nearby. Unsurprisingly the study found that cat living in homes backing on to woodland or countryside were particularly bad for wildlife. The RSPB admits there is not enough evidence to say that cats are significantly damaging bird life however with species like starlings now critically endangered, protection is important. The full impact on mammals species in still unclear though it has been found that cats are not good at hunting rats, researchers believe this is due to the strength and ferocity of a rat compared to a mouse or a vole.
Most cat owners would not be happy with keeping their cat indoors as shown by a recent study, which also suggested that most owners in the UK are unaware or in denial about how much damage their cat actually does. In contrast “house cats” are common and make up 50-60% of cats in the United States. The British Mammal Society argues that cats should not be let out at night to try and limit their hunting but as the study suggests, most owners won’t do that. In reality there are many things you can do to reduce your cats hunting, I’ll put the links below but it is really fairly simple stuff. Putting bird feeders and nest boxes high up and not near places cats can hide or something like using a bird table and not putting food on the ground is an option. A full list can found below and may be useful if you are trying to deter someone else’s cat from scaring the birds in your garden.