When it comes to fighting New York’s notoriously bold city rats, setting the cats on them might not be as good a solution as you’d expect.
For the first time, researchers have quantified the effects of feral cats in an area overrun with large rodents, tracking the interactions between predator and prey at a New York City waste recycling center.
And, they found the cats weren’t very effective at curbing the rat population.
Over the course of 79 days, the cats only made three kill attempts – one of which ended unsuccessfully because the cat lost interest in its target.
When it comes to fighting New York’s notoriously bold city rats, setting the cats on them might not be as good a solution as you’d expect. File photo
‘New Yorkers often boats their rats “aren’t afraid of anything” and are the “size of a cat,” Parsons said.
‘Yet cats are commonly released to control this relatively large, defensive and potentially dangerous prey.’
The new research provides evidence that there are few benefits to releasing cats into the urban ecosystem.
If anything, the researchers say doing so will do more harm than good, as cats prefer smaller prey such as birds and can be a threat to local wildlife.
Rats, on the other hand, are larger and much better able to defend themselves.
‘Like any prey, rats overestimate the risks of predation,’ said lead researcher Dr. Michael H. Parsons.
‘In the presence of cats, they adjust their behaviour to make themselves less apparent and spend more time in burrows.
‘This raises questions about whether releasing cats in the city to control rats is worth the risks cats pose to wildlife.’
Researchers studying a colony of over 100 rats in an NYC waste center were presented with an opportunity when a group of feral cats invaded the space as well.
The rats had all been microchipped, and once the cats moved in, the researchers installed motion-capture cameras.
This allowed them to observe the interactions between the two in a natural setting.
‘Until now, no one has provided good data on the number of city rats killed by cats,’ said co-author Michael A Deutsch, from Arrow Exterminating Company Inc.
‘But the data have been very clear as to the effect of cats on native wildlife.’
For the first time, researchers have quantified the effects of feral cats in an area overrun with large rodents, tracking the interactions between predator and prey at a New York City waste recycling center. File photo
‘We wanted to know whether the number of cats present would influence the number of rats observed, and vice versa,’ Parsons said.
‘We were also interested whether the presence of cats had any effect on eight common rat behaviors or their direction of movement.’
Over 79 days, the researchers captured 306 videos, revealing as many as three cats active beside the rats every day.
But in all this time, there were only 20 stalking events, and two successful kills – both of which took place when the cats encountered a rat in hiding.
The rats did, however, spend less time out in the open when the cats were around.
‘The presence of cats resulted in fewer rat sightings on the same or following day, while the presence of humans did not affect rat sightings,’ says Parsons.
‘We already knew the average weight of the rats was 330g, much more than a typical 15g bird or 30g mouse.
DO CATS RULE THE HOUSEHOLD? STUDY SHOWS THEY BULLY DOGS
In a study of homes with both pets, more than half of owners say their cat has lashed out threateningly at their dog.
Yet fewer than one in five have seen their dog menace their cat.
Some 56.5 per cent said their cat had threatened their dog, compared with 18 per cent whose dog had threatened the cat.
And although cats are typically smaller than dogs, they still manage to inflict injury on their domestic rivals. Almost a tenth of owners reported their cat had injured the dog, but fewer than 1 per cent said their dog had harmed the cat.
The findings come from a study of almost 750 owners, who overwhelmingly believe cat is king.
While dogs and cats can live together amicably, they said, it is rarely a ‘close relationship’ – and whether they get on at all is mainly up to the cat. Cats that are frequently uncomfortable around dogs were less likely to form an amicable relationship, they added.
Study co-author Dr Sophie Hall, of the School of Life Sciences at the University of Lincoln, said: ‘On the face of it, these results suggest that the cat is the kingpin in a household with dogs. They are the princess and the dog is lower down in the hierarchy.
‘It may be that cats’ threatening acts are more obvious to owners, as they hiss or strike out with their paws at a dog.
‘But it may also be the case that cats are less domesticated in their behaviours. It is important to note that these findings are the owners’ perceptions of their pets’ relationships, but it seems that the cat has to be happy and content, rather than the dog, for them to live happily together.’
The study, published in the Journal of Veterinary Behaviour, said that cats and dogs may get along better if the cat is younger when they begin sharing a space.
‘As such, we expected a low predation rate on the rats – and our study confirmed this.’
According to the researchers, the findings don’t mean cats won’t ever hunt rats if given the opportunity.
But, conditions must be right or they’re more likely to go for an easier target.
‘The cat must be hungry, have no alternative less-risky food source, and usually needs the element of surprise,’ Deutsch said.
‘People see fewer rats and assume it’s because the cats have killed them – whereas it’s actually due to the rats changing their behaviour,’ Parsons said.
‘The results of our study suggests the benefits of releasing cats are far outweighed by the risks to wildlife.’