Push for cat controls after tern chicks eaten
A cat devouring nationally endangered bird chicks has prompted a river group to call for a council bylaw to tackle the problem.
The Ashley Rakahuri Rivercare Group in North Canterbury is pushing for Waimakariri District Council to introduce a bylaw to require owners to register, microchip, desex their cats and to limit the number of cats allowed per household.
The group presented a letter and photographs of cats attacking the vulnerable nests to Waimakariri mayor Dan Gordon. ‘‘We do this on behalf of all river inhabitants, particularly braided river birds, and to prevent continuing cruelty to cats which are often abandoned to lead a precarious existence in the wild,’’ the letter said.
The group’s operations manager Grant Davey said cats were the secondworst predator of endangered braided river birds on the river, Norway rats being the worst.
Davey said he had suspected for many years that cats were a major threat to the river birds. ‘‘In the last couple of years we are really starting to see evidence of this. We have quite a few motion detection cameras out on the river and have started to see cats at nests eating blackfronted tern chicks. One camera had also captured a cat carrying an adult blackfronted tern.
The cats were also eating young fledglings who had left the nest, but this was harder to capture evidence of, he said.
Davey had been conducting a trial on baits for traps and over three months he saw cats 79 times – which was more than any other predator. The group sets traps for rats and stoats, but the traps do not capture cats, he said.
He said he estimated he saw the same 14 cats, five of whom were likely domestic. ‘‘Houses are so close to the river domestic cats are an utter inevitability. The cat that ate the black-fronted tern chicks I’m almost certain was crossing the river at night,’’ he said.
He also thought unwanted cats were being abandoned at SH1 near the Ashley River bridge.
Davey believed a limit on household cats and owners making sure cats were desexed and kept in at night would make a difference to the birds as well as the feral cat population.
The black-fronted terns had a fledgling survival rate of only one bird per 10 nests over the past four years and there were only between 5000-10,000 left in New Zealand. Controls would add a layer of protection for endangered birds, giving the various species a chance to breed successfully.
‘‘Bylaws to control cats will, in the long term, lead to fewer cats being dumped and breeding in the wild. We know from experience in Canterbury that feral cat populations are huge, and not easily controlled,’’ he said.
The group wanted the Waimakariri District Council to go further than the Selwyn District Council, which has a bylaw requiring registration and microchipping of cats.
Group member Mike Hamblin said New Zealand needed to have a nationwide discussion on cat control as animal rescue organisations were overrun and birds were being killed. ‘‘I am an animal lover. I value the benefit of companion pets, but we have to support councils to make decisions that will control feral cat populations,’’ he said.
He said if all pet cats were microchipped the group could use live traps and return pets to their owners and educate them to not allow their cats to roam at night.
He understood that 20 New Zealand councils had bylaws about cat ownership and some had limits of three cats per household. Gordon had told the group he was willing to look into it, Hamblin said.
The council and Gordon were approached for comment.