The poison warning sign at the beach entrance in Pacific View Drive. Photo / Talia Parker
Baited rat traps in the Pāpāmoa sand dunes have been labelled inhumane by an animal welfare expert and come under fire from local residents.
But the city council says bait stations are the most cost-effective way of controlling rodents in a large area and do not cause secondary poisoning indogs - and a local vet says the traps have been laid responsibly.
Tauranga City Council this month laid bait stations with diphacinone and brodifacoum and put up signs on some beach accessways.
The traps have been laid in an effort to protect the New Zealand dotterel during its breeding season.
SPCA science officer Christine Sumner identified the poisons as anti-coagulants, "which means they disrupt normal blood-clotting processes".
"The manner of death is to bleed out over a number of days and even weeks.
"SPCA does not consider the use of anticoagulants to be a humane method of controlling rodent populations due to the symptoms they experience such as pain, severe haemorrhage, abnormal behaviour, altered postures, breathlessness, weakness, lethargy, and weight loss, and the prolonged time to death once they have ingested the poison.
"SPCA is also concerned about the animals not targeted by these poisons but who still consume them, and animals who are indirectly poisoned after they have ingested an animal that has already been poisoned."
Sumner said the SPCA advocated using "non-rodenticide" traps that had "passed standardised welfare performance testing".
"Traps that pass this type of testing are more likely to minimise the time it takes for a trapped animal to become insensible followed by death."
Sumner said efforts to control populations when necessary "should be conducted with the utmost concern for the welfare of all animals".
A Mount Maunganui resident, who would only be known by her first name of Susan, was concerned about the traps.
"There was no consultation with ratepayers, no advanced warning for beachgoers and dog owners. Limited signage was put up on the day it happened and no warnings on the beach side of dunes either.
"The beach is not only a child's playground but a paradise for dogs and their owners. [It's] supposedly a safe environment to exercise."
She said she believed residents "would likely prefer trapping methods" to poison bait, "which would mean it was more specific to the rodents and the dead carcasses would be contained".
A Mount Maunganui resident and dog owner, who spoke on condition of anonymity, said she was told by the council the traps were permanent.
She said there was "no such thing as a secure trap where other animals are concerned".
In her opinion: "That it was the start of the school holidays was spectacularly dumb ... [kids] might be curious about a box, a parent could be a long way away."
She believed the community should have been consulted to see if it would prefer alternative trapping methods.
But Tauranga City Council manager of parks and recreation Warren Aitken said the type of bait used in the traps "does not cause secondary poisoning, meaning that if a dog ate a rodent that died from eating the bait, it would not poison the dog".
He said rats were one of the biggest predators of the New Zealand dotterel, which is nearing its breeding season.
"Rats eat the eggs and chicks of rare birds. They're an undesirable species, especially in coastal reserves.
"Tauranga City Council was approached by Forest & Bird New Zealand regarding the protection of the dotterel in the Pāpāmoa Beach Rd area. Bait stations were put in place on Thursday, July 7, in response to this request.
"We are not required to consult the public on general maintenance. Signage is in place to warn people when there are bait stations in the area."
He said the bait stations are "small, locked plastic boxes that have a tunnel only big enough to allow rats to enter and the bait is secured inside with wire".
"These types of bait stations are the most cost-effective way of controlling rodents in a large area.
"Bait stations are located away from tracks and public walkways. We encourage people to keep to the walkways provided to help conserve the dunes and for dog owners to manage their dog's behaviour responsibly."
Tony Austwick, a veterinarian at the Bayfair Vets clinic, said it seemed the council had taken measures to protect dogs from the bait.
"The council looks like it's laid [the poison] in tamper-proof bait stations, which is really good.
"It looks to me ... that they've [the council] actually shown pictures of bait stations and have been very responsible in trying to protect dogs and cats, and dogs in particular, from trying to get access directly to the bait."
Austwick said the biggest problem for pets was people laying their own bait at home, which poisons dogs "far too often".
He urged the public to "always use a bait station, and even then keep the bait station out of anywhere that a dog could get it".
Predator Free BOP co-ordinator Luke Judd said rats in sand dunes posed a significant threat to ground-nesting birds, which evolution had not trained to be wary of introduced pests.
While Judd did not know exactly how significant the number of rats was on the dunes, he said rats were "a growing problem", especially as more houses were built.
"Near [Pāpāmoa], there's just a lot of houses where people chuck food on the lawn or chuck it over the fence ... rodents will go wherever the food is."
While Predator Free BOP exclusively used "kill traps", which don't use poison bait, Judd said he could understand why the council was using poison stations. He said they used kill traps so "there's no toxins entering the environment — the downside of that is it's very ... expensive [in time and staff]".
The symptoms of rat-bait poisoning in pets include lethargy, pain, pale and/or bleeding gums coughing, and coughing up blood.