Three Mallard ducks were euthanized after being found preying on Pūteketeke chicks in Canterbury's Mackenzie basin. The Department of Conservation rangers were shocked when a person sent in photos of the ducks hunting and killing freshly hatched native Pūteketeke (Australasian crested grebe) chicks next to Lake Alexandrina, south of Lake Tekapo. The Pūteketeke gained international attention in 2023 when comedian John Oliver successfully campaigned for it to win the Forest and Bird's Bird of the Century crown. In a press release, principal biodiversity ranger Dean Nelson said staff were horrified to see graphic photos of the chicks being eaten alive, as it was unusual for ducks to prey on other birds. "Mallard ducks usually eat plant material, with a little bit of protein from insects and snails during the breeding season," he said. "It was shocking to see them eating Pūteketeke chicks. We went out there straight away and I observed three mallard ducks in the outlet creek where the grebe nests are." Nelson said the ducks were 'actively scoping out the Pūteketeke nests to see if they had chicks'. The adult Pūteketeke didn't see the danger as they don't perceive the ducks as a threat. Duck behavior of this nature was unknown to Department of Conservation experts, with further concern it could spread, as ducks learned from each other, Nelson said. "There was a case which was referenced in a research paper from a Cambridge University scientist describing how a group of mallard ducks were attacking and eating the chicks of two common bird species in Romania in 2017. It claimed this was a world first and the ducks may have been searching for a source of protein before laying eggs and nesting," he said. The person who raised concerns did the right thing by calling the department and taking photos as evidence, Nelson said. "This is a great example of people taking action for nature and looking out for our vulnerable species. While some people think the Pūteketeke is introduced because of its name, the reality is they're native and are classed as nationally vulnerable," he said. "We want the public to be really engaged with nature. People can be our eyes and ears out 'naturing' and that's fantastic for us, as our rangers can't be everywhere." Campers and boaties around Canterbury's popular Lake Benmore shoreline were asked to look out for Pūteketeke over the summer period last December following reports of nests being disturbed at the Ōhau C campground. Many nests neighbored the boat ramp and spread out around the lake shore. The Pūteketeke colony had 40 to 50 nests annually for the last five breeding seasons and birds had raised their young much later than usual in the outlet creek next to Lake Alexandrina. DOC staff caught the three ducks in question with nets and removed them from the site and humanely euthanized them. Staff were also heading out again on Wednesday to check no other mallard ducks had repeated the behavior.
