Endangered gulls killed
One of the season’s most important breeding colonies of a critically endangered native bird has collapsed, and experts believe a dog was to blame.
About 500 threatened blackbilled gulls, which had already survived flooding in Canterbury last week, have abandoned their nesting site in the upper Waimakariri River near Woodstock.
Now all that remains of them is a few abandoned eggs and the bodies of two dead gulls.
Black-billed gulls, or tara¯puka, are considered nationally critical – as endangered as ka¯ka¯po¯.
Environment Canterbury (ECan) braided rivers biodiversity adviser David Owen said the council’s ornithologist suspected a dog attack was responsible.
The dead birds appeared to have broken bones, and had been carried away from the colony site without being eaten, he said.
The colony had also collapsed suddenly and without warning.
‘‘‘The nesting site where the birds were found looked to be one of the most critically important nesting sites for the season, due to the number and type of species that were there.’’
While ECan could not say for certain the colony’s collapse had been caused by a dog, Owen said it was still a sad reminder of the fragility of braided river birds and the importance of being careful when out and about – ‘‘dog in tow or not’’.
‘‘It’s essential to consider how our presence might impact our native species, especially birds during their nesting season. Braided river birds nest in amongst rocks, so it’s often hard for us to see their eggs.’’
Owen said the colony had been widely supported by volunteers, with some even stationing themselves nearby to educate river users about the nests and their vulnerability.
The Department of Conservation (DOC) has restrictions in place about dogs on public conservation land to protect vulnerable wildlife, particularly during the spring and summer breeding seasons.