Reef heron declining to a critical degree, survey shows

While some of our precious native coastal birds are thriving in the Wellington region, a survey of 460 kilometres of coastline highlights how some species, including the reef heron, are continuing to decline to a critical degree.

Greater Wellington Regional Council have recently gathered the results of a region-wide coastal bird survey carried out in 2017-18 which shows patterns in the distribution and abundance of coastal birds in our region.

Greater Wellington Senior Environmental Scientist Roger Uys says among the declining birds surveyed were reef heron, whose conservation status is Nationally Endangered and Regionally Critical.   

"Only 15 adult reef herons were counted during this survey, and were sparsely but widely distributed throughout the region's coastline. This result confirms that reef heron are now one of our region's rarest breeding bird species."

The future of reef heron may be found off the south coast of Wellington in a small island, which is proving to be a refuge for these rare birds.

This survey confirmed a pair bred successfully on Taputeranga Island, during the summer of 2018/2019, as they have in previous years at this site.

Six of the 14 sites where reef herons were encountered are identified as "coastal habitats of significance" and are listed under Greater Wellington's Natural Resources Plan.

Sixty-nine bird species were identified during the survey, 51 of which are native or endemic to New Zealand with 25 of those ranked as either Nationally Threatened or At Risk under the New Zealand Threat Classification System. 

The survey, mandated by Maritime New Zealand, saw Wildlife Management International's Nikki MacArthur and Samantha Ray walk the region's coastline. With the help of the Department of Conservation and the Greater Wellington Harbours Team, surveys were also done around the off-shore islands.

There are multiple factors that could be affecting bird populations, Roger explains. 

"This could be down to a combination of habitat loss through coastal development, predation by pest animals, disruption by uncontrolled use from people, vehicles and dogs, and declines in food stocks."

Greater Wellington Environment Committee Chair Penny Gaylor says there are some simple things people could do to help prevent the loss of these precious birds.

"This includes not driving on beaches in significant bird areas, and supporting predator control across the region.

"The report provides Council with an abundance of valuable information and will now be used to review the schedule of Coastal Habitats of Significance for Indigenous Birds in the Natural Resources Plan, as well as to plan and prepare for the risk of marine oil spill," Cr Gaylor says.

The survey has provided a better idea of sensitive areas along the coastline and if there is a significant oil spill, Council will know what sort of wildlife is in each area and where the biggest risks are.

Roger says the survey did not pick up on penguin numbers so that is now his next focus.

"We are working with local penguin experts and the Department of Conservation to try identify where penguins occur in the region. There are potentially 700 to 1000 penguins around our coastline and we would like to get a better idea of their location and numbers."