Welcome to Shagville
The shag population of Timaru’s port keeps expanding, with more than 1000 of the threatened birds making themselves at home.
Timaru has a new community – ‘‘Shagville’’.
More than 1000 shags, many of them ‘‘earthquake refugees’’ from Banks Peninsula, are inhabiting Timaru’s port area, and one bird expert believes the town may be the ‘‘lifeguard’’ to help the threatened species recover.
PrimePort Timaru chief executive Phil Melhopt said, ‘‘we often have to clean shag excrement off walls and equipment with water blasting’’.
‘‘We work around them, it’s only in the fringe areas of the port that they have a presence.’’
Melhopt said shag numbers appeared to have increased, but they settled in older structures and breakwaters in the port where they were less likely to be disturbed.
While they were annoying,
PrimePort Timaru recognised the shags were a protected species and rules applied as to how they were treated, he said.
The shags had only presented one operational problem, in October 2018, when they nested on a cantilever at the port which was being used as part of a $2 million project to widen the port channel.
‘‘It delayed the project as we had to wait for the fledglings to fly the coop,’’ Melhopt said.
‘‘It created a challenge but that was a one-off. They don’t nest where we’re actually working.’’
Ornithologist Andrew Crossland said in the past 18 months Timaru’s shag population had risen to over 1000 at times.
Most were spotted shags, which bred at Banks Peninsula.
‘‘The quakes hit Banks Peninsula in a massive way with a large collapse of bird nests,’’ Crossland said.
Shag numbers there had dropped from 22,000 to 8500 last year, according to counts made.
‘‘The birds began to move to other locations as alternative breeding areas.
‘‘A lot roost at the Ashburton River mouth, up to 9000 birds, and birds have discovered Timaru harbour where they are breeding in increasing numbers.
‘‘There are two species nesting in Timaru harbour, the spotted shag from Banks Peninsula, and what used to be known as the Stewart Island shag, or Otago shag, which traditionally bred between North Otago and Stewart Island.’’
A large colony of Otago shags have taken over a derelict wharf at Oamaru, Sumpter Wharf, where up to 650 nests have been counted. ‘‘The first record we have of them being this far north was in 2015 at Washdyke. They’ve been coming to Timaru harbour for the last two years.’’
Globally, Crossland said shags were endangered and numbers had dropped sharply in one of their main New Zealand habitats, the Hauraki Gulf.
He did not know how big numbers would get in Timaru.
‘‘It depends how much space they can occupy and the food they can find off Timaru and the breeding success at Banks Peninsula.
‘‘There, they bred on volcanic cliffs where there was less risk from predators, stoats and weasels. After the earthquakes, they’re now breeding in smaller colonies in tussocks and the risk has increased.
‘‘In Timaru, the predators will be rats, cats and dogs. I don’t know how successful their breeding will be there.
‘‘I do hope the Timaru people understand the spotted shags are in trouble and in decline. Timaru might be the lifeguard to help the species recover.
‘‘It’s a good thing for the South Island.’’
Crossland said he also hoped PrimePort Timaru would think about providing a habitat for them with some adjacent space away from port activities.