Fish & Game central South Island senior officer Hamish Stevens said that even with a special two-week shooting season at the beginning of February the shelduck would certainly be "in the hunters’ sights" in the first week of May when the official shooting season started.
With shooters able to bag up to 25 shelduck a day in season the limit was fairly liberal.
Mr Stevens said the brief February season had been to give cropping landowners respite by helping to disperse game birds, and to give shooters a window of opportunity.
"We know that post-moult ducks can have an impact on unharvested crops and green-feed."
Mr Stevens said Fish & Game would this week aerially survey game bird populations across the central plains region to just south of Oamaru.
This would mainly focus on dabbling duck species but also shelduck, with those numbers expected to to be stable overall.
Mr Stevens said while the species seemed quite noticeable now this did not necessarily reflect an upward population trend.
"What’s happening now is that the birds are coming out of their moult period where they congregated on water bodies. They’re hungry."
This lined up with the post-harvest period and birds could be seen resting on crop stubble picking up what was left on the ground post-harvest.
Mr Stevens said the shelduck population in the central South Island region seemed to be "relatively stable".
Paradise shelduck were managed by Fish & Game as a region-wide population all the way from south of Oamaru to North Canterbury.
This included regular monitoring of sites on the North Otago border: the Wainono Lagoon between the Hook and Waihao river mouths, and in the Hakataramea Valley.
"In terms of the sites we monitor, they’re not escalating."
While the shelduck used to be considered a high-country bird, and a rarity on the plains, this had changed in line with land development, Mr Stevens said.
"They certainly take advantage of the habitat available ...
"We have noticed ... with the advent of storage ponds, they are utilising those habitats for moulting sites.
"Previously they would go to the high country. Now they can utilise these [pond] sites."
Mr Stevens said Fish & Game was looking to review its survey methodology in order to get better randomised sampling.
