The Southern Black-backed Gull.

Local Gull Cull


Vetent wish to draw attention to the Southern Black-backed Gull (SBBG) control plans currently taking place. The planned control initiative to reduce numbers of the Gull will take place on the Waimakariri River’ northern edge – opposite Intake Road, on the Selwyn side. The cull uses alpha-chloralose – which is an anaesthetic compound registered for black-backed gull control. The objective of control is to reduce numbers of the Gull as humanely as possible and with the least amount of risk to humans and other non-target species, including folk’s beloved fur friends! Alpha-chloralose bread baits will be used, and the baits, as well as poisoned gull carcasses, are toxic to domestic animals and people if eaten. Control areas will be well-signposted.

“We’d ask that our clients in the this region avoid the control areas while signs remain in place and not to take their pets into these areas,” said a Vetent spokesperson. “If your pet has been anywhere near the control area, and you notice any of these symptoms, please call us immediately as these can be signs of alpha-chloralose poisoning: seizures, muscle tremor, hyperaesthesia, hypothermia, salivation, myosis, stupor, coma and loss of body control.

The control of SBBG by Environment Canterbury is part of a regular programme that has been ongoing for the past eight years with the aim of improving the biodiversity values of the region’s precious braided rivers.

SBBG are large, predatory birds that have a significant negative impact on the braided river environment through predation, harassment and displacement of other threatened bird species, negative impacts on water quality, and risk of bird strike to overhead air traffic.

The most effective and humane way to reduce SBBG numbers in most circumstances is through alpha-chloralose control. There are some exceptions where alpha-chloralose is not accepted as the most effective method (i.e. outside of breeding season or if harm to non-target species is likely). In these cases other methods such as shotgun control can be considered, in consultation with an ornithologist.

Environment Canterbury follows a Best Practice Technical Standard for completing alpha-chloralose control in the Waimakariri River, which helps ensure the control is contained within a very small area and that risk of by-kill to other species is minimised.

The site is checked and cleared within 24 hours, including removing all uneaten baits and gull carcasses.

Warning signs are placed at entry points to the operational areas and not removed until birds have been removed from the site.

“Although alpha-chloralose bread baits and carcasses can be toxic to domestic animals or people, this is a very rare occurrence because of the targeted and contained nature of the programme. We strongly advise people to avoid the control areas while signs remain in place and to not take their pets into these areas,” the Environment Canterbury spokesperson concluded.