Wanted - information on best methods for black-backed gull control

[schmechf]

What are the best methods of southern black-backed gull control and what are the main issues with control methods (and how are they resolved)?

[Dave Houston]

Apparently controlling them is not the answer - the Dunedin City Council have decided to educate their gulls instead using a bit of "tough love".

http://www.odt.co.nz/your-town/dunedin/69221/some-poisoned-gulls-be-resuscitated039

[Brian Thomson]

I understand that some black-backed gull control operations involve the use of standard grade vegetable oil to coat the gull eggs. The oiling effectily suffocates the egg depriving it of oxygen which kills the developing embryo. It keeps the egg in better condition for longer compared to injecting poison. This method thereby increases the time before egg relaying occurs, which in turn reduces productivity.

Timing of the control is best in November but each season needs to be monitored to ensure eggs are treated before they get a chance to hatch.

[Dave Houston]

Another Otago Daily Times article about gull control in a urban environment that's worth reading.

http://www.odt.co.nz/your-town/dunedin/76781/karoro-bird-a-mire

[Bruce McKinlay]

Egg pricking can be as effective as anything else in reducing reproductive success. However this won't reduce numbers for the  number of years it takes the old birds to start dying. 

The reason the DCC got into trouble is that they could not explain what they were trying to achieve.  (This is mixed in with a storm over parking and the stadium so all the motives are a bit mixed).

The main method with current control methods for gulls is that they seem to be applied at one site when black backed gulls can move large distances and so negate small scale control.  Being clear about whats the effective population you are dealing with is essential.

Bruce

[afairweather]

Technical Grade Alphachloralose is registered for black-back gull control.

Key points re its use are:
You need to be an approved handler to use technical grade alphachloralose;
It can only be mixed with maragaine and applied to bread baits;
Baiting needs to occur in the evening when temperatures are cool;
It is best used around breeding colonies/or roosts where birds are aggregated;
You need to pick up remaining baits and carcasses very early the morning after the baiting;
You still need to humanely kill any chicks and eggs; &
Birds can fly considerable distances before dying.