If you are a regular on Dunbar High Street or planning to visit don’t forget the brolly! It is raining today, but at other times you are in for a different sort of shower. For the Herring Gulls (aka Larus argentatus) are back to regale us with their raucus call and much more. By April / May in most years the High Street, parked cars and windows are already getting decorated with multi-colored guano, birds seem to have a perpetual diarrhea. If you are lucky enough, you may get hit from on high by the foul smelling stuff.
If you live on and around the High Street, and there is a nest or more nearby, expect to have to wash your car, windows and patios/decks several times a week at least, even daily if you’re on a flight path.
Nesting starts late April laying early / mid May and the gestation period is 3 weeks. Chicks generally fledge in August and then take three or four years to reach maturity and breed. Herring gulls live for about 20 years and are very faithful to their nest sites.
Dunbar has a healthy number of breeding pairs, a colony of around 50 strong, apparently, nesting on flat sections of roofs and tall chimney stacks. They seem to prefer very exposed positions – with good visibility. But why urban areas? And why Dunbar? Often it is said there is an abundant food supply in urban areas in gardens, street litter and open bags/bins, but a more convincing explanation is the presence of safe nesting sites and a decline of food sources at sea (e.g. by-catch discards) and inland (e.g. open waste disposal). I am told that the population in Dunbar is quite recent (not known to nest before the 1970s?). I am inclined to think that the measures to displace gulls from the Isle of May could have something to do with it (about the 1970s), along with changes in the management of landfill at the nearby site, now owned by Viridor. Arguably the increase in lighting in the town and harbour – 24/7 floodlighting – creates an ideal extension of feeding times too, which, a bit like our convenience economy is actually pretty inconvenient for shopkeepers, residents and visitors alike.
Despite the increases in urban areas (Dunbar is not unique), the total herring gull population is now at its lowest level since monitoring began in the late 60s, though some authorities, like John Coulson, disagree with the counting method. The overall decline is not well understood and different factors may be at play, which combined make a difference. Ground nesting gulls are more prone to predation than before, with active gamekeeping reduced in many areas. Botulism is another possible cause (landfill sites may be the source of the Clostridium botulinum bacterium), on top of decreases in the availability of food scavenged from landfill sites and reductions in discards from fisheries already mentioned.
The current number of urban nesting gulls in Scotland or the UK is not known exactly, but one study I read from the 80s calculated that 14% were now breeding in urban areas.
So what to do? Well the problem is not exactly easy. All birds in the UK have varying degrees of protection, and wait for this the Herring Gull is also on endangered species lists. It is Red listed in Birds of Conservation Concern 3 (2009 update) and a UK Biodiversity Action Plan – priority species.
Under licence it is permissible to regulate the Herring Gulls individually or at subpopulation level and many Local Authorities have an active programme of control. More rarely it is possible to intervene to remove them (e.g. if the are endangering domestic animals and humans). Culling is non-invasive, usually performed by preventing eggs from reaching maturity. This stops the Gulls from re-laying in the same year (hopefully) and if carried out twice in the season likely to be very effective. I don’t think 2 treatments have ever been applied in Dunbar and we don’t know much about the effectiveness of the treatments, as this is not disclosed publicly.
However, if treatment is missed, e.g. the weather doesn’t permit or your Council decides it no longer has a budget, we’ll notice immediately as the breeding activity and noise will be heightened from hatching to fledging. When the young start to fly they get vocal encouragement from the family group and this is very entertaining to witness. The big danger is some 3-4 years later, when the young are of breeding age.
East Lothian Council’s programme used to be carefully monitored and statistics were gathered and sent to Sottish Natural Heritage, from whom they received a control licence, but we don’t know more than this.
Now more than ever they need our support, the gulls to find suitable alternative nesting places and the local council to realise that the costs of inaction (borne by householders, visitors and shopkeepers) are actually greater than the small costs of regular annual control.
It is doubtful we will ever love Herring Gulls as much as we love our Kittiwakes (a much prettier gull, but equally noisy and messy bird), but we can all help to reduce their impact.
What would a seaside town be without its sea gulls?