In the seventh in a series of articles looking at the effects of the changes in Human behaviour caused by the Covid-19 restrictions on pest species populations and behaviour, we look at the common species of seagull. 

At the tail end of March 2020, the UK was plunged into conditions none of us have seen in our lifetime. Governments around the world have limited the movement of citizens and closed non-essential businesses to the public with the goal of minimizing the spread of the Sars-Cov2 virus, now that we are in the grips of second national lockdown, we can see how well gulls fair with a protracted change in fortunes.

Seagull

In their natural habitat, seagulls are beautiful animals to watch, but they can be a nuisance around property causing harm, producing constant noise, causing mess and health risks from their droppings. They are extremely intelligent and learn behaviour from each other. In common with all other animals, they learn through a process of operant conditioning, learning that a set behaviour or action reaps a reward. In foraging behaviour this is illustrated by “tap dancing” on grass to bring worms to the surface. This behaviour is passed on to subsequent generations. In recent years, more extreme behaviours have be learnt, including “dive bombing” to cause people to jump and spill their food and stealing food directly from shops. It only takes a couple of successes for this behaviour to be learnt. Birds may also become aggressive during the breeding season if they feel threatened.

Seaside towns and villages were highly enticing for seagulls to feed their young people and raise them. In the UK, there are around 140,000 pairs of herring gulls in the breeding season and 740,000 individual birds in the winter. The great black-backed gull has 17,000 pairs, and 76,000 birds in the UK in winter, according to the RSPB. These birds require a large amount of food as they can grow to weigh up to 1.2kg.

With the restrictions to our movements through the lockdown, feeding options for gulls became very limited, particularly in the second and third months. Many nesting sites were abandoned with eggs left to chill. During lockdown there was a clear change in behaviour. Most breeding pairs had built their nests as lockdown hit. Some raised young but not vey well. Some didn’t even lay eggs this year. This poor year has been documented around the globe. In one case in Minnesota a colony of 2000 breeding pairs failed to raise a single chick to fledging.

It has been well documented that British towns faced the worst ever invasion of aggressive seagulls. Seaside resorts have brought in measures to fight off the invasion of gulls, including removing eggs, falconry, egg oiling, and bird proofing to exclude gulls. Coupled with the reductions in feeding opportunities gull numbers have dropped around the coastal holiday parks. However, gulls are opportunistic feeders and will diversify their diet. It has been reported that herring gulls have been observed taking live prey in the form of rats and pigeons. Their numbers on landfill sites and waste management site have also massively increased.

It will be interesting to see how many gulls return next year from their overwintering sites on the continent. It is likely that feeding opportunities will be equally restricted and this may have a greater impact on the population than a single failed breeding year.