larus argentus | everyday nature trails

Tags

colwyn bay beach, herring gull, herring gull feeding behaviour, herring gull juveniles begging for food, larus argentus

Walking along the sea shore the other day I came across a Herring Gull in the process of eating a fish. I have no idea what species of fish it was, all I can say is that it was a flat fish and either whole or almost-whole, either way, large enough for me to be amazed that a bird could even attempt swallow it.

17/9/11-The gull with most of the fish in its gullet

17/9/11- It was not going down easily, so it had to come back up again

17/9/11-A second attempt -and this time the fish disappeared

17/9/11- All that remained was a lump in the gull's crop - it should keep him going till at least lunchtime

Herring Gulls are omnivores and opportunists like most Larus gulls, and will scavenge from rubbish dumps, landfill sites, and sewage outflows; food obtained this way may comprise up to half of the bird’s diet. Despite their name, they have no special preference for herrings — in fact, examinations have shown that echinoderms and crustaceans comprised a greater portion of these gulls’ stomach contents than fish.

On Colwyn Bay seashore I witnessed more gull feeding behaviour, this time two juveniles were begging an adult, presumably a parent, to feed them.

Young Herring gulls persuading a parent to feed them

Juveniles use their beaks to “knock” on the red spot on the beaks of adults to indicate hunger. Parents typically disgorge food for their offspring when they are “knocked”.

Parent gulls will feed their offspring for up to 6months if they continue to beg

Chicks are generally fed by their parents until they are 11–12 weeks old but the feeding may continue up to six months of age, if the young gull continues to beg. The male feeds the chick more often than the female before fledging, the female more often post-fledging.

The adult was persuaded to disgorge what it had eaten onto the sand

The young birds begging did the trick and the adult disgorged whatever it had eaten onto the beach, which did not look at all appetising from where I was standing, but the three birds seemed to be happy with it.

Tags

herring gull, herring gull nuisance, herring gull status, herring gulls in towns, herring gulls nesting on roofs, larus argentus

April 2011

A pair of Herring Gulls are regularly visiting the flat roof immediately below the window of the bedroom I am staying in. At the moment they are not roosting here overnight, but they arrive back early each morning, announcing their arrival with much raucous calling and strutting around. I have been very aware of Herring gulls locally, flying around, perching on rooftops and up amongst the chimney pots, but put it down to being so close to the seashore where there appears to be plenty of natural food. However it would seem that a number of pairs have claimed several of the chimney-rich sites as nest locations. Their strongly territorial and aggressive-defensive behaviour makes them difficult and, sadly, dreaded birds to have as close neighbours, which is a pity as when viewed closely and unemotionally, they are very clean-looking and handsome birds, if a touch arrogant in demeanour.

European Herring Gull – Larus argentatus

Length 55-67cm; Wingspan 130-158cm

The Herring Gull is one of the commonest gulls of Northern European coasts, bigger than a Common Gull it has rather fierce-looking pale eyes with a yellow iris and pink legs and feet.

A visit to the seaside wouldn’t be the same without the sound of gulls, but when they are intent on sharing your house, you rather wish they’d turn the volume down. A very noisy bird it makes a variety of squealing notes, sometimes sounding like it may be chuckling and also producing some quite dog-like yelping and ‘barking’ sounds.

A Herring Gull peacefully resting in the sun

The male gull brought in some strange ‘tokens’ for his chosen mate, a turkey-leg bone and a fairly large piece of stone amongst them, and they began to display bonding behaviour, the female ‘begging’ for food, and greeting one another vocally and with body contact.

I am very interested in the ways in which wildlife interacts (and learns to exploit) people and although I had no previous experience of living this closely to them, I was aware that herring gulls had a reputation for some anti-social behavioural traits. We had a chat with the next-door neighbour, who related her previous experiences with locally nesting gulls that could have come from the Hitchcock horror story. She alleged attacks made against herself, her visitors and particularly her dog, whilst minding their own business in their own garden! She had rung the RSPCA who had told her there was nothing she could do as the birds were protected, and that the nuisance would only last for seven weeks while the birds were nesting!

A herring gull nest built on a flat roof

I was keen to learn more, so began to research the subject, beginning by checking out the status of the gulls. Surprisingly perhaps, the herring gull has been accorded red status by the RSPB, the highest conservation priority, as its numbers have declined dramatically in its former haunts, disappearing completely from some areas. (There are 40% less herring gulls now than in 1970) To quote from a page on their website , this means that:

” Gulls, like all UK wild bird species, are protected under the Wildlife and Countryside Act 1981. This makes it a criminal offence to kill, injure or take a gull; or to take, damage or destroy its nest whilst the nest is in use or being built. It is also a criminal offence to take or destroy their eggs.”

The best general information I found concerning the bird-human interaction was on Wikipedia and thought it worth reading in full:

” The European Herring Gull is an increasingly common roof-nesting bird in urban areas of the UK. The Clean Air Act of 1956 forbade the burning of refuse at landfill sites, providing the European Herring Gull with a regular and plentiful source of food. As a direct result of this, European Herring Gull populations in Britain sky-rocketed. Faced with a lack of space at their traditional colonies, the gulls ventured inland in search of new breeding grounds. Dwindling fish stocks in the seas around Britain may also have been a significant factor in the gulls’ move inland.

The gulls are found all year round in the streets and gardens of Britain, due to the presence of street lighting, (which allows the gulls to forage at night), discarded food in streets, food waste contained in easy-to-tear plastic bin bags, food intentionally left out for other birds (or the gulls themselves), the relative lack of predators and readily available, convenient, warm and undisturbed rooftop nesting space in towns and cities. Particularly large urban gull colonies (composed primarily of European Herring Gulls and Lesser Black-backed gulls are now present in the cities of Cardiff, Bristol, Gloucester and Aberdeen to name but a few.

The survival rate for urban gulls is much higher than their counterparts in coastal areas, with an annual adult mortality rate of less than 5%. It is also common for each European Herring Gull pair to successfully rear three chicks per year. This, when combined with the long-lived nature of European Herring Gulls, has resulted in a massive increase in numbers over a relatively short period of time and has brought the species into conflict with humans.

Once familiar with humans, urban European Herring Gulls show little hesitation in swooping down to steal food from the hands of humans. During the breeding season, the gulls will also aggressively ‘dive bomb’ and attempt to strike with claws and wings (sometimes spraying faeces or vomit at the same time) at humans that they perceive to be a threat to their eggs and chicks — often innocent passers-by or residents of the buildings on which they have constructed their nests. Large amounts of gull excrement deposited on property and the noise from courting pairs and begging chicks in the summer months is also considered to be a nuisance by humans living alongside the European Herring Gull. Non-lethal attempts to deter the gulls from nesting in urban areas have been largely unsuccessful. The European Herring Gull is intelligent and will completely ignore most ‘bird-scaring’ technology after determining that it poses no threat. Rooftop spikes, tensioned wires, netting and similar are also generally ineffective against this species, as it has large, wide feet with thick, leathery skin which affords the seagull excellent weight distribution and protection from sharp objects (the bird may simply balance itself on top of these obstacles with little apparent concern). If nests are removed and eggs are taken, broken, or oiled, the gulls will simply rebuild and/or re-lay, or choose another nest site in the same area and start again.

Attempts to scare the gulls away using raptors are similarly ineffective. Although they are intimidated by birds of prey, European Herring Gulls, in addition to being social birds with strength in numbers, are large, powerful and aggressive as individuals and are more than capable of fighting back against the potential predator, particularly if they consider their chicks to be at risk. European Herring Gulls are also naturally accustomed to predators (such as Skuas and Great Black-backed Gulls) living in the vicinity of their nest sites in the ‘wild’ and are not particularly discouraged from breeding by their presence.

Despite the increasing number of urban European Herring Gulls in the UK, the species, when taken as a whole is declining significantly across the country, its population having decreased by 50% in 25 years. In 2009, the RSPB placed the European Herring Gull on its ‘Red List’ of threatened bird species, affording it the highest possible conservation status. In response, Natural England in January 2010, following a public consultation, removed the European Herring Gull from the list of species covered by its general licenses, which had previously permitted authorized persons (e.g. landowners or occupiers) to kill the birds under certain circumstances (e.g. to prevent serious damage to crops or livestock, to prevent disease, or to preserve public health or safety) without requiring additional permission. ”

It would seem that there is no easy quick-fix solution to the problem and currently not a lot you can do if the birds take a fancy to nesting on your roof, there doesn’t seem to be a great deal of advice or help available to householders either, a bit worrying bearing in mind that many of them won’t be aware of the law.

A LOCALLY-RELATED SNIPPET FROM THE ABOVE ARTICLE: