The Herring Gull
Length: 60 cm
Weight: 950 grams (females) 1,200 g (males).
Wingspan: 144 cm. Life span: about 12 yrs
One of three large gulls, the Herring Gull is probably the original “seagull”. This is not a good name for them, as some nest inland or on city roofs and they regularly range over farmland looking for food in winter. An adult has a white head and body, silver grey wings, black wing tips with white spots. The legs are pink and the bill is yellow with a red spot on the lower part nearer the tip.
Herring Gulls are much scarcer now than they used to be 40 years ago. In fact they are Red-listed as the Irish breeding population declined from 60,000 pairs to 6,000 pairs between 1969/70 and year 2000 (90%). There are signs that the population is beginning to increase and at the same time more are turning to an urban lifestyle.
It takes 4 years for a Herring Gull to ‘grow up’; the juvenile is dull streaky brownish grey and over the next 3 years the amount of streaking diminishes and the wings gradually become the characteristic silver grey.
Generally speaking Herring Gulls are considered a resident species and the majority rarely move more than about 100 km from the natal colony and will probably return to breed there when they are four years old. More northerly Herring Gull populations show greater migratory tendencies and such birds may boost numbers around Irish coasts in the winter.
The factors behind the decline of Herring Gulls are complex. Thousands of breeding pairs have been culled (killed) in the name of ‘reducing the risk of bird strike’ in the vicinity of Dublin Airport; badly managed refuse dumps have encouraged gulls to scavenge on food waste but the relatively recent practise of using black plastic sacks creates an warm environment for toxic (to gulls and some other waterbirds) bacteria to proliferate. This gives the birds a condition known as botulism and the birds become paralysed and usually die of hypothermia. Dumps are better managed nowadays and rubbish is quickly covered and thereby inaccessible to the birds. This may be a reason aiding the recovery of the species.
Herring Gulls breed all around the Irish coast, usually on islands, cliff tops and ledges where they build a nest on the ground out of grass and other vegetation in which they lay 3 large eggs, usually in May. These are incubated for about 28-30 days and chicks hatch in June. The young tend to stay in the nest for a few days before hiding in/behind vegetation and rocks. The parents feed them by regurgitation and the typically fledge about 5 weeks later in July or early August. On islands Herring Gulls nest colonially but on mainland cliffs pairs are more isolated. The largest colony in Ireland is on Lambay off the coast of north County Dublin with just over 300 pairs recorded in the 2009 census.
Roof-nesting has occurred for some time particularly in the vicinity of fishing harbours such as Dunmore East in Waterford and Howth, Skerries and Balbriggan in Dublin. However, by the time of the census in year 2000, Herring Gulls together with some Lesser Black-backed Gulls, were regularly nesting in Dublin City where they are to exploit takeaway and fast food leftovers discarded in the streets or parks. Nests can either be built on flatter office/factory roofs or between chimney pots on residential properties.
Some things you may not know
- Herring Gulls typically live to about an age of 12 years although one (ringed) bird nearly reached the grand old age of 31.
- About 88% of adult gulls survive from one breeding season to the next.
- Most mortality occurs in the first few months of life when juveniles have to learn to forage on their own.
- Herring Gulls regularly scavenge fishery waste discarded at seas or try and snatch fish as catches are landed but they are also able to catch their own fish at sea or shellfish on beaches and intertidal rocks.
- Young Herring Gulls and other seabirds are sometimes accidently killed by lunge feeding whales (Finn, Humpback and Minke) off the south coast of Ireland.
Herring Gulls are often considered as the coastal equivalent of the Magpie – the bird we love to hate. BirdWatch Ireland would urge you reconsider: yes they are loud, noisy etc. but they have been treated rather badly in the past and given they are Red-listed, we should now take more interest in their plight and give them a more favourable press.