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| SCIENTIFIC
CLASSIFICATION |
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| COMMON
NAME: |
gull |
| KINGDOM: |
Animalia |
| PHYLUM: |
Chordata |
| CLASS: |
Aves |
| ORDER: |
Charadriiformes |
| FAMILY: |
Laridae |
| GENUS
SPECIES: |
Most
species in the genus Larus; roughly 43 species
total |
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| DESCRIPTION: |
In
general, gulls are robust, long winged birds that
have bills that are stout and hooked and fully webbed
feet except for the hind toes. Unlike terns, which
are found in similar habitats, gulls have broader
wings and squared-off or rounded tails. Many gull
species exhibit different colorations due to seasonal
changes or maturity level and it is often very difficult
to identify a given gull's species. Bill and leg
coloration are excellent distinguishing characteristics
to use identifying gulls. |
| MALE |
Males
are generally slightly larger than females and have
larger bills. |
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| SIZE: |
Generally
gulls range in length from 28-81 cm (11-32 in.) |
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| DIET: |
Gulls
are mainly scavengers, but they also prey on fishes,
insects, mollusks, crustaceans, worms, mice, young
birds, bird eggs, seaweed and berries. |
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| INCUBATION: |
For kelp gulls, the eggs begin to hatch after about
27 days, and the chicks leave the nest soon after.
Mortality rates can be high, as egg and chick cannibalism
by other gulls results in up to 50% mortality rates
in some colonies. |
| CLUTCH
SIZE: |
Gulls
usually nest in colonies, laying 2-3 eggs in shallow
nests composed of stones, seaweed, mosses, and feathers. |
| FLEDGING
DURATION: |
They
are capable of flight about 5-6 weeks after hatching
and are independent at 7-8 weeks after hatching. |
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| LIFE
SPAN: |
Some
gulls may live to 20 or more years |
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| RANGE: |
These
cosmopolitan birds inhabit many different areas
of the world. For example, ringbill gulls (Larus
delawarensis) are found from North America to
South America and into the Caribbean; laughing gulls
(L. atricilla) can be seen in Brazil, Peru,
and both coasts of the United States; and kelp gulls
(L. dominicanus) are distributed around Australia,
New Zealand, sub-Antarctic islands, South America,
and South Africa. |
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| HABITAT: |
Gulls
inhabit coastlines of oceans, bays, and major lakes.
They typically prefer to stay within sight of land
- some travel far inland to find food. |
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| POPULATION: |
GLOBAL |
Unknown |
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| STATUS: |
IUCN |
2
species of gulls are listed as Endangered |
| CITES |
1
species, the relict gull, Larus relictus,
is listed as Appendix I |
| USFWS |
8
species listed as either Vulnerable or Lower Risk |
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| 1. |
Some
gulls follow behind plows to consume upturned grubs
while others are known to drop hard-shelled mollusks
onto rocks to break them open. |
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| 2. |
Many
species of gulls are kleptoparasitic and steal prey
from other birds of the same or different species.
Kelp gulls have been seen to mob penguins in order
to take their food, and also harass and rob other
birds of their catches. |
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| In
the United States, the Migratory Bird Act legally
protects gulls. |
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|
|
Grant,
P.J. Gulls: A Guide to Identification.
Staffordshire. T & A D Poyser, Ltd. 1982.
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| Harrison,
P. Seabirds: An Identification Guide. Boston.
Houghton Mifflin Co. 1983. |
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| Line,
L. The Audubon Society Book of Wild Birds.
New York. Harry Abrams, Inc. 1976. |
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| http://animaldiversity.ummz.umich.edu/search/simple/ |
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| http://www.audubon.org/bird/ |
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