The Volcano Island, Iceland. Birdlife from the very beginning. (original) (raw)

Completely exhausted and emaciated, this tiny little bird, a meadow pipit, Anthus pratensis,
arrived at Surtsey after a 20-24 hours flight from Scotland.
On arrival the weight was only 12.0 grammes!

great black-backed gull Larus marinus

Summer 1986, 23 years after the eruption, a few pairs of Larus fuscus were breeding
on a lava terrain on the southern part of Surtsey. In he following years they increased largely
in numbers, and a colony was slowly formed also including Larus fuscus, Larus marinus
and Larus argentatus.

The formation of the gull colony marked a new era in plant colonization and succession on Surtsey, as these gulls had considerably stronger impact than other breeding birds earlier established on the island.

In the first weeks of the Surtsey eruption gulls were seen roosting on the shores of the
new-born island. Ever since, birds have been important in the development of the
exosystem on Surtsey through enrichment of the soil with their excrements and sispersal
of plant seeds to the island.

Fulmar (Fulmarus glacialis) and black guillemot (Cepphus grylle) were the first species
of birds to nest on Surtsey in 1970, when one nest of each species was found in the cliffs
on the southern part of the island. In 1974 great black-backed gull (Larus marinus)
started breeding on Surtsey, kittiwake (Rissa tridactyla) in 1975, herring gull (Larus argentatus) in 1981,
lesser black-backed gull (L_arus fuscus)_ in 1986 and finally glaucous gull **(Larus hyperboreus)**in 1993.

Gulls outside one of the plots inside the gull-colony.
© c/o www.vulkaner.no

The gull species build nests of vegetation, sea-weed, feathers and other available meterial,
while the fulmar (Fulmarus glacialis) and black guillemot (Cepphus grylle) do not use
nest building materials or only slightly arrange pebbles under their eggs.

The nests of the black guillemot (Cepphus grylle) and kittiwake (Rissa tridactyla) are confined to sea-cliffs of the island, which are very unstable and change considerably between years due to wave erosion. Vegetation has not become established at their nest sites.
The kittiwake (Rissa tridactyla), however, roosts in great numbers on the northern ness
of Surtsey and enriches the soil with excrements.

In the early years the nests of the fulmar (Fulmarus glacialis) were mostly confined to
the sea cliffs but in the last 15 years it has also established nes sites inland, mainly in
the cliffs of the old craters where small concentrations of about 5 - 15 pairs are now
found in five different locations on the island.

Gull watching the area around the gull-colony.
© c/o www.vulkaner.no

In 1986 the first nests of the lesser black-backed gull (Larus fuscus)were found on
a lava flat on the southern part of Surtsey. This marked the initiation of the dense gull colony
on the island that now consists of the lesser black-backed (Larus fuscus), herring,
(Larus marinus) and glaucous gull **(Larus hyperboreus). These species, with the exception
of the great black-backed gull_(Larus marinus)**_, usually nest in colonies and the nests
can be within a short distance (<10 m) of each other. They build nests that are mostly
made of plant material.

This clearly shows the connection between the increasing numbers of birds - and the
vegetation.The more vegetation - then more nest-building material, and the more birds -
the better the soil and so more plants will grow up.

A nest of great black-backed gull (Larus marinus) in a patch of Honkenya peploides plant 1977

In 1990 more than 150 pairs were in the colony, but it is estimated that the number had risen
to at least 300 pairs in 1999. When the first plots were established in the gull colony in 1990
the effects of the gulls on the vegetation were noticable. At that time only two species were
found in each plot and vegetation cover was around 30% (all Honkenya). In 1998 the
number of species in the plots had risen to between eight and ten and several species in
addition to honkenya etc had attained a high cover in the plots. Total vegetation cover
in the plots at that time had reached 100%. Outside the gull-colony there has not been
an increase in species number.

The gulls were spspected to have negative influence on the development of plant succession
by tearing up plants for use as nest material. It has now become obvious, that the gulls have proved to be very important components in the simple life community now established on
Surtsey (1981).

Obviously the importance of the gulls was not just confined to the nest. The gulls or their
young seek shelter in the Elymus tufts leaving droppings and food remains behind, enriching
the soil. A selfsufficient ecosystem has been established on Surtsey, composed of vascular
plants, fungi, various invertebrates with different demands, birds and no douby different microorganisms. The ecosystem is of course simple and probably unstable, but it is
obviously the beginning of a more complicated ecosystem to be developed in the future.

That was in 1981, and since then there is no doubt that it has developed, and so it has
to a much larger extent than many thought when Surtsey came up from the bottom of
the ocean back there in 1963.

Text mainly extracted from reports made by Borgthór Magnússon and Sigurdur H. Magnússon, Icelandic Institute of Natual History, Reykjavik, Iceland. Surtsey Research Report No. XI

Birds found in the text above:

norwegian	english	latin	picture
Hettemåke	Black-Headed Gull	Larus ridibundus
Gråmåke	Herring Gull	Larus argentatus
Svartbak	Great Black-Backed Gull	Larus marinus
Sildemåke	Lesser Black-Backed Gull	Larus fuscus
Polarmåke	Glaucous Gull	Larus hyperboreus
Krykkje	Kittiwake	Rissa tridactyla
Havhest	Northern Fulmar	Fulmarus glacialis
Teist	Black Guillemot	Cepphus grylle

Gull: Sea-bird of Charadriiformes order, sub-order Lari, whcih includes:

black-headed gull Larus ridibundus
herring gull Larus argentatus
great black-backed gull Larus marinus (1,75 m vingespenn)
lesser black-backed gull Larus fuscus
glaucous gull Larus hyperboreus
Krykkje kittiwake rissa tridactyla

Other birds:

Havhest, northern fulmar fulmarus glacialis Teist black guillemot cepphus grylle

Here you can find more about:

	Bird migration
	Plants
	Insects
	Sealife
	Fossils on Surtsey
	How life developed
	The eruption
	Picture-review

See the last report from Surtsey Research - 2009. Click here

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