Daily Archives: Monday,October 20, 2003

Larus canus: Mew gull –The Race Rocks taxonomy

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An adult Mew Gull: photos by Julie Bowser, July 2012

 

Physical description

  • slender, yellowish, or green legs, with webbed feet
  • gray wings and back with a plain white head, greenish – yellow bill
  • brown plumage and spotted tan
  • dark beak with a pink undertone
  • max lifespan up to 24 years

Habitat: Mew Gulls flourish in and along coastal ranges, tidal estuaries, interior lakes, and marshy grassland.

Behavior: Mew Gulls will not stray far from land and are known to seek the shore first in the occurence of stormy weather. The gull will also advace further inland in large flocks, into agricultural districts, to feast on the exposed worms and larvae after the land has been plowed. Northern gulls will migrate south when breeding season begins.

Food Eaten: herring, worms, insects, berries, grains, crustaceans, clams, mussels, young sea birds.

Predation: Cannibalistic adult gulls will eat eggs and hatchlings.

Predators: gulls, sharks

Migration: Mew gulls migrate in summer through-out Northwestern Canada and Alaska, winter along the Pacific Coast. They rarely migate inland South of its breeding range.
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Aves
Order Charadriiformes
Family Laridae
Genus Larus
Species canus
Common Name: Mew Gull

Other Members of the Class Aves at Race Rocks.
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams. October 20 2003 Tya Arizona PC year 30

Serpula vermicularis: Calcareous tubeworm– The Race Rocks taxonomy

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This patch of calcareous-tubed serpulid worms is exposed on the north east corner of Great Race Rock in a crevasse at low tide. Many other invertebrate species are associated with it in this picture.

Domain Eukarya
Kingdom Animalia
Phylum Annelida
Class Polychaeta
Order Sabellida
Family Serpulidae
Subfamily Serpulinae
Genus Serpula
Species vermicularis
Linnaeus,1767
Common Name: Calcareous tubeworm

Description

Serpula vermicularis is a slender, tube-dwelling polychaete between 5 and 7 cm length with about 200 segments. The tubes are cylindrical with occasional rings and irregular lengthwise ridges cut into blunt teeth. The operculum is calcareous and funnel shaped with radial grooves and a serrated circumference.

The color of the body of the worm varies from pale yellow to brick red. The tube is pinkish-white and the operculum is patterned with red and white rays.

Size: up to 7cm

Growth form: vermiform segmented

 

Distribution

These are common at Race Rocks in the subtidal area. They are often seen by divers as small bright red spots which seem to disappear when approached. Their gills withdraw rapidly into the white calcareous tube.

These worms are commonly found throughout north-west and south-west coasts of England and are distributed in the north-east Atlantic and the Mediterranean.

Physiographic preferences: open coast, offshore seabed, estuary

Habit info

The calcareous tubes of Serpula vermicularis can be found attached to hard substrates such as rocks, stones, bivalve shells and ship hulls from low water to the sublittoral in depths up to 250 m. In some very sheltered areas the tubes aggregate together to form small reefs. Often a mass of coiled white tubes shows up on the shore after a storm attached to the holdfasts of kelp .

Reproduction

Type: Gonochoristic

Frequency: annual episodic

Development mechanism: Planktotrophic

Life span: 2-5 years

 An interesting feeding method, kleptoparasitism, of the larva is documented inresearch:

Other Members of the Phylum Annelida at Race Rocks 
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

 October,2003-  Martina Naschberger (PC)

Martina Naschberger

 

Larus thayeri : Thayer’s Gull — The Race Rocks taxonomy

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In October of 2005, a large population of Thayer’s Gulls has settled in to overwinter at Race Rocks.These scenes are from

the South West corner, just outside the Marine Science Centre at Race Rocks.

History:

Formerly considered as a subspecies of Herring Gulls. It is sometimes regarded as a subspecies of Iceland Gulls.

Physical Appearance: 221/2″ – 25″ wide Mantle slightly darker grey Grey on the underside of the wing tips is distinctive. Yellow bill with red spot on lower mandible. Pale to brown eyes, with a purple-red ring around it. Darker pink legs.
Sound: Long mewing call: hiyah Warning call: gah-gah-gah
Nesting: Usually 2 or 3 olive-brown, heavily blotched eggs in grass nest on sea cliffs in the high arctic. They only overwinter at Race Rocks, feeding on the small herring and krill in the surrounding waters.

Habitat: They are seabirds of the arctic, coastal rocks and rocky headlands. They are usually located on the Pacific coast on North America during winters. At Race Rocks, they often number in the hundreds out on the South West corner of the larger island, as the numbers below show
Christmas Bird Counts 1997= 390, 1998=213, 1999=48, 2000=220, 2001=530, 2002=2000, 2004=450 , 2005=600, 2006= 2200

Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Aves
Order Charadriliformes
Family Laridae
Genus Larus
Species thayeri
Common Name: Thayer’s Gull

Other Members of the Class Aves at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC.

Date:
20 Oct 2003 		Kevin Mingyui Chau

It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Larus thayeri: Thayer’s gull – The Race Rocks taxonomy

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Thayer’s Gulls aligned for wind, November, 2005

Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Aves
Order Charadriliformes
Family Laridae
Genus Larus
Species thayeri
Common Name: Thayer’s Gull

History: Formerly considered as a subspecies of Herring Gulls. It is sometimes regarded as a subspecies of Iceland Gulls.

Physical Appearance:22 1/2″ – 25″ wide Mantle slightly darker grey Grey on the underside of the wing tips is distinctive. Yellow bill with red spot on lower mandible. Pale to brown eyes, with a purple-red ring around it. Darker pink legs.

Sound: Long mewing call: hiyah
Warning call: gah-gah-gah

Nesting: Usually 2 or 3 olive-brown, heavily blotched eggs in grass nest on sea cliffs in the high arctic. They only overwinter at Race Rocks, feeding on the small herring and krill in the surrounding waters.

Habitat: They are seabirds of the arctic, coastal rocks and rocky headlands. They are usually located on the Pacific coast on North America during winters. At Race Rocks, they often number in the hundreds out on the South West corner of the larger island, as the numbers below show.

Immature Gulls: They are similar to herring gulls, but slightly smaller and with proportionately smaller bill.
Other Members of the Class Aves at Race Rocks.
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams. March 8 2003- Kevin Mingyui Chau