Transcript Threatened Eiders of North America

Threatened Eiders of
North America
Byram L. Feltner
Bio 586
Eiders of North America
(4 species)
• Common Eider
• King Eider
• Spectacled Eider (Threatened)
• Steller’s Eider (Threatened)
Eider Characteristics
• Large diving ducks (some can dive to depths
of 180 feet)
• Feed mainly on mollusks and invertebrates.
Some diets can consist of some plant matter
(rarely exceeds 5%).
• Found in extreme northern habitats. (Some
spend the winter in openings of the sea ice.)
Nesting
• Typically line nest w/
down feathers
• Usually nest near rocky
areas above water.
Classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Suborder: Anseres
Family: Anatidae
Subfamily: Anatinae
Tribe: Mergini
Common Eider
Somateria mollissima
• Largest duck in North
America (Length: 17”,
Wingspan: 41”)
• Feed primarily on
mollusks
• Population: 1-1.5 million
Common Eider Range
King Eider
Somateria spectabilis
• Large Duck (Length: 16”,
Wingspan: 37”)
• Feeds primarily on
mollusks
• Population: <1 million
King Eider Range
Spectacled Eider
Somateria fischeri
• Threatened Species
• Large Duck (Length: 15”,
Wingspan: 36”)
• Diet varies according to
time of year.
• Population: <100,000
Spectacled Eider Identification
•
Identification Tip:
–
•
Adult male:
–
–
–
–
•
Pale green head with large
white patch around eye
Yellow bill
Black underparts
White upperparts
Adult female:
–
–
•
Bill feathered to nostril
Dark brown plumage with fine
black barring
Pale brown patch around eye
Similar species:
– The male is very distinctive. The female may be mistaken for another eider
female, but the eye patch and extensive feather on the bill sets it apart.
Spectacled Eider Diet
• Breeding/Growth Season
– Insects and Vegetation
• Rest of Season
– Mollusks and Vegetation
Threatened Listing
• Effective Date: June 9, 1993
– Populations had declined by 94-98% within the
principle breeding range.
• Alaska’s population declined 14% the following year
(1994).
Steller’s Eider
Polysticta stelleri
• Threatened Species
• Smallest of Eiders
(Length: 12”, Wingspan: 29”)
• Feeds mainly on
crustaceans (amphipods,
isopods, and barnacles)
• Population: 150,000 –
200,000
Steller’s Eider Identification
• Identification Tips:
– Gray unfeathered bill
– Squarish head
– Long tail
• Adult male alternate:
–
–
–
–
–
–
–
White head and flanks
Black on throat and back
Black around eye
Greenish patch on lores and rear of head
Black spot on breast
Black and white scapulars
Brownish belly
• Adult female:
– Dark brown plumage
– Pale eyering
– Square head
• Similar species:
– Male is distinct. The female could be missidentified as another eider.
The female Steller’s has and unfeathered bill, squarer head, longer
tail, and is smaller in size.
Steller’s Eider Diet
• Throughout Year
– Mainly on various crustaceans (amphipods, isopods,
barnacles)
Threatened Listing
• Effective Date: 1997
– Alaskan breeding populations has nearly
disappeared.
• Estimates range from hundreds to low thousands.
• Problem not well understood.
Cause for Listing
(Steller’s and Spectacled)
1.
2.
3.
4.
5.
Destruction, Modification, or Curtailment of
Habitat or Range
Over utilization for Commercial,
Recreational, Scientific, or Educational
Purposes
Disease or Predation
Inadequacy of Existing Regulatory
Mechanisms
Other Natural or Manmade Factors
1.
Destruction, Modification, or
Curtailment of Habitat
• Destruction of habitat is low.
–Many areas unaltered and uninhabited
• Alaskan North Slope
–Altered by oil and gas development
–Only small portion of breeding range
• Marine habitat still poorly understood
• Persistent Organic Pollutants (POPs). Elevated
concentrations of many trace elements, noticeably
cadmium, selenium, and copper, but these were
below levels associated with toxicological risk to
marine birds.
2. Overutilization for Commercial,
Recreational, Scietific, or Educational
Purposes
• Were traditionally harvested during migration
• Alaskan and Siberian natives
– Take eggs and birds for food
•
•
•
•
Skin and feathers used for clothing.
Bones used for household purposes
Feathers were used in fans for tourists
Spring harvest supplied traditional source of meat
to coastal communities.
• Illegal harvest for taxidermy trade
– Magnitude unknown
3. Disease and Predation
• Increases in fox and common raven
populations.
– Never proven to have affected populations.
• Gull (glaucous-winged) populations increased
due to fish processing wastes.
– Prey on chicks
• Parasites (acanthocephalans)
– Lowering reproduction/survival.
– Not affected in good habitat.
4. Inadequacy of Existing Regulatory
Mechanisms
• Harvest was regulated under authority of the
Migratory Bird Treaty Act (16 U.S.C. 703-711).
– Hunting has been closed since 1991
• Historically hunted in Russia
– Estimates for harvest is high
• No records of harvest was recorded in Russia
• Hunting was not regulated strictly despite the M.B.T.
(Prohibited hunting between March 10 and
September 1)
– This was due to the fact that many residents historically
and traditionally took eiders for food.
5. Natural or Manmade Factors
• Oil Spills
• Oil Fields
– Low nesting numbers in active fields
• Pollution
– From offshore oil development and fishery vessels
• Fishing Nets
• Lead shot
– Very few cases
• Severe weather
– Natural die off
Conservation Measures Taken
1.
2.
3.
4.
Recognition
Recovery Actions
Requirements for Federal Protection
Prohibition against certain practices
1.
Recognition
• Encourages and results in conservation actions
by Federal, State, and local governments and
private agencies, groups and individuals.
2. Recovery Actions
• Act provides for possible land acquisition and
cooperation with the states and requires that
recovery actions be carried out for all listed species.
• Land isn’t always secured!
– The spectacled eider is one of the many migratory
species that depend on the globally unique habitat at
Teshekpuk Lake inside the National Petroleum ReserveAlaska along Alaska's western Arctic coast. The area is
also critical to Pacific black brant, yellow-billed loons,
tundra swans, king eiders, and northern pintails. But the
Bush administration wants to lease the lands along
Teshekpuk Lake to the oil and gas industry.
3. Requirements for Federal
Protection
• Prohibits taking and harm of the listed species.
• Provided habitat protection rather than just species
protection that was covered in the M.B.A.
4. Prohibition against certain
practices
• Scientific studies
– Permit system
• Zoological exhibition, educational purposes
– Permit system
• No threatened species on exhibit
Como Zoo, MN
Importance
• Balance
– Keystone species
• Specific niche
Ten Most Wanted
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Spectacled Eider
Ross’s Gull
Ivory Gull
White morph Gyrfalcon
Snowy Owl
Albatross
White-tailed Tropicbird
Atlantic Puffin
Trogon
Ivory-billed Woodpecker
Most Wanted