Patterns of marine bird use over the inshore portion of the Scotian Shelf

Patterns of marine bird use over the inshore portion of the Scotian Shelf John Chardine and Andrew Boyne Canadian Wildlife Service Environment Canada...
Author: Camron Baker
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Patterns of marine bird use over the inshore portion of the Scotian Shelf John Chardine and Andrew Boyne Canadian Wildlife Service

Environment Canada

Environnement Canada

Canadian Wildlife Service

Service canadien de la faune

Canada

“Inshore” Scotian Shelf

Scotian Shelf marine birds

• • • • • •

Fulmars, shearwaters and storm-petrels Cormorants and gannets Gulls, terns, auks, phalaropes Seaducks, geese loons herons

Marine bird ecological categories • Summer – Breeders (most could range over 12 mile limit during feeding trips) – Southern hemisphere migrants (pelagic, infrequent within 12 mile limit) – Northern hemisphere non-breeders (pelagic, infrequent within 12 mile limit) – Staging/moulting waterfowl (coastal) – In transit (coastal, inshore and pelagic)

• Winter – Breeders dispersed from colonies (inshore and pelagic) – Overwintering migrants from northern Canada, Greenland and Europe (episodic inshore and pelagic) – Over-wintering waterfowl (coastal)

Inshore Scotian Shelf marine bird notes Species

Status

Realm

Season

Northern Fulmar

Visitor

Pelagic

AY

Leach’s Storm-Petrel

Breeder

Pelagic

Su,F

Shearwaters, Wilson’s Storm-Petrel

Visitor

Pelagic

Su

Cormorants

Breeders,visitors

Coastal

AY

Northern Gannet

Transient

Coastal, inshore, pelagic

Sp,F

Gulls

Breeders, visitors

Coastal, inshore, pelagic

AY

Terns

Breeders

Coastal, inshore

Su

Red Phalarope

Transient

Coastal, inshore, pelagic

Sp,F

Auks: Razorbill, Atlantic Puffin, Black Guillemot

Breeders, visitors, transients

Coastal, inshore, pelagic

AY

Auks: Murres, Dovekie

Visitors, transients

Coastal, inshore, pelagic

W

Common Loon

Visitor

Coastal

F,W

Red-throated Loon

Transient

Coastal

F,W,Sp

Great Blue Heron

Breeder

Shoreline

Su

Common Eider

Breeder, visitor, transient

Coastal

All year

Other ducks and geese

Visitors, transients

Coastal

F,W,Sp

Marine bird feeding ecology Species

Feeding methods

Prey

storm-petrels

surface pickers

Myctophid fish, plankton

shearwaters

surface pickers and shallow divers

fishes, crustacea, squid, waste

cormorants

pursuit divers

fishes

Northern Gannet

plunge diver (to 15 m)

herring, capelin, larger pelagics, squid

gulls

surface picker, scavenger

fishes, mussels, waste, seabirds

terns

surface plunge diver

small fishes

Red Phalarope

surface picker

plankton, copepods

auks less Dovekie

pursuit divers or benthic

fishes, euphausiids, other inverts

Dovekie

pursuit diver

plankton

Common Eider

benthic diver

shellfish, mussels

dabbling waterfowl

surface

eel grass, vegetation, snails, inverts

diving waterfowl

pursuit and benthic divers

fishes, mussels, inverts

loons

pursuit divers

fishes

Great Blue Heron

shallow water seizing

fishes, amphibians

Marine bird databases • CWS Waterbird Colony Database – Locations and censuses of colonial waterbirds in Atlantic Region – Covers entire coastline (except Labrador)

• CWS Coastal Waterfowl Survey Database – Aerial counts of waterfowl in each CWS coastal block – Covers entire coastline and some inland areas

• Seabirds at Sea Database – Counts of seabirds at sea from ships of opportunity – Covers ocean area out to shelf edge – Data poor for inshore areas and in winter

Colonies

Scotian Shelf marine bird colonies (n = 457 historical locations)

Data source: CWS Waterbird Colony Database

Colony attributes •mammalian predator-free •suitable substrate/vegetation to provide nesting place (ground/cliff/tree), protection from weather, avian predators •optimum distance from preferred food sources given: –power requirements of brood –maximum payload size –food transport method (in gut or bill) –flight energetics

Many islands or isolated mainland sites on the Scotian Shelf shore fulfil these requirements

Breeding species diversity (14 species) Tube-noses (petrels)

Leach’s Storm-Petrel

Pelican-like species

Double-crested Cormorant Great Cormorant

Auks

Atlantic Puffin Razorbill Black Guillemot

Gulls

Herring Gull Great Black-backed Gull Black-legged Kittiwake

Terns

Common Tern Arctic Tern Roseate Tern

Herons

Great Blue Heron

Ducks

Common Eider

Top breeding species by number of colonies (n = 457) Species

Colonies n (%)

Great Black-backed Gull

278 (60)

Herring Gull

224 (49)

Terns (Common, Arctic, Roseate)

178 (39)

Cormorants (Double-crested, Great)

113 (25)

Common Eider

74 (16)

Top breeding species by population size of breeders Species Leach’s Storm-Petrel Great Black-backed Gull

Breeders (n) 238,043 18,016

Herring Gull

9,673

Common Eider

5,869

Double-crested Cormorant

8,473

Terns

4,019

Colony locations: top breeding species Breeding individuals

add auks, kittiwakes

lls gu

Data source: CWS Waterbird Colony Database

c s, n r , te

ts ran o orm

rs ide e ,

Large Leach’s Storm-Petrel colonies Breeding individuals

Country I.

Bon Portage I. Data source: CWS Waterbird Colony Database

CWS coastal blocks

Top five waterfowl species: summer Species Common Eider

Birds/block/ survey 319

Black Scoter

44

Scoter spp.

3

Long-tailed Duck

3

Surf Scoter

3

Top five waterfowl species: winter Species

Birds/block/ survey

Common Eider

175

Canada Goose

130

Black Duck

64

Goldeneye spp.

22

Long-tailed Duck

20

Waterfowl distribution and abundance: summer (Apr-Nov)

Data source: CWS Coastal Waterfowl Survey Database

Waterfowl distribution and abundance: winter (Dec-Mar)

Data source: CWS Coastal Waterfowl Survey Database

Summary • • • • • • •

a wide variety of marine bird species use the inshore Scotian Shelf locals are joined by species from southern hemisphere, Arctic and northern Europe different uses are made at all times of year individuals take advantage of the breeding habitat, protection, and food available in the area food availability is most important driver of distribution and abundance colony distribution does not suggest "hotspots" but more analysis is required coastal waterfowl distribution suggests several, seasonally dependant "hotspots"

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