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"