BIOLOGICAL DATA AND HABITAT REQUIREMENTS
WILDLIFE SPECIES: Chen caerulescens | Snow Goose 



TIMING OF MAJOR LIFE HISTORY EVENTS : 
Pair Formation- second winter of life; usually monogamous 
Nesting- June, usually in large colonies 
Clutch- three to four eggs over a 12-day period 
Incubation- 22 days 
Fledge- 42 days 
Maturity- 2 years but often not successful nesters until 3 years 
[7,13,16]


PREFERRED HABITAT : 
Snow geese prefer coastal lagoons and marshes, agricultural land and
adjacent prairies, tidal flats, estuaries, and tundra areas [15].  They
roost in large flocks on dry, flat land on wintering grounds and feed on
inland lakes and marshes or large estuaries.  During cold weather snow
geese will roost in places with tall marsh vegetation, such as common
reed (Phragmites australis) [15].  Sometimes geese create their own
roost sites by grazing vegetation so low that they are able to make
their own holes in the ground; these holes eventually turn into small
ponds.  Snow geese tend to feed on tidal flats and deltas that have the
newest sediment deposits and where water is shallow (about 7.9 inches
[20 cm] deep).  They will move inland with flooding or cool, windy
weather [15].  Lesser snow geese breed within 6 miles (10 km) of water
in low tundra, while greater snow geese choose rockier sites on the lee
side of mountains in wet tundra [16].  Snow geese often feed on
agricultural land when the tide is in or when crops are just emerging
[8].


COVER REQUIREMENTS : 
Snow geese need areas free from human disturbance, since they will
abandon feeding or nesting areas if frequently disturbed [15].  Lesser
snow geese need low, grassy tundra for breeding with flat basins near
lakes, rivers, flood plains, or seas.  Greater snow geese need rocky
terrain near grassy tundra and areas where flat, marshy lands are
protected from the north by mountains [13].  Mosses and grasses are
needed for nests, and large bodies of water are needed for flocking
since snow geese are gregarious birds [13].  In Manitoba studies have
shown that they tend to be more successful nesters in areas that have
tall willow (Salix spp.) shrubs (greater than 16 inches [40 cm])
compared to areas with short (less than 15 inches [30 cm]) or no willow
shrubs [12].  Presumably the shrubs offer protection from predators.


FOOD HABITS : 
Snow geese feed primarily on emergent marsh vegetation.  Some species
include saltgrass, wild millet (Echinochloa spp.), spikerush (Eleocharis
spp.), feathergrass (Leptochloa fascicularis), panic grass, seashore
paspalum (Paspalum baginatur), delta duckpotato (Sagittaria
platyphylla), bulrush, cordgrass, cattail, ryegrass (Lolium spp.), and
wild rice [15].  Rice is a very important food on wintering grounds in
Texas and Louisiana along with smartweed (Polygonum spp.), dropseed
(Sporobolus spp.), bluestem (Andropogon spp.), and fescue (Festuca spp.)
[13].  Puccinellia phryganodes is important in arctic salt marshes [2],
and corn is important in the Central Flyway states [1].  Because snow
geese do not have crops they must eat large amounts of food in a short
period of time [15].  They also need areas where they can eat grit in
the form of sand or shell fragments.  They will often fly long distances
from feeding areas to get it [15].


PREDATORS : 
Snow geese predators include humans and arctic foxes (Alopex lagopus).
On nesting grounds in the Soviet arctic reindeer (Rangifer spp.) can
destroy nesting colonies by trampling [16].


MANAGEMENT CONSIDERATIONS : 
Enhancing feeding areas with grit is an important management technique
to improve wintering grounds [15].  Sand and fine gravel used in road
surfacing could provide the necessary grit for snow geese food
digestion.  They also need areas that provide fresh water for drinking,
although snow geese can use brackish water for a "considerable time"
[15].  

Several studies demonstrated the effects of snow geese grazing on
certain food plants [2,3,10].  Along the Hudson Bay in Manitoba, geese
can delay the succession of Puccinellia phryganodes-Carex subspathacea
plant communities to Calamagrostis deschampsioides-Festuca rubra
communities through grazing, but they cannot prevent it entirely [10].
The latter is not preferred forage whereas the former is very important
in geese diets.  Geese grazing on three-square bulrush (Scirpus
americanus) in Quebec resulted in a marked decrease in belowground
growth of plants compared to plots that were ungrazed for 3 years;
however, no difference in nutrient value was noted between the two plots
[3].  Grazing resulted in a significant increase in net aboveground
primary production of Puccinellia phryganodes compared to ungrazed areas
[2].


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Chen caerulescens | Snow Goose