Where do surf scoters nest?

The surf scoter (Melanitta perspicillata) is a large sea duck that breeds in northern forests and winters in marine habitats along the coasts of North America. Surf scoters are diving ducks that forage for mollusks, crustaceans, and other small invertebrates in shallow nearshore waters. Their breeding habitat ranges across Canada and Alaska, while their wintering grounds extend along the Pacific, Atlantic, and Gulf coasts of the United States and Mexico. Knowing where surf scoters nest and reproduce is important for monitoring and conserving their populations.

Breeding Range and Habitat

Surf scoters nest in boreal forests across Canada and Alaska. Their breeding range extends from Alaska across northern Canada to Labrador and Newfoundland. They breed near lakes, ponds, rivers, and wooded wetlands within the boreal forest. Key nesting areas include:

• Alaska – Central and coastal regions.
• Yukon and Northwest Territories – Throughout.
• British Columbia – Central and northern regions.
• Alberta – Northern boreal forests.
• Saskatchewan and Manitoba – Northern boreal forests.
• Ontario – Boreal forests north of Lake Superior.
• Quebec – Boreal forests north of the St. Lawrence River.
• Newfoundland and Labrador – Interior and northern regions.

Surf scoters often nest near ponds or lakes within boreal forest habitats. They build nests on the ground concealed by vegetation, usually within 15 meters of water. Surf scoter pairs will defend nesting territories, but nests may be clustered loosely in suitable habitat.

Key habitat features for nesting include:

• Boreal forest with wetlands, lakes, or ponds.
• Nesting areas near water for foraging.
• Vegetation for nest concealment and cover.
• Low predation risk.

Surf scoters have very large breeding ranges across the northern forests of North America. Estimates indicate their breeding range covers over 4 million square kilometers. Within this vast region, they nest in suitable boreal forest habitat with wetland features.

Nesting Chronology

Surf scoters have a relatively short nesting season timed for optimal conditions to raise young. Their breeding chronology is as follows:

• April – Arrive at breeding grounds and form pairs.
• May – Select nest sites and build nests.
• June – Eggs are laid and incubated for about 4 weeks.
• July – Ducklings hatch in early July.
• August – Ducklings fledge after about 60 days.
• September – Adults and juveniles depart breeding grounds.

Most young are hatched during July after a nesting period of around 30 days. The female alone incubates the eggs while the male will remain nearby to guard the nest. Scoter ducklings become capable of flight after about two months, at which point they will migrate with their mother to wintering areas.

Key Nesting Dates

Timing their nesting chronology allows surf scoters to maximize food availability for egg production in spring, avoid overheating ducklings in mid-summer, and grow juveniles large enough for migration in late summer/early fall.

Clutch Size and Duckling Production

Surf scoters lay relatively large clutches for ducks. Typical clutch sizes average around:

• 8-10 eggs
• Range from 6-12 eggs

Large clutch sizes allow surf scoters to compensate for losses of eggs and ducklings to predation. Hatching success for their nests can be 50% or less. Predators like foxes, bears, gulls, and ravens will consume eggs. Duckling survival rates are highly variable, but may range from 10-60% over the brood rearing period. Overall, a typical successful nest may fledge around:

• 3-6 ducklings

Production of young can vary substantially across the breeding range and between years. Regional averages may range from 2-7 ducklings fledged per breeding pair depending on habitat quality and predation pressures. Annual fluctuations reflect factors like weather, food supplies, and predator populations.

Typical Surf Scoter Reproductive Statistics

Managing wetland habitats and controlling nest predators where surf scoters breed may help increase duckling survival and population levels.

Population Status and Trends

Surf scoters remain abundant across their breeding range, though some populations have declined regionally in recent decades. Their total breeding population is estimated at over 650,000 pairs. Breeding populations trends include:

• Increasing in eastern Canada (Quebec, Labrador, Newfoundland).
• Stable or variable across mid-continent regions.
• Declining in Alaska and western Canada.

Loss of boreal wetlands, increasing predation, and changing food supplies have contributed to regional declines. Conservation efforts for northern nesting habitats will help maintain healthy scoter populations.

More robust monitoring is needed over the immense scoter breeding range. Targeted conservation efforts in regions of decline will help ensure abundant scoter populations across their northern nesting habitats.

Threats and Conservation

Surf scoters face a variety of threats and conservation issues across their northern breeding range, including:

Habitat Loss

• Draining or degradation of boreal wetlands
• Forestry clearing of mature forest nesting habitat

Increasing Predation

• High nest losses to predators like foxes, bears, gulls
• Duckling vulnerability to predators such as ravens, mink

Disturbance

• Human activity near nesting sites
• Cottage and recreation development
• Mining/industrial disturbance

Contaminants

• Mercury and toxins accumulation on breeding grounds
• Effects on reproduction and duckling health

Climate Change

• Altered habitat suitability in boreal regions
• Changes in food supplies and wetland ecology

Conservation efforts for surf scoters should focus on protecting and managing key nesting habitats, controlling predators, limiting disturbance, and monitoring environmental contaminants. Maintenance of healthy boreal forest ecosystems will benefit scoters and other waterfowl.

Research and Monitoring Needs

Some research and monitoring needs to better understand and conserve surf scoter populations include:

• More extensive surveys across remote boreal regions
• Banding studies to track migration and demographics
• Research on nesting habitat requirements
• Assessing nesting chronology and reproductive success
• Understanding population limiting factors
• Effects of environmental contaminants on breeding grounds
• Impacts of climate change and habitat alteration

Filling knowledge gaps across the vast scoter breeding range can guide habitat conservation and management strategies. Tracking surf scoter populations and demographics provides key insights into the health of this species.

Conclusion

In summary, surf scoters nest in boreal forest regions across Canada and Alaska near lakes, ponds, and wetlands. Their breeding season lasts from spring through early fall, with eggs hatching in early July. Surf scoters lay large clutches, but have variable duckling survival. Their continental population is abundant overall, though local declines have occurred in western regions. Conservation efforts focused on nesting habitat protection, predator management, reducing disturbance, and monitoring environmental threats will help maintain healthy scoter populations across their northern breeding grounds. Filling knowledge gaps through research and monitoring is key. With sound science guiding habitat conservation, this fascinating sea duck can continue thriving across its vast boreal forest nesting range.