There are two species of swans that can be found in the Chesapeake Bay area – the mute swan and the tundra swan. The mute swan was introduced to North America from Europe in the late 1800s and has become established along the Atlantic coast, including in the Chesapeake Bay. The tundra swan is a native species that migrates through the region in large numbers each winter. In this article, we will look at the history, population status, and ecology of both species in the Chesapeake Bay.
Mute Swans
The mute swan is a large, white waterfowl native to Europe and Asia. It gets its name from being less vocal than other swan species. Mute swans were first brought to North America in the late 1800s to ornament parks, zoos and estates. They later escaped or were intentionally released and began to establish feral populations along the Atlantic coast.
The first feral mute swan nest in the Chesapeake Bay was recorded in 1962. Since then, the population has grown substantially. As of the last survey in 2015, there were over 4,100 mute swans in Maryland’s portion of the Bay, centered mainly in the mid-Bay region. This represents one of the largest populations of mute swans along the Atlantic coast.
Mute swans are a non-migratory, year-round resident in the Chesapeake Bay. They build large nests of aquatic vegetation along shorelines and feed on submerged aquatic vegetation (SAV). One study estimated that the Maryland mute swan population may consume over 4 million pounds of SAV per year. This has raised concern about damage to Bay grasses that provide critical habitat for native waterfowl and fish.
There is also evidence that increasing mute swan densities have negative impacts on native waterfowl species. Mute swans exhibit aggressive behavior to other birds during the breeding season and have been documented displacing native waterfowl from nesting and feeding areas. Their presence may also deter native waterfowl from using certain habitats year-round.
To limit further population growth, mute swans have been included in Maryland and Virginia’s resident game bird hunting seasons. The current population appears to have stabilized but mute swans remain abundant and widespread throughout the Maryland portion of the Bay. Continued management will be needed to minimize future impacts to native wildlife and habitats.
Tundra Swans
The tundra swan is a native waterfowl species that migrates through the Chesapeake Bay region every winter. The eastern North American population of tundra swans breeds during the summer months in the Canadian Arctic. In late fall, they migrate south to wintering grounds that center along the Atlantic coast of Maryland and Virginia.
It is estimated that 60-80% of the entire eastern tundra swan population – more than 100,000 birds – winter in the Chesapeake Bay each year. They arrive in late November and typically remain until early April when they migrate back north to the breeding grounds.
Tundra swans use a variety of habitats while in the Chesapeake Bay including shallow bay waters, agricultural fields, impoundments and flooded marshes. They feed heavily on SAV in shallow waters and grain from agricultural fields. Some key habitats include the Susquehanna Flats, Tangier Sound and fields on Maryland’s Eastern Shore.
A major threat to tundra swans is the decline in SAV in the Chesapeake Bay. The swans are dependent on these grass beds as a main food source and loss of habitat could limit growth and survival. Conservation programs that restore SAV would benefit migrating tundra swans.
Hunting of tundra swans is not permitted, though they may be unintentionally shot during goose hunting seasons. Because most of the population winters in the Chesapeake region, protecting their key habitats here is vital for conserving the broader eastern population of the species.
Comparisons of Mute and Tundra Swans
Mute and tundra swans have some clear differences in their status and ecology in the Chesapeake Bay region:
| Category | Mute Swan | Tundra Swan |
|---|---|---|
| Conservation Status | Non-native introduced species | Native species |
| Population Size | 4,100 in Maryland (stable currently after population growth) | 100,000+ (wintering population is major portion of entire eastern population) |
| Migration Pattern | Non-migratory year-round resident | Long-distance migrant from Arctic breeding areas |
| Winter Range | Year-round resident | Winter only in Chesapeake region |
| Habitat Use | Shallow bay waters and nearshore marshes | Variety – shallow bay, fields, marshes |
| Food Habits | Mainly submerged aquatic vegetation | Submerged aquatic vegetation and agricultural grains |
| Protections | Game bird – hunting allowed | Fully protected – no hunting |
The tundra swan is a high priority for conservation in the region as a migrating native species that uses the Chesapeake Bay as a critical wintering area. Mute swans are more of a management challenge as a non-native species that competes with native waterfowl and habitats. Understanding the similarities and differences between these two swan species can help inform management programs and maintaining healthy ecosystems in the Chesapeake Bay.
Swan Watching in the Chesapeake Bay
The Chesapeake Bay region provides excellent opportunities to observe both mute swans and tundra swans, especially during the winter months. Here are some of the top spots:
– Susquehanna Flats – A broad, shallow area at the mouth of the Susquehanna River that attracts large flocks of tundra swans as well as mute swans. Public boat launches provide access.
– Blackwater National Wildlife Refuge – Extensive marshes on Maryland’s Eastern Shore that hold thousands of tundra swans in winter, along with many year-round mute swans. A wildlife drive and walking trails allow viewing.
– Tangier Island – This island in the middle of the Bay is a key tundra swan wintering location, with shallow water feeding habitats. Mute swans also present year-round. Daily ferries provide access.
– Elkhorn Slough, Chesapeake Bay – A protected coastal estuary that draws in many species of migratory waterfowl in winter, including tundra swans. Mute swans frequent the area. Trails and kayak launches allow viewing access.
– Deal Island Wildlife Management Area – An area on Maryland’s Eastern Shore with impoundments, tidal marshes and fields for migratory waterfowl. Large mixed flocks of tundra and mute swans are common in winter. Open for seasonal hunting as well as wildlife observation.
Early mornings and late afternoons provide the best viewing opportunities to see flocks of swans flying between feeding and resting areas. Always observe from a distance and use binoculars to respect the birds’ space and avoid startling them. With good timing, observers may be rewarded with hundreds or even thousands of elegant swans using their Chesapeake Bay wintering grounds.
Management and Conservation
Both tundra swans and mute swans receive some focused management attention in the Chesapeake Bay region:
Tundra Swans
Tundra swans are not hunted and receive full legal protections under the Migratory Bird Treaty Act. Conservation priorities include:
– Protecting key habitats like the Susquehanna Flats through water quality improvements, limits on disturbance, and preventing damage to submerged aquatic vegetation.
– Managing impoundments and agricultural habitats on public lands to provide feeding and roosting sites.
– Monitoring and limiting lead poisoning from incidental ingestion of lead shot while feeding in terrestrial habitats.
– Public education about identification and avoiding disturbance to tundra swan flocks.
Mute Swans
Because mute swans are a non-native species, management takes a different approach:
– Population control through controlled egg addling and regulated hunting seasons in Maryland and Virginia.
– Habitat management focused on enhancing conditions for native waterfowl rather than favoring mute swans.
– Discouraging feeding and artificial support for mute swans.
– Monitoring populations and negative impacts on submerged aquatic vegetation, native waterfowl and other species.
A balanced approach allows for appreciation and conservation of migrating tundra swans as part of the natural ecosystem, while also controlling expansion and limiting habitat damage from non-native mute swans. Cooperation between wildlife agencies, private landowners and the public is key for effective management of both species.
Conclusion
The Chesapeake Bay provides vital habitat for two species of swans – the native migratory tundra swan that winters in the area in high numbers, and the non-native mute swan that has become well-established as a year-round resident. Careful management and habitat protections are needed to conserve tundra swans that depend on the region as a migratory stopover. Simultaneously, population controls and habitat policies for mute swans can limit further expansion and ecosystem impacts from this introduced species. With informed conservation measures, the spectacular sight of wintering swans on the Chesapeake can be maintained for future generations to enjoy.
