World News, Today World News, Latest International News, World Breaking News, Trending News of World - Times of India
· collected 2026-08-21 · by TOI World Desk
In 1962, five mute swans escaped from an estate in Talbot County, Maryland, and their descendants now number nearly 4,000 in the Chesapeake Bay region. According to a US Geological Survey report from 2002, the population had grown to around 4,500. The Maryland Invasive Species Council estimates that the mute swans consume about 10.5 million pounds of aquatic grasses annually, with individual birds eating over eight pounds per day. Concerns have been raised about the impact of these invasive species on native waterfowl and the region's ecosystem, particularly in relation to underwater vegetation restoration efforts.
Written by the local model on 2026-08-21,
using this article's own text rather than the other coverage of the
same event (that is the story summary below).
In 1962, five mute swans escaped from an estate in Talbot County, Maryland.
asserted
swans → escape → County
More than four decades later, their descendants had grown to nearly 4,000 in the Chesapeake Bay region.
asserted
descendants → grow → region
As their numbers rose across the Chesapeake Bay region, so did concerns about how much underwater vegetation they were consuming and how they were affecting native birds.
asserted
they → rise → birds
The
Maryland Invasive Species Council said in 2005 that the population had more than doubled nine times in 40 years and was approaching another doubling.
asserted
population → say → doubling
The US Geological Survey, in a 2002 publication, put the Chesapeake Bay population at about 4,500.
asserted
Survey → put → 4,500
Mute swans are native to Europe and Asia and are considered an invasive species in the Chesapeake Bay.
asserted
swans → consider → Bay
They are large white waterfowl, with adults growing up to five feet long, having a wingspan of seven to eight feet and weighing as much as 25 pounds.
asserted
adults → grow → pounds
These swans feed heavily on submerged aquatic vegetation, also known as SAV, which includes underwater grasses such as eelgrass and widgeon grass.
asserted
which → feed → eelgrass
The Maryland Invasive Species Council estimated that the region's mute swans were eating about 10.5 million pounds of aquatic grasses every year.
asserted
swans → estimate → grasses
A fast-growing population
The five swans that escaped in 1962 became the starting point of a population that grew rapidly in the Chesapeake Bay region.
asserted
that → grow → region
By the late 1990s, the population had increased sharply.
asserted
population → increase → 1990s
A
USGS report said the number had risen by 1,200% between 1986 and 1999.
asserted
number → say → 1986
The report also noted that the Chesapeake Bay population represented about 30% of the total Atlantic Flyway mute swan population at the time.
asserted
population → note → time
Unlike tundra swans, which visit the Chesapeake Bay during winter, mute swans remain in the region throughout the year.
asserted
swans → visit → year
That means the birds continue feeding on the Bay's aquatic vegetation during spring and summer.
asserted
birds → mean → spring
Native waterfowl also eat these grasses, but they are only present in the region for part of the year.
asserted
they → eat → year
The Maryland Invasive Species Council said mute swans could also interfere with efforts to restore aquatic grass beds.
uncertain
swans → say → beds
The birds can consume new plants that are important for the recovery of these underwater habitats.
asserted
that → consume → habitats
According to the council, they could wipe out a restoration planting in only a few days.
uncertain
they → accord → days
Info source: Wildlife Nomad
Why underwater grasses matter
Aquatic grasses are an important part of the Chesapeake Bay ecosystem.
asserted
grasses → matter → ecosystem
The Maryland Invasive Species Council described them as the base of many food chains in the Chesapeake estuary.
asserted
Council → describe → estuary
A range of plants and animals depend on these grasses, including species that are important to commercial activities.
asserted
that → depend → activities
Mute swans feed by putting their heads and long necks underwater.
asserted
swans → feed → heads
They can pull out whole plants, including their roots and rhizomes.
asserted
They → pull → roots
The
Chesapeake Bay Program says adult mute swans eat more than eight pounds of underwater grasses each day.
asserted
swans → say → grasses
Their diet includes eelgrass and widgeon grass.
asserted
diet → include → eelgrass
The USGS report found that widgeon grass made up 56% of the food found in the birds' gullets, while eelgrass accounted for 43%.
asserted
eelgrass → find → %
Other submerged aquatic vegetation and invertebrates made up a much smaller share.
asserted
vegetation → make → share
The birds also change their diet at different times of the year.
asserted
birds → change → year
During winter, they can eat wheat and other grains from farm fields.
asserted
they → eat → fields
But underwater grasses remain an important food source, particularly during spring and summer.
asserted
grasses → remain → spring
Pressure on native birds
Mute swans are known for aggressive behaviour, and the Maryland Invasive Species Council said this had led to native birds being displaced from nesting and feeding areas.
asserted
birds → know → areas
The USGS also reported that populations of black skimmers and least terns nesting on beaches and oyster shell bars had been eliminated by molting mute swans.
asserted
populations → report → swans
The Chesapeake Bay Program says a male becomes particularly protective while the female is incubating eggs and when the cygnets are young.
asserted
cygnets → say → eggs
It may hiss at and chase away people and other birds that come too close.
uncertain
that → hiss → people
The rapid growth of the population led Maryland resource managers to consider ways to control mute swan numbers.
asserted
growth → lead → numbers
The issue became controversial, with animal rights groups opposing control measures.
asserted
groups → become → measures
The Maryland Invasive Species Council said animal rights groups had argued that state and federal wildlife agencies were using mute swans as a scapegoat for wider environmental problems.
asserted
agencies → say → problems
The USGS reported that proposed control measures included addling eggs, which prevents eggs from hatching, as well as killing adult swans.
asserted
which → report → swans
The issue also became contentious among some residents of the Chesapeake Bay area.
asserted
issue → become → area
…and 3 more, not listed.
