The Grasshopper Sparrow (Ammodramus savannarum) is a small songbird found in grasslands and prairies across much of North America. They get their name from the buzzing, insect-like song of the males. Grasshopper Sparrows have declined in numbers in recent decades as grasslands have been lost to development and changing agricultural practices. But are they truly rare birds? Let’s take a closer look at the status and population trends of the Grasshopper Sparrow to find out.
Grasshopper Sparrow Population and Conservation Status
The Grasshopper Sparrow is listed as a Species of Least Concern by the IUCN Red List. This means it does not qualify as threatened, near threatened, or endangered globally. However, some local populations and regional subspecies are in decline and considered rare.
According to the North American Breeding Bird Survey, Grasshopper Sparrow populations declined by 68% between 1966-2015. The species is considered endangered in Ontario, threatened in New Jersey and Iowa, and a species of special concern in several other states and provinces.
Organization | Conservation Status |
---|---|
IUCN Red List | Species of Least Concern |
COSEWIC | Threatened |
NatureServe | Secure |
So while Grasshopper Sparrows remain relatively common and widespread at the continental level, local populations are struggling in parts of their range. Habitat loss on the breeding grounds and exposure to pesticides on wintering grounds in Mexico are major threats.
Breeding Range and Habitat
Grasshopper Sparrows breed across much of the United States (except the Pacific Northwest, California, and southern Florida), southern Canada, and down into northern Mexico.
They inhabit dry grasslands including native prairies, pastures, hayfields, grassy meadows, fallow crop fields, and open pine savannas. Dense, tall grasses with scattered shrubs and bare ground patches are preferred.
The highest breeding densities occur on untilled native prairie habitats, but Grasshopper Sparrows have adapted to use some human-created habitats. Non-native, tame pastures support lower densities than native grasslands.
Winter Range and Habitat
In winter, most Grasshopper Sparrows migrate to the southern United States, Mexico, and the Caribbean. Their winter range stretches from southern California and Texas south through Mexico, and along the Atlantic Coast from Florida through the Caribbean to Venezuela.
On the wintering grounds, they inhabit weedy fields, grasslands, open woodlands, forest edges, and scrub. Continued exposure to pesticides on agricultural fields in Mexico may be contributing to declining populations.
Migration
Grasshopper Sparrows are long-distance migrants. They form large flocks during fall migration from their breeding grounds to their winter range. Spring migration to the breeding grounds starts in late March and peaks in late April.
Their migrations are prolonged, with the birds stopping to rest and feed frequently. This makes them vulnerable to collisions with buildings and other structures during migration.
Population Estimates and Trends
The total global population of Grasshopper Sparrows is estimated at 14 million birds. Trend data from the North American Breeding Bird Survey shows significant declines in Grasshopper Sparrow numbers:
- Overall population declined by 68% from 1966-2015
- Declines averaging 2.3% per year from 1966-2015
- Steepest declines in the eastern portion of the breeding range
However, trend estimates from the Breeding Bird Survey may be inaccurate for species like Grasshopper Sparrows that inhabit open grasslands and prairies poorly covered by survey routes. More research is needed to precisely estimate population sizes and trends.
Threats and Conservation Challenges
The major threats contributing to Grasshopper Sparrow declines include:
- Habitat loss – Conversion of grasslands to crops or development
- Changing agricultural practices – Increasing field sizes, earlier haying cutting grass before young fledge
- Nest parasitism by Brown-headed Cowbirds
- Pesticide exposure on breeding and wintering grounds
To conserve Grasshopper Sparrows, conservation strategies must focus on protecting and properly managing remaining grassland habitats. Strategies include:
- Conserving native prairies through easements and nature reserves
- Managing grasslands for heterogeneity – mix of grass heights, bare ground, etc.
- Delaying haying of grasslands until after peak breeding season
- Working with farmers and ranchers to develop bird-friendly agricultural practices
- Controlling Brown-headed Cowbird populations
- Limiting pesticide use in agricultural areas where Grasshopper Sparrows occur
Rarity and Conservation Status Summary
- Grasshopper Sparrows remain common and widespread overall, but are declining across parts of their range
- Listed as Least Concern globally but endangered, threatened, or of special concern in some states/provinces
- Population declined by an estimated 68% from 1966-2015 in North America
- Habitat loss, changing agricultural practices, nest parasitism, and pesticides are major threats
- Conservation efforts needed to protect remaining grasslands and improve habitat management
So in summary, while Grasshopper Sparrows are still relatively common in many areas, significant population declines and local rarity make this species a conservation concern. Ongoing habitat loss and threats on their breeding and wintering grounds must be addressed to ensure the long-term survival of Grasshopper Sparrow populations.
Conclusion
The Grasshopper Sparrow remains a widespread species across North America, but has suffered considerable population declines in recent decades. While not globally rare or endangered, local populations are at risk and the species is listed as threatened or endangered in parts of its range. Conservation efforts focused on habitat protection, grassland management, and reducing threats are needed to protect this iconic bird of prairies and grasslands. Their insect-like buzzing song could become a rarity without sustained conservation action.