Grasshopper Sparrow

(Ammodramus savannarum)

Status: Special Concern (ESA 2015, SARA 2013)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Similar Species
Threats/Reasons for Being Endangered
Conservation and Recovery Strategies
How You Can Help

Species Identification:

The Grasshopper Sparrow is a small songbird that is mottled brown, and has a white or tan coloured underbelly. They have a large bill, a sharp tail, and pale legs. Their head is flat on top and has a white stripe down the middle. Both males and females look very similar to each other. They are most often identified by their buzzy song, which is said to sound like a grasshopper, or a “buzzy trill”.

Diet:

The Grasshopper Sparrow gets its name from having a diet that is largely made up of grasshoppers. Their breeding diet besides grasshoppers is mostly insects like beetles, caterpillars, and spiders which make up 80% of their diet in some areas. In the winter, seeds make up a larger portion of their diet. They feed off of the ground or from the bases of plants, so exposed ground is important for their habitat.

Map taken from Wildlife Species Canada: https://wildlife-species.canada.ca/species-risk-registry/virtual_sara/files/cosewic/sr_Grasshopper%20Sparrow_2013_e.pdf

Habitat and Range:

The Grasshopper Sparrow breeds throughout most of the eastern United States, and within the southern parts of the Canadian provinces from British Columbia to Quebec. The Eastern Grasshopper Sparrow subspecies is only found in Ontario and Quebec within Canada. About 10% of the global breeding population of this subspecies is within Canada. Grasshopper Sparrows will either remain on their breeding grounds for the winter, or migrate south. The northern populations will make a longer journey to the southern United States, while more southerly populations will either make a smaller migration, or remain where they are.

Grasshopper Sparrows prefer medium to large grasslands with sparse vegetation and few low shrubs as well as areas with well-drained and poor soils (usually shallow soils over limestone beds). Tall grass stalks and scattered shrubs may be used as perches. In Ontario, Grasshopper Sparrows are found in a variety of agricultural fields and in open areas like the Carden and Napanee Alvars. The highest concentrations of grasshopper sparrows in the province are in areas of natural grasslands around Rice Lake, Lake Simcoe-Rideau, and the Carden Plain area - all located within The Land Between.

Biology and Behaviour:

The male Grasshopper Sparrows return to their Ontario breeding grounds in late April or early May. Females arrive 5-10 days later and form pair bonds. The females build a cup nest with grass and dead vegetation. An average of 4-5 eggs are laid, and hatchlings are fed by both parents for about a week. The young fledge from the nest starting at the end of June, and rely on parents for another three weeks. Fall migration begins in late August.

The Grasshopper Sparrow breeding success depends largely on the amount of predation pressure they face. Success rates range from 7 to 83%. Predators are thought to include skunks, foxes, squirrels, crows, raccoons, snakes, and domestic cats.

Similar Species:

Le Conte’s Sparrow has a white central stripe down its crown, grey cheeks, and dark striping down its sides
The Nelson’s Sharp-tailed Sparrow has a grey central stripe down its crown, and an orange face
Henslow’s Sparrow has dark streaks on their under feathers, and a triangular ear pattern

Threats/ Reasons for being at Risk:

1. Loss of grassland habitat: Hayfields and pastures are being converted to more intensive crops like corn, soybeans, and grains to meet the ever increasing needs of food production. Natural grassland habitats are even more rare, and are constantly under urbanization and development pressures.

2. Habitat fragmentation and predation: Grasshopper Sparrows need large uninterrupted spaces. Habitat fragmentation is caused by the increasing need for development and roads, which leads to patch isolation, and therefore local extirpations. Breeding success is higher in larger patches (>30 hectares in some areas). Higher predation rates also occur along forest edges, making the Grasshopper Sparrow more vulnerable to predators.

3. Mowing and livestock grazing: Mowing of tall grasses cannot be tolerated during the breeding and nesting season, as Grasshopper Sparrows rely on tall grasses for courting and nest making. As habitat loss becomes an increasing issue, Grasshopper Sparrows rely more on other types of habitats with tall grass that are often mowed for either aesthetics or agricultural purposes. Modern agricultural techniques and the warming climate also promotes earlier hay cutting, and while many pastures are being converted into crops, what is left is being overgrazed by livestock. This in turn will alter vegetation composition and make it more difficult for the Grasshopper Sparrow to find adequate food, nesting material, and safe habitat.

4. Climate change: Climate change is making weather more unpredictable which affects the timing of spring precipitation and vegetation growth. Cold snaps and extreme weather events can also lead to mortality or starvation if the insect population is impacted.

5. Pesticides and fertilizers: Agricultural chemicals may affect Grasshopper Sparrows directly through contact, or indirectly by targeting their food source or remaining in the environment. Studies have shown a worldwide decline in insect populations and have found chemical buildups in the environment and in wildlife.

6. Suppression of grassland fires: Natural fire suppression is impacting native grassland composition. Natural wildfires are a healthy way of restoring balance to an environment and to increase native plant diversity. Suppression of fires is also allowing invasive species to move in and take over.

Conservation and recovery strategies:

As with other grassland birds, some simple changes in management technique could make a huge difference. Most conservation efforts are through voluntary conservation efforts, since much of their habitat occurs on private land. There have also been some efforts to create special incentive programs to encourage stewardship in agriculture. Delaying hay cutting until mid-August or September could be very beneficial for these birds. Recovery programs in place for the Loggerhead Shrike should also help populations of Grasshopper Sparrows. Both of these bird species nest on the Carden and Napanee Alvars. Since the Grasshopper Sparrow is listed as Special Concern in Ontario and nothing is directly being done to conserve this species, voluntary programs and aiding other Species at Risk will also help the Grasshopper Sparrow.

How can you help?

Report any sightings of the Grasshopper Sparrow to the NHIC.
Support local farmers who follow sustainable practices and best management practices for bird habitat.
Controlled burns have been successful in restoring grassland habitat for Grasshopper Sparrows, except in areas where the invasive White Sweet Clover is prevalent. Mechanical mowing may also be effective, but only before or after breeding and nesting season.

Additional Resources:

Cornell Lab of Ornithology page
COSEWIC 2013 Assessment and Status Report
Controlling White Sweet Clover in Ontario (document)
Animal Diversity Web. Grasshopper Sparrow page
Ontario Ministry of Environment profile

Sources:

Bezener, A. 2000. Birds of Ontario. Lone Pine Publishing. Edmonton, ON.

COSEWIC. 2013. COSEWIC assessment and status report on the Grasshopper Sparrow pratensis subspecies Ammodramus savannarum pratensis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ix + 36 pp. (www.registrelepsararegistry.gc.ca/default_e.cfm).