The song sparrow ( Melospiza melodia) is one of the most widespread and diverse songbirds in North America. Its diet, like its appearance and habitat, is remarkably adaptable to its environment. This article delves into the intricacies of the song sparrow's diet, exploring its food preferences, foraging behaviors, and how these factors contribute to its survival and ecological role.
Habitat and Distribution Influence Diet
Song Sparrows are found in an enormous variety of open habitats, including tidal marshes, arctic grasslands, desert scrub, pinyon pine forests, aspen parklands, prairie shelterbelts, Pacific rain forest, chaparral, agricultural fields, overgrown pastures, freshwater marsh and lake edges, forest edges, and suburbs. You may also find Song Sparrows in deciduous or mixed woodlands. This adaptability to diverse environments is reflected in their varied diet. What a song sparrow eats depends greatly on what is common across its extensive range.
Seasonal Dietary Shifts
The song sparrow's diet changes with the seasons, reflecting the availability of different food sources.
Summer Diet: Insects and Invertebrates
During the summer breeding season, insects and other invertebrates become a crucial part of the song sparrow's diet, especially for protein and to feed their young. Common prey items include:
- Weevils
- Leaf beetles
- Ground beetles
- Caterpillars
- Dragonflies
- Grasshoppers
- Midges
- Craneflies
- Spiders
- Snails
- Earthworms
Females may consume insects or other invertebrates to supplement their diet.
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Winter Diet: Seeds and Fruits
As insect populations decline in the fall and winter, song sparrows shift their focus to seeds and fruits. Plant foods include:
- Buckwheat
- Ragweed
- Clover
- Sunflower
- Wheat
- Rice
- Blackberries
- Blueberries
- Strawberries
- Raspberries
- Mulberries
- Wild cherries
Plant seeds accounted for 86% of a Song Sparrow’s normal diet in winter. Song Sparrows select their seeds based on what is the most abundant and easiest (fastest) to open - such as millet. They also eat shoots and leaves, flower buds, or even algae in the spring, which tend to have higher levels of protein than old growth.
Foraging Behavior
Song Sparrows forage mostly on the ground, sometimes scratching in the soil to turn up items. They also sometimes forage in very shallow water (fractions of an inch deep) and up in shrubs and trees. Song Sparrows often seem secretive in their behavior, but birds living close to people can become very tame.
Song Sparrow’s forage for food on the ground by using a double-scratch technique of kicking away debris by hopping forward while sweeping both feet quickly back along the ground.
While they may visit bird feeders, especially those placed close to good cover, Song Sparrows rarely feed in flocks and usually search for their food alone or in the company of one or two other birds.
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Diet in Specific Habitats
Birds in coastal marshes and on islands also feed on small crustaceans and mollusks, perhaps rarely on small fish.
Nutritional Efficiency
On average, Song Sparrows digest and absorb between 80 - 90% of the food they eat.
Threats and Conservation
Song Sparrows are abundant in appropriate habitats throughout their range. Song Sparrows are widespread and common across most of the continent, but populations have declined by about 27% between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 130 million and rates them 8 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. These birds have vanished from two islands off Southern California, the result of more frequent fires and introduced hares that have altered the sparrows’ habitat.
Song sparrows are preyed upon by a number of small predators. The Song Sparrow is probably parasitized by the Brown-headed Cowbird more often and over a greater area of North America than any other bird.
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