Thrushes are a family of small to medium-sized passerine birds that occur mainly but not exclusively in the Old World. They are found in Europe, Africa, Asia and Australasia. There are more than 65 recognised species in the thrush family Turdidae. They are closely related to the Old World flycatchers and the chats.
Thrushes are plump, soft-plumaged, small to medium-sized birds, inhabiting wooded areas, and often feeding on the ground or eating small fruit. The smallest thrush may be the forest rock thrush, at 21 g (0.74 oz) and 14.5 cm (5.7 in). However, the shorter, 10 cm (3.9 in) Przevalski’s rubythroat, which was once classed as a thrush, is smaller. The largest thrushes are the blue whistling thrush, at 178 g (6.3 oz) and 33 cm (13 in), and the bluebird of paradise, at 300 to 350 g (11 to 12 oz) and 36 to 40 cm (14 to 16 in). The long-tailed ground roller also reached a length of 33 cm (13 in) and 350 g (12 oz).
Thrushes have soft, often colorful, plumage. They inhabit forests and woodlands worldwide. Most species are year-round residents. Many of the forest species are dark brown above and light below. Some species have black patches on the face and throat. They have loud, distinctive songs and often display complex and unpredictable patterns of migration. They are omnivorous, eating a wide range of insects, earthworms, berries and small vertebrates. While many thrush species gather in flocks during the non-breeding season, they are territorial and solitary nesters.
Thrush Diets
Most thrush species are omnivorous, eating a combination of insects, earthworms, fruit and berries. Their diets vary by species and depending on the time of year and local food availability.
Many thrushes actively hunt and forage on the forest floor, flipping leaves to uncover insects, earthworms and snails. Species like the wood thrush, hermit thrush and veery feed heavily on insects and worms during the summer breeding season to provide high-protein food for their chicks.
In the fall and winter, thrushes switch over to eating more berries and fruit. They play an important role as seed dispersers, ingesting the fruits of trees and shrubs and spreading the seeds through their droppings. Species like the American robin feed heavily on berries such as juniper, dogwood, sumac and black cherry.
Some thrush species also occasionally eat small amphibians, reptiles and mammals. Larger thrushes like the blue whistling thrush will take small snakes, frogs, lizards and rodents.
Do Thrush Eat Ants?
Most thrush species do opportunistically eat ants as part of their varied insectivorous diet. Ants provide a good source of protein and fat for thrushes.
Ground-foraging thrushes like the wood thrush, hermit thrush and American robin frequently pick ants off the forest floor and eat them. These species will actively dig into ant mounds to feed on ant eggs, larvae and pupae as well.
Other thrushes that feed more heavily on fruit and berries also eat ants when the opportunity arises. For example, the missel thrush and fieldfare feed mainly on fruits like mistletoe berries and rowan, but will still consume ants opportunistically, especially when feeding their young.
Thrushes employ various techniques for ant consumption. Many thrushes use their beaks to capture and kill individual ants. Some species like the American robin may stamp on ant mounds to flush the ants out into the open where they can easily pick them off. Thrush may also use sticks or small rocks to break open rotting logs to access ant colonies inside the decaying wood.
Overall, while ants do not make up a primary component of thrush diets, they do provide a nutritious supplementary food source that most thrushes will take advantage of when available. The propensity of different thrush species to eat ants depends on their natural histories and typical foraging behaviors.
Thrush Species and Ant Consumption
American Robin
The American robin is widespread and abundant across North America. It feeds heavily on ants during the spring and summer, especially when feeding nestlings. Robins often stamp on ant mounds to flush them out and will also dig into mounds to get ant larvae. Ants provide an important source of protein for robin chicks. Robins also opportunistically eat ants in the fall and winter.
Wood Thrush
The wood thrush of eastern North American forests feeds frequently on ants which it finds by flipping over leaf litter on the forest floor. Ants and other insects make up over half of the wood thrush’s diet during the breeding season. Their propensity for ants depends on availability, decreasing in the fall when they switch to eating more berries.
Hermit Thrush
The hermit thrush consumes a wide variety of insects including ants. They actively hunt ants on the forest floor by probing into ant mounds, rotten logs and under rocks. Ants are an especially important food source for breeding hermit thrushes feeding their young. Their ant consumption decreases in winter.
Veery
The veery eats large amounts of ants which make up around 30% of its diet. It uses its beak to capture individual ants on the ground and will also dig into ant nests for larvae and pupae. Veeries eat more ants during breeding season to feed their chicks the high protein content.
Eurasian Blackbird
The Eurasian blackbird has a varied omnivorous diet consisting of insects, worms, fruits and berries. They opportunistically eat ants on the ground and dig into ant hills. However, ants do not make up a primary food source and blackbirds prefer larger prey like earthworms and beetles when available.
Song Thrush
Song thrushes consume a wide variety of soil-dwelling invertebrates like earthworms and snails. They also eat large numbers of ants by probing into ant nests in the ground and predating on ant trails. Song thrushes teach their young to eat ants and ant consumption peaks during breeding season.
Mistle Thrush
The mistle thrush eats a primarily fruit-based diet heavy on mistletoe berries. However, they opportunistically consume ants on the forest floor throughout the year, especially when breeding. They use their beaks to pick ants off the ground and will dig into ant mounds.
Fieldfare
The fieldfare has a winter diet based mainly on berries, seeds and fallen fruit like apples. During the breeding season, they switch to eating more invertebrates like ants which provide their chicks with needed protein. They use their beaks to capture and kill individual ants.
Clay-Colored Thrush
The clay-colored thrush of Central America feeds heavily on ants, making up over half of its diet. It actively hunts ants on the ground, digging into ant hills and breaking open rotten logs. Ant consumption peaks during breeding season when adults collect ants to feed their young.
Bare-eyed Thrush
Endemic to the island of Sri Lanka, the bare-eyed thrush consumes a range of insects including ants. It opportunistically feeds on ants throughout the year by probing its beak into ant nests in the soil and preying on above-ground ant trails.
Comparative Ant Consumption Among Thrush Species
Species | Extent of Ant Consumption |
---|---|
American Robin | High – Important food source especially when breeding |
Wood Thrush | Moderate to High – More than 50% of diet during breeding season |
Hermit Thrush | Moderate – Actively hunted food source |
Veery | Moderate – Around 30% of diet |
Eurasian Blackbird | Low to Moderate – Opportunistic consumption |
Song Thrush | Moderate – Important food for chicks |
Mistle Thrush | Low – Opportunistic consumption |
Fieldfare | Moderate – More when breeding |
Clay-Colored Thrush | Very High – Up to 50% of total diet |
Bare-eyed Thrush | Moderate – Opportunistic consumption |
As seen, the extent to which different thrush species consume ants varies widely based on their natural history, habitat, and typical diet. Some thrushes like the American robin and clay-colored thrush feed heavily on ants which make up a significant portion of their diet. Other species like the mistle thrush only opportunistically or supplementally eat ants. In general, ant consumption is highest during the breeding season when thrushes require ample protein to feed their chicks.
Foraging Behaviors for Eating Ants
Thrushes exhibit a range of foraging behaviors and techniques specifically for finding and eating ants:
- Using their beaks to pick individual ants off the ground
- Flipping over leaves, rocks and rotting logs to uncover ants
- Stamping on the ground to disturb and flush out ant nests
- Digging directly into ant mounds and tunnels
- Probing their beaks into logs and tree trunks to extract carpenter ants
- Following ant trails and predating along the pheromone path
- Using sticks and rocks to break open dead logs harboring ant colonies
- Picking flying ants out of the air
Some thrushes like the American robin employ tactile foraging by stamping their feet to cause vibrations that simulate rainfall. This prompts ants to rush out of their tunnels, allowing the birds to quickly pick them off.
Thrushes teach these ant-foraging techniques to their young by demonstrating the behaviors and bringing ants back to nestlings. The chicks eventually learn to find and capture ants on their own.
Benefits of Ants for Thrushes
Ants offer several key benefits as a food source for thrushes:
- High in protein and fat – Essential for breeding thrushes to feed their chicks
- Abundant and renewable resource – Ant colonies contain many individuals
- Available habitat-wide – Found across forest floors, in dead logs, and underground
- Nutrient-dense – Good source of energy relative to volume consumed
- Reliable prey – Ant colonies persist year-round; not seasonal
The protein content of ants is especially vital for growing thrush chicks during breeding season. The abundance and accessibility of ants across the habitat also makes them a stable food source.
Some risks associated with ant consumption include aggression from soldier ants that can bite and sting. Thrush beaks help protect them from ant venom and chemical defenses. There is also the risk of spreading pathogens and parasites that concentrate in some ant colonies. Overall however, the benefits appear to outweigh these risks for most thrushes.
Conclusion
Ants form an important part of the diet for many thrush species around the world. While the extent of ant consumption varies, most thrushes opportunistically feed on ants to some degree using specialized foraging techniques. The high protein and ready availability of ants make them particularly beneficial to thrushes during the breeding season when adults require extra nutrition to raise their chicks. The propensity of different thrush species to eat ants depends on factors like their habitat, natural food preferences, and the time of year. However, the dietary flexibility and insectivorous behavior of thrushes provide them with the adaptations to take advantage of ants as a nutritious and abundant food source across many ecosystems.