Swallows are small passerine birds in the family Hirundinidae. There are around 90 species of swallows which are found in most parts of the world. Swallows are aerial insectivores, which means they catch and eat insects while in flight. Some key facts about swallows:
– Swallows have adapted to hunting insects while in flight. They have slender bodies and long, pointed wings which allow great maneuverability and speed in flight. Their feathers are structured to provide aerodynamic efficiency.
– Swallows nest in sheltered sites such as trees, cliffs, or buildings. The nests are cups or bowls made of mud or saliva mixed with plant material. Many species of swallows live in close proximity to humans and nest on human structures.
– Swallows are social birds and often nest in colonies. Both parents participate in building the nest, incubating the eggs and feeding the chicks.
– Swallows are migratory in the northern parts of their range. They migrate south to warmer climates for the winter. Some swallow species can travel thousands of miles between their breeding and wintering grounds.
Diet of Swallows
The diet of swallows consists almost entirely of insects which are caught and eaten while the birds are in flight. Swallows have evolved a wide gape to scoop up insects while flying. Their diet commonly includes:
– Flies
– Mosquitoes
– Moths
– Butterflies
– Bees
– Wasps
– Flying ants and termites
– Beetles
– Mayflies
– Grasshoppers
– Crickets
– Cicadas
– Dragonflies
Swallows will occasionally eat spiders and have been observed drinking while flying over water. But they get nearly all their nutrients and proteins from insects. Swallows are constantly on the hunt for insects while in flight. They fly continuously during the daytime hours to catch enough insects to sustain their high metabolism.
Some species of swallows show a preference for certain insects. Cliff swallows tend to eat flies, barn swallows target flying ants and beetles, while tree swallows eat moths and flying insects like mayflies. But in general, all species of swallows are opportunistic and eat whatever insects are abundant as they fly past.
How Do Swallows Feed Their Young?
When swallows breed, the parents work together to feed their chicks. Here is how swallows feed their babies:
– Both the male and female swallow participate in gathering insects to bring back to the nest. The parents take turns leaving the nest to hunt, while the other stays behind to look after the chicks.
– The parent swallows catch insects in flight and store them in their beak and cheek pouches. Their mouths can stretch to hold a remarkable number of insects at once.
– Returning to the nest, the parent swallow perches on the rim of the nest and regurgitates the insects directly into the gaping mouths of the chicks.
– The chicks make a constant harsh begging call when hungry, stimulating the parents to gather more insects. The parents make numerous feeding trips per hour to keep up with the demand.
– As the chicks grow, the parents gradually provide larger insects. The chicks need the protein from the insects to support their rapid growth and development.
– Both parents feed the chicks with equal diligence from morning to night. In some swallow species, the parents may feed the young up to 400 times per day.
– Feeding activity decreases as the chicks near fledging. The parents encourage the chicks to leave the nest when their wings are developed enough for flight.
So in summary, swallow parents work incredibly hard to catch vast quantities of insects while flying and stuff them into the mouths of their hungry brood. The nutrition from the insects enables the chicks to grow and get ready to take their first flight.
What Insects Do Swallows Feed Their Babies?
Swallow parents are not picky about what insects they feed their chicks. They simply gather whatever insects are available in abundance as they fly past. However, some key insects that commonly appear in the diet of swallow nestlings include:
Flies
Flies are a major component in the diet of many swallow species. Flies provide a lot of nutrition in a small package, making them an excellent food source for growing chicks. Swallows are one of the most important predators of flies.
Some common flies fed to chicks include:
– House flies
– Stable flies
– Blow flies
– Fruit flies
– Fungus gnats
Bees and Wasps
Bees, wasps, and other winged hymenopterans are also important prey for swallows. They provide substantial protein and fat for developing chicks. Swallows have been observed feeding their young the following insects:
– Honeybees
– Bumblebees
– Cicada-killer wasps
– Mud dauber wasps
– Paper wasps
– Yellowjackets
The parents remove the stings before feeding bees and wasps to the nestlings.
Butterflies and Moths
Butterflies and moths are a frequent prey item for aerial insectivores like swallows. Moths in particular make up a large proportion of the insects fed to chicks for many swallow species. Some moths and butterflies commonly consumed include:
– Armyworm moths
– Cutworm moths
– Gypsy moths
– Cabbage white butterflies
– Monarch butterflies
– Swallowtail butterflies
Mayflies
Mayflies are an excellent source of nutrients for growing chicks. Swallows gorge on mayflies when they emerge in large swarms, feeding the surplus to their young. Some species known to be fed to swallow chicks:
– Sulfur dun mayflies
– Drakes/spinner mayflies
– Lake flies
– Fishflies
Beetles
Beetles make up a substantial portion of the diet for many swallows. Their hard wing covers and legs require the parents to break them into pieces before feeding nestlings. Some beetles fed to chicks include:
– Ladybugs/ladybirds
– Japanese beetles
– June bugs
– Scarab beetles
– Ground beetles
– Leaf beetles
– Weevils
– Fireflies
Ants and Termites
Swallows will gather ants and termites to feed growing chicks. Especially important are the following species:
– Flying ants
– Velvet ants
– Winged termites
The protein-rich ants and termites provide important nutrition for feather growth and proper development.
Miscellaneous Insects
In addition to the main groups above, swallow parents will supplement their chicks’ diet with other insects like:
– Mosquitoes
– Midges
– Crane flies
– Aphids
– Cicadas
– Leafhoppers
– Treehoppers
– Lacewings
– Flying cockroaches
– Dragonflies
– Damselflies
They gather whatever insects are available in abundance to satisfy their chicks’ voracious appetite. The wide variety of insects provides the full range of nutrients needed for the nestlings to grow and fledge successfully.
How Much Food Do Swallow Chicks Require?
Swallow chicks have an incredibly high metabolism and demand a lot of food. Here are some details on swallow chick nutrition requirements:
– Growth Rate: Chicks can gain up to 10-15% of their body weight per day.
– Number of Feedings: Chicks are fed as often as 400 times per day. Feedings occur every 1-3 minutes though the day.
– Food per Feeding: Chicks may eat around 10 insects or more at each feeding session.
– Total Volume: Chicks consume 25-35% of their body weight in insects each day. A brood may eat hundreds of thousands of insects before fledging.
For example, a brood of 5 barn swallow chicks was estimated to consume over 67,000 insects before leaving the nest. At their peak, the parents made nearly 2,000 feeding trips per day to satisfy their offspring.
The table below shows the incredible amount of food swallow chicks require:
Days after Hatching | Body Weight (g) | Amount Eaten per Day (g) |
---|---|---|
2 | 2.5 | 0.5 |
5 | 7 | 2 |
8 | 11 | 3.5 |
12 | 16 | 5 |
This enormous amount of high-protein insect food is essential for the chicks to achieve the rapid weight gain needed to be ready for their first flight at around 20 days old. The diligent feeding efforts of the swallow parents ensure the chicks grow quickly and become strong fliers able to feed themselves and migrate long distances.
Adaptations for Collecting Food
Swallow parents have many special adaptations that enable them to collect the vast number of insects required to raise their chicks:
Aerodynamic Body Shape
Swallows have a streamlined, tapered body shape and long, pointed wings which maximize airborne maneuverability and speed, allowing them to nimbly chase down insects while flying. Their short legs also reduce air resistance.
Wide Gape
Swallows have a huge gape that allows them to scoop and trap insects while in flight. Their gape spans nearly the entire width of their head.
Large Mouth and Cheek Pouches
The mouth and cheek pouches of swallows are able to stretch enormously to temporarily hold the many insects carried in each foraging trip. The pouches do not hinder the aerodynamics of the birds.
Forked Tail
The forked tail of swallows aids in aerial agility and precision turning to pursue insects. The long outer tail streamers help provide lift and stability in flight.
Fast Flying Speed
Swallows are able to fly at speeds over 30 mph when hunting insects. Their rapid speed allows them to overtake flying insects.
Excellent Vision
Swallows have outstanding eyesight which helps them spot tiny insects from a distance. They also open their beaks to help funnel prey in while flying rapidly.
All-day Activity
Swallows spend all their daylight hours on continuous foraging flights to find enough food for their offspring. Their high activity level enables them to provision the nest.
So in summary, swallows have a remarkable suite of behavioral and physical adaptations that enable them to be highly efficient aerial insect hunters. These traits allow them to supply their metabolically demanding chicks with the enormous amounts of insects they require to grow and successfully leave the nest. The evolution of these features has been driven by the selective pressures to raise fast-developing young.
Conclusion
In conclusion, swallow parents work tirelessly to provide their chicks with the right quantity and quality of insects to sustain their rapid growth. Swallow nestlings need huge amounts of high-protein insects like flies, bees, wasps, moths, mayflies, and beetles which the parents deliver up to 400 times per day. To meet this demand, swallows have evolved a host of superb adaptations for catching insects in flight such as their streamlined body shape, large gape and cheek pouches, forked tail, swift flying speed, and sharp eyesight. Their incredible effort ensures that the chicks get adequate nutrition to grow their flight feathers and leave the nest prepared for their migratory journey. The formidable hunting abilities of swallows also provide an important check on insect populations, benefitting humans and ecosystems. Understanding the swallow’s aerial insectivore niche provides insight into their natural history, evolution, and importance in global food webs.