Did you ever pause on a summer day to admire the swallows doing aerial gymnastics overhead? Those swallows are designed to maneuver incredibly quickly while flying at speeds up to 40 miles/hour. Swallows are aerial insectivores and catch 99% of their diet while diving, banking hard, and wheeling through the air. Fortunately for us, their favourite food is the larger insects that pester us: mosquitoes, grasshoppers, beetles, and flies. A single swallow eats approx. 60 insects an hour, and from a utilitarian perspective, swallows make great neighbors.
The traditional farm offered ideal habitat for swallows. The barn swallow (Hirundo rustica) was a common summer resident on the farm, which offered these birds outbuildings in which to build their nests, fields and ponds for foraging, and livestock to attract their insect prey. In exchange for a safe location to raise their broods, the swallows feasted on the insects that pestered the farmer, his crops, and his animals. Coincidentally, the North American population of barn swallows has dropped significantly since the mid-1980s, which is around the time that the conversion from family farms to mega farms began to level out. While the causes for the decline in barn swallow populations are not fully understood, a loss of nesting and foraging habitat is suspected to play a substantial role
If you are lucky enough to have barn swallows on your property - congratulations! If you do not, but wish you did, you can take steps to improve the likelihood of hosting these birds. Either way, you could have more swallows by looking at your property from their perspective and enhancing the features that attract them. The payoff for you will be less insects to pester you and your family, as well as the knowledge that you are taking steps to help a beautiful and valuable species.
• Barn swallows do not like forested or urbanized areas because they need open air space to forage. Instead, the swallows choose grasslands, fields, marshes, and bodies of water. What follows is a list of some basic habitat requirements for swallows.
• Areas of open grass: swallows need it for foraging and if an expanse of grass is mown less frequently, then more insects will inhabit it and provide more food for the swallows. Hay fields are excellent places for swallow to forage.
• Bodies of water: swallows drink by skimming over the surface of ponds, lakes or wide streams and scooping up mouthfuls of water. Bodies of water also abound in insects.
• Open areas with few trees: trees obstruct the swallows flight and make foraging difficult. Tree swallows, a cousin of barn swallows nest in tree cavities and nest boxes and don’t mind a few trees.
• No pesticides or insecticides: swallows are insectivores - no insects, no swallows.
• Spots to perch: All swallows like to perch on wires, clotheslines, or antennas; and will commonly nest near power lines.
Barn swallows construct their mud nests under an overhang to protect it from the rain and wind. The nests are constructed by a pair of barn swallows who visit a mud puddle, mix a beakful of mud with grass stems and form it into a little pellet, and then ‘glue’ it to the side of a vertical surface and to each other. In the end, a mud cup lined with fine grasses and feathers provides a dry home for a clutch of eggs.
Traditionally barn swallows nested in caves. Today, as their common name suggests, their favourite locations are eaves, rafters, and cross beams in barns, sheds and stables. They also use the underside of bridges, wharves, and culverts. Barn swallows don’t mind company and large colonies are common where suitable habitat exists. Each pair will defend a small territory around their nest between 4 - 8 square metres. Below is a list of features that will entice barn swallows to breed on your property.
Mud puddles: barn swallows construct their nests out of mud. And even though they will reuse an old nest, they still want to dab new mud pellets along the top rim to refresh the nest. A working farm should have no problem providing mud. For others, allowing a spot for mud to form under a downspout provides nest material for a pair of swallows.
Access to buildings: if you can do so, leave open a door or window so the swallows can enter and leave at will.
Platforms for nest placement: the swallows will either affix their nests to a vertical surface, or construct it upon a shelf. Having a shelf or platform to build upon saves the swallows from needing to construct one of their own from mud pellets and allows them to skip this step. From scratch, it can take a pair of swallows over 1,000 trips to the mud puddle to construct a new nest. A nesting platform can be as simple as a 2x4 ledge.
Leave old nests: given that it takes swallows a lot of effort to construct a new nest, they would prefer to reuse an existing nest. Adults have strong site fidelity and will return to the same locations.
If you feel inspired to go even further in attracting barn swallows, you can hang artificial nest cups and nesting shelves or erect a special nesting structure. Richard and Diane Van Vleck of American Artifacts observed that barn swallows preferred to use the artificial nest cups (which can be constructed of wood, clay, or concrete affixed to a wooden backing). The swallows still added some mud pellets to the rim. Here is a summary of the key points if you wish to hang artificial nests:
Place the cups where you want the swallows: since they prefer the artificial nests, you can use the nest draw the swallows away from a less than satisfactory location.
No hot spots: don’t place cups under a roof that has no insulation or ventilation and that receives afternoon sun; the microclimate will be too hot.
Head room: artificial nests or nesting shelves should be 6 in. (15 cm) from the ceiling
Foot traffic: barn swallows typically nest 8 - 10 feet above the ground where foot traffic is minimal. The birds like to nest farther above ground where traffic is heavy. The swallows will become used to the same people coming and going and don’t seem to mind some human activity.
Dealing with droppings: for the first two weeks the parents will remove fecal sacs from the nest. After that point the nestlings will defecate over the edge of the nest. If you wish to keep the ground/building below a nest clean, you could lay down some newspaper and remove it after the young have fledged. Some old-timers believed that barn swallows spread salmonella, but a Swedish study proved otherwise*. In fact, barn swallows are not a significant source of disease†.
Clean nests: if you can clean out the artificial nest, a pair of swallows will likely reuse it. An annual cleaning will ensure the nests are ready for each new year.
If you or someone you know is handy, you could construct a barn swallow nesting structure. I’ve come across these structures used as mitigation tools to preserve barn swallow nesting colonies. For example, the structures can replace demolished barns and outbuildings. The nesting structures are typically a long, roofed box with an open bottom supported by four wooden posts. Within the box, dividers hang down to provide each pair of swallows with its own compartment. Metal flashing wraps each post to deter predators.
Barn swallows are beautiful birds and their presence should be a welcome sign. If you take steps to attract them to your property, I hope you will be rewarded with their aerial gymnastics and insatiable appetite for insects.
If an old building that houses a barn swallow nesting colony is to be demolished, you should erect the new nest structure the year before so the birds can investigate it as a potential nest site for next year. Adding artificial nest cups will make the structure even more attractive.
Resources: * Haemig, Paul D.; Hernandez J.; Waldenström J.; Bonnedahl J.; Olsen B (2008). "Barn swallows (Hirundo rustica) test negative for Salmonella". Vector-Borne and Zoonotic Diseases. 8 (4): 451–454. †BSC
Rebecca Harrold homesteads and homeschools on a 23-acre property in rural Ontario, where she is engaged with all types of wiser living skills. She believes that restoring the land to its healthy, sustainable state will increase its resilience, and in turn, the resilience of the people who depend upon it. Connect with Rebecca at Harrold Country Home and on Instagram. Read all of Rebecca’s MOTHER EARTH NEWS posts here.
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