Wednesday, May 25, 2011

Barn Swallows


This is the time of year when our barn swallows go wild.  They return from their South American vacation and reclaim their mud nests that are glued to the rafters of our 100 year old barn.  They originally nested on cliffs but have expanded their numbers and range as humans built structures seemingly made just for them.

Click to enlarge

Barn Swallows (Hirundo rustica) are the most common of the swallow species, occurring in Europe, Asia and Africa as well as the Americas.  Like the swifts, they feed on the wing, flying up to 600 miles a day as they patrol up and down the creek at high speeds grabbing every tiny insect that we can't even see.  I become their new best friend when I run the tractor between the riparian plantings, stirring up a whole new crop of flying insects.  If I stop, they will patiently perch on the fence, waiting for me to flush their next flying crop.

They are less friendly when we enter the barn.  Their nests are filling with eggs and will soon have little peepers peering over the edge of them.  The parents get a little crazy, swooping in and out over my head with an ineffectual mix of "a twittery series of squeaky notes, often with dry rattle in the middle" as heard at allaboutbirds.org.

Swallow in flight
In the morning and evening, they patrol the garden, competing with the dragonflies for their flying meal.  Even at high speeds I can make out their deeply forked tail that is distinctive from the flat tail of the swallows.  This is apparently a big turn-on for lady swallows.  According to whatbird.com, "Females prefer to mate with males that have the longest and most symmetrical tails and a dark red chest color."  They apparently have read the studies which show that longer tailed males are stronger, more disease resistant and live longer.

A few other interesting facts:
  • A group of barn swallows are known collectively as a "kettle" of swallows.
  • The killing of Barn Swallows for their feathers was one of the problems that led to the founding of the Audubon Society and the passage of the Migratory Bird Treaty Act.
  • When building the mud nest, both male and female make up to 1000 trips collecting mud.
Wikipedia  has extensive information on these fascinating neighbors of ours.

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