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Wednesday, September 22, 2010

BARNS, BARN SWALLOWS AND POPULATION DECLINE

PLEASANT VIEW FARM BARN, RICHMOND KENTUCKY AREA
My son and I made a trip to the above historic farm to check out some old farm  structures that  still remain on the early 1800s property. We were unaware of the beautiful twentieth-century barn that rested on a knoll at the back of property. 


As we approached the barn a burst of approximately 30 - 50 Barn Swallows flew out from unknown corners of the barn and swirled about in the air. They eventually settled down on bare branches and telephone wires giving us a look- over. 

My son escaped into the barn from the swirling birds and discovered their nests built on the barn beams. Since this was mid-August we presumed that the nests were empty?

Afterwards, back at my house we talked about the beautiful birds and their place in the environment. I decided to do a bit of "digging" to find information on their behavior and history.
BARN INTERIOR WITH BARN SWALLOW NESTS ON UPPER BEAMS

In the photo above, if one looks at the top barn rafters, one can make out the many barn swallow nests. 


Barn swallows are found over much of the globe. Here, I am only discussing those found in the North American continent. These birds are migratory, spending the winters in South America. Their diet is mainly insects that they grab in the air as they fly. They migrate to South America as winter in North America provides little in the way of insects. They spend their summers in North America breeding and raising their young on a rich abundance of insects. 


BARN SWALLOWS -- (hirundo - rustica)
PERCHING ON NEARBY  ELECTRICAL WIRES OUTSIDE OF ABOVE BARN
Their population remains somewhat steady but declines in populations are being observed. As an example, they are still common in Washington State but the Breeding Bird census indicates that swallows have decreased significantly in the state since 1980

OLDER BARN SWALLOW CHICKS IN THEIR NEST
(Wikipedia -- Walter Siegmund photo)
The main reasons for decline seems to be urban development and industrial agriculture. Barn swallow habitat requires open fields and meadows, water availability and structures such as old barns that one finds in the country. In these old structures they can colonize their nests and be somewhat protected from their main predators such as owls, hawks, and snakes. However, barns and other farm outbuildings are being torn down as industrial agriculture and urban growth reach their tentacles into the countryside. Another factor is that family farms are ceasing operation, forced out by economic reasons, reducing insect populations to 50% resulting in a 50% reduction in barn swallows in these small farm areas. 

Barn swallows play an important role in controlling insects in cultivated areas where they dine on mosquitoes, crickets, flies, grasshoppers and other flying insects. 


What measures can be taken to stop Barn Swallow decline?


Barn Swallow at Nest
(Reference-Artificial Barn Swallow Nests Site)
A suggestion is being made on the site, Artificial Barn Swallow NestsOpening passage is as follows:
"In the past two years since posting these personal pages, several hundred people have emailed asking about either how to get rid of barn swallows nesting on the light fixture over their front door or how to attract swallows to their property. The majority of people emailing us about swallows have a single pair nesting on their porch or under their eaves or deck. They often state that they had several pair in their yard in the spring, but only one pair stayed to nest. The frequency of single pair nestings was a surprise to me, since my experience has been with large or smaller colonies, both on our property and elsewhere. Here in the East, old barns are disappearing at an alarming rate and many long term colonies of swallows have been forced to disperse ..." 


Click here to read the entire article mentioned above that encourages nesting boxes or shelves to provide places for our beleaguered Barn Swallows.

To learn more about breeding, mating and other interesting Barn Swallow facts check out the identification tips and links below. 
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U.S. GEOLOGICAL SURVEY IDENTIFICATION TIPS:

  • Length: 6 inches
  • Tiny bill
  • Dark orange forehead and throat
  • Pale orange underparts
  • Dark, iridiscent upperparts
  • Long, deeply forked tail
  • Juvenile similar to adult but paler underneath with a shorter tail
  • Most often seen flying
  • Will nest communally in mud nests under bridges, in barns and caves, etc

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LINKS:


Bird Web; Washington State, Seattle Audubon Society


University of Michigan Museum of Zoology Animal Diversity Web


Life Histories of Familiar North American Birds 1942 Smithsonian Institute


Artificial Barn Swallow Nests

13 comments:

  1. I love barn swallows. We have several nestings in a cabana at one of the lakes. I just love watching them zip over the water gathering insects.

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  2. Barbara,
    Thanks so much for this post. We have Tree Swallows that come and nest each year. And we have Barn Swallows that come and zip back and forth, hunting over our garden. But despite lots of nesting possibilities, we've never had them nest here on the farm. I can't figure out why. We actually have ideal habitat for them. But they are nesting over what used to be our barn across the road, never venturing closer. He does have an adjacent pond...as in right next to the barn...so that probably trumps our spaces. Sure would love to get a colony started here!

    Thank you so much for this lovely post!
    Elora

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    Replies
    1. Barn swallows are a bit fickly, they might not choose a certain place when there are no other swallows nearby.

      They like a bit of space between their nests..circa 1 metre, but also prefer to nest where already other swallows have their brood.

      So if you make artificial nests, either using plaster, some hay, ground charcoal for coloring and rough cloth so the plaster holds together well(similiar to a cast) and molding it over a bowl with 15 cm diameter, cutting it vertical to have two halves and mount them on a board..

      ...or using wood-cement, a mixture of cement, fine saw dust, calciumdichlorid, also molding it and either glueing or screwing it on a wooden board to mount it on a nice place on the wall

      ..than the swallows may see those nests when they hunt on your grounds and the young ones may decide to nest there.

      For further instructions hit me up on my blog.

      Plastercast-nests are fast and simple to make,but wood-cement ones are very durable, last for 10,15 years and are secure against woodpeckers who may seek to open swallow nests and eat the eggs and young

      If you offer a shallow but big pan with clay-mud and add some extra calcium through ground egg shells or calcium-carbonat, they will built their nests with the clay.

      You also can offer nearby finely ground egg shells and grit to boost their mineral intake, offering better eggshells and more hatching young.

      Especially martins take to the offered minerals fast when put in a pile nearby or on the side of a claypuddle.

      Some fine hay strewn around is also helping with adding nesting material

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  3. Elora -- nature is strange to us humanoids. Sometimes we think we have the ideal situations to attract some species and they never give us the nod. Perhaps in your case it is the water availability? I have an abandoned small barn on my property that has never had barn swallows, ever, though it was pasture land for years .. and water nearby. I can tell it was never used by barn swallows as their is no nesting shadows on the interior where their nests would have been. They do keep the same nests year after year. Thanks for the nice comment Elora -- barbara.

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  4. NCmountainwoman -- interesting that you mention the barn swallows in cabanas. Elora's post has all the necessary elements to draw barn swallows and none take up residence. And here you have cabanas and they take up residence! Maybe its the proximity to water?
    -- barbara

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  5. Thanks for the comments you left on my post about doves. I had forgotten (overlooked) the connection of the dove and Noah's flood - it brought back a branch indicating dry land. So I suspect that this could be a common symbolic use of the dove. Also, mariners frequently carried pigeons with them, releasing them to go in search of dry land. It probably how the pigeons got to NA.

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  6. Chris -- thanks for stopping by. I enjoy your blog, Tails of Birding -- not only for your beautiful photos and bird talk but that you weave in behavior, culture and symbolism. barbara

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  7. Coincidentally I just snapped a couple of shots of the swallows nests underneath a bridge on Monday here in Oz, the other side of the world lol.
    I'll post it up online soon ;)
    Love these birds, so cheeky and full of character and life :)

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  8. Nice post. They are such beautiful birds. We have lots of barn swallows -- and lots of old barns and outbuildings and lots of bugs. Perfect!

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  9. Thanks for the good post, Barbara. Raising awareness of wildlife issues is important. In Ontario, breeding bird surveys in 1985 and 2005 showed a 35% decrease in barn swallows over the 20 year period. Many other aerial insectivores such as other swallows, nighthawks and swifts are also in decline. The causes of the decline are still not well understood but are likely related to a decline in aerial insect abundance. We have barn swallows nesting in our old barn here. They are beautiful birds and amazing flyers.

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  10. barefootheart --
    Thanks for the excellent information about aerial insectivores. I feel that many factors contribute to their decline. Some of those I didn't mention are such environmental impacts like the overuse of pesticides and herbicides plus the extensive ranges of polluted water and air. All these latter factors along with those in my post are in part contributors. I feel this is an issue that needs to be studied more and made public. Perhaps there are some great studies already done on this subject but I was unable to find any. -- barbara

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  11. Jayne -- how is the swallow population doing in your part of the world? About nesting under bridges -- another favorite spot for the Barn Swallows. -- thanks for the comment -- barbara

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  12. Vicki -- Great that you have the right environment for the lovely birds. -- barbara

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