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Pestgon FactSheet
“
If they fly they die…if they crawl they fall”
CLIFF SWALLOW (Petrochelidon pyrrhonota)
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Description:
The cliff swallow is a bird about 5 to 6 inches in length and when not on
the nest, is constantly on the fly for insects. They are also recognized
by their long pointed wings as they dart about the sky with great speed and
maneuverability. Up close they are pale, orange-brown rump, white forehead,
dark rust-colored throat, and steel blue crown back and wings. Normally,
swallows are not seen on the ground except when collecting mud for their
gourd-shaped nests.
Biology:
Cliff Swallows are made famous by the romantic song, “When the Swallows
Return to Capistrano”. This happens in the spring. Cliff Swallows feed
on insects and spend a large part of time in the air catching flies, gnats,
beetles, and mosquitoes. These swallows build mud nests attached to eves
and overhangs of buildings and other structures, a habit that sometimes puts
them into conflict with building owners and commercial property managers.
This is particularly true when the Cliff Swallow decides to build a colony
of mud nests, sometimes dozens of mud nests. The nests are cemented with
mud to underside of an overhang of buildings, bridges, or other vertical
surfaces. Once they start, their habit is to form a dense cluster or colony
of gourd-shaped, mud nests.
Economic Impact:
A colony of Cliff Swallows nesting on a commercial building can become
a big nuisance adding to the cost of maintenance and sanitation, due to
their
messy droppings. Pestgon, Inc. has seen where mud nests and droppings have
stained the stucco and other surfaces of beautiful commercial buildings,
defacing the professional appearance of a building. Cliff swallows are
colonial so the number of nesting birds will increase significantly from
year to year.
Their copious droppings present a potential health hazard. Swallow nests
contain mites and insects and swallow bugs (bed bugs) that can enter buildings.
The decaying mud nests eventually fall to the ground and can cause harm,
particularly if the nests are above a door or walkway. So while there may
be something romantic about the swallows returning to Capistrano, when
they have attached themselves to your commercial building, they are not
just a
nuisance but, an economic liability.
Management Methods:
Managing problems with swallows should be started as soon as they appear
and are identified. Pestgon, Inc. finds that they are best managed by nest
removal and exclusion techniques. Their mud can be washed off or removed
prior to nesting, so it is imperative to act quickly upon their arrival.
Netting can provide an effective physical barrier between the birds and
the nest site. Under the Migratory Bird Treaty Act of 1918, Cliff Swallows
are
protected by state and federal regulations, as migratory insectivorous
birds. During nesting a permit authorizing nest removal can only be issued
by the,
U.S. Fish and Wildlife Service, and only if it can be justified by strong,
compelling reasons such as health or hazard. If eggs or young are in the
nest when a permit is requested, the application will probably be denied.
Additional Links:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7482.html