Posts Tagged ‘Swallow colonies’

Swallows

 

 

Swallows – 8 species in 6 genera

Bahama, Bank, Barn, Cave, Cliff, Northern Rough-winged, Tree,

Violet Green

Cliff – buff & rust rump w/drk rust brown throat, wht spotted forehead

Northern-Rough-winged – grayish brown, light under side

The two most prevalent in San Juan Capistrano are the Cliff and Northern Rough-winged.

 HISTORICAL POINTS

Past 100 to 150 years the swallows have extended their range across the North America as far as Alaska to the north and to the Eastern coast in part due to the development of bridges and buildings.  They provide nesting sites.

In 1776 in Utah a Spaniard, Silvestre Velez de Escalante observed the Cliff Swallow.  The Cliff Swallow was one of the first North American birds to be described.

Spring Migration:  moving North from South America.  First arrive in Southern California early February.  Recorded on February 24, 1994 a continuous flock of swallows of 150 birds/min.

Fall Migration: generally peak time is in August and September back to So. America.  There is little information of the migratory behavior.

Food:  flying insects

Cliff Swallows prefer nesting in colonies but can have a single nest sight.  Their tail is squared off compared to a Barn Swallow who has a distinctive forked tail (refer to my illustrations on Swallows).  Numbers can range from 200-400 nests and a site in Nebraska recorded 3700.   Courtship occurs soon after arrival and they visit nest sites future and/or existing.  Once paired up begin next building. Both male and female help to build the mud gourd shaped nest.  They gather mud in their bills along streams or new housing tracks.

A pair can bring 44 mud pellets in a 30 min period. Approx. 7 days to build a complete nest.

Number of Eggs 4-5,   incubation 14 –16 days.  Both parents tend to eggs and young.

The Cliff Swallow has the distinctive gourd shaped nest made of hundreds of mud pellets.