Denmark-Barn Swallow ( Hirundo rustica)

Delightful illustration of a pair of   Barn Swallow  ( Hirundo rustica) 

from the 1999 Migratory Birds series cancelled at Copenhagen

USA- Purple Martin (Progne subis)

The Purple Martin (Progne subis) is the largest North American Swallow. Theses birds have great speed and agility in flight at the same time also  feeding on insects in the air. In the eastern parts of the USA , artificial nesting boxes are provided for the birds which migrate south after breeding season. Populations of Purple martins are under threat from introduced European starlings as they compete for breeding sites.
The Purple Martin stamped envelope is for 1st class mail at the 1 ounce rate. The illustration  was created by  American artist Matthew Frey, featuring a  Purple martin perching and a smaller illustration showing the bird in flight.