A starling native to the Iberian Peninsula and western Mediterranean. Adults have glossy dark plumage, and bill color and pale feather tips change with season.
Adults are glossy black, with pale feather tips showing as spots in winter. The bill is yellow in summer, with a bluish base in males and pinkish base in females; it darkens in winter. Juveniles are brown.
In central Spain, researchers followed a Spotless Starling colony for three years after nest boxes were installed in 2004. DNA and box records helped identify parents. In the first year, 37 of 77 boxes were used by males breeding in more than one nest, and about 30% of fathers had bred with more than one female.
By 2006, the share of fathers breeding in multiple nests had fallen to about 12%, while more females laid eggs in another female’s nest. The researchers linked the changes to new recruits joining the colony and stronger competition for nest places and mates.
DNA tests showed that females laid eggs in other females’ nests and males fathered young in several nests. Box maps let the team examine how nest spacing related to these patterns.
An extinction-risk assessment has not been added yet.
All nest boxes were occupied in the first year. During the next two years, fewer males bred in multiple nests while more females laid eggs in other females’ nests. The authors linked these changes to new recruits and competition for nest places and mates.