Hirundo rustica

Composed of two groups: erythrogaster (Barn Swallow) breeding in North America and rustica (European Swallow) breeding in Eurasia (AOU 1998). Zink et al. (1995) found that populations on Asian and North American sides of Beringia exhibited a level of mtDNA differentiation intermediate between populations and species; however, sample sizes were small and no formal taxonomic change was recommended. See Sheldon and Winkler (1993) for information on intergeneric phylogenetic relationships of Hirundininae based on DNA-DNA hybridization. May form a superspecies with H. lucida, H. aethiopica, H. angolensis, H. albigularis, H. dumicola, H. tahitica, and H. neoxena (AOU 1998)

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern. (Birdlife International, 2014)

BREEDING: south-coastal and southeastern Alaska, across much of Canada south through much of U.S. to central Mexico; also eastern Buenos Aires province, Argentina, in early 1980s (Ridgely and Tudor 1989); across Eurasia to Mediterranean region, northern Africa, China, Japan. NON-BREEDING: mainly South America, regularly from Costa Rica and West Indies to Tierra del Fuego (but in low numbers south of central Chile and northern Argentina, Ridgely and Tudor 1989); Africa and southern Asia; uncommon in Puerto Rico. Accidental in Hawaii.

This species is represented by a large number of occurrences (subpopulations). It has an extremely large range and extremely large population size. Partners in Flight (2013) estimate its global population to be 120 million.

See Turner and Rose 1989 for comments on status in Old World. In general, has benefited from presence of humans and their structures. Small numbers inadvertently killed by intentional spraying of Dickcissel (SPIZA AMERICANA) roosts in Venezuela in non-breeding season (Basili and Temple 1999). On balance, human activity has had strongly positive effects on this species: construction of artificial structures has provided abundant nesting sites, leading to population size that is probably several orders of magnitude greater than before European settlement of North America. Barn Swallows are popular with people, and farmers often protect (rarely persecute) the birds on their property. The species seems to have adapted well to nesting in human-altered habitats in North America and worldwide. House Sparrows can be serious nest-site competitors, apparently extirpating Barn Swallows from parts of New England in 1800s (Brewster 1906); sparrows reduced Barn Swallow fledging success by 45% at 1 site in Maryland (Weisheit and Creighton 1989). Cold and rainy weather occurring in late spring and early summer causes mortality among both adults (Brown and Brown 1999) and nestlings (Mason 1953, Anthony and Ely 1976) as result of starvation. (Brown and Brown, 1999)