Welcome to the Birds of North America Online!
Welcome to BNA Online, the leading source of life history information for North American breeding birds. This free, courtesy preview is just the first of 14 articles that provide detailed life history information including Distribution, Migration, Habitat, Food Habits, Sounds, Behavior and Breeding. Written by acknowledged experts on each species, there is also a comprehensive bibliography of published research on the species.
A subscription is needed to access the remaining articles for this and any other species. Subscription rates start as low as $5 USD for 30 days of complete access to the resource. To subscribe, please visit the Cornell Lab of Ornithology E-Store.
If you are already a current subscriber, you will need to sign in with your login information to access BNA normally.
Subscriptions are available for as little as $5 for 30 days of full access! If you would like to subscribe to BNA Online, just visit the Cornell Lab of Ornithology E-Store.
Smith’s Longspurs have one of the most unusual social breeding systems known among songbirds. Unlike the majority of birds that form socially monogamous relationships for breeding, Smith’s Longspurs are polygynandrous—each female pairs and copulates with two or three males for a single clutch of eggs, at the same time that each male pairs and copulates with two or more females. Males do not defend territories, but instead guard females by following them closely and compete for fertilizations by copulating frequently in order to dilute or displace sperm from other males. Over a period of one week in the early spring, a female longspur will copulate over 350 times on average; this is one of the highest copulation rates of any bird. Males are well-equipped to deliver such large numbers of ejaculates—their testes are about double the mass of those of the monogamous and congeneric Lapland Longspur (C. lapponicus). As expected from their mating behavior, most Smith’s Longspur broods contain chicks of mixed paternity. At such nests, two or more males may assist females in feeding nestlings although the amount of investment provided by a given male depends on the number of young he has sired within a nest. The mating system of Smith’s Longspurs is much more promiscuous than that found in other longspurs and exactly why it differs is still a mystery. Perhaps the advantages females obtain from extra male help in raising offspring may explain why they pair and mate with more than one male.
Smith’s Longspur was first described by William Swainson as the “Painted Bunting” in 1831 from a specimen collected by John Richardson in Saskatchewan. Audubon later renamed this species in honor of his friend Gideon B. Smith of Baltimore in 1844 from new specimens collected in Illinois. Kemsies (1968) summarized the life history of this species in Bent’s classic series but the remoteness of the sub-arctic breeding range of the Smith’s Longspur meant the first systematic descriptions of breeding biology did not appear until Jehl’s (1968a, b) pioneering work in northern Manitoba. Details of the unusual social mating system of Smith’s Longspurs was later worked out by Briskie (1992, 1993, 1999) and Briskie et al. (1998) reported the first genetic profiling of paternity and the relationship between paternity and parental care. Systematic studies of the wintering ecology of Smith’s Longspur were first undertaken by Gzybowski (1982, 1983a,b), with later work by Dunn and Dunn (1999), and Ormston (2000).