Topic
Larus smithsonianus
About: Larus smithsonianus is a research topic. Over the lifetime, 3 publications have been published within this topic receiving 49 citations.
Papers
TL;DR: The results show that extensive unidirectional mtDNA introgression from Larus smithsonianus into Larus marinus in North America cannot be explained by ancestral polymorphism but most likely results from ancient hybridization events occurring when Larus Marinus invaded the North America.
Abstract: Recent genetic studies have shown that introgression rates among loci may greatly vary according to their location in the genome. In particular, several cases of mito-nuclear discordances have been reported for a wide range of organisms. In the present study, we examine the causes of discordance between mitochondrial (mtDNA) and nuclear DNA introgression detected in North American populations of the Great Black-backed Gull (Larus marinus), a Holarctic species, from the Nearctic North American Herring Gull (Larus smithsonianus). Our results show that extensive unidirectional mtDNA introgression from Larus smithsonianus into Larus marinus in North America cannot be explained by ancestral polymorphism but most likely results from ancient hybridization events occurring when Larus marinus invaded the North America. Conversely, our nuclear DNA results based on 12 microsatellites detected very little introgression from Larus smithsonianus into North American Larus marinus. We discuss these results in the framework of demographic and selective mechanisms that have been postulated to explain mito-nuclear discrepancies. We were unable to demonstrate selection as the main cause of mito-nuclear introgression discordance but cannot dismiss the possible role of selection in the observed pattern. Among demographic explanations, only drift in small populations and bias in mate choice in an invasive context may explain our results. As it is often difficult to demonstrate that selection may be the main factor driving the introgression of mitochondrial DNA in natural populations, we advocate that evaluating alternative demographic neutral hypotheses may help to indirectly support or reject hypotheses invoking selective processes.
56 citations
1 Dec 2007
TL;DR: It is proposed that Larus smithsonianus be treated as specifically distinct from the Old World Herring Gull Larus argentatus and take the English name Smithsonian Gull.
Abstract: The gull Larus smithsonianus Coues, 1862 was based on specimens in the collections of the Smithsonian Institution, but no type material has been identified and the type locality was never restricted beyond the eastern and western coasts of North America. We here designate USNM 18216 as lectotype, and the restricted type locality thus becomes Henley Harbour, Strait of Belle Isle, Newfoundland Labrador, Canada. It is proposed that Larus smithsonianus be treated as specifically distinct from the Old World Herring Gull Larus argentatus and take the English name Smithsonian Gull.
1 Feb 2013
TL;DR: This paper investigated the abundance and distribution patterns of a range of seabird species in the Lower Estuary and Gulf of St Lawrence in the western North Atlantic using ship-based surveys during the summers of 2007, 2008 and 2009.
Abstract: We investigated the abundance and distribution patterns of a range of seabird
species in the Lower Estuary and Gulf of St Lawrence in the western North Atlantic
Ocean using ship-based surveys during the summers of 2007, 2008 and 2009. This
area is known to be of particular importance for several seabird and cetacean
species. We analysed distribution and abundance of common seabird species in mid
and late summer, and estimated total numbers for the Southern Gulf, which was
most intensively surveyed. Northern Gannets Morus bassanus were overall most
abundant and widespread. Our at-sea estimate of 150,000 birds for the Southern
Gulf constitutes 64% of the North American breeding population, rendering the site
one of the most important areas for this species worldwide during this period. Our
at-sea estimates suggest that according to the 1% threshold of the Ramsar
Convention considerable proportions of the Canadian breeding population of
Razorbills Alca torda (5–11%), Common Guillemots Uria aalge (2–3%), Black-legged
Kittiwakes Rissa tridactyla (2–4%) and Black Guillemots Cepphus grylle (1–2%) use
the Southern Gulf. Relative to their biogeographic populations, at-sea totals were
also considerable in American Herring Gulls Larus smithsonianus (3–4%), Great
Black-backed Gulls L. marinus (1–4%) and Great Northern Divers Gavia immer
(1–4%). Areas of high seabird densities and multispecies aggregations (hotspots)
occurred around the Gaspe Peninsula (Northern Gannets, alcids, Black-legged
Kittiwakes, Larus gulls), in the Northwestern Gulf, along the Lower North Shore
(near St Mary’s Islands), along the west coast of Newfoundland (Bay of Islands to St
Georges Bay), in Cabot Strait, around Cape Breton Island and the Magdalen Islands,
as well as west and east of Prince Edward Island.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2014 | 1 |
| 2013 | 1 |
| 2007 | 1 |