| reciprocal selection causes a coevolutionary arms race between crossbills and lodgepole pine. | few studies have shown both reciprocal selection and reciprocal adaptations for a coevolving system in the wild. the goal of our study was to determine whether the patterns of selection on rocky mountain lodgepole pine (pinus contorta spp. latifolia) and red crossbills (loxia curvirostra complex) were concordant with earlier published evidence of reciprocal adaptations in lodgepole pine and crossbills on isolated mountain ranges in the absence of red squirrels (tamiasciurus hudsonicus). we found ... | 2003 | 12858263 |
| can selection by an ectoparasite drive a population of red crossbills from its adaptive peak? | the bill structures of different call types of red crossbills (loxia curvirostra complex) in western north america usually approximate the predicted optima for foraging on single species of conifers. one clear exception is the call type in the south hills, idaho, that is coevolving in an evolutionary arms race with rocky mountain lodgepole pine (pinus contorta ssp. latifolia). although south hills crossbills forage only on the cones of these lodgepole pines, their average bill depth is smaller t ... | 2005 | 16261739 |
| survival and population size of a resident bird species are declining as temperature increases. | 1. a large number of migratory bird species appear to be declining as the result of climate change, but whether resident bird species have or will be adversely affected by climate change is less clear. we focus on the south hills crossbill (loxia curvirostra complex), which is endemic to about 70 km(2) of rocky mountain lodgepole pine (pinus contorta latifolia) forest in southern idaho, usa. 2. our results indicate that the south hills crossbill has declined by over 60% between 2003 and 2008, a ... | 2011 | 22010811 |
| the natural history of the south hills crossbill in relation to its impending extinction. | increasingly, the species that we discover will be uncommon, area restricted, and vulnerable to extinction. i describe the natural history of a newly discovered seed-eating finch from the rocky mountain region, the south hills crossbill (loxia curvirostra complex). it relies on seeds in the closed cones of the fire-adapted rocky mountain lodgepole pine (pinus contorta latifolia) and is found only in the higher elevations of two small mountain ranges in southern idaho. here crossbills and pine ar ... | 2016 | 27860509 |
| divergent selection drives the adaptive radiation of crossbills. | knowledge of how phenotype influences fitness is necessary if we are to understand the basis of natural selection and how natural selection contributes to adaptive radiations. here i quantify selection on a wild population of red crossbills (loxia curvirostra complex) in the south hills, idaho. bill depth is the target of selection and selection on bill depth is stabilizing. i then show how fitness is related to both bill depth and performance. i use these and previously published relationships ... | 2003 | 12836833 |