title: Large increase in nest size linked to climate change: an indicator of life history, senescence and condition.
abstract: Many animals build extravagant nests that exceed the size required for successful reproduction. Large nests may signal the parenting ability of nest builders suggesting that nests may have a signaling function. In particular, many raptors build very large nests for their body size. We studied nest size in the goshawk Accipiter gentilis, which is a top predator throughout most of the Nearctic. Both males and females build nests, and males provision their females and offspring with food. Nest volume in the goshawk is almost three-fold larger than predicted from their body size. Nest size in the goshawk is highly variable and may reach more than 600 kg for a bird that weighs ca. 1 kg. While 8.5% of nests fell down, smaller nests fell down more often than large nests. There was a hump-shaped relationship between nest volume and female age, with a decline in nest volume late in life, as expected for senescence. Clutch size increased with nest volume. Nest volume increased during 1977-2014 in an accelerating fashion, linked to increasing spring temperature during April, when goshawks build and start reproduction. These findings are consistent with nest size being a reliable signal of parental ability, with large nest size signaling superior parenting ability and senescence, and also indicating climate warming.
authors.affiliation: Laboratoire d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, 91405, Orsay Cedex, France. anders.moller@u-psud.fr.
authors.forename: Anders Pape
authors.initials: AP
authors.lastname: Møller
authors.affiliation: , Espedal 4, Tolne, 9870, Sindal, Denmark.
authors.forename: Jan Tøttrup
authors.initials: JT
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D001717:Birds; D049628:Body Size; D057231:Climate Change; D052284:Clutch Size; D046093:Falconiformes; D005260:Female; D008297:Male; D009425:Nesting Behavior; D020304:Raptors / Q000033:anatomy & histology / Q000502:physiology*; D012098:Reproduction; D012621:Seasons; D013696:Temperature
keywords: Accipiter gentilis; Climate change; Extended phenotype; Goshawk; Senescence; Signal