Although the biogeographic history of thrushes (Turdidae) has been extensively studied, a concise discussion of this topic is still lacking. Therefore, in this study we aimed to investigate: (1) the evolutionary origin of the migratory behaviour of the Turdus thrushes in a biogeographic context including (2) trans-Atlantic dispersal events, (3) possible colonization routes into the Nearctic, and (4) relationships among life history traits, ecological factors, and migratory strategies within the most comprehensive taxon set of 72 Turdus thrushes to date. We estimated the ancestral ranges of the studied species, primarily by comparing main biogeographic models (dispersal-vicariance, dispersal-extinction-cladogenesis, BayArea models), and performed phylogenetic generalized least squares analyses to identify relationships among distribution patterns, diet, body measurements, clutch size, and migratory behaviour. We found that the most probable ancestral regions for all Turdus species were located in the East Palearctic realm, followed by early colonization of the western Palearctic and Africa, and that several trans-Atlantic movements occurred between 11 and 4 million years ago, which is earlier than previously thought. Migration emerged as an ancestral behaviour of the genus Turdus, and differences in clutch size and main food types were significant between migratory and non-migratory species. Correlated evolution was found between migration and along-latitudinal mobility, main food type, and the shift in main food type between the seasons. We conclude that along-latitudinal movements may have evolved earlier, simultaneously with the radiation of the Turdus thrushes, followed by the appearance of meridional migration, associated with orographic and climatic changes. The increased clutch sizes observed in migratory species and documented here for thrushes could serve as an important mechanism to compensate for losses due to mortality during migration. Phylogenie, Zugverhalten, Lebensgeschichte: ein Versuch, Lücken in der Biogeographie und Herkunft der Turdus -Drosseln zu schließen. Obwohl die biogeographische Geschichte der Drosselartigen (Turdidae) schon umfassend untersucht wurde, fehlt jedoch eine umfassende Diskussion zu diesem Thema. Deswegen wollten wir in dieser Studie untersuchen: (1) den evolutionären Ursprung des Zugverhaltens in einem biogeographischen Kontext, einschließlich, (2) transatlantische Ausbreitungsereignisse, (3) mögliche Kolonisationswege in die Nearktis und (4) Beziehungen zwischen lebensgeschichtlichen Merkmalen, ökologischen Faktoren und Zugstrategien innerhalb des bisher umfassendsten Taxonbestandes von 72 Turdus-Drosseln. Wir haben die Herkunftsareale der untersuchten Arten berechnet, vor allem durch den Vergleich der hauptsächlichen biogeographischen Modelle (DIVA, DEC, BayArea) und wir haben generalisierte phylogenetische Analysen der kleinsten Quadrate (PGLS) durchgeführt, um die möglichen Beziehungen zwischen Verbreitungsmustern, Nahrung, Körpermaßen, Gelegegröße und Zugverhalten festzustellen. Wir fanden, dass das wahrscheinlichste Herkunftsgebiet aller Turdus-Arten die östliche Paläarktis ist, gefolgt von einer sehr frühen Besiedlung der Westpaläarktis und von Afrika, und dass mehrere transatlantische Bewegungen zwischen 11-4 Millionen Jahren stattgefunden haben, also früher, als zuvor angenommen. Zugverhalten entstand schon in der Herkunftspopulation der Gattung Turdus, mit signifikanten Unterschieden in Gelegegröße und Nahrung von ziehenden und nicht-ziehenden Arten. Wir haben eine korrelierte Evolution zwischen Zugverhalten und der latitudinalen Ausbreitung, der hauptsächlichen Nahrung und saisonalem Nahrungswechsel. Wir schließen, dass sich die latitudinale Ausbreitung schon sehr früh entwickelt hat, etwa gleichzeitig mit der Radiation der Turdus-Drosseln, unmittelbar gefolgt von der Entwicklung meridionalen Zugverhaltens als Folge orographischer und klimatischer Veränderungen. Die bei Zugvogelarten beobachteten erhöhten Gelegegrößen und hier auch für die Drosseln, könnten wichtiger Kompensationsmechanismus zum Ausgleich der Mortalitätsverluste während des Zuges sein.

Many bird species incorporate anthropogenic materials (e.g. sweet wrappers, cigarette butts and plastic strings) into their nests. Anthropogenic materials have become widely available as nesting materials in marine and terrestrial environments globally. These human-made objects can provide important benefits to birds such as serving as reliable signals to conspecifics or protecting against ectoparasites, but they can also incur fundamental survival and energetic costs via offspring entanglement and reduced insulative properties, respectively. From an ecological perspective, several hypotheses have been proposed to explain the use of anthropogenic nest materials (ANMs) by birds but no previous interspecific study has tried to identify the underlying mechanisms of this behaviour. In this study, we performed a systematic literature search and ran phylogenetically controlled comparative analyses to examine interspecific variation in the use of ANM and to examine the influence of several ecological and life-history traits. We found that sexual dimorphism and nest type significantly influenced the use of ANMs by birds providing support for the ‘signalling hypothesis’ that implies that ANMs reflect the quality of the nest builder. However, we found no support for the ‘age’ and ‘new location’ hypotheses, nor for a phylogenetic pattern in this behaviour, suggesting that it is widespread throughout birds. This article is part of the theme issue ‘The evolutionary ecology of nests: a cross-taxon approach’.

Migration plays a fundamental part in the life of most temperate bird species. The regular, large-scale seasonal movements that characterize temperate migration systems appear to have originated in parallel with the postglacial northern expansion of tropical species. Migratoriness is also influenced by a number of ecological factors, such as the ability to survive harsh winters. Hence, understanding the origins and evolution of migration requires integration of the biogeographic history and ecology of birds in a phylogenetic context. We used molecular dating and ancestral state reconstruction to infer the origins and evolutionary changes in migratory behavior and ancestral area reconstruction to investigate historical patterns of range evolution in accipitrid birds of prey (Accipitriformes). Migration evolved multiple times in birds of prey, the earliest of which occurred in true hawks (Accipitrinae), during the middle Miocene period, according to our analyses. In most cases, a tropical ancestral distribution was inferred for the non-migratory ancestors of migratory lineages. Results from directional evolutionary tests indicate that migration evolved in the tropics and then increased the rate of colonization of temperate habitats, suggesting that temperate species might be descendants of tropical ones that dispersed into these seasonal habitats. Finally, we found that diet generalization predicts migratoriness in this group.

The causes and consequences of interspecific variation in sex-specific contributions to animal parental care are relatively well understood during pregnancy or incubation and during offspring provisioning, but comparative patterns of sex-biased investment during nest-, den-, or other shelter-building have been almost completely overlooked. This is surprising because birthing shelters’ protective properties have important fitness consequences for both parents and offspring. Here, we address this gap in our knowledge by testing predictions concerning sex-specific contributions to avian nest building in more than 500 species of Western Palearctic birds in relation to the time available to breed and sex-specific reproductive effort, while also examining correlates with nesting site and nest structure. Using multivariate phylogenetic comparative and path analysis approaches, we found that, opposite to what had been predicted, species in which females build nests alone have shorter breeding seasons and breed at higher latitudes. In addition, species in which females lay larger clutch sizes and incubate eggs alone are more likely to have nests built by females alone, again countering predictions that reproductive contributions are not traded-off between the sexes. Finally, however, sex-specific nest building contributions were predictably related to nest site and structure, as species in which females built nests alone were more likely to have open cup nests relative to enclosed, domed nests of species in which both parents build. Our study provides important new insights, and generates several new questions for experimental research into the adaptive dynamics of sex-specific contributions prior or at the onset of parental care.

Aggressive sibling competition for parental food resources is relatively infrequent in animals but highly prevalent and extreme among certain bird families, particularly accipitrid raptors (Accipitriformes). Intense broodmate aggression within this group is associated with a suite of traits including a large adult size, small broods, low provisioning rates, and slow development. In this study, we apply phylogenetic comparative analyses to assess the relative importance of several behavioral, morphological, life history, and ecological variables as predictors of the intensity of broodmate aggression in 65 species of accipitrid raptors. We show that intensity of aggression increases in species with lower parental effort (small clutch size and low provisioning rates), while size effects (adult body mass and length of nestling period) are unimportant. Intense aggression is more closely related to a slow life history pace (high adult survival coupled with a restrained parental effort), rather than a by‐product of allometry or food limitation. Consideration of several ecological variables affecting prey abundance and availability reveals that certain lifestyles (e.g., breeding in aseasonal habitats or hunting for more agile prey) may slow a species’ life history pace and favor the evolution of intense broodmate aggression.