Many bird species use specific vocalizations in the context of courtship or (attempted) copulations. These vocalizations can be used to gain information about the courtship behaviour of individuals, even when courtship or copulation behaviour itself is difficult to observe. We recorded courtship vocalizations of Blue Tits Cyanistes caeruleus during three breeding seasons. In 2014, we recorded courtship calls at 14 locations spread out over a 40 ha forest containing a nestbox-breeding population of Blue Tits. Courtship calls occurred throughout the breeding season, but were most common in the period just before and during egg-laying. The rate of courtship calling showed a clear daily peak around dawn. In 2012 and 2013, we recorded courtship calls during the fertile period of the male's social mate. We monitored the presence of the female inside the nestbox and describe the occurrence of courtship calls that are apparently not directed to the social mate. The rate of these potential extrapair courtships correlated positively with a male's extra-pair paternity gain in 2012, but not in 2013. Extra-pair courtship call rate did not relate to paternity loss in the male's own brood.

Forest management usually reduces the diversity and amount of substrates in which woodpeckers can excavate holes. In such conditions the recorded patterns of nest site selection could reflect a more reduced array of substrates than the species' nest site preferences. We analysed new data on nest sites of Middle Spotted Woodpeckers Leiopicus medius collected during 27 breeding seasons (1987–2013) in the strictly protected fragments of the Białowieża National Park in Poland. The birds could use diverse excavation substrates, of various statures, that varied in condition from living and healthy to dead and completely rotten. Middle Spotted Woodpeckers used a wide array of tree species, with little overlap in the species used in the riverine habitat (mostly Alnus glutinosa, and Fraxinus excelsior) and oak—hornbeam habitats (Carpinus betulus and Quercus robur). The birds preferred to excavate in Q. robur but avoided Tilia cordata and Picea abies. They placed holes in large trees (median girth at breast height: 202 cm), high above the ground (median 13 m), mostly in dead trees or dead fragments of living trees (66%), and often in limbs (46%). Entrances of 34% of holes were facing downwards. This pattern of hole placement differed from that found in the managed woods elsewhere, but was similar to those recorded in other old-growth forests. We suggest that Middle Spotted Woodpecker choose nest sites in places least accessible for nest predators and with a favourable microclimate.

Although shorebirds (Charadriiformes: suborders Scolopaci and Charadrii) face physiological stress during migration and experience a wide range of vector-suitable habitats across their distributions, haemosporidian parasites (order Haemosporida) have rarely been detected in these species worldwide. We ask whether shorebirds remain infection-free when wintering in areas where parasite transmission occurs among landbird species. Blood samples were collected at three locations in Argentina: Patagonia, with an avian assemblage dominated by shorebird species; Mar Chiquita Lagoon, a high-salinity water basin where shorebird and landbird species co-occur; and inland sites in Chaco and Cordoba provinces, where host assemblages included mostly landbird species. We screened 650 samples for the presence of haemosporidian infections and sequenced a part of the parasite mitochondrial cytochrome b gene to determine parasite lineages. Of 342 landbirds, 91 were infected with haemosporidian parasites, compared to only three of 318 shorebirds. Wintering location had no effect on the prevalence of haemosporidian parasites in shorebirds. Haemosporidian infections are rare in shorebirds even when these co-occur with landbird species in inland areas suitable for parasite transmission. The few infections detected in shorebirds might represent spillover infections from landbirds, as the parasite lineages were also found in common landbird species. We suggest that shorebirds are resistant to haemosporidian parasites, and either do not become infected or quickly clear occasional infections.

In this study we analyse factors affecting nest survival in Blue-fronted Parrots Amazona aestiva breeding in the Chaco region of northern Argentina. We combined temporal and environmental variables in order to determine which best explain variation in overall nest survival and in predation dependent nest survival. We predicted that high and deep cavities, that are inaccessible to snakes and other predators, would have high daily survival rates. We compared the relative effects on nest survival of time of the breeding season, stage of the nesting cycle, and characteristics of the nest cavity. We modelled daily survival rate (DSR) for all observed nests, and daily survival rate for nests that had been predated (daily survival rate in relation to predation exclusively, DSR_p). Nest predation accounted for 50% of nest failures. DSR was on average 0.989, translating into an apparent hatching success of 0.39. DSR decreased with time of breeding and increased with nest age. DSR_p decreased with time of breeding and inclination of the nest cavity entrance hole and increased with height from the ground of the entrance hole. There was a quadratic effect of nest age on DSR_p, such that daily survival was highest during incubation, lowest at hatching and the early nestling stage, but increasing throughout the remainder of the nestling stage. This effect became more pronounced as the breeding season advanced. Year and observer effects did not affect the probability of survival. Temporal patterns and characteristics of the nest cavity explained most of the variation in nest survival in Blue-fronted Parrots, which highlights the relevance of including these covariates in future studies of nest survival in parrots, and has important management and conservation implications.

Declines in farmland bird populations are often linked to changes in agricultural practices, but little is known about the demographic changes underlying these adverse trends. Identifying the demographic drivers of population change is critical for understanding why populations are declining. In this study we assessed the demographic changes in the declining Dutch Starling Sturnus vulgaris population. We estimated productivity per breeding attempt and survival rates over a period of 52 years (1960–2012). The results show that juvenile survival decreased significantly over time. Adult survival fluctuated between years, with (non-significant) lower survival rates between 1990 and 2012. No trend in reproductive output was found over the study period. A population model was built for three different phases of population change within the study period: 1960–1978, 1978–1990 and 1990–2012. The contribution of changes in demographic parameters to population growth rate (lambda) between the different periods was examined by performing a life table response experiment (LTRE). The LTRE analysis showed that changes in juvenile survival explained most of the differences in population growth rate between periods. Our results therefore suggest that a decline in juvenile survival rather than changes in adult survival or reproductive success is the most important cause of the decline of the Starling population in The Netherlands.

Carotenoid-based ornaments have been proposed to signal the ability to find food. The good-parent hypothesis suggests that females may rely on these carotenoid-based traits to assess male parental quality. A key question is whether the quality of these ornaments correlates with their performance at the moment of breeding. In this study, we assessed the parental investment of Mediterranean Great Tits Parus major in the early morning as a function of several environmental factors and of parental ornamentation. We measured this by the time that parents started feeding their offspring at the start of the day. In the morning, parents need to rapidly respond to the food demands of their offspring, after a long night without food. An earlier start of provisioning could indicate higher parental investment (and/or greater foraging ability). Our data indicate that fathers that show higher hue in their carotenoid-based plumage — more greenish individuals — started feeding their offspring earlier, thereby expanding the time window in which they work, while females did not show a significant relationship between the onset of provisioning and ornamentation. Parents, particularly mothers, that started earlier, worked more intensely across the whole observation period. Furthermore, parents started earlier when they had larger broods. Finally, more ornamented parents worked at lower rates, while more ornamented mothers raised offspring that had better body condition, which is in line with the good parent hypothesis. Although our results indicate that more ornamented males start feeding their offspring earlier, overall we found mixed support for the hypothesis that carotenoid-based ornaments signal the parental quality of a mate.

Many bird species express sexual dimorphism in body size, which is one of the most significant targets of natural and sexual selection, for it is tightly linked with fitness. During field studies in the breeding season of 2013 and 2014, we found significant differences in body morphometrics between sexes in a breeding population of Elliot's Laughingthrush Trochalopteron elliotii: males are larger than females in all body measurements. Positive assortative mating, based on culmen length, tarsus length and body mass, was found across breeding pairs. Male territory defence behaviour and assortative mating based on body size provide evidence that sexual selection may be responsible for sexual size dimorphism in this species.

The Little Bittern is one of the least studied heron species in its breeding range. The nominate, Palaearctic race Ixobrychus m. minutus has been generally assumed to be single-brooded only, yet detailed studies of its breeding biology and mating system are lacking. The present paper provides the first observational evidence of successful double-brooding in the nominate race of the Little Bittern and gives the first record of time-overlapping double-brooding in the species. Potential determinants of this breeding strategy as well as the frequency of its occurrence are discussed.