Identifying causal relationships of cancer treatment and long-term health effects among 5-year survivors of childhood cancer in Southern Sweden.

Background: Survivors of childhood cancer can develop adverse health events later in life. Infrequent occurrences and scarcity of structured information result in analytical and statistical challenges. Alternative statistical approaches are required to investigate the basis of late effects in smaller data sets.

A complete multilocus species phylogeny of the tits and chickadees (Aves: Paridae).

The avian family Paridae (tits and chickadees) contains c. 55 species distributed in the Palearctic, Nearctic, Afrotropics and Indomalaya. The group includes some of the most well-known and extensively studied avian species, and the evolutionary history, in particular the post-glacial colonization of the northern latitudes, has been comparably well-studied for several species.

Habitat-specific demography and source-sink dynamics in a population of Siberian jays.

1. There are a number of models describing population structure, many of which have the capacity to incorporate spatial habitat effects. One such model is the source-sink model, that describes a system where some habitats have a natality that is higher than mortality (source) and others have a mortality that exceeds natality (sink).

Delayed dispersal as a route to breeding: territorial inheritance, safe havens, and ecological constraints.

The relative roles of ecological constraints, the benefits of philopatry, and the role of life history continue to be debated in the evolution of natal philopatry and cooperative breeding. We compare three routes to breeding: departing to search for territories as a floater, staying and queuing to inherit the natal territory, or queuing and eventually shifting to a neighboring vacancy. Our model assumed a dominance-structured population.

Delayed dispersal: youth costs carry lifetime gains.

An analysis of reproductive success in the green woodhoopoe Phoeniculus purpures challenges the view that delayed dispersal is costly. Females delaying dispersal for longer had more reproductive events in life and higher lifetime production of offspring.

Impact of forestry practices on fitness correlates and population productivity in an open-nesting bird species.

In the boreal forests of Fennoscandia, over 99% of forest area has been altered by forestry practices, which has created forest with age structures and stand characteristics that differ from primary forest stands. Although many researchers have investigated how forestry affects species abundance, few have assessed how forestry practices affect fitness correlates of species living in altered habitats, and this has negatively affected management efforts. We experimentally addressed the effect of standard forestry practices on fitness correlates of an open-nesting, long-lived bird species typical to boreal forests of Eurasia, the Siberian Jay (Perisoreus infaustus).

Reduced mortality selects for family cohesion in a social species.

Delayed dispersal is the key to family formation in most kin-societies. Previous explanations for the evolution of families have focused on dispersal constraints. Recently, an alternative explanation was proposed, emphasizing the benefits gained through philopatry.

Experimentally increased food resources in the natal territory promote offspring philopatry and helping in cooperatively breeding carrion crows.

Kin-based societies, where families represent the basic social unit, occur in a relatively small number of vertebrate species. In the majority of avian kin societies, families form when offspring prolong their association with the parents on the natal territory. Therefore, the key to understanding the evolution of families in birds is to understand natal philopatry (i.

Predation risk induces changes in nest-site selection and clutch size in the Siberian jay.

Life-history theory predicts that an individual should reduce its reproductive efforts by laying a smaller clutch size when high risk of nest predation reduces the value of current reproduction. Evidence in favour of this 'nest predation hypothesis', however, is scarce and based largely on correlative analyses. Here, we manipulated perceived risk of nest predation in the Siberian jay Perisoreus infaustus using playback involving a mixture of calls by corvid nest predators in the vicinity of nest sites.

Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies.

Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative 'Corvida' branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral.

Kin selection in cooperative alliances of carrion crows.

In most cooperative vertebrates, delayed natal dispersal is the mechanism that leads to the formation of kin societies. Under this condition, the possibility that kin-based cooperative breeding is an unselected consequence of dispersal patterns can never be ruled out because helpers can only help their relatives. Here we show that a population of carrion crows (Corvus corone corone) fully fits the central prediction of kin selection theory that cooperative breeding should arise among relatives.

Why offspring delay dispersal: experimental evidence for a role of parental tolerance.

Approximately 3% of all bird species live in families based on a prolonged parent-offspring association. Formation of family groups often appears to be associated with various constraints on the possibilities of independent reproduction for the offspring. However, delayed dispersal is not the only alternative for offspring that defer reproduction.

History, environment and social behaviour: experimentally induced cooperative breeding in the carrion crow.

Kin-based cooperative breeding, where grown offspring delay natal dispersal and help their parents to rear new young, has a long history in some avian lineages. Family formation and helping behaviour in extant populations may therefore simply represent the retention of ancestral features, tolerated under current conditions, rather than a current adaptive process driven by environmental factors. Separating these two possibilities challenges evolutionary biologists because of the tight coupling that normally exists between phylogeny and the environmental distribution of species and populations.

REPRODUCTIVE COST, AGE-SPECIFIC SURVIVAL AND A COMPARISON OF THE REPRODUCTIVE STRATEGY IN TWO EUROPEAN TITS (GENUS PARUS).

Theoretical analyses of optimal reproductive rates usually assume a trade-off between offspring production and parental survival. This study verified a survival cost for willow tit males; nonbreeding males survived better than males attending a brood. Theory also predicts a smaller clutch size in birds that are less successful in transforming reproductive investments into mature offspring.