Trans-equatorial long-distance migrations of high-latitude breeding animals have been attributed to narrow ecological niche widths. We suggest an alternative hypothesis postulating that trans-equatorial migrations result from a possible increase in the rate at which body stores to fuel migration are deposited with absolute latitude; that is, longer,… (More)
Molt is a major component of the annual cycle of birds, the timing and extent of which can affect body condition, survival, and future reproductive success through carry-over effects. The way in which molt is fitted into the annual cycle seems to be a somewhat neglected area which is both of interest and of importance. Study of the causes of annual… (More)
BACKGROUND Geolocators are useful for tracking movements of long-distance migrants, but potential negative effects on birds have not been well studied. We tested for effects of geolocators (0.8-2.0 g total, representing 0.1-3.9 % of mean body mass) on 16 species of migratory shorebirds, including five species with 2-4 subspecies each for a total of 23 study… (More)
The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates,… (More)
Preliminary observational data relating to slot machine gamblers in two amusement arcades were collected over 3 mo. in the winter in Plymouth (south-west England). Arcades were frequented largely by males most of whom appeared to be adolescent. Slot machine gambling seemed to be an essentially solitary activity even when people entered the arcades in groups.