Territoriality is an important process shaping population dynamics, and the defence of a
territory is crucial for individuals to increase the duration of territory occupancy and …

Highlights•We tested whether male yodels convey information about age in common
loons.•Dominant frequency of a dominant syllable (Fintro3) in male yodels increased with …

Most studies of vertebrate breeding success have been unable to pinpoint the cause for a
simple and almost universal pattern: its steady increase during an animal's lifetime. Yet …

Animals that show aggression often risk injury and incur steep energetic costs. Thus,
aggression should occur at such times and towards such opponents as to maximize fitness …

Modern evolutionary theory provides a theoretical framework for functional analyses of
animal behaviour. In order to investigate the adaptive value of individual behaviour patterns …

In addition to resource value, the cost of finding mates may affect how much males invest in
fights for females. The cost of finding females may be imposed through natural factors …

Adult birds may use the production of offspring as a measure of habitat quality when
prospecting for territories, increasing competition for productive territories. We evaluated the …

Die moderne Evolutionstheorie liefert einen theoretischen Rahmen für funktionale Analysen
einzelner Verhaltensweisen. Zur Untersuchung der Angepasstheit des Verhaltens ist es …

In socially monogamous species, male reproductive success consists of 'within-pair'offspring
produced with their socially-paired mate (s), and 'extra-pair'offspring produced with …

This dissertation explores various components of male life-history theory using a species-
specific approach focusing on Weddell seals (chapters 2 and 4) and a comparative …