Morphometric estimates of body condition are widely used by ornithologists, but which
estimates work best is a matter of debate. We review morphometric approaches (body mass …

Polyandry, by elevating sexual conflict and selecting for reduced male care relative to
monandry, may exacerbate the cost of sex and thereby seriously impact population fitness …

Physiological Adaptations for Breeding in Birds is the most current and comprehensive
account of research on avian reproduction. It develops two unique themes: the consideration …

Body condition indices are widely used by ecologists, but many indices are used without
empirical validation. To test the validity of a variety of indices, we compared how well a …

High temperatures can pose significant thermoregulation challenges for endotherms, and
determining how individual species respond to high temperatures will be important for …

Hormonal control systems are complex in design and well integrated. Concern has been
raised that these systems might act as evolutionary constraints when animals are subject to …

In species with biparental care, one parent may escape the costs of parental care by
deserting and leaving the partner to care for the offspring alone. A number of theoretical …

A fundamental tenet of sexual conflict theory is that one sex may increase its reproductive
success (RS) even if this harms the other sex. Several studies supported this principle by …

Melanin-based ornaments are often involved in signaling aggression and dominance, and
their role in sexual selection is increasingly recognized. We investigated the functions of a …

Desertion of offspring before its independence by one of the parents is observed in a
number of avian species with bi-parental care but reasons for this strategy are not fully …