Sperm velocity and longevity trade off each other and influence fertilization in the sea urchin Lytechinus variegatus.

Intensity of nest defence is related to offspring sex ratio in the great tit Parus major.

Sex-ratio optimization with helpers at the nest.

Parentage, reproductive success and breeding behaviour in the greater horseshoe bat (Rhinolophus ferrumequinum).

Persistence of bat defence reactions in high Arctic moths (Lepidoptera).

Copulatory courtship and cryptic female choice in red flour beetles Tribolium castaneum.

Web tuning of an orb-web spider, Octonoba sybotides, regulates prey-catching behaviour.

Sensory compensation and the detection of predators: the interaction between chemical and visual information.

Acoustic preference functions and song variability in the Hawaiian cricket Laupala cerasina.

A long photoperiod overrides non-photoperiodic factors in blue tits' timing of reproduction.

Individual state controls temperature dependence in a butterfly (Lasiommata maera).

Relationships between root density of the African grass Hyparrhenia diplandra and nitrification at the decimetric scale: an inhibition-stimulation balance hypothesis.

Effective population size may limit the power of laboratory experiments to demonstrate sympatric and parapatric speciation.

Field data do not support a textbook example of convergent character displacement.

Phylogenetically patterned speciation rates and extinction risks change the loss of evolutionary history during extinctions.

Estimating the time to extinction in an island population of song sparrows.

Least-inclusive taxonomic unit: a new taxonomic concept for biology.