Age-related foetal sex ratio bias in Iberian red deer (Cervus elaphus hispanicus): are male calves too expensive for growing mothers? Tomás Landete-CastillejosChristian GortázarLaureano Gallego Original Article 13 February 2004 Pages: 1 - 8
Division of labor and the evolution of task sharing in queen associations of the harvester ant Pogonomyrmex californicus Sara Helms CahanJennifer H. Fewell Original Article 13 February 2004 Pages: 9 - 17
Factors affecting vigilance within wild mixed-species troops of saddleback (Saguinus fuscicollis) and moustached tamarins (S. mystax) Andrew C. SmithShaleyla KelezHannah M. Buchanan-Smith Original Article 22 January 2004 Pages: 18 - 25
How Kentish plovers, Charadrius alexandrinus, cope with heat stress during incubation Juan A. AmatJosé A. Masero Original Article 04 February 2004 Pages: 26 - 33
Male-male interference competition decreases spawning rate in the European bitterling (Rhodeus sericeus) Martin ReichardPavel JurajdaCarl Smith Original Article 10 February 2004 Pages: 34 - 41
Differential reproductive success among subfamilies in queenless honeybee (Apis mellifera L.) colonies Caroline G. MartinBenjamin P. OldroydMadeleine Beekman Original Article 10 February 2004 Pages: 42 - 49
Multiple paternity and colony homeostasis in Lasius niger ants Else J. Fjerdingstad Original Article 10 February 2004 Pages: 50 - 58
Female courtship in the Banggai cardinalfish: honest signals of egg maturity and reproductive output? Niclas Kolm Original Article 27 January 2004 Pages: 59 - 64
Sperm swimming speed and energetics vary with sperm competition risk in bluegill (Lepomis macrochirus) Gary BurnessStephen J. CasselmanRobert Montgomerie Original Article 23 January 2004 Pages: 65 - 70
Functional reference in an alarm signal given during nest defence: seet calls of yellow warblers denote brood-parasitic brown-headed cowbirds Sharon A. GillSpencer G. Sealy Original Article 30 January 2004 Pages: 71 - 80
Brood neglect and contingent foraging behavior in a pelagic seabird Sue LewisKeith C. HamerThomas N. Sherratt Original Article 13 February 2004 Pages: 81 - 88
Help or disperse? Cooperation in termites influenced by food conditions Judith KorbSandra Schmidinger Original Article 31 January 2004 Pages: 89 - 95