Female activity patterns and aggressiveness in the strawberry poison frog Dendrobates pumilio (Anura: Dendrobatidae)

Abstract

Female strawberry poison frogs (Dendrobates pumilio) exhibit highly evolved maternal care, including tadpole transport and tadpole provisioning with unfertilized eggs. We observed that tadpole-rearing and mating activity are mutually exclusive behavioura l states in a Costa Rican population. Tadpole-rearin g females did not engage in courtship activity. Only non-rearing females courted. Non-rearing females occupied larger home ranges than tadpole-rearing females, which may be related to female selection of mates. For the rst time aggressive female-female interactions were observed in the eld. Tadpole-rearing females were signi cantly more aggressive than non-rearing females, especially in the vicinity of their offspring-rearin g sites.Resumen. Las hembras de la ranita roja Dendrobates pumilio ejecutan cuidado parental altamente desarrollado que incluye el transporte y la alimentación de los renacuajos. En una población costaricense encontramo s que el cuido materno y la actvidad sexual son comportamientos mutualmente exclusivos: Las hembras que estan cuidando a su cría son sexualmente inactivas, solamente las hembras sin renacuajos se aparean. Las hembras sexualmente activas poseian un rango de actividad más grande que las hembras cuidando a renacuajos. Los rangos de actividad en el primer grupo de hembras eran más grandes probablement e porque ellas visitan los territorios de varios machos con el n de seleccionar una pareja. Además, por la primera vez interacciones aggressivas entre las hembras de la ranita roja fueron observado s en el campo, siendo más aggressivas las hembras con rencuajos, particularment e en la vencidad de los hábitats de su cría.

Territorial Behavior in Dendrobatid Frogs

“…Donnelly (1989a,b) provides convincing evidence that tadpole-rearing sites are a limited resource in the strawberry poison frog Dendrobates pumilio. These results have been confirmed through research on another D. pumilio population in which it was shown that the distribution of suitable tadpole-rearing sites influences the distribution of males and females in this species (Prö hl, 2002;Prö hl and Berke, 2001). Nevertheless, it has never been confirmed that males defend tadpole-rearing sites by agonistic interactions against intruders in their territories.…”

“…Intrasexual aggressiveness in female D. pumilio has not been reported from other populations (McVey et al, 1981;Bunnell, 1973;Donnelly, 1989a;Prö hl and Hö dl, 1999). It might be peculiar to the population studied by Haase and Prö hl (2002) in which tadpole-rearing sites are inordinately abundant, and as a consequence female density was unusually high (6 10 females per 100 m 2 , A. Haase pers. comm.).…”

“…A recent study of D. pumilio shows that females are aggressive toward other females during tadpole rearing, but the reason for the observed agonistic interactions (e.g., defense of tadpolerearing sites or offspring) could not be identified (Haase and Prö hl, 2002). Intrasexual aggressiveness in female D. pumilio has not been reported from other populations (McVey et al, 1981;Bunnell, 1973;Donnelly, 1989a;Prö hl and Hö dl, 1999).…”

Does aggression and explorative behaviour decrease with lost warning coloration?

“…D. pumilio males and, to a lesser extent females, are intrasexually competitive (Pröhl & Berke, 2001;Haase & Pröhl, 2002). Pröhl & Berke (2001) reported that females choose their breeding territories based on the presence of tadpole rearing sites, whereas males choose their territories based on the presence of females.…”

Female–female aggression is linked to food defence in a poison frog

“…Like in mammals, female O. pumilio heavily invest in maternal care mainly consisting of tadpole provisioning with nutritive eggs whose production requires high amounts of energy. There is another aspect in which female frogs behave like female mammals during pregnancy and lactation (Rosvall, ): females of the strawberry poison frog are more aggressive towards other females during periods of tadpole feeding (Haase & Pröhl, ).…”