Interspecific Dominance Via Vocal Interactions Mediates Altitudinal Zonation in Neotropical Singing Mice

• Published in: The American naturalist 2013-11, Vol.182 (5), p.E161-E173
• Main Authors: Pasch, Bret, Bolker, Benjamin M., Phelps, Steven M.
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Aggression; Altitude; Animal behavior; Animal Communication; Animal vocalization; Animals; Arvicolinae - physiology; Behavior, Animal; Competitive Behavior; Costa Rica; E-Article; Ecology; Experimentation; Habitats; Interspecific competition; Male; Male animals; Mice; Mountains; Population Dynamics; Rodents; Singing; Species; Species Specificity
• ISSN: 0003-0147; 1537-5323
• DOI: 10.1086/673263

Interspecific aggression between ecologically similar species may influence geographic limits by mediating competitive exclusion at the range edge. Advertisement signals that mediate competitive interactions within species may also provide social information that contributes to behavioral dominance and spatial segregation among species. We studied the mechanisms underlying altitudinal range limits in Neotropical singing mice (Scotinomys), a genus of muroid rodent in which males vocalize to repel rivals and attract mates. We first delineated replacement zones and described temperature regimes on three mountains in Costa Rica and Panama where Chiriquí singing mice (S. xerampelinus) abruptly replace Alston’s singing mice (S. teguina). Next, we conducted interspecific behavioral trials and reciprocal removal experiments to examine if interspecific aggression mediated species replacement. Finally, we performed reciprocal playback experiments to investigate whether response to song matched competitive interactions. Behavioral trials and removal experiments suggest thatS. xerampelinusis behaviorally dominant and excludesS. teguinafrom higher, cooler altitudes. Playback experiments indicate that subordinateS. teguinais silenced and repelled by heterospecific song, whereasS. xerampelinusresponded to heterospecifics with approach and song rates comparable to responses to conspecifics. Thus, interspecific communication reflects underlying dominance and suggests that acoustic signaling contributes to altitudinal zonation of ecologically similar congeners. Our findings implicate the use of social information in structuring spatial distributions of animal communities across landscapes and provide insight into how large-scale patterns are generated by individual interactions.