Showing papers by "Trevor D. Price published in 2013"
TL;DR: Heterospecific responses to avian alarm signals that drive the formation of anti-predator groups but are also used during intraspecific interactions are studied and it is demonstrated experimentally that signal copying allows strong responses even without previous exposure.
Abstract: Signals relevant to different sets of receivers in different contexts create a conflict for signal design. A classic example is vocal alarm signals, often used both during intraspecific and interspecific interactions. How can signals alert individuals from a variety of other species in some contexts, while also maintaining efficient communication among conspecifics? We studied heterospecific responses to avian alarm signals that drive the formation of anti-predator groups but are also used during intraspecific interactions. In three species-rich communities in the western Himalayas, alarm signals vary drastically across species. We show that, independently of differences in their calls, birds respond strongly to the alarm signals of other species with which they co-occur and much more weakly to those of species with which they do not co-occur. These results suggest that previous exposure and learning maintain heterospecific responses in the face of widespread signal divergence. At an area where only two species regularly interact, one species' calls incorporate the call of the other. We demonstrate experimentally that signal copying allows strong responses even without previous exposure and suggest that such hybrid calls may be especially favoured when pairwise interactions between species are strong.
52 citations
TL;DR: The results strongly support the inclusion of the Fire-capped Tit (Cephalopyrus flammiceps), currently placed in the Remizidae, as the most basal member of the Paridae and a new classification that is in accordance with this phylogeny.
52 citations
TL;DR: It is shown that a necessary condition for the permanent establishment of mutual displays in the pair bond is that the benefit of investment by the pair is more than twice that resulting from investment by a single individual.
Abstract: Although sexual selection is an important cause of display evolution, in socially monogamous species (e.g. many birds), displays continue after formation of the pair bond. Here, we consider that these displays evolve because they stimulate the partner to increase investment in offspring. Our study is motivated by elaborate mutual displays in species that are largely monomorphic and have long-term pair bonds (e.g. the great crested grebe, Podiceps cristatus) and by many empirical results evidencing that display manipulation affects parental investment. Using population genetic models, we show that a necessary condition for the permanent establishment of mutual displays in the pair bond is that the benefit of investment by the pair is more than twice that resulting from investment by a single individual. Pre-existing biases to respond to displays by increased investment are a necessary component of display evolution. We also consider examples where one sex (e.g. males) stimulates increased investment in offspring by the other sex. Here, display and additional investment cannot evolve permanently, but can increase and linger at high frequency for a long time before loss. We discuss how such transient effects may lead to the evolution of permanent displays as a result of evolution at additional loci.
28 citations
TL;DR: Little studied and little visited, northeast India is thought to be second only to the northern Andes in terrestrial species density.
Abstract: Little studied and little visited, northeast India is thought to be second only to the northern Andes in terrestrial species density ([ 1 ][1]). Because of its distance from Delhi and its predominantly tribal culture, minimal regulation protects biodiversity in the region. As a result, there has
7 citations