Humans in strong social relationships are more likely to live longer because social relationships may buffer stressors and thus have protective effects. However, a shortcoming of human studies is that they often rely on self-reporting of these relationships. By contrast, observational studies of non

In mutualistic interactions, the decision whether to cooperate or cheat depends on the relative costs and benefits of each strategy. In pollination mutualisms, secondary nectar robbing is a facultative behavior employed by a diverse array of nectar-feeding organisms, and is thought to be a form of c

Trapline foraging—repeated sequential visits to a series of feeding locations—presents interesting problems seldom treated in foraging models. Work on traplining is hampered by the lack of statistical, operational approaches for detecting its existence and measuring its strength. We propose several

Biological processes, such as predator-prey or competitive interactions, occur at multiple spatial and temporal scales, but their impacts on the distribution, abundance, and fitness of organisms may only be detectable at some scales. This is because 1) small scale (local) processes may be constraine

It is found that pseudoflower fragrance can attract visitors by itself, and the ability of insects to differentiate pseudoflowers from true flowers by their fragrance may be important in the evolution of the mimicry system.

1. A standardized protocol for analysing the behaviour of pollinators foraging on more than one plant type (species or morph) is needed. 2. A protocol is presented in which the first step is to test whether foraging trips are homogeneous in the frequency of visits to each plant type, or whether ther

A pervasive idea among pollination biologists is that bees cannot see red flowers. This idea has led many workers to assume that red coloration is an adaptation by which flowers exclude bees as visitors. However, recent empirical and theoretical evidence strongly supports the alternative view, that

The evolution of flowering phenology has most often been examined in light of one set of organisms, namely pollinators. However, the patterns of flowering phenology observed in nature are likely to reflect evolutionary compromises in response to a variety of selective forces. Two of the most importa

Alarm calling in group-living yellow-bellied marmots is a form of direct parental care and inclusive fitness, broadly defined, is of little importance for the maintenance of alarm calling.

Yellow-bellied marmots, Marmota flaviventris were reported to produce qualitatively different alarm calls in response to different predators, but there was significant individual variation in call structure, but acoustic parameters that were individually variable were not used to communicate variati

Closely related species often have remarkably different vocalizations. Some of the variation in acoustic structure may result from species adapting their calls to maximize transmission through their acoustic environ- ments. We document the relative magnitude of inter- and intraspecific variation in

While sociality has been hypothesized to drive the evolution of communicative complexity, the relationship remains to be formally tested. We derive a continuous measure of social complexity from demographic data and use this variable to explain variation in alarm repertoire size in ground-dwelling s