Small mammals as indicators of cryptic plant species diversity in the central Chilean plant endemicity hotspot

AbstractIndicator species could help to compensate for a shortfall of knowledge about the diversity and distributions of undersampled and cryptic species. This paper provides background knowledge about the ecological interactions that affect and are affected by herbaceous diversity in central Chile, as part of the indicator species selection process. We focus on the ecosystem engineering role of small mammals, primarily the degu Octodon degus. We also consider the interacting effects of shrubs, trees, avian activity, livestock, slope, and soil quality on herbaceous communities in central Chile. We sampled herbaceous diversity on a private landholding characterized by a mosaic of savanna, grassland and matorral, across a range of degu disturbance intensities. We find that the strongest factors affecting endemic herbaceous diversity are density of degu runways, shrub cover and avian activity. Our results show that the degu, a charismatic and easily identifiable and countable species, could be used as an indicator species to aid potential conservation actions such as private protected area uptake. We map areas in central Chile where degus may indicate endemic plant diversity. This area is larger than expected, and suggests that significant areas of endemic plant communities may still exist, and should be identified and protected

Toward an integrative understanding of social behavior: new models and new opportunities.

Social interactions among conspecifics are a fundamental and adaptively significant component of the biology of numerous species. Such interactions give rise to group living as well as many of the complex forms of cooperation and conflict that occur within animal groups. Although previous conceptual models have focused on the ecological causes and fitness consequences of variation in social interactions, recent developments in endocrinology, neuroscience, and molecular genetics offer exciting opportunities to develop more integrated research programs that will facilitate new insights into the physiological causes and consequences of social variation. Here, we propose an integrative framework of social behavior that emphasizes relationships between ultimate-level function and proximate-level mechanism, thereby providing a foundation for exploring the full diversity of factors that underlie variation in social interactions, and ultimately sociality. In addition to identifying new model systems for the study of human psychopathologies, this framework provides a mechanistic basis for predicting how social behavior will change in response to environmental variation. We argue that the study of non-model organisms is essential for implementing this integrative model of social behavior because such species can be studied simultaneously in the lab and field, thereby allowing integration of rigorously controlled experimental manipulations with detailed observations of the ecological contexts in which interactions among conspecifics occur

Allonursing in Captive Guanacos, Lama guanicoe: Milk Theft or Misdirected Parental Care?

Females in several ungulates transfer milk to non-filial (NF) offspring, in a process known as allonursing. This behavior is less common in monotocous species, including most ungulates, and it has been associated with parasitic behavior of calves or mothers who have lost their own offspring. To examine whether the calves ‘steal’ milk from the females or whether females fail to discriminate their own calves in guanacos, allonursing behavior was observed. If milk theft drives allonursing, mothers should reject NF offspring, they should search for their own calves, and calves attempting to suckle from alien mothers should adopt parallel (as opposed to the anti-parallel) position during allonursing. Alternatively, if allonursing is caused by mothers unable to discriminate own offspring, mothers are not expected to reject NF offspring, and alien calves should use parallel and antiparallel position similarly when allonursing. Allonursing was investigated during the first 3 mo of lactation in two groups of captive guanacos composed of 15 and 14 mother-calf pairs, respectively. While 40% and 62.5% of mothers in groups 1 and 2 performed allonursing, high individual variation prevailed; some females exhibited this behavior infrequently (4.1% and 6.5 % in groups 1 and 2). The rejection rate to NF nursing attempts was threefold higher than the rejection rate to filial nursing attempts. The occurrence of nursing to NF was associated to a parallel posture by the calves. Our findings suggest that ‘milk theft’ is a more plausible hypothesis to explain allonursing in guanacos than ‘misdirected parental care’

Sociality in New World hystricognath rodents is linked to predators and burrow digging

The importance of predation and burrow digging in explaining the evolution of sociality is generally unclear. We focused on New World hystricognath rodents to evaluate three key predictions of the predation hypothesis. First, large-bodied surface-dwelling species will be more vulnerable because they are more detectable; thus sociality should be associated with body size. Second, surface-dwelling, diurnal species would be more vulnerable to predators than nocturnal species; thus sociality should be associated with the evolution of diurnality. Third, species living in open habitats will be more vulnerable; thus sociality should evolve in species living in open habitats. Regarding the importance of burrows, we tested if species that dig burrows can benefit from communal labor; thus, sociality should be associated with burrow digging. All traits had significant phylogenetic signal, thus comparative analyses should explicitly address this. In a comparative analysis on independent contrasts we found that sociality was correlated with body size (larger species were more social), diurnality (diurnal species were more social), and burrowing (burrowing species were more social), but we found no effect of overhead plant cover of habitat on sociality in hystricognath rodents. Somewhat different results were found when we analyzed the raw data. Taken together, our results provide support for a link between predation risk, burrow digging, and sociality in this group. Copyright 2006.burrow digging; diurnality; group living; New World rodents; plant cover; predation risk

Scientific impact of Chilean-based animal behavioralists is positively associated with co-authorships from developed countries, high impact factor journals, but not with gender

Abstract Background Previous bibliometric studies in scientific researchers from developed countries generally support that sharing efforts during research enhances productivity and impact and suggest these effects may be important for researchers from less developed countries exhibiting more exiguous science budgets. We examined whether researchers in the field of animal behavior in an economically less developed country compensate for this burden by collaborating with researchers from developed countries, and whether this effect is gender specific. Methods We quantified collaborations of 30 Chilean-based focal animal behavioralists with peers from developed countries based on co-authorships within 664 animal behavior papers. We examined whether the mean number, or mean proportion of such co-authorships was positively associated with productivity (number of research papers) and impact (h-index, citations per research paper) when gender, author role (i.e., first or corresponding author), and other covariates were considered. We complemented these analyses with a survey to focal researchers to estimate the perceived relevance of collaborations with peers from developed countries. Results The h-index, but not the number of animal behavior papers published by focal researchers, increased with the mean number (but not with the mean proportion) of international co-authors from developed countries, an effect not gender-specific, but that supported the perceived importance of collaborations with peers from developed countries. The number of papers and the individual impact of focal researchers increased with academic age. The number of citations of individual papers increased with journal impact factor, year since publication, but not with the role (first or corresponding author) played by collaborators from developed countries. Conclusions Our bibliometric and survey-based approach supported that establishing collaborations with researchers from developed countries and publishing in high impact factor journals are correlated with the career-long impact of Chilean-based animal behavioralists, and that this association is not contingent on gender, or influenced by the role (first or corresponding author) played by collaborators