- Chile
Rodrigo Vasquez
Universidad de Chile, Ecological Sciences, Faculty Member
- I am a biologist, with diverse interest on basic and applied research in wild animals.edit
In Chile, the manipulation for scientific purposes of terrestrial vertebrates from natural populations is conducted previous authorization of the Agricultural and Livestock Service and various Bioethics Committees. Obtaining such... more
In Chile, the manipulation for scientific purposes of terrestrial vertebrates from natural populations is conducted previous authorization of the Agricultural and Livestock Service and various Bioethics Committees. Obtaining such authorizations is becoming increasingly complex. The procedures do not fit the reality of scientific work, and they seem to be based on unjustified assessments of the effects of animal handling on natural populations. The aim of this commentary is to initiate a discussion in order to establish a norm of scientific manipulation of terrestrial vertebrates adjusted to biological reality and that does not interfere with scientific research.
Research Interests:
Research Interests:
We evaluated the extent to which manipulation of early olfactory environment can influence social behaviours in the South American Hystricognath rodent Octodon degus. The early olfactory environment of newborn degus was manipulated by... more
We evaluated the extent to which manipulation of early olfactory environment can influence social behaviours in the South American Hystricognath rodent Octodon degus. The early olfactory environment of newborn degus was manipulated by scenting all litter members with eucalyptol during the first month of life. The social behaviour of sexually mature animals (5-7 months old) towards conspecifics was then assessed using a y-maze to compare the response of control (naïve) and treated animals to two different olfactory configurations (experiment 1): (i) a non-familiarized conspecific impregnated with eucalyptol (eucalyptol arm) presented against (ii) a non-familiarized unscented conspecific (control arm). In addition, in dyadic encounters, we assessed the behaviour of control and eucalyptol treated animals towards a non-familiarized conspecific scented with eucalyptol (experiment 2). We found that control subjects explored and spent significantly less time in the eucalyptol arm, indicati...
Research Interests:
Research Interests:
The foraging ecology of hummingbirds involves the exploitation of a high number of patchily distributed flowers. This scenario seems to have influenced capabilities related to learning and memory, which help to avoid recently visited... more
The foraging ecology of hummingbirds involves the exploitation of a high number of patchily distributed flowers. This scenario seems to have influenced capabilities related to learning and memory, which help to avoid recently visited flowers and to allocate exploitation to the most rewarding flowers, once learning has occurred. We carried out two field experiments with the green‐backed firecrown hummingbird (Sephanoides sephaniodes, Trochilidae) in order to examine the ability of birds, first, to recall a nectar location, and secondly, to remember the location of the most rewarding flower among lower quality flowers. The first experiment showed that subjects were able to recall the location of nectar among flowers of identical appearance. In the second experiment, hummingbirds were also able to recall the location of the most rewarding nectar among less rewarding flowers with the same appearance. The results of this study suggest that S. sephaniodes can remember the location of the ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Climate variability, Biology, Ecology, Medicine, Habitat, and 15 moreEnergetics, Female, Animals, Male, Body Mass Index, Ecosystem, Environmental Conditions, Interspecific competition, Intraspecific Competition, Indexation, Food Habit, Mean Annual Temperature, Diet Quality, Biochemistry and cell biology, and Basal Metabolism
Despite the fact that insect learning capacity has been broadly demonstrated, the role that this process plays during mate searching has been scarcely explored. We studied whether the sexual behaviour of a male parasitic wasp can be... more
Despite the fact that insect learning capacity has been broadly demonstrated, the role that this process plays during mate searching has been scarcely explored. We studied whether the sexual behaviour of a male parasitic wasp can be conditioned to the odours from two alternative host plant complexes (HPCs) present during its first copulation. The experimental subjects were newly emerged males of the aphid parasitoid,Aphidius ervi, and two alternative HPCs (alfalfa or wheat). In the training protocol, copulation experience corresponded to an unconditioning stimulus and HPC odours to the conditioning stimuli. The initial (just after eclosion) and trained responses were assessed in a glass Y-olfactometer. The results showed that neither alfalfa HPC nor wheat HPC stimuli elicited sexual-related behaviours in initial male responses. Conversely, both HPCs triggered strong attraction and wing fanning courtship behaviour in trained responses when the male was exposed to a female plus HPC du...
Research Interests:
Research Interests:
Nest-mate recognition and territorial behaviour in ants are widely studied phenomena. However, few studies have analysed, under field conditions, how nest-mate recognition varies with distance from the resident's colony. In a natural... more
Nest-mate recognition and territorial behaviour in ants are widely studied phenomena. However, few studies have analysed, under field conditions, how nest-mate recognition varies with distance from the resident's colony. In a natural population of Camponotus chilensis in central Chile, we studied nest-mate recognition and spatial variation in aggressive behaviour. C. chilensis individuals were able to discriminate nest-mates from intruders, showing no aggression toward nest companions, while aggressiveness toward allo-colonial con-specifics decreased significantly with distance. Further, the overall number of interactions and the aggressiveness of the resident ants were significantly greater at 25 cm from their colony than at further distances. Given that antennation behaviour is regularly present at all distances from the nest, it seems to entail information acquisition. Biting and intruder-dragging, the most conspicuous aggressive displays, were mainly observed at distances cl...
Research Interests:
Although foraging comprises a set of behaviours that typically vary with resource availability and/or climatic conditions, few studies have analysed how foraging, particularly food hoarding, varies across populations inhabiting different... more
Although foraging comprises a set of behaviours that typically vary with resource availability and/or climatic conditions, few studies have analysed how foraging, particularly food hoarding, varies across populations inhabiting different habitats. We carried out an inter‐population study on foraging behaviour with the caviomorph rodent Octodon degus collected from two geographically separated populations in central Chile, with contrasting climates. One population was located in a mountainous zone (at 2600 m elevation) characterized by a high‐altitude climate. The other population was from a low‐altitude Mediterranean climate zone (450 m elevation). Under laboratory conditions, we measured population‐specific differences in food consumption and hoarding by recording food utilization. We also assessed whether acclimation played a role in behavioural differences, by using two different sets of animals that had been in captivity for (1) 2 wk or (2) 6 mo, under common conditions. The res...
Research Interests: Evolutionary Biology, Zoology, Ethology, Psychology, Biology, and 4 moreEcology, Foraging, Population, and Captivity
Populations of the same species can vary substantially in their behavioral and morphometric traits when they are subject to different environmental pressures, which may lead to the development of different adaptive strategies. We... more
Populations of the same species can vary substantially in their behavioral and morphometric traits when they are subject to different environmental pressures, which may lead to the development of different adaptive strategies. We quantified variation in exploratory behavior and morphometric traits among two rufous-collared sparrow populations that occur at low and high elevations in central Chile. Moreover, we used census and δH values of feather and blood to evaluate migration. We found that individual sparrows inhabiting high elevations were larger and showed more intense exploratory behavior in comparison with those that were captured at lower elevation. Moreover, we observed a steady decline in sparrow abundance during the winter and similar δH values for blood collected in the winter and summer at this site, which were significantly lower than blood δH values observed at low elevation. This pattern suggests that individuals do not move long distances during winter, and likely t...
Research Interests:
Research Interests:
Research Interests:
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... more
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 mode...
Research Interests:
Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability.... more
Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria pa...
Research Interests: Malaysia, Medical Microbiology, Biology, Climate, Medicine, and 15 morePlant Secondary Metabolites, Animal Feed, Plant Secondary Metabolism, Female, Animals, Male, Australasia, Ecosystem, Captive Wild Animals, Haemoproteus, Leucocytozoon, Haemosporida, Haemoparasites, Bird diseases, and blood parasites
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Zoology, Geography, Ornithology, Biology, Ecology, and 15 moreSocial status, Arrival Date, Male-Male Competition, Corticosterone, Patch Size, Glucocorticoid, Environmental Conditions, Migratory Birds, Heat Shock Proteins, Heat Shock Protein, Metabolite, Glucocorticoids, Time of Arrival, ENVIRONMENTAL SCIENCE AND MANAGEMENT, and Territorial Behavior
Research Interests:
Research Interests:
Research Interests: Evolutionary Biology, Geography, Biology, Ecology, Biological Sciences, and 12 moreEnvironmental Sciences, DNA analysis, Species Richness, Latitudinal Gradient, Southern Hemisphere, Forest ecosystem, Migratory Birds, Host Specificity, Haemoproteus, Long Distance, Australian ecology, and Forest birds
Rufous-collared sparrows (Zonotrichia capensis peruviensis) from valleys in the Atacama Desert of Chile, live in an extremely stable environment, and exhibit overlap in molt and reproduction, with valley-specific differences in the... more
Rufous-collared sparrows (Zonotrichia capensis peruviensis) from valleys in the Atacama Desert of Chile, live in an extremely stable environment, and exhibit overlap in molt and reproduction, with valley-specific differences in the proportion of birds engaged in both. To better understand the mechanistic pathways underlying the timing of life-history transitions, we examined the relationships among baseline and stress-induced levels of corticosterone (CORT), testosterone, and bacteria-killing ability of the blood plasma (BKA), as well as haemosporidian parasite infections and the genetic structure of two groups of sparrows from separate valleys over the course of a year. Birds neither molting nor breeding had the lowest BKA, but there were no differences among the other three categories of molt-reproductive stage. BKA varied over the year, with birds in May/June exhibiting significantly lower levels of BKA than the rest of the year. We also documented differences in the direction of...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Physiology, Climate variability, Biology, Population Dynamics, Medicine, and 15 moreEnergetics, Female, Animals, Male, Body Mass Index, Metabolic rate, Ecosystem, Environmental Conditions, Reproducibility of Results, Indexation, Species Specificity, Food Habit, Mean Annual Temperature, Diet Quality, and Biochemistry and cell biology
We studied effects of habitat structure on routine travel velocities, intermittent locomotion, and vigilance by the degu (Octodon degus), a diurnal rodent of central Chile. We predicted that travel speed, pauses during locomotion, and... more
We studied effects of habitat structure on routine travel velocities, intermittent locomotion, and vigilance by the degu (Octodon degus), a diurnal rodent of central Chile. We predicted that travel speed, pauses during locomotion, and vigilance would be greater in open (riskier) than in ...
Research Interests:
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... more
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.
Research Interests:
Research Interests:
Locomotion velocity during foraging activities is determined by factors such as travel distance, habitat structure and load mass among others. However, few studies on foraging behavior have analyzed the influence of spatial heterogeneity... more
Locomotion velocity during foraging activities is determined by factors such as travel distance, habitat structure and load mass among others. However, few studies on foraging behavior have analyzed the influence of spatial heterogeneity and food transportation on the locomotion velocity of ants under natural conditions. In order to study the mentioned factors, we selected 20 nests of the ant Dorymyrmex goetschi (subfamily Dolichoderinae), in a lower Andes locality of central Chile. Half of the nests were offered a food patch located at 10 cm from the nest entrance, and at 20 cm for the other half. We measured the duration of trips between nest and food patch and vice versa, and the distances traveled. We also recorded spatial heterogeneity of the substratum and soil temperature. Temperature was used as a covariate in the statistical analysis. Travel speed was significantly slower when worker ants returned to the nest with a food load, compared to the velocity of foragers without load that traveled from the nest to the patch. When the food patch was located at greater distance, locomotion velocity was significantly faster. Spatial heterogeneity did not affect movement speed. The reduction in locomotion velocity in ants carrying a load of 5.6 mg represents an energetic cost of transportation equivalent to 79% of the costs involved in moving a body mass of 1.6 mg. Faster velocities at larger patch distances can be interpreted as a strategy to maintain an efficient resource exploitation, by way of decreasing the time exposed to higher predation risk.
Research Interests:
Research Interests:
Page 1. NOTE Eur. J. Entomol. 102: 557-559,2005 ISSN 1210-5759 Associative odour learning affects mating behaviour in Aphidius ervi males (Hymenoptera: Braconidae) Cristian A. VILLAGRA, Rodrigo A. VÁSQUEZ and Hermann ...
Research Interests:
Climbing ability can be a major component of the capability of terrestrial mammals to use vertical habitats. Previous studies suggest that small mammals from central Chile have low climbing capabilities. However, those studies have not... more
Climbing ability can be a major component of the capability of terrestrial mammals to use vertical habitats. Previous studies suggest that small mammals from central Chile have low climbing capabilities. However, those studies have not disentangled the influence of tree diameter ...