Arik Kershenbaum
I am interested in the behavioural ecology of animals, their vocal communication, and particularly how it relates to their distribution in space. Some animals have habitat requirements that are scarce in the environment, or spread out, so that the animals have to move around to meet their needs. Populations become more or less isolated and aspects of their behaviour - such as their vocalisations - may diverge. Examples of isolated habitats include boulder piles for hyraxes, and breeding pools for salamanders.
Specifically, I am looking at how the patterns of vocalisations of the hyrax vary with their location, and whether nearby animals "learn" particular songs from their neighbours.
I am also interested in the mathematical modelling of the effect of environmental change on the ecology of such species, and to predict the outcome of environmental disturbance. Man-made environmental changes can destroy these micro-habitats, or multiply them. How does this affect the migratory or foraging behaviour of these animals, and is it likely to cause conservation problems (for endangered species) or unwanted proliferation (for pest species)?
Research interests
-
InterestsBehavioural Ecology, Animal Vocalization, Mathematical Ecology, movement ecology, Ecological Modeling, Animal Behavior
Publications
-
4.11Impact points
Syntactic structure and geographical dialects in the songs of male rock hyraxes.
Proceedings. Biological sciences / The Royal Society. 04/2012;
Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex s... [more] Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex syntactic vocalizations in a small social mammal: the rock hyrax (Procavia capensis: Hyracoidea). We adopted three algorithms, commonly used in genetic sequence analysis and information theory, to examine the order of syllables in hyrax calls. Syntactic dialects exist, and the syntax of hyrax calls is significantly different between different regions in Israel. Call syntax difference is positively correlated to geographical distance over short distances. No correlation is found over long distances, which may reflect limited dispersal movement. These findings indicate that rich syntactic structure is more common in the vocalizations of mammalian taxa than previously thought and suggest the possibility of vocal production learning in the hyrax.
-
3.99Impact points
Unraveling seasonality in population averages: an examination of seasonal variation in glucose levels in diabetes patients using a large population-based data set.
Chronobiology international. 05/2011; 28(4):352-60.
It has been shown that the population average blood glucose level of diabetes patients shows seasonal variation, with higher levels in the winter than summer. However, seasonality in the population averages could be due to a tendency in the individual to seasonal variation, or alternatively due to o... [more] It has been shown that the population average blood glucose level of diabetes patients shows seasonal variation, with higher levels in the winter than summer. However, seasonality in the population averages could be due to a tendency in the individual to seasonal variation, or alternatively due to occasional high winter readings (spiking), with different individuals showing this increase in different winters. A method was developed to rule out spiking as the dominant pattern underlying the seasonal variation in the population averages. Three years of data from three community-serving laboratories in Israel were retrieved. Diabetes patients (N = 3243) with a blood glucose result every winter and summer over the study period were selected. For each individual, the following were calculated: seasonal average glucose for all winters and summers over the period of study (2006-2009), winter-summer difference for each adjacent winter-summer pair, and average of these five differences, an index of the degree of spikiness in the pattern of the six seasonal levels, and number of times out of five that each winter-summer difference was positive. Seasonal population averages were examined. The distribution of the individual's differences between adjacent seasons (winter minus summer) was examined and compared between subgroups. Seasonal population averages were reexamined in groups divided according to the index of the degree of spikiness in the individual's glucose pattern over the series of seasons. Seasonal population averages showed higher winter than summer levels. The overall median winter-summer difference on the individual level was 8 mg/dL (0.4 mmol/L). In 16.9% (95% confidence interval [CI]: 15.6-18.2%) of the population, all five winter-summer differences were positive versus 3.6% (95% CI: 3.0-4.2%) where all five winter-summer differences were negative. Seasonal variation in the population averages was not attenuated in the group having the lowest spikiness index; comparison of the distributions of the winter-summer differences in the high-, medium-, and low-spikiness groups showed no significant difference (p = .213). Therefore, seasonality in the population average blood glucose in diabetes patients is not just the result of occasional high measurements in different individuals in different winters, but presumably reflects a general periodic tendency in individuals for winter glucose levels to be higher than summer levels.
-
Rock hyrax (Procavia capensis) den site selection: preference for artificial sites
Wildlife Research. 01/2011; 38:244-248.
Context: Objective assessments of habitat requirements for endangered species are often lacking when planning management strategies, and inappropriate landscape manipulation can sometimes turn an endangered species into a pest. Recent expansive population growth of the rock hyrax Procavia capensis i... [more] Context: Objective assessments of habitat requirements for endangered species are often lacking when planning management strategies, and inappropriate landscape manipulation can sometimes turn an endangered species into a pest. Recent expansive population growth of the rock hyrax Procavia capensis in northern Israel has been attributed largely to the proliferation of man-made boulder piles on the fringes of new residential developments. Aims: The hyrax is a protected species, yet when in proximity to residential areas, can be a garden pest and is medically important as a reservoir of cutaneous leishmaniasis. Management should thus consider both preservation of hyrax populations, combined with minimising pest potential. We examined the hypothesis that hyraxes prefer artificial boulder piles to natural outcrop crevices as den sites. Methods: We surveyed all 57 potential den sites in a 1 km x 1 km area around a village in northern Israel, and conducted logistic regression to examine the correlation of hyrax presence with site type (pile/crevice), size, distance from the village, distance from other den sites, and network centrality within the den site network. We used the Aikaike Information Criterion (AIC) to compare logistic models. Key results: Occupancy was well predicted by site type, site size, and distance from other sites, explaining 59% of the variation in the logistic regression. These three predictors were selected both by considering the combination of predictors that gave the lowest AIC value, and also by the stepwise logistic algorithm. Conclusions & Implications: Hyrax den site preference, in particular preference for boulder piles over natural crevices, should be integrated into managing this species simultaneously for conservation and pest control in the face of continuing residential encroachment on natural areas.
-
Spatiotemporal reproductive strategies in the fire salamander: a model and empirical test
Behavioral Ecology. 01/2011; 22:670-678.
Although density-dependent processes and the risk of pool desiccation dominate temporary pool ecology literature, the spreading of larvae across pools and time as a strategy for managing these central stress factors has not been rigorously addressed as an adaptive mechanism. We develop a state-depen... [more] Although density-dependent processes and the risk of pool desiccation dominate temporary pool ecology literature, the spreading of larvae across pools and time as a strategy for managing these central stress factors has not been rigorously addressed as an adaptive mechanism. We develop a state-dependent oviposition habitat selection model predicting that females of the endangered fire salamander, Salamandra infraimmaculata, will split their larval load temporally during the rainy season and across multiple pools and will adjust the number of larvae deposited according to pool quality. These strategies are predicted to reduce the negative effects of larval density-dependence and limited habitat duration. We tested the qualitative predictions of the model in an outdoor experiment. Consistent with our predictions, gravid females, when allowed to choose deposition sites among pools of different depths, spread their larvae both spatially and temporally and deposited more larvae into deeper pools. This study
-
Predation risk can drive cycles in zoonotic disease prevalence
Israel Journal of Ecology and Evolution. 01/2010;
-
Modelling Transmission of Vector-Borne Pathogens Shows Complex Dynamics When Vector Feeding Sites Are Limited
PLoS ONE. 7(5):e36730.
The relationship between species richness and the prevalence of vector-borne disease has been widely studied with a range of outcomes. Increasing the number of host species for a pathogen may decrease infection prevalence (dilution effect), increase it (amplification), or have no effect. We derive a... [more] The relationship between species richness and the prevalence of vector-borne disease has been widely studied with a range of outcomes. Increasing the number of host species for a pathogen may decrease infection prevalence (dilution effect), increase it (amplification), or have no effect. We derive a general model, and a specific implementation, which show that when the number of vector feeding sites on each host is limiting, the effects on pathogen dynamics of host population size are more complex than previously thought. The model examines vector-borne disease in the presence of different host species that are either competent or incompetent (i.e. that cannot transmit the pathogen to vectors) as reservoirs for the pathogen. With a single host species present, the basic reproduction ratio R<sub>0</sub> is a non-monotonic function of the population size of host individuals ( H ), i.e. a value <inline-graphic xmlns:xlink=http://www.w3.org/1999/xlink xl
Following (6)
-
Amiyaal Ilany
Tel-Aviv University -
Mirjam Knörnschild
Universität Ulm -
Ben Aviss
BBC -
Shai Markman
University of Haifa -
Théa M. Machado
Universidade Federal de Viçosa (UFV)
