A test of the haploid susceptibility hypothesis using a species with naturally occurring variation in ploidy

The haploid susceptibility hypothesis (HSH) was proposed as an explanation for how behavioral roles in haplodiploid social systems evolved. It posits that haploid males are more susceptible to disease than diploid females due to decreased genetic variability at key disease resistance loci. The resulting decreased immunocompetence is hypothesized to have played a role in the evolution of social behavior by limiting the behavioral repertoire haploids perform. Here, we test this hypothesis in a study system that separates ploidy from behavioral sex roles: Polistes dominulus, a social wasp, has colonies with naturally occurring diploid males. We report results from two immune function assays—hemolymph phenoloxidase activity and encapsulation response—performed on haploid males, diploid males, and diploid females. Our data suggest that ploidy is not a significant contributor to immune function in P. dominulus; thus, our data do not support the HSH for the evolution of behavioral roles. Instead, our data indicate that time of emergence is the best predictor of immune function in Polistes. We speculate that seasonal trends result from seasonal differences in pathogens and parasites.     

Toxoplasma,testosterone, and behavior manipulation: the role of parasite strain,host variations,and intensity of infection

Toxoplasma gondii is an intracellular parasite involved in the etiology of various behavioral and hormonal alterations in humans and rodents. Various mechanisms, including induction changes of testosterone production, have been proposed in the etiology of behavioral alterations during T. gondii infection. However, controversy remains about the effects of T. gondii infection on testosterone production; in some studies, increased levels of testosterone were reported, whereas other studies reported decreased levels. This is a significant point, because testosterone has been shown to play important roles in various processes, from reproduction to fear and behavior. This contradiction seems to indicate that different factors--primarily parasite strains and host variations--have diverse effects on the intensity of T. gondii infection, which consequently has diverse effects on testosterone production and behavioral alterations. This paper reviews the role of parasite strains, host variations, and intensity of T. gondii infection on behavioral alterations and testosterone production, as well as the role of testosterone in the etiology of these alterations during toxoplasmosis.     

Surviving the Cold, Dry Period in Africa: Behavioral Adjustments as an Alternative to Heterothermy in the African Lesser Bushbaby (Galago moholi)

Behavioral and physiological adaptations are common and successful strategies used by small endothermic species to adjust to unfavorable seasons. Physiological adaptations, such as heterothermy, e.g., torpor, are usually thought to be more effective energy-saving strategies than behavioral adjustments. The African lesser bushbaby, Galago moholi, is physiologically capable of torpor but expresses heterothermy only under conditions of extreme energy limitation, suggesting that it has evolved alternative strategies to compensate energetic bottlenecks. We hypothesized that Galago moholi survives the unfavorable winter period, without —or only rarely— employing torpid phases to save energy, by using behavioral thermoregulation. We compared the ecology and behavior of Galago moholi in summer and winter by telemetric tracking and examined food availability by determination of arthropod and gum availability. We found a significant increase in huddling behavior and a significant increase in the use of enclosed and insulated sleeping sites during winter, as well as a reduction in nightly activity. Galago moholi hunted for insects significantly less in winter than in summer, and increased gum intake in winter, when gum showed an increase in energy content. The availability of high-quality food, albeit in low quantities, presumably enables Galago moholi to stay normothermic throughout the cold, dry period and to focus on reproduction activities. We propose that Galago moholi favors ecological and behavioral adjustments over torpor because these are sufficient to meet energy requirements of this species, and their advantages (flexibility, unrestricted activity, and reproduction) outweigh the energetic benefits of heterothermy.     

Standardized ethograms and a device for assessing amphibian thermal responses in a warming world

Most predictions of how populations and species of ectotherms will respond to global warming are based on estimates of the temperature at which organisms lose motor control (i.e., CT_max - the Critical Thermal Maximum). Here, we describe a non-lethal protocol and ethograms to estimate the relative tolerance of amphibians to increasing temperatures. These methods—suitable for field or laboratory conditions—are replicable, inexpensive and applicable to both post-metamorphic stages and organisms with direct development. We illustrate the use of this standardized protocol for four amphibians from a tropical cloud forest in Veracruz, Mexico with contrasting life histories: a lungless salamander (Aquiloeurycea cafetalera: Plethodontidae), a leaf-litter frog (Craugastor rhodopis: Craugastoridae), a semiaquatic frog (Lithobates berlandieri: Ranidae), and a tree frog (Rheohyla miotympanum: Hylidae). We identified four behavioral responses preceding CT_max for all amphibians included in this study: 1) Optimal Activity Range, 2) Supra-optimal Activity Range, 3) Heat Stress Range, and 4) Involuntary Movements Range. Additionally, we identified a fifth parameter associated with resilience to heat shock: 5) Recovery Stage after reaching CT_max. We conclude that the behavioral responses preceding the Critical Thermal Maximum are as informative as CT_max. Using behavioral responses to estimate thermal tolerance has the additional advantage of reducing the risk of injury or death of amphibians during physiological experiments.     

AVPR1A Variation in Chimpanzees (Pan troglodytes): Population Differences and Association with Behavioral Style

Primates and other mammals show measurable, heritable variation in behavioral traits such as gregariousness, timidity, and aggression. Connections among behavior, environment, neuroanatomy, and genetics are complex, but small genetic differences can have large effects on behavioral phenotypes. One of the best examples of a single gene with large effects on natural variation in social behavior is AVPR1A, which codes for a receptor of the peptide hormone arginine vasopressin. Work on rodents shows a likely causal association between AVPR1A regulatory polymorphisms and social behavior. Chimpanzees also show variation in the AVPR1A regulatory region, with some individuals lacking a ca. 350-bp segment corresponding to a putative functional element. Thus, chimpanzees have a “short” allele (segment deletion) and a “long” allele (no deletion) at this locus. Here we compare AVPR1A variation in two chimpanzee populations, and we examine behavioral and hormonal data in relation to AVPR1A genotypes. We genotyped AVPR1A in a captive population of western chimpanzees (Pan troglodytes verus, New Iberia Research Center; N = 64) for which we had quantitative measures of personality (based on 15 behavioral style indices, calculated from 3 yr of observational data), dominance rank, and baseline testosterone levels. We also provide the first assessment of AVPR1A genotype frequencies in a wild eastern chimpanzee population (Pan troglodytes schweinfurthii, Ngogo community, Kibale National Park, Uganda; N = 26). Our results indicated that the AVPR1A long allele was associated with a “smart” social personality in captive western chimpanzees, independent of testosterone levels. Although the frequency of the long allele was relatively low in captive western chimpanzees (0.23), it was the major allele in wild eastern chimpanzees (0.62). Our finding that allele and genotype frequencies for the AVPR1A polymorphism differ among chimpanzee populations also highlights the need for comparative studies —across subspecies and research sites— in primate behavioral genetics.     

Activity patterns of the Ryukyu flying fox on a subtropical island: responses to seasonal changes in night length

Almost all chiropteran species are nocturnal, but some species are occasionally active during the daytime. We conducted radio-tracking surveys and direct observations of the Ryukyu flying fox, Pteropus dasymallus, in two different habitats—urbanized and forested areas—on a subtropical island from April 2002 to January 2006. We recorded the departure time and return time from/to day roosts as well as behavioral time budgets during the night. The departure and return times shifted in correspondence with seasonal changes in sunset and sunrise times. The Ryukyu flying fox tended to depart earlier in summer when the night length was shorter, suggesting that it adjusts its active period by departing earlier. On the contrary, the amount of foraging performed by the bats in urbanized areas decreased in the summer when fruits of Ficus microcarpa were more abundant, suggesting that the bats adjust their behavioral time budgets in line with local food availability. Daytime activity was observed only in the forested area. In conclusion, the duration of Ryukyu flying fox activity was found to primarily depend on seasonal changes in the light–dark cycle, and this bat may adjust its behavioral time budget according to local food availability and the intensity of human activities.     

Comparative accuracy of two new electronic devices for the noninvasive determination of blood pressure

Recent developments in behavioral approaches to cardiovascular disease have called for physiological monitoring devices that reduce experimenter bias, are easy to operate, can be used ambulatorily, and/or provide ongoing, automated monitoring of pertinent cardiovascular functions—i.e., blood pressure and heart rate. Neither the invasive monitoring (via catheterization) nor the standard auscultatory method of blood pressure determination, however, has these characteristics. In the present study, two new methods/devices — (1) a low-weight, low-cost, battery-operated sphygmomanometer (SM), and (2) a more expensive automated electronic SM with electrical pump — are compared with each other and with the more common auscultatory method and a standard mercury SM. Both new devices were also compared with a standard pulse count. Data were derived from 10 readings of 10 healthy subjects each across the three possible comparisons, thus totalingN=30. Correlation coefficients and average differences were computed and indicated high intercorrelations (betweenr=.89 andr=.99) between each pairing of the new electronic devices and the mercury SM. Intercorrelations of blood pressure determination with the two new electronic devices, however, were only moderate. Potential reasons for the variability are discussed, and guidelines for the optimal use of the new, easy-to-operate electronic devices are presented.     

Performance-based measures and behavioral ratings of executive function in diagnosing attention-deficit/hyperactivity disorder in children

Deficits in real-world executive functioning (EF) are a frequent characteristic of attention-deficit/hyperactivity disorder (ADHD). However, the predictive value of using performance-based and behavioral rating measures of EF when diagnosing ADHD remains unclear. The current study investigates the use of performance-based EF measures and a parent-report questionnaire with established ecological validity and clinical utility when diagnosing ADHD. Participants included 21 healthy controls, 21 ADHD—primary inattentive, and 21 ADHD—combined type subjects aged 6–15 years. A brief neuropsychological battery was administered to each subject including common EF assessment measures. Significant differences were not found between groups on most performance-based EF measures, whereas significant differences (p?<?0.05) were found on most parent-report behavioral rating scales. Furthermore, performance-based measures did not predict group membership above chance levels. Results further support differences in predictive value of EF performance-based measures compared to parent-report questionnaires when diagnosing ADHD. Further research must investigate the relationship between performance-based and behavioral rating measures when assessing EF in ADHD.     

Do post-menopausal women provide more care to their kin?: evidence of grandparental caregiving from two large-scale national surveys

Drawing on the logical principles of life-history theory, it may be hypothesized that—compared to pre-menopausal women—post-menopausal women will spend more time caring for grandchildren and other kin. This hypothesis was tested in two studies, on results obtained from two large datasets documenting altruistic behaviors of pre-menopausal and post-menopausal women in the United States (n = 7161) and Australia (N = 25,066). Results from both studies revealed that (even when controlling statistically for age, health, financial resources, and other pertinent variables), post-menopausal women devoted more time to grandparental caregiving. This effect was specific to kin care: Menopause status was not as strongly related to a measure of non-kin-directed altruistic behavior (time spent volunteering). These results provide the first empirical support for a previously-untested behavioral implication of menopause.     

Experience teaches plants to learn faster and forget slower in environments where it matters

The nervous system of animals serves the acquisition, memorization and recollection of information. Like animals, plants also acquire a huge amount of information from their environment, yet their capacity to memorize and organize learned behavioral responses has not been demonstrated. In Mimosa pudica—the sensitive plant—the defensive leaf-folding behaviour in response to repeated physical disturbance exhibits clear habituation, suggesting some elementary form of learning. Applying the theory and the analytical methods usually employed in animal learning research, we show that leaf-folding habituation is more pronounced and persistent for plants growing in energetically costly environments. Astonishingly, Mimosa can display the learned response even when left undisturbed in a more favourable environment for a month. This relatively long-lasting learned behavioural change as a result of previous experience matches the persistence of habituation effects observed in many animals.     

Behavioral differences of various ecological groups of roach Rutilus rutilus and perch Perca fluviatilis

The intrapopulation morphological and behavioral polymorphism of roach (Rutilus rutilus) and perch Perca fluviatilis) was studied. It was shown that marker indices for distinguishing intrapopulation groups are the size of the mouth opening and the index of the body shape in roach and the coefficient of pigmentation in perch. Based on analysis of the data of indices, it was found that there are two ecological groups—coastal and pelagic in populations of roach and perch. Several behavioral differences in individuals of various ecological groups were revealed. Comparison of the defense reaction of perch individuals belonging to various ecological groups was performed. The assessment of the effects of hydrodynamic activity on the survival of perch individuals belonging to various ecological groups was made. Differences in the swimming capacity of juvenile roach developing under conditions of biotopes of various types were established. Suggestions were made on the mechanisms of formation of intrapopulation groups of roach and river perch.     

Taste preferences and feeding behavior of three-spined stickleback Gasterosteus aculeatus of populations of basins of the Atlantic and Pacific oceans

The absence of population specificity of taste spectra in fish was confirmed. It was found that the three-spined stickleback Gasterosteus aculeatus of populations of the North (Norway), Baltic (Latvia), and Okhotsk (Kamchatka Peninsula) seas has similar taste preferences to classical taste substances (sodium chloride, calcium chloride, and sucrose—10%; citric acid—5%) and to 21 free amino acids (L-isomers, 0.1–0.001 M). For fish of all populations, glutamine, glutamic and aspartic acids, and alanine have the most attractive taste; cysteine, asparagine, and histidine have slightly less attractive taste. In Baltic Sea and Sea of Okhotsk sticklebacks, relatively not numerous amino acids that cause a significant decrease in pellet consumption—phenylalanine, tryptophane, leucine, and tyrosine—coincide (in the North Sea stickleback, substances with deterrent taste were not revealed). In sticklebacks of different populations, no differences in manifestation of feeding behavior were found, and correlations between different elements of fish response to pellets are similar or close the same. It was shown that intraoral sensory testing of food objects in three-spined stickleback can proceed along two alternative behavioral stereotypes similar in fish of the studied populations. The dependence of stereotypes of intraoral testing on taste qualities of the food object was revealed for the first time.     

Primate subsistence patterns: Collector-predators and gatherer-hunters

Hominization via predation has become a pervasive anthropological theme in recent years. Indeed, the assumption that hunting behavior originated within the primate phylogenetic sequence as a “human” subsistence pattern has generated numerous subsidiary hypotheses about how secondary traits were initiated, propagated or enhanced when a terrestrial, savanna-dwelling, meat-eating hominid line emerged from an arboreal, forest-dwelling, plant-eating ancestral stock. New field evidence on the behavioral and organizational features of subsistence in nonhuman and human primates now provides the basis for reconsidering these views.Many monkey, ape and human populations no longer seem to fit the stereotyped images sketched in past decades, when little or no comparative information was available to anthropologists. The discrepancy between the old concepts and new facts is particularly evident in Sub-Saharan Africa, where numerous primate taxa have been studied in climatically and biotically similar zones. In this region alone, more than 364 cases of predation, involving 22 different species of mammalian prey, have been recorded among at least 10 supposedly “vegetarian” baboon and chimpanzee populations dispersed between Ethiopia and South Africa. Furthermore, many of the human populations living within this same region—such as the Mbuti pygmies, the Hadza and the Kalahari bushmen—have been characterized as “hunters” but actually subsist for the most part on foods other than meat. These basic facts about collector-predator and Gatherer-hunter subsistence patterns are a mere beginning, however, for popular conceptions of primate lifestyles are eroding swiftly along many axes of investigation. It is becoming clear, for instance, that many primates—from prosimians to humans—are actually omnivores even though anthropologists have persistently miscast them as frugivores or carnivores. This false dichotomization of nonhuman versus human diets has led to a series of equally erroneous dichotomies in nonhuman versus human behavior. Thus, the possession of culture, technology, language and other similarly amorphous traits, many of which were in fact derived from this presumed shift in subsistence, have become entrenched as concepts of human uniqueness. In recent years, however, many new discoveries in primatology, and in ethnography and archeology, have weakened the theoretical structure to which “man-the-hunter” has been pinned. It is probable that savanna-dwelling, tool-using, seed-eating, scavenging and other independent schemes can now be replaced by a single, much simpler model wherein subsistence shifts among both nonhuman and human primates are perceived as smooth transitions within a graded continuum of evolution. Thus, the central objective of this report is to show that the subsistence activities of several extant cercopithecid, pongid and hominid populations in Africa can be arranged along an integrated spectrum which reflects gradual processes in the evolution of primate behavior and organization. This spectrum serves as the crux for a unifying model of behavioral evolution, and can in turn be broken down into a linked series of subsidiary models which elucidate specific aspects of primate prehistory.     

Foraging in space and time structure an African small mammal community

We used live-trapping and foraging to test for the effect of habitat selection and diet on structuring a community of six small mammals and one bird within the Soutpansberg, South Africa. We established grids that straddled adjacent habitats: woodland, rocky hillside, and grassland. Trapping and foraging were used to estimate abundance, habitat use, and species-specific foraging costs. The species with the highest abundance and foraging activity in a habitat, activity time, or food was considered the most efficient and presumed to have a competitive advantage. All species exhibited distinct patterns of spatial and temporal habitat preference which provided the main mechanism of coexistence, followed by diet selection. The study species were organized into three assemblages (α diversity): grassland, Rhabdomys pumilio, Dendromus melanotis, and Mus minutoides.; woodland, Aethomys ineptus and Micaelamys namaquensis; and rock-dwelling, M. namaquensis and Elephantulus myurus. Francolinus natalensis foraged in open rocky areas and under wooded islands within the grassland. Species organization across the habitats suggested that feeding opportunities are available within all habitats; however, distinct habitat preferences resulted from differing foraging aptitudes and efficiencies of the competing species. At Lajuma, species distribution and coexistence are promoted through distinct habitat preferences that were shaped by competition and species-specific foraging costs. The combination of trapping and foraging provided a mechanistic approach that integrates behavior into community ecology by ‘asking’ the animal to reveal its perspective of the environment. Using spatial and temporal foraging decisions—as behavioral indicators—enables us to guide our understanding for across-taxa species coexistence.     

Type of rheoreaction in the early ontogenesis of roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) as a factor determining its biotopic distribution

The specific features of rheoreaction in roach Rutilus rutilus (L.) larvae from open and protected shallows of the Rybinsk Reservoir have been studied. Data on length and weight of roach sampled at various habitats at B–E developmental stages are presented. It has been revealed that the type of roach larvae rheoreaction is a behavioral mechanism of their distribution over different types of habitats, not only in rivers but also in the waterbodies with slow water turnover rates—lakes and reservoirs. By the time of developmental stage E, this mechanism provides the sustainable spatial separation of juvenile fish, which in the future may lead to intrapopulation differentiation in roach.     

New names inPhanerogamae 5

103 new nomenclatural combinations are proposed for taxa of European flora, 95 for species, 8 for subspecies. Most of them have resulted from a more natural delimitation of genera. The majority of new combinations are made in the segregants ofCentourea (Acosta—16,Colymbada— 8),Hieracium (Pilosella—16),Scabiosa (Trochocephalus—14),Serratula (Klasea—13) andLeontodon (Scorzoneroides—8). Taxonomie or nomenclatural problems of some taxa (Arum orientale, Colobium taraxacoides, Klasea, Leucanthemopsis alpina agg.,Psyllium, Scorzoneroides, Tephroseris cantabrica) are discussed. Names omitted from the Index Kewensis and corrections of publication places are added (17 names).     

To dare or not to dare? Risk management by owls in a predator–prey foraging game

In a foraging game, predators must catch elusive prey while avoiding injury. Predators manage their hunting success with behavioral tools such as habitat selection, time allocation, and perhaps daring—the willingness to risk injury to increase hunting success. A predator’s level of daring should be state dependent: the hungrier it is, the more it should be willing to risk injury to better capture prey. We ask, in a foraging game, will a hungry predator be more willing to risk injury while hunting? We performed an experiment in an outdoor vivarium in which barn owls (Tyto alba) were allowed to hunt Allenby’s gerbils (Gerbillus andersoni allenbyi) from a choice of safe and risky patches. Owls were either well fed or hungry, representing the high and low state, respectively. We quantified the owls’ patch use behavior. We predicted that hungry owls would be more daring and allocate more time to the risky patches. Owls preferred to hunt in the safe patches. This indicates that owls manage risk of injury by avoiding the risky patches. Hungry owls doubled their attacks on gerbils, but directed the added effort mostly toward the safe patch and the safer, open areas in the risky patch. Thus, owls dared by performing a risky action—the attack maneuver—more times, but only in the safest places—the open areas. We conclude that daring can be used to manage risk of injury and owls implement it strategically, in ways we did not foresee, to minimize risk of injury while maximizing hunting success.     

Genetic confounding of the relationship between father absence and age at menarche

Research in evolutionary psychology, and life history theory in particular, has yielded important insights into the developmental processes that underpin variation in growth, psychological functioning, and behavioral outcomes across individuals. Yet, there are methodological concerns that limit the ability to draw causal inferences about human development and psychological functioning within a life history framework. The current study used a simulation-based modeling approach to estimate the degree of genetic confounding in tests of a well-researched life history hypothesis: that father absence (X) is associated with earlier age at menarche (Y). The results demonstrate that the genetic correlation between X and Y can confound the phenotypic association between the two variables, even if the genetic correlation is small—suggesting that failure to control for the genetic correlation between X and Y could produce a spurious phenotypic correlation. We discuss the implications of these results for research on human life history, and highlight the utility of incorporating genetically sensitive tests into future life history research.