Show me your best side: Lateralization of social and resting behaviors in feral horses.

Growing evidence shows a variety of sensorial and motor asymmetries in social and non-social interactions in various species, indicating a lateralized processing of information by the brain. Using digital video cameras on tripods and drones, this study investigated lateralization in frequency and duration of social behavior patterns, in affiliative, agonistic, and resting contexts, in a feral population of horses (Equus ferus caballus) in Northern Portugal, consisting of 37 individuals organized in eight harem groups. Affiliative interactions (including grooming) were more often performed, and lasted longer, when recipients were positioned to the right side. In recumbent resting (animals lying down) episodes on the left side lasted longer. Our results of an affiliative behavior having a right side tendency, provide partial support to the valence-specific hypothesis of Ahern and Schwartz (1979) - left hemisphere dominance for positive affect, affiliative behaviors. Longer recumbent resting episodes on the left side may be due to synchronization. However, in both instances it is discussed how lateralization may be context dependent. Investigating the position asymmetries of social behaviors in feral equids will contribute to a better understanding of differential lateralization and hemispheric specialization from the ecological and evolutionary perspectives.

Feral horses' (Equus ferus caballus) behavior toward dying and dead conspecifics.

In the rapidly expanding field of comparative thanatology, reports from a wide range of taxa suggest that some aspects of a concept of death may be shared by many non-human species. In horses, there are only a few anecdotal reports on behaviors toward dead conspecifics, mostly concerning domestic individuals. Here, we describe the case of a 2-month-old, free-ranging male foal that died around 12 h after being found severely injured due to a presumed wolf attack, focusing on other individuals' reactions to the dying foal. We also placed camera traps near horse carcasses to investigate reactions by other horses. Kin and non-kin of both sexes showed unusual interest in the dying foal. However, horses appeared to avoid dead conspecifics. Recording individual reactions to dead and dying conspecifics in naturalistic settings will enhance our knowledge about death-related behaviors in horses, allowing comparisons with other species that have been more thoroughly studied, to understand the evolutionary basis of these behaviors.

Developmental changes in the endocrine stress response in orangutans (Pongo pygmaeus).

Non-invasive measures of stress are crucial for captive and conservation management programs. The adrenal hormone dehydroepiandrosterone-sulfate (DHEAS) has recently been adopted as a stress marker, but there is little investigation of its relationship to glucocorticoids (GC), well-known indicators of stress. This study examined the influence of age, reproductive state and environment on GC and DHEAS levels in orangutans, to test whether the GC/DHEAS ratio can provide an index of stress response in primates. We measured fecal GC (fGC) and fecal DHEAS (fDHEAS) concentrations in 7 captive orangutans from zoological parks in Japan and 22 wild orangutans from Danum Valley Conservation Area, Malaysia. We found that in a stressful condition (transportation), fDHEAS levels increased 2 days after the fGC response, which occurred 1 day after the stressor. One pregnant female had elevated levels of both hormones, and a higher fGC/fDHEAS ratio than baseline. Females in the first year of lactation had fGC levels and the fGC/fDHEAS ratio significantly higher than both baseline and females in the second and subsequent years of lactation. There was no effect of age on fGC levels, but the fGC/fDHEAS ratio was higher in infants than adults and adolescents. fDHEAS concentrations were lower in infants than juveniles, adolescents and adults, a phenomenon known as adrenarche, shared with humans and other great apes. We suggest that changes in DHEAS during orangutan life history are associated with changes in the dynamics of maintaining homeostasis that vary with age and reproductive state. The GC/DHEAS ratio index is useful to evaluate age-related abilities of responding to stressful challenges.

Molecular and morphological characterization of the predatory mite Amblyseius largoensis (Acari: Phytoseiidae): surprising similarity between an Asian and American populations.

The accurate characterization of biological control agents is a key step in control programs. Recently, Amblyseius largoensis from Thailand were introduced in Brazil to evaluate their efficiency for the control of the red palm mite, Raoiella indica. The aim of this study was to confirm their identification and to characterize the population from Thailand, comparing it to populations of the Americas and Indian Ocean islands. In addition, a population of A. largoensis from New Caledonia, Oceania, of which DNA sequences were available, was included in phylogenetic analyses. Morphometric data obtained for the population of A. largoensis from Thailand were compared to those of populations from Reunion Island and the Americas through univariate and multivariate analyses. Two DNA fragments were amplified and sequenced: the nuclear ribosomal region ITSS and the mitochondrial 12S rRNA. Haplotypes (12S rRNA) and genotypes (ITSS) were identified and phylogenetic analyses using both fragments were conducted separately and combined using maximum likelihood and the Bayesian information criterion. The integrative approach reveals morphometric and molecular variabilities among populations of A. largoensis and shows that the population identified as A. largoensis collected in Thailand, as well as that from New Caledonia, are conspecific to the populations of the Americas and Indian Ocean islands. Populations from the Americas and Asia are more related to each other than with that from the Indian Ocean islands. Hypotheses to explain this clustering are proposed. Data on the molecular intraspecific variability of this predatory mite from remote areas will be helpful for the development of molecular diagnosis.

Touch-screen-guided task reveals a prosocial choice tendency by chimpanzees (Pan troglodytes).

Humans help others even without direct benefit for themselves. However, the nature of altruistic (i.e., only the other benefits) and prosocial (i.e., self and other both benefit) behaviors in our closest living relative, the chimpanzee, remains controversial. To address this further, we developed a touch-screen-guided task that allowed us to increase the number of trials for a thorough test of chimpanzees' prosocial and altruistic tendencies. Mother-offspring dyads were tested in the same compartment; one was the actor while the other was the recipient. In Experiment 1, the actor chose among three options: prosocial, selfish (only the actor benefited) and altruistic. To better understand the nature of the chimpanzees' choices and to improve experimental control, we conducted two additional experiments. Experiment 2 consisted of two-option choices interspersed with three-option choices, and in Experiment 3 the two-option choice were blocked across all trials. The results of Experiment 1 clearly showed that chimpanzees acted prosocially in the touch-screen-guided task, choosing the prosocial option on an average of 79% of choices. Five out of the six chimpanzees showed the preference to act prosocially against chance level. The preference for the prosocial option persisted when conditions were changed in Experiments 2 and 3. When only selfish and altruistic options were available in Experiments 2 and 3, chimpanzees preferred the selfish option. These results suggest that (1) most individuals understood the nature of the task and modified their behavior according to the available options, (2) five out of the six chimpanzees chose to act prosocially when they had the option to, and (3) offspring counterbalanced between altruistic and selfish, when given those two options perhaps to avoid suffering repercussions from the mother.

Comparison of the social systems of primates and feral horses: data from a newly established horse research site on Serra D'Arga, northern Portugal.

Horses are phylogenetically distant from primates, but considerable behavioral links exist between the two. The sociality of horses, characterized by group stability, is similar to that of primates, but different from that of many other ungulates. Although horses and primates are good models for exploring the evolution of societies in human and non-human animals, fewer studies have been conducted on the social system of horses than primates. Here, we investigated the social system of feral horses, particularly the determinant factors of single-male/multi-male group dichotomy, in light of hypotheses derived from studies of primate societies. Socioecological data from 26 groups comprising 208 feral horses on Serra D'Arga, northern Portugal suggest that these primate-based hypotheses cannot adequately explain the social system of horses. In view of the sympatric existence of multi- and single-male groups, and the frequent intergroup transfers and promiscuous mating of females with males of different groups, male-female relationships of horses appear to differ from those of polygynous primates.

Development and behavior of wild infant-juvenile East Bornean orangutans (Pongo pygmaeus morio) in Danum Valley.

Orangutans have a long period of immaturity and the longest inter-birth interval (IBI) of all mammals, which can be explained by their solitary life style, preventing the mother from rearing two offspring simultaneously (solitary life hypothesis) [corrected]. We collected data on mother-offspring dyads living in a primary lowland forest in Danum Valley, East Borneo in an effort to examine the developmental and behavioral patterns of the subspecies Pongo pygmaeus morio. We analyzed developmental changes in mother-offspring distance, contact, and activity budgets in orangutans ranging from 1 to 7 years of age. The results indicated decreased resting and playing with increasing age, whereas feeding, traveling and social play all increased significantly. Mothers' feeding and traveling time were good predictors of their offspring's feeding and traveling activities. Mother-offspring contact lasted longer in resting contexts; contact during traveling was almost non-existent after 4 years of age. Comparisons with previously published data on the Sumatran species Pongo abelli revealed no fundamental differences in these behavioral measures. However, a shorter association time with the mother after behavioral independence is documented for this East Bornean population in comparison to Sumatran populations. These results are best explained by the solitary life hypothesis, in agreement with previous studies. We suggest that environmental constraints in Bornean forests, as well as a lower population density, should be considered when interpreting the differences between Sumatran and Bornean orangutans in both the period of association with mother and the IBI.

The predatory mite Neoseiulus paspalivorus (Phytoseiidae) in Brazil: taxonomic status, reproductive compatibility and morphological and molecular variability.

The predatory mite Neoseiulus paspalivorus (De Leon) is often found in association with the coconut mite, Aceria guerreronis Keifer. The identification of natural enemies is essential for the definition of biological control strategies. Therefore, the present study aimed to confirm whether the mite populations from different Northeastern Brazilian states identified as N. paspalivorus belong to the same species. This determination was accomplished through the study of morphometric variability in 33 anatomical characters and of molecular variability in two DNA fragments: Internal Transcribed Spacer (ITS) rDNA and cytochrome c oxidase subunit I (COI) mtDNA. This study also determined whether there is reproductive isolation between the two most morphologically distinct populations (Rio Grande do Norte and Paraíba). Intraspecific morphometric variability was observed among the five populations of N. paspalivorus. Despite this variability, the crosses and backcrosses of the most morphologically distinct populations did not show reproductive incompatibility. The molecular analysis indicated the absence of genetic differences among the N. paspalivorus populations for the ITS fragment. Three haplotypes were identified for the COI fragment, and the genetic distance ranged from 0 to 0.2 %. Despite the morphometric differences, the results of the molecular and biological analysis corroborate the previous identification of N. paspalivorus for all of the studied populations. The present study contributes to the systematics of Phytoseiidae predatory mites and to the biological control of A. guerreronis by the accurate identification and characterization of one of its main natural enemies along extensive areas in Brazil.

A critical review on some closely related species of Tetranychus sensu stricto (Acari: Tetranychidae) in the public DNA sequences databases.

Taxonomic misidentification of the specimens used to obtain DNA sequences is a growing problem reported for different groups of organisms, which threatens the utility of the deposited sequences in public DNA databases. This paper provides new evidence of misidentifications in molecular DNA public databases in phytophagous mites of the Tetranychidae family belonging to the group Tetranychus (Tetranychus). Several species in this group are of economic and quarantine importance in agriculture and among them Tetranychus urticae, a highly polyphagous mite causing outbreaks in many crops worldwide, is certainly the most studied. We analyzed and evaluated the identity of 105 GenBank accessions of ITS2 rDNA and 138 COI mtDNA sequences which were deposited as T. urticae and those of 14 other taxa morphologically closely related to Tetranychus sensu stricto. In addition, ITS2 and COI sequences of 18 T. urticae samples collected for this study and identified by morphological criteria, were generated and included in the analyzed dataset. Among the deposited sequences in the GenBank database, numerous cases of apparently mistaken identities were identified in the group Tetranychus s. str., especially between T. urticae, T. cinnabarinus, T. kanzawai and T. truncatus. Unreliable sequences (misidentified or dubious) were estimated at nearly 30%. In particular the analysis supports the invalidity of the controversial species status of T. cinnabarinus. More generally, it highlights the need of using combined morphological and molecular approaches to guarantee solid species diagnostics for reliable sequence accessions in public databases.

South American spider mites: new hosts and localities.

In order to contribute to taxonomic information on Tetranychid mites (Acari: Tetranychidae) in South America, surveys were conducted in Brazil (15 States and the Federal District) and Uruguay (one Department); 550 samples of 120 plant species were collected. Tetranychid mite infestations were confirmed in 204 samples, and 22 species belonging to seven genera of the Bryobiinae and Tetranychinae subfamilies were identified on 58 different host plants. Thirty-six new plant hosts were found in Brazil, South America, and worldwide for the following species: Eutetranychus banksi (McGregor); Mononychellus tanajoa (Bondar); Oligonychus anonae Paschoal; O. mangiferus (Rahman and Sapra); Tetranychus bastosi Tuttle, Baker and Sales; T. desertorum Banks, 1900 , T. evansi Baker and Pritchard; T. ludeni Zacher; T. mexicanus (McGregor); T. neocaledonicus André; and T. urticae Koch. Four new localities in Brazil were reported for Eotetranychus tremae De Leon; O. anonae; Panonychus ulmi (Koch); and T. gloveri Baker and Pritchard.