Diel and lunar variation in diving behavior of rough-toothed dolphins (Steno bredanensis) off Kauaʻi,Hawaiʻi

Observational studies describe rough-toothed dolphins (Steno bredanensis) actively foraging during the day on epipelagic species. Using data from depth-transmitting satellite tags deployed on nine individuals off Kauaʻi, we investigated diving behavior and the effects of lunar phase and solar light levels on vertical movements. Overall, tagged rough-toothed dolphins primarily used near-surface waters, spending between 83.6% and 93.7% of their time in the top 30 m of the water column. When diving, grand mean, median, and maximum dive depths were 76.9 m, 67.5 m, and 399.5 m, although individuals were in water with depths from approximately 700–1,450 m. Dive rates varied by time of day, being lowest during the day and at dawn and highest at dusk and night. Dives were deepest (M = 133.7 m, SD = 52.6 m, median = 106.5 m) and longest (M = 4.0 min, SD = 0.4 min, median = 4.0 min) at dusk, suggesting dolphins were taking advantage of prey rising to the surface in response to reduced light levels. Lunar phase indirectly affected diving, with deeper and longer dives occurring with increasing illumination. The variations in dive behavior across solar and lunar cycles indicate diving patterns shift based on the distribution of prey.     

How long do dolphins live? Survival rates and life expectancies for bottlenose dolphins in zoological facilities vs. wild populations

Survival rates and life expectancies are commonly agreed upon indicators of well‐being for animals in zoological facilities, but even the most recent survival statistics for bottlenose dolphins (Tursiops truncatus) in marine mammal parks and aquariums use data that are now more than 25 yr old. The current study provides a comprehensive assessment of life expectancy and survival rates for bottlenose dolphins in U.S. zoological facilities from 1974 to 2012, utilizing three different analyses (annual survival rate, age‐at‐death, and Kaplan‐Meier), examining historical trends, and comparing to comparable data from wild populations. Both survival rate and life expectancy for dolphins in zoological facilities increased significantly over the past few decades, with a modern ASR of 0.972, and mean and median life expectancies calculated via Kaplan‐Meier of 28.2 and 29.2 yr, respectively. Survival rates and life expectancies for dolphins in U.S. zoological facilities today are at least as high as those for the wild dolphin populations for which there are comparable data.     

Staying close to home? Genetic differentiation of rough-toothed dolphins near oceanic islands in the central Pacific Ocean

Rough-toothed dolphins have a worldwide tropical and subtropical distribution, yet little is known about the population structure and social organization of this typically open-ocean species. Although it has been assumed that pelagic dolphins range widely due to the lack of apparent barriers and unpredictable prey distribution, recent evidence suggests rough-toothed dolphins exhibit fidelity to some oceanic islands. Using the most comprehensively extensive dataset for this species to date, we assess the isolation and interchange of rough-toothed dolphins at the regional and oceanic scale within the central Pacific Ocean. Using mtDNA and microsatellite genotyping (nDNA), we analyzed samples of insular communities from the main Hawaiian (Kaua‘i n = 93, O‘ahu n = 9, Hawai‘i n = 57), French Polynesian (n = 70) and Samoan (n = 16) archipelagos, and pelagic samples off the Northwestern Hawaiian Islands (n = 18). An overall AMOVA indicated strong genetic differentiation among islands (mtDNA F_ST = 0.265; p < 0.001; nDNA F_ST = 0.038; p < 0.001), as well as among archipelagos (mtDNA F_ST = 0.299; p < 0.001; nDNA F_ST = 0.055; p < 0.001). Shared haplotypes (n = 4) between the archipelagos may be a product of a relatively recent divergence and/or periodic exchange from poorly understood pelagic populations. Analyses using STRUCTURE and GENELAND identified four separate management units among archipelagos and within the Hawaiian Islands. These results confirm the presence of multiple insular populations within the Pacific and island-specific genetic isolation among populations attached to islands in each archipelago. Insular populations seem most prevalent where oceanographic conditions indicate high local productivity or a discontinuity with surrounding oligotrophic areas. Our findings have important implications for a little studied species that faces increasing anthropogenic threats around oceanic islands.     

Is male-infant caretaking related to paternity and/or mating activities in wild Barbary macaques (Macaca sylvanus)?

In species with a promiscuous mating system, the functions of male-infant caretaking remain unclear in the absence of genetic paternity tests. We tested paternal investment and hypotheses concerning reproductive tactics in wild groups of Barbary macaques, including results of genetic paternity tests. Our study revealed that male-infant caretaking was not related to the probability of paternity. In principle, males could use access to females to estimate paternity. However, we found that mating success was not related to paternity, so males could invest in infants that they had not sired, and caretaking of non-offspring was actually observed. Accordingly, males might be 'deceived' with respect to their paternal investment. In that case, one would expect a positive relation between mating success and the subsequent rate of male caretaking of infants. Such a relation is also lacking, leading to comprehensive rejection of the paternal investment hypothesis in Barbary macaques. By contrast, there was evidence that males showing infant care achieved higher mating frequencies than other males with the mothers of the relevant infants. Thus, male Barbary macaques do not show a 'mate-then-care' pattern, but they do exhibit a 'care-then-mate' pattern.     

Does differential seed siring success change over time or with pollination history in wild radish, Raphanus sativus (Brassicaceae)?

Previous work with wild radish has shown that pollen donors sire different numbers of seeds and that the condition of the maternal tissue affects seed paternity, suggesting that both pollen donor characteristics and maternal tissue affect mating. However, because these results are from the greenhouse, it is difficult to know whether they would hold true in the field. Here, we performed hundreds of crosses on several maternal plants to simulate changes during the flowering season of field plants. During the experiment, maternal resource availability changed due to the costs of producing fruits, and we determined the pollination history of a plant by performing crosses in specific orders. Examination of seed paternity showed that there were small differences in pollen donor success at the beginning of the experiment when maternal resources were abundant. Differential pollen donor success was greatest slightly later in the flowering period, but declined toward the end of the experiment. Thus, maternal plants may distinguish most among pollen donors when they have both abundant resources and experience with the differences in quality of available pollen donors. In contrast, there were few significant effects of the recent pollination history of plants on pollen donor success. Finally, despite the changes in mating performance over time, there were strong overall differences in pollen donor success, suggesting that seasonal changes in the field will not eliminate the potential for nonrandom mating.     

Are degraded habitats from agricultural crops associated with elevated faecal glucocorticoids in a wild population of common vole (Microtus arvalis)?

The severe impact of agriculture on species’ abundance and diversity is widely recognized. However, its effects on the physiology of wild animal populations are poorly known. We analyzed faecal glucocorticoids levels in wild common voles (Microtus arvalis) living in a farmland landscape to test whether living in degraded habitats, such as crops, is correlated with increased glucocorticoids. Other factors such as sex, reproductive status, and population density were also considered. We captured voles with Sherman traps in crops and in their field margins which were comprised of semi-natural vegetation. We collected fresh faecal samples from captured individuals and quantified their levels of faecal corticosterone metabolites (FCM) in the laboratory. The quantification of FCM concentrations was performed by competitive enzyme immunoassay. Individuals captured within the crops had higher levels of FCM than those in field margins; females and breeding individuals exhibited higher FCM levels. In addition, FCM concentrations positively correlated with abundance of voles. Our results suggest that degraded habitats in agricultural landscapes are associated with increased glucocorticoid levels on common voles likely caused by a higher disturbance from agricultural practices and a lesser vegetation cover in crops compared with field margins.     

Symbolic communication in wild chimpanzees?

The language abilities of captive chimpanzees give rise to the question of the existence and use of similar capabilities in wild chimpanzees. In Taï forest, wild chimpanzees seem to use drumming on buttressed trees to convey information an changes of travel direction, resting periods or both information combined. This communication system is iconic and relies on some arbitrariness. Emergence of symbol-like communication in wild chimpanzees seems mainly dependent on a low visibility environment, a high predation pressure and a large group of males.     

Why do dolphins jump? Interpreting the behavioural repertoire of bottlenose dolphins (Tursiops sp.) in Doubtful Sound,New Zealand

Only a limited number of studies have tried to determine the purpose of surface behavioural events performed by dolphins. To date only one study has attempted to aggregate the behavioural events observed in a population in contextual groups using co-occurrence as the grouping factor. In the present study, I tried to characterise the behavioural repertoire of a bottlenose dolphin population (Tursiops sp.) present in Doubtful Sound, New Zealand. I first looked at the relationship between events performed by individuals depending on the behavioural state of their schools. I then assessed the likelihood for events to co-occur. Four main behavioural categories (orientation, travel, social displays and fights) emerged from this analysis. Aerial events (jumps) did not fall into one category, showing that different aerial behaviours play different roles. Moreover, it appears that dolphins used side-flopping and upside-down lobtailing to communicate motivation. Side-flops occurred when the focal schools finished a behavioural bout and started to travel, while upside-down lobtails occurred when the focal schools instigated a behavioural bout after travelling. This non-vocal communication can take place over a few meters to hundreds of meters. Having signals that are effective over very short ranges avoids unwanted signalling to prey, predators or conspecifics.     

Consciousness in dolphins? A review of recent evidence

For millennia, dolphins have intrigued humans. Scientific study has confirmed that bottlenose dolphins are large-brained, highly social mammals with an extended developmental period, flexible cognitive capacities, and powerful acoustic abilities including a sophisticated echolocation system. These findings have led some to ask if dolphins experience aspects of consciousness. Recent investigations targeting self-recognition/self-awareness and metacognition, constructs tied to consciousness on some accounts, have analyzed the dolphin’s ability to recognize itself in a mirror or on a video as well as to monitor its own knowledge in a perceptual categorization task. The current article reviews this work with dolphins and grapples with some of the challenges in designing, conducting, and interpreting these studies as well as with general issues related to studying consciousness in animals. The existing evidence does not provide a convincing case for consciousness in dolphins. For productive scientific work on consciousness in dolphins (and other animals including humans), we need clearer characterizations of consciousness, better methods for studying it, and appropriate paradigms for interpreting outcomes. A current focus on metamemory in animals offers promise for future discovery in this area.     

True handedness in the cotton-top tamarin (Saguinus oedipus)?

Hand use for 8 activities was studied in 20 captive cotton-top tamarins (Saguinus oedipus). The purpose of the study was to discover if hand preferences existed across tasks and across subjects, and, if so, whether these followed the patterns of preference inMacNeilage et al.'s (1987) “postural origins” theory of the evolution of hand preference and hemispheric specialization in primates. This theory suggests that, for haplorines, the right hand is used preferentially for manipulative acts while the left hand is used preferentially for visually guided acts. The study showed statistically significant right hand preferences for six of the seven actions which produced sufficient data to be tested. The strength and consistency of this preference makes this study the first to suggest true handedness in a non-human primate species. Deviations from the pattern were seen in scratching and other actions when performed in a vertical posture, but these deviations took the form of a weakening of the right hand preference rather than a reversal. The findings of the study may be seen as supportingMacNeilage et al.'s (1987) theoryonly if the actions studied are all considered to be manipulative, which can be argued to be the case, though some of the actions were also visually guided.     

Does anthocyanin affect outcrossing rates in Datura Stramonium (Solanaceae)?

In this paper, I investigate whether the presence or absence of anthocyanin is neutral with respect to reproduction in Datura stramonium. The observations concern the portion of the life cycle spanning pollination to germination. Pollinators do not appear to distinguish between floral morphs, as revealed by nonbiased distribution of fluorescent powder used as a pollen analogue. Pollen-tube growth is also equal for the two morphs. Seed germination is affected by the presence of anthocyanin, but apparently only by the genotype of the mother at the anthocyanin locus, and not by the genotype of the embryo itself. In addition, there was an interaction between maternal morph and the maternal source population, with seeds from high-elevation anthocyanin-producing mothers germinating most rapidly and seeds from low-elevation anthocyanin-producing mothers germinating most slowly in a common garden at low elevation. However, because germination of anthocyanin-producing and anthocyaninless progeny proceed equally quickly, the anthocyanin marker provides unbiased estimates of outcrossing rates. The results overall support the use of anthocyanin as a neutral marker, with the alternate phenotypes unlikely to be differentially impacted by the processes of pollination, pollen-tube growth, and germination. Fluctuating selection on conditions for dormancy release may be partially responsible for the maintenance of the anthocyanin polymorphism in Datura stramonium.     

Is there a plastid in Perkinsus atlanticus (Phylum Perkinsozoa)?

Perkinsus atlanticus is a pathogenic protist that infects the clam Ruditapes decussatus. The recent proposal for the inclusion of the genus Perkinsus in a new phylum, Perkinsozoa, in the infra-kingdom Alveolata, gave rise to controversies whether this genus should form a phylum on its own. Molecular analysis of some conserved nuclear genes shows a closer proximity of the genus Perkinsus to the dinoflagellates than to the apicomplexans. Studies on extranuclear genomes, however, could also be very helpful for a more precise definition of those phyla. In Perkinsozoa, there have been until now no reports about the isolation of mitochondria as well as no conclusive results about the presence of any plastids, therefore a comparison with the data already obtained in Apicomplexa and Dinoflagellata has not yet been possible. In this work, we identify a plastid in Perkinsus atlanticus, using ultrastructural techniques and inhibition growth tests. It will be important to analyze the plastid genome at a molecular level, in order to confirm if the plastid in Perkinsus is more similar to those of Dinoflagellata or Apicomplexa. Such information will doubtless contribute to a more precise determination of the phylogenetic position of the genus Perkinsus.     

Stereotypic behavior in wild marine carnivores?

Stereotypic behavior is observed in many species within zoological institutions. Attempts to reduce such behavior typically involve some form of environmental enrichment that provides opportunities for species appropriate behavior or some degree of control within the environment. However, environmental enrichment has never been completely successful in eliminating stereotypic behavior for an entire group of animals within a zoological facility. In the wild, stereotypic behavior is rarely observed. Documenting the occurrence of stereotypic behavior in the wild, and circumstances in which it occurs, could help provide insight into the causes of such behavior within zoological institutions. The following commentary details the observations of wild lemon sharks (Negaprion brevirostris) engaging in a stereotyped swimming pattern behind a research vessel north of Grand Bahama Island, Bahamas. We consider a possible explanation for the sharks' behavior and hope to stimulate conversation as well as increase examination of animal management routines in zoological facilities. Zoo Biol 30:365–370, 2011. © 2010 Wiley‐Liss, Inc.     

Reticulate or tree-like chloroplast DNA evolution in Sileneae (Caryophyllaceae)?

Despite sampling of up to 25kb of chloroplast DNA sequence from 24 species in Sileneae a number of nodes in the phylogeny remain poorly supported and it is not expected that additional sequence sampling will converge to a reliable phylogenetic hypothesis in these parts of the tree. The main reason for this is probably a combination of rapid radiation and substitution rate heterogeneity. Poor resolution among closely related species are often explained by low levels of variation in chloroplast data, but the problem with our data appear to be high levels of homoplasy. Tree-like cpDNA evolution cannot be rejected, but apparent incongruent patterns between different regions are evaluated with the possibility of ancient interspecific chloroplast recombination as explanatory model. However, several major phylogenetic relationships, previously not recognized, are confidently resolved, e.g. the grouping of the two SW Anatolian taxa S. cryptoneura and S. sordida strongly disagrees with previous studies on nuclear DNA sequence data, and indicate a possible case of homoploid hybrid origin. The closely related S. atocioides and S. aegyptiaca form a sister group to Lychnis and the rest of Silene, thus suggesting that Silene may be paraphyletic, despite recent revisions based on molecular data.     

Growth factors in asexually reproducing catenulida and macrostomida (Plathelminthes)?

Summary The occurrence and localization of immuno-reactivity (IR) to epidermal growth factor receptor (EGF-r), epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), revealed by the present study, indicate growth-factor-like substances in the asexually reproducing flatworms,Stenostomum leucops andMicrostomum lineare. IR to all three antibodies occurs in the nervous system. Differences in the number of positive cells and intensity of IR during asexual development of new individuals were observed. By confocal scanning laser microscopy, immunopositive growth cones of nerve fibres were seen in developing zooids, and weakly or unstained perikarya were observed in close contact with the positive nerve fibres. Antibodies to the growth factors EGF-r, EGF and bFGF as well as to the neuroactive substances 5-HT and RF-amide had a negative influence on the growth and asexual reproduction of culturedS. leucops. No significant differences in the influence of antibodies to growth factors and antibodies to the neuroactive substances were observed.     

Does self-pollination provide reproductive Assurance in Aquilegia Canadensis (Ranunculaceae)?

The ability to produce seeds when pollinators or potential mates are scarce is thought to be one of the main advantages of self-fertilization in flowering plants. However, whether autonomous selfing increases seed set in natural populations has seldom been tested, and even fewer studies have evaluated the advantage of selfing across a gradient of pollen availability. This study examines the fertility consequences of autonomous selfing in Aquilegia canadensis (Ranunculaceae), a short-lived, spring-flowering perennial typically found in small, patchy populations on rock outcrops. We used a pollinator exclusion experiment to confirm reports that A. canadensis has a well-developed capacity for autonomous selfing resulting from incomplete protogyny and close proximity of stigmas and anthers during dehiscence. Flowers excluded from pollinators set 87% as many seeds per carpel (X +/- 1 SE = 7.1 +/- 1.4 seeds) as hand-pollinated flowers (8.1 +/- 1.3 seeds), and seed production in unpollinated flowers correlated negatively with the distance between stigmas and anthers (r = -0.46). Autonomous selfing could be potentially valuable in providing reproductive assurance because only 2.7 +/- 0.5 pollen grains were deposited on each stigma before anther dehiscence, compared to 134.1 +/- 17.9 pollen grains by the end of anther dehiscence. However, prevention of autonomous selfing by anther removal before dehiscence did not decrease seed set, even for plants at low plant densities where outcross pollen may have been in short supply. Emasculated flowers set as many seeds per carpel (9.3 +/- 0.9) as intact flowers (8.4 +/- 1.1), indicating that sufficient cross pollen is deposited for full seed set. These results do not support the hypothesis that autonomous selfing by A. canadensis has been selected because it provides reproductive assurance.     

Mixed reproductive strategy in Tubifex tubifex (Oligochaeta, Tubificidae)?

Despite the wide use of the tubificid oligochaete Tubifex tubifex in eco-toxicological studies, the reproductive strategy adopted by the species, that can reasonably be assumed to be the key to its ecological success, is still not well investigated. This study reports on breeding experiments analysed by allozyme markers (Pgi, Pgm, and Idh), accompanied by a study of the sperm production in the species, with the aim to: (1) clarify the type of uniparental reproduction adopted by the species, (2) test the hypothesis that uniparental reproduction is reversible, (3) investigate the occurrence of biparental reproduction in laboratory cultures. Studies of parent-offspring comparison at polymorphic allozyme loci showed parthenogenetic reproduction and maintenance of asexuality in the parthenogenetic individuals. A cross-breeding test performed with couples made up of randomly assorted individuals, whose genotype combinations were suitable for discriminating between sexual and asexual reproduction, failed to show biparental reproduction in laboratory cultures: T. tubifex always reproduced parthenogenetically. Unexpectedly, spermiogenetic analysis indicated that both kinds of sperm produced by the species (eusperm and parasperm) were differentiated in individuals raised either in cohort cultures or in isolation (first, second, and third parthenogenetic generations), with a similar pattern of sperm production correlated to the sexual stage. Interestingly, there was no avoidance of mating in any of the collective cultures analysed. Concomitance between parthenogenetic reproduction and a "normal" male functionality, which is typical of a sexually reproducing species, could be justified by a mixed reproductive strategy or a pseudogamy process occurring in T. tubifex. However, several aspects of the reproductive behaviour of the species deserve further investigation.     

The origin of variation in “wild”Raphanus sativus (Cruciferae) in California

Analyses of populations ofRaphanus growing in the central part of California, from the Sierra Nevada foothills to the Pacific coast, show that pureR. raphanistrum can be found only in the Central Valley, while over the remainder of the area populations of the so-called wild (weedy)R. sativus occur. More detailed morphological studies of a number of populations in this area have revealed that the populations of wildR. sativus originated by hybridization of the cultivated forms of this species (the radish) with another introduced species, already a weed,R. raphanistrum. The composition of each hybrid population with respect to the proportion of characters of the one or the other species depends upon the habitat it occupies and its geographic location. Populations in inland areas display a high proportion ofR. raphanistrum characters, while in those near the coastR. sativus characters predominate.Artificial hybrids betweenR. raphanistrum and a cultivated form ofR. sativus exhibited about 50% pollen fertility and were heterozygous for a reciprocal translocation. Examination of wild populations ofR. sativus revealed that plants heterozygous for a reciprocal translocation are present in varying proportions. Experimental evidence is produced to show that this translocation is identical with that separatingraphanistrum from cultivated forms ofsativus. Thus a cytological proof of the introgression is added to the morphological evidence. Introgression ofraphanistrum characters appears to have been a major factor in converting the erstwhile crop plant,R. sativus, into a highly successful weed in California.