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Dr. M. Brock Fenton has been intrigued by the diversity of bats throughout his long career, and has combined his research and photography skills to capture the extensive morphological diversity found across the order Chiroptera. In this paper, we honour Brock's fascination with diversity by conducting a review of the external and internal characteristics of the bat nose, a morphological feature that Brock's photographs have beautifully captured in many bat species. Specifically, we explore variation in form and function of the bat rostrum and its role in respiration, echolocation, and olfaction in bats, with an emphasis on the noseleaves of nasal-emitting echolocators, as well as how turbinate morphology may be impacted by nasophonation. While our review is not an extensive dive into all that is known about bat noses, our goal is to highlight the diversity we see in form across the order Chiroptera while exploring how function has been shaped by selection, particularly in relation to mode of echolocation signal emission. [ABSTRACT FROM AUTHOR]

The article offers information on Zoological Endeavours Inspired by A. Richard Palmer held during the Annual Meeting of the Canadian Society of Zoologists on May 14-16, 2019.

Brock Fenton has devoted his career to the study of the ecological adaptations of bats and their diversity. In this paper, we describe his interest and research on the subject of bat evolution and how he has used phylogenetic hypotheses to revise our understanding of divergences and convergences of specific traits within this mammalian order. While he has always been fascinated by the evolution of echolocation, he has also written about the evolution of reproductive, morphological, and behavioural traits and his recent methods of documenting diversity incorporates his lifelong love of photography. We describe these and taxonomic attempts to honour his contributions to the study of bat species diversity. Brock has supported hundreds of students and colleagues with his endless enthusiasm and generosity and inspired them with his ongoing research on bats. [ABSTRACT FROM AUTHOR]

The water scavenger beetle Ephydrolithus Girón and Short, 2019 contains five species, all occurring in the southeastern region of Brazil. In this paper, 5 new species are described from the Brazilian Shield, bringing the number of species in the genus to 10: Ephydrolithus bentoi sp. nov., Ephydrolithus cipo sp. nov., Ephydrolithus mucugensis sp. nov., Ephydrolithus serro sp. nov., and Ephydrolithus vivas sp. nov. New geographical records in the Brazilian Shield are provided for Ephydrolithus hamadae Girón and Short, 2019, Ephydrolithus spiculatus Girón and Short, 2019, and Ephydrolithus teli Girón and Short, 2019. Corroborating the previously described habitat for the genus, all new species are associated with hygropetric zones such as wet rocks, waterfalls, and seepages. An updated key to identify adults of Ephydrolithus is provided. [ABSTRACT FROM AUTHOR]

An introduction to the special issue of the journal is presented which includes information on papers from a symposium entitled "Advances in animal flight studies" which has perspectives on biology of flight of insects, pterosaurs and bats and mentions information of the editor of the issue.

The article informs that the current issue of the journal is comprised of papers presented in the "Crossing boundaries and building bridges: integrative zoology" symposium held in Montréal, Quebec from May 25-29, 2015 along with information on its editors Angela L. Shamchuk and Heath A. MacMillan.

We evaluated the quality of information about taxonomic identifications in 710 papers published in seven zoological journals in 2017. We found that only 10.7% of papers cited identification methods, 29.2% made available specimen-level material for later verification, and 6.9% indicated taxon concepts applied to studied animals. Only 4.0% provided details about all three practices, while almost two-thirds provided none. Invertebrate papers were more likely than vertebrate papers to provide identification methods and deposit vouchers, but taxon concepts were rarely provided, and none of the three practices were common in any category. In short, our data suggest that most zoological research is irreplicable. To address this problem, journals should require submitted manuscripts to meet the following guidelines: (1) methods used to identify studied taxa must be stated; (2) literature supporting these identifications must be cited; (3) taxon concept(s) applied to species-level taxa must be indicated; (4) specimen-level material should be available for later examination. We argue that research which falls short of these guidelines is not replicable. We provide recommendations for how authors can better document how studied animals are identified and permit others to verify their identifications, which is necessary for transparent, replicable, and ultimately scientific zoological research. [ABSTRACT FROM AUTHOR]

The article offers information on the annual meeting of Canadian Society of Zoologists on topic "Animal Mitochondria: Evolution, Performance and Plasticity" that was held in University of Guelph, Ontario on May 13-17, 2013.

The article discusses valuable contributions to our understanding of factors potentially affecting aerial insectivorous bird populations. Most of the papers in this collection were presented as part of the symposium. Topics include the diversity of stressors potentially contributing to aerial insectivore declines at multiple scales and during different parts of the annual cycle.

Partial migration, the phenomenon in which animal populations are composed of both migratory and nonmigratory individuals, is widespread among migrating animals. The proportion of migrants in these populations has direct influences on population genetics and dynamics, ecosystem dynamics, mating systems, evolution, and responses to environmental change, yet there are very few studies that measure the proportion of migrants. This is because existing methods to estimate the proportion of migrants are time-consuming and expensive. In this paper, we demonstrate a new method for estimating the proportion of migrants in a population based on sex ratio measurements. Many partially migratory taxa exhibit sex-biased migration or residency, and in these cases, the sex ratios of migrants and nonmigrants are fundamentally related to the proportion of migrants in the population. We define this relationship quantitatively and show how it can be used to infer the proportion of migrants in a population through a process we term "sex-ratio balancing". We obtain Bayesian estimates of proportion of migrants and quantify the uncertainty in these estimates with highest posterior density intervals. Lastly, we validate the sex-ratio balancing approach with a Chinook salmon (Oncorhynchus tshawytscha Walbaum in Artedi, 1792) data set. Sex-ratio balancing holds promise as a tool for quantifying partial migration and filling a key data gap about partially migratory taxa. [ABSTRACT FROM AUTHOR]

Fish are consumed by many predators in addition to humans. Identifying the agent responsible for an archaeological fish bone accumulation is a crucial yet far from straightforward task in the absence of diagnostic criteria. It is for this reason that exploring the features of fish bone collections produced by animals constitutes a key issue of archaeozoological research. In this paper, one such study is presented for the Yellow-legged Gull (Larus michahellis J.F. Naumann, 1840). A total of 48 pellets were collected in a colony of the species on two islands of the Chafarinas archipelago (Mediterranean Sea). The analyses demonstrate that fish remains, represented by 13 species and 1 genus, made up 93% of the 2789 identified remains. Most assemblages were dominated by the European pilchard (Sardina pilchardus (Walbaum, 1792)). Our study indicates that digestive processes modify skeletal elements through abrasion and fragmentation. Based on the modifications that were recorded, a set of diagnostic criteria is proposed to serve as proxies for spotting fish bone deposits produced by Yellow-legged Gulls on archaeological assemblages. [ABSTRACT FROM AUTHOR]

Male little brown bats ( Myotis lucifugus (Le Conte, 1831)) and northern long-eared bats ( Myotis septentrionalis (Trouessart, 1897)) often roost under exfoliating bark, within trunks, and within cavities of trees during summer. Current lack of knowledge about the roosting ecology of these species in boreal forest limits our understanding of how they may be affected by logging. The main objective was to identify tree and forest stand features that were selected by bats for roosting within a balsam fir ( Abies balsamea (L.) Mill.) - paper birch ( Betula papyrifera Marshall) forest of Quebec, Canada. Over 3 years, we captured and fitted radio transmitters to 22 individual bats to locate their roost trees for 7-14 days following release. We measured tree and forest stand features in the field and using light detection and ranging (LiDAR) technology. Roost trees were compared with random trees using generalized linear mixed models. Male Myotis bats selected larger and taller snags, within stands containing a higher proportion of canopy gaps and a larger number of snags compared with random trees. Vegetation clumps of 0.1 ha containing a minimum of 10 snags with a diameter at breast height (DBH) ≥ 10 cm should be maintained to preserve roosting habitat that is used by male Myotis bats in balsam fir - paper birch forests. [ABSTRACT FROM AUTHOR]

Managers and policymakers in eastern Canada embrace science-based management of nonindigenous species and may benefit from having comprehensive regional species checklists at subnational jurisdictional levels. In this paper, regional checklists provide an account of the richness of ascidians in eastern Canada. Records of 58 ascidians resulted from reviewing 108 published sources, accessing data from two online databases, and collecting some common indigenous ascidian specimens. Analysis comparing the similarity of species among nine regions indicates that there is greater similarity in species composition between contiguous regions than between noncontiguous regions and suggests that there are four zoogeographic clusters in eastern Canada. Our checklists can inform managers and policymakers of the diversity of the ascidian taxa and can minimize taxonomic uncertainties of established nonindigenous and prospective invading species, for example, by identifying indigenous species that are congeners of nonindigenous species. The maintenance of checklists can be a valuable tool for the management of nonindigenous species as baselines to estimate changes in richness and to document the invasion status of nonindigenous species over time. For example, more importance can be placed on the spread of nonindigenous ascidians from one zoogeographic cluster to another than spread within the same cluster. [ABSTRACT FROM AUTHOR]

Noise can cause marine mammals to interrupt their feeding, alter their vocalizations, or leave important habitat, among other behavioural responses. The current North American paradigm for regulating activities that may result in behavioural responses identifies received levels (RL) of sound at which individuals are predicted to display significant behavioural responses (often termed harassment). The recurrent conclusion about the need for considering context of exposure, in addition to RL, when assessing probability and severity of behavioural responses led us to conduct a systematic literature review (370 papers) and analysis (79 studies, 195 data cases). The review summarized the critical and complex role of context of exposure. The analysis emphasized that behavioural responses in cetaceans (measured via a linear severity scale) were best explained by the interaction between sound source type (continuous, sonar, or seismic/explosion) and functional hearing group (a proxy for hearing capabilities). Importantly, more severe behavioural responses were not consistently associated with higher RL and vice versa. This indicates that monitoring and regulation of acoustic effects from activities on cetacean behaviour should not exclusively rely upon generic multispecies RL thresholds. We recommend replacing the behavioural response severity score with a response/no response dichotomous approach that can represent a measure of impact in terms of habitat loss and degradation. [ABSTRACT FROM AUTHOR]

Nudibranch molluscs of the genus Dendronotus Alder and Hancock, 1845 are widely distributed in the Northern Hemisphere. Taxonomic studies on the genus Dendronotus have been problematic due to high variability in the colour pattern of many species, as well as in the external morphology and anatomy. In the present paper, we studied specimens of Dendronotus from northern Pacific presumably belonging to the species Dendronotus albus MacFarland, 1966 (white frond-aeolis). Molecular and morphological data revealed the existence of two distinct species among the material examined: D. albus, which has a wide range from Kamchatka and the Kurile Islands (from where we report this species for the first time) to California in North America, and the pseudocryptic species Dendronotus diversicolor Robilliard, 1970 (multicolor frond-aeolis), which has been previously considered a junior synonym of D. albus. Dendronotus diversicolor occurs from California, USA, to British Columbia, Canada, in sympatry with D. albus. Dendronotus albus and D. diversicolor can be clearly distinguished by colour pattern, internal and external morphology, and molecular sequence data. Despite some similarities in radular and external morphology between D. albus and D. diversicolor, these two species are phylogenetically distant and belong to different clades within the genus Dendronotus, which suggests convergent evolution. [ABSTRACT FROM AUTHOR]

Few studies have addressed whether terrestrial insects assess predation risk via chemical cues. We exposed predator-naïve fall field crickets (Gryllus pennsylvanicus Burmeister, 1838) to filter paper containing the chemical cues of three wolf spiders (Hogna helluo (Walckenaer, 1837), Rabidosa rabida (Walckenaer, 1837), Rabidosa punctulata (Hentz, 1844)), the house cricket (Acheta domesticus L., 1758,) and blank filter paper. Crickets exhibited greater immobility and reduced speed of movement when exposed to chemical cues of all three spider species. Crickets exhibited reduced speed with increasing mass of R. punctulata, suggesting that larger spiders may pose a greater risk. Cricket response did not differ between cues of H. helluo fed conspecific crickets versus H. helluo fed house crickets, suggesting that crickets cannot distinguish between cues from H. helluo fed phylogenetically similar crickets. Our work nevertheless demonstrates that naïve field crickets respond to chemical cues of several species of wolf spiders. [ABSTRACT FROM AUTHOR]

In prairie voles, Microtus ochrogaster (Wagner, 1842), the onset of parental caring differs by sex and reproductive condition. Maternal caring is displayed abruptly at parturition, whereas paternal caring intensifies gradually during the reproductive period. To determine if changes in odor responsiveness contribute to sex differences in onset of parental behavior, voles were given a choice to investigate various odors at different times during the reproductive cycle. Subjects were either sexually naïve or mated. Mated pairs cohabited until mid-gestation, late gestation, or 3 days postpartum. Voles crossed a tunnel to explore a row of three filter papers covered with infant odor, orange extract, or saline. Males and females exhibited different odor preferences. Males preferred infant odor to saline and orange extract, whereas females preferred infant odor and saline to orange extract. Mating changed the odor investigative behaviors in both males and females. Some voles vigorously manipulated odor-covered papers. The number of females manipulating the papers increased abruptly at late gestation. The number of males manipulating the papers was particularly high at mid-gestation and after the birth of young. Results suggest that mating and cohabitation in prairie voles influences odor responses in a sex-specific manner. [ABSTRACT FROM AUTHOR]

Despite its role as a keystone species, few studies have investigated the habitat requirements of the Yellow-bellied Sapsucker (Sphyrapicus varius (L., 1766)) in the northwestern part of its range, where the current forest harvesting rotation schedule and targets for reducing the prevalence of old and mixedwood stands may reduce the optimal habitat for this species. We studied nesting and foraging habitat requirements of nesting sapsuckers in a boreal mixedwood forest of northwestern Canada by collecting data on nesting sites and foraging substrates on twenty-four 16- to 56-ha plots distributed among four habitat types in 1998 and 2002. Nests (n = 68) were generally found in large (≥22 cm diameter at breast height) trembling aspen (Populus tremuloides Michx) that were alive but declining and that showed high incidence (81.1%) of heartwood rot infection (Phellinus tremulae (Bondarzev) Bondarzev & Borisov in Bondarzev). Nest-site use by sapsuckers was predicted mainly by the presence of external fungal conks and tree diameter. Among tree species used as foraging substrates, paper birch (Betula papyrifera Marsh.) (65.6%) and green alder (Alnus viridis (Vill.) Lam. & DC.) (21.3%) were used most frequently. The use of birch was strongly correlated with its availability. Mature forests had higher densities of nesting sites and foraging substrates than immature aspen stands. In addition to reconfirming the importance of mature mixedwood forests for Yellow-bellied Sapsuckers, our study also indicates that forest harvest rotations in northwestern Canada should exceed 90 years to promote the keystone role of this species. [ABSTRACT FROM AUTHOR]

The comment by Romero and Kannada is presented as a critique of our previous work and suggests that our conclusions are in direct conflict with the historic whaling information reviewed in their paper. However, the critique is based on a misinterpretation of the geographical, temporal, and taxonomic focus of our previous work. The source of the putative conflict appears to stem from the misinterpretation that our results, focused solely on the impact of Basque whaling in the 16th and 17th centuries on the western North Atlantic right whale, were intended to be representative of all whaling of both right and bowhead whales throughout the North Atlantic. To demonstrate this, we briefly review our original results and conclusions and show that the information reviewed by Romero and Kannada does not challenge any aspect of our original work. As such, their comment is not a critique of our paper, but rather a brief review of the history of whaling in the North Atlantic. [ABSTRACT FROM AUTHOR]

With 210 genera and 2010 species, Cyprinidae is the largest freshwater fish family in the world. Several papers, based on morphological and molecular data, have been published and have led to some solid conclusions, such as the close relationships between North American phoxinins and European leuciscins. However, the relationships among major subgroups of this family are still not well resolved, especially for those East Asian groups. In the present paper, the mitochondrial DNA (mtDNA) control region, 896–956 base pairs, of 17 representative species of East Asian cyprinids was sequenced and compared with those of 21 other cyprinids to study their phylogenetic relationships. After alignment, there were 1051 sites. The comparison between pairwise substitutions and HKY distances showed that the mtDNA control region was suitable for phylogenetic study. Phylogenetic analysis indicated that there are two principal lineages in Cyprinidae: Cyprinine and Leuciscine. In Cyprinine, the relationships could be a basal Labeoinae, an intermediate Cyprininae, and a diversified Barbinae (including Schizothroaxinae). In Leuciscine, Rasborinae is at the basal position; Gobioninae and Leuciscinae are sister groups; the East Asian cultrin–xenocyprinin taxa form a large mono phyl etic group with some small affiliated groups; and the positions of Acheilognathinae and Tincinae are still uncertain. [ABSTRACT FROM AUTHOR]

The fossil record of the Echinodermata is relatively complete, and is represented by specimens retaining an abundance of features comparable to that found in extant forms. This yields a half-billion-year record of evolutionary novelties unmatched in any other major group, making the Echinodermata a primary target for studies of biological change. Not all of this change can be understood by studying the rocks alone, leading to synthetic research programs. Study of literature from the past 20 years indicates that over 1400 papers on echinoderm paleontology appeared in that time, and that overall productivity has remained almost constant. Analysis of papers appearing since 1990 shows that research is driven by new finds including, but not restricted to, possible Precambrian echinoderms, bizarre new edrioasteroids, early crinoids, exquisitely preserved homalozoans, echinoids at the K-T boundary, and Antarctic echinoids, stelleroids, and crinoids. New interpretations of echinoderm body wall homologies, broad-scale syntheses of embryological information, the study of developmental trajectories through molecular markers, and the large-scale ecological and phenotypic shifts being explored through morphometry and analyses of large data sets are integrated with study of the fossils themselves. Therefore, recent advances reveal a remarkable and continuing synergistic expansion in our understanding of echinoderm evolutionary history.Les fossiles d'échinodermes sont bien connus et les spécimens qui les représentent possèdent plusieurs caractères qui prévalent encore chez les formes modernes. On se retrouve donc devant un inventaire de caractères évolutifs inédits étalé sur un demi–milliard d'années, inégalé parmi les autres groupes principaux d'animaux, ce qui fait des échinodermes le groupe cible idéal pour l'étude des changements biologiques. Ces changements ne peuvent être compris au seul examen des roches, d'où la création de programmes de recherche de synthèse. L'examen de la littérature des derniers 20 ans indique que plus de 1400 articles sur la paléontologie des échinodermes ont été publiés durant cette période et que la productivité globale est demeurée presque constante. L'analyse des articles publiés depuis 1990 montre que la recherche est stimulée par les nouvelles découvertes, entre autres, de la présence d'échinodermes au Précambrien, de nouveaux édrioastéroïdes bizarres, de crinoïdes anciens, d'homalozoaires remarquablement conservés, d'échinoïdes à la limite Crétacé-Tertiaire et d'échinoïdes, stelléroïdes et crinoïdes de l'Antarctique. J'ai intégré aux fossiles eux-mêmes de nouvelles interprétations des homologies de la paroi du corps des échinodermes, des synthèses sur une grande échelle des données embryologiques, l'étude des trajectoires du développement au moyen de marqueurs moléculaires et les modifications écologiques et phénotypiques globales qui sont explorées par la morphométrie et par l'analyse de grands ensembles de données. Ainsi, les progrès récents mettent en lumière une expansion synergiste remarquable et continue de notre compréhension de l'histoire évolutive des échinodermes.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Managing predators to restore threatened or endangered species is often controversial. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029-1037) report on the efficacy of wolf ( Canis lupus L., 1758) reduction as a recovery strategy in the Little Smoky population of boreal woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) range in Alberta, which generated a lot of media attention. As such, the authors were invited by the journal editor who handled the original paper to write this addendum to provide clarification regarding the methodology used in the original paper. Wolf reduction was conducted by Government personnel in accordance with appropriate policy and laws (i.e., federal and provincial Species at Risk Acts; Alberta Wildlife Act; Alberta Woodland Caribou Policy). University-based researchers were involved only in data analysis and writing, and thus did not require approval by a university-based animal welfare board. Collaboration between independent university-based scientists and government biologists is essential to effective assessment of such controversial management practices. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029-1037) in fact concluded that such wolf reductions, by themselves, would only 'buy time' and would not restore woodland caribou alone without effective habitat protection. [ABSTRACT FROM AUTHOR]

It is currently unclear how Toxoplasma gondii (Nicolle and Manceaux, 1908) persists in arctic tundra ecosystems in the absence of felid definitive hosts. To investigate potential transmission routes of T. gondii in a terrestrial arctic food web, we collected samples from two migratory herbivores, Ross's Geese ( Chen rossi (Cassin, 1861)) and Lesser Snow Geese ( Chen caerulescens (L., 1758)), and from two resident herbivores, Nearctic brown lemmings ( Lemmus trimucronatus (Richardson, 1825)) and collared lemmings ( Dicrostonyx groenlandicus (Traill, 1823)), trapped at Karrak Lake, Nunavut, Canada. Antibodies were detected in 76 of 234 (32.4%) serum samples from Ross's Geese and 66 of 233 (28.3%) serum samples from Lesser Snow Geese. We did not detect T. gondii antibodies in filter-paper eluate tested from thoracic fluid samples collected from 84 lemmings. We did not detect T. gondii DNA in brain tissue from these lemmings. Although a small sample size, our findings suggest that lemmings in this terrestrial arctic ecosystem are not exposed to, or infected with, the parasite. This suggests that oocysts are not introduced into the terrestrial arctic ecosystem at Karrak Lake via freshwater runoff from temperate regions. This study demonstrated that live adult arctic-nesting geese are exposed to T. gondii and therefore migratory herbivorous hosts are potential sources of T. gondii infection for predators in terrestrial arctic ecosystems. [ABSTRACT FROM AUTHOR]

In nature, mollusk shells have a role in protecting the soft body of the mollusk from predators and from the external environment, and the shells consist mainly of calcium carbonate and small amounts of organic matrices. Organic matrices in mollusk shells are thought to play key roles in shell formation. However, enough information has not been accumulated so far. High toughness and stiffness have been focused on as being adaptable to the development of organic-inorganic hybrid materials. Because mollusks can produce elaborate microstructures containing organic matrices under ambient conditions, the investigation of shell formation is expected to lead to the development of new inorganic-organic hybrid materials for various applications. In this review paper, we summarize the structures of mollusk shells and their process of formation, together with the analysis of various organic matrices related to shell calcification. [ABSTRACT FROM AUTHOR]

Sex is a costly form of reproduction compared with parthenogenesis, but sex persists because of the more resistant and competitive descendants that it produces. We obtained thelytokous offspring from unmated female Doru lineare (Eschscholtz, 1822) earwigs, a species of insect in which parthenogenesis has never before been reported, and found that their number and survival rate did not differ from offspring of mated females. Current hypotheses support advantages of sex or parthenogenesis, but never equilibrium between them like the one reported in this paper. We suggest that parthenogenesis is how females multiply their entire genome and renew themselves. [ABSTRACT FROM AUTHOR]

This paper provides the first description of the cellular composition of the gill epithelium of feeding adults of Ichthyomyzon unicuspis Hubbs and Trautman, 1937 (silver lamprey), a parasitic species of lamprey that is confined to fresh water. The surface layer of this epithelium consists solely of pavement cells and intercalated mitochondria-rich cells, which are the only cell types found in all freshwater stages of lampreys and thus considered responsible for the uptake of Na+ and Cl- in hypotonic environments. This epithelium does not contain, however, the chloride cells present during the marine parasitic phase of anadromous lamprey species, such as Petromyzon marinus L., 1758 (sea lamprey), and which are responsible for secreting excess Na+ and Cl-. The absence of this cell type in parasitic adults of I. unicuspis also differs from its presence in parasitic adults of landlocked P. marinus and metamorphosing individuals of the exclusively freshwater nonparasitic species Lethenteron appendix (DeKay, 1842) (American brook lamprey), and which thus reflects the retention of a cell type that was crucial for osmoregulation during the marine phase of their respective anadromous parasitic ancestors. The absence of chloride cells in I. unicuspis is consistent with the hypothesis that Ichthyomyzon, which is at or close to the base of the phylogenetic tree for Northern Hemisphere lampreys (Petromyzontidae), evolved in fresh water or has been confined to fresh water for a very long period. [ABSTRACT FROM AUTHOR]

Intense browsing by abundant large herbivores can threaten the ecological integrity of ecosystems by inducing modifications in the structure and composition of vegetation that trigger trophic cascades affecting plant and animal communities. We investigated the relationships between density of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)), forest succession after clear-cut, and songbird communities on Anticosti Island, Quebec, Canada. We hypothesized that lower deer densities would alter the trajectory of forest succession after clear-cutting and lead to a rapid recovery of habitat attributes favorable to songbirds associated with a dense complex shrub layer. Six years after establishing a controlled browsing experiment (0, 7.5, 15, and >27 deer·km-2) in recent clearcuts, reducing deer densities ≤7.5 deer·km-2 initiated the restoration of balsam fir ( Abies balsamea (L.) Mill.) forests and increased the regeneration of paper birch ( Betula papyrifera Marshall). Increasing birch ground cover from 10% to 20% increased songbird total abundance, species richness, and diversity by 17%, 39%, and 31%, respectively. Alder Flycatcher ( Empidonax alnorum Brewster, 1895) was only present at ≤7.5 deer·km-2 and strongly associated with birch regeneration. The regeneration of browse-resistant plants such as white spruce ( Picea glauca (Moench) Voss) in some areas at high deer density favored the maintenance of many shrub-dependent songbirds but also species usually associated with forest canopy. Active management of deer populations in Canadian harvested boreal forests will mitigate losses in vegetation and songbirds caused by over-browsing. [ABSTRACT FROM AUTHOR]

Assessing sperm viability is a popular means of testing hypotheses related to ejaculate quality. This technique has produced interesting results; however, the sperm viability assay itself may kill sperm. This is a serious pitfall, as assay-related mortality could confound results and produce artificially low estimates of viability. To avoid spurious results, it has been recommended that investigators include sperm number in their viability analyses. Unfortunately, studies conducted to date on internal fertilizers have not included sperm counts in their analyses, so it is not possible to assess whether this factor can indeed produce artefactual results. In this paper, we use male house crickets ( (L., 1758)) to show that sperm viability is dependent on sperm number and exclusion of this factor from statistical analyses affects our interpretation of experimental treatment results. We show that mechanically rupturing a spermatophore significantly reduces sperm viability, but this does not appear to drive the nonindependent relationship between viability and number. Instead, our study shows that nonindependence is due to processes other than differential physical damage to the sperm during collection. We also show that allowing a spermatophore to evacuate its sperm without rupturing for 10 min maximizes both sperm number and viability. [ABSTRACT FROM AUTHOR]

Several lamprey species form pairs, comprising an anadromous parasitic species and a derivative nonparasitic species that neither leaves fresh water nor feeds as an adult. This paper provides the first description of the radical changes undergone by the cellular composition of the gill epithelium during the major phases in the life cycle of a nonparasitic lamprey (American brook lamprey, (DeKay, 1842) (= (DeKay, 1842)) and discusses their potential functional and evolutionary significance. The gill epithelium of the larva of L. appendix contains ammocoete mitochondrion-rich cells (AMRCs), intercalated mitochondrion-rich cells, and pavement cells, as does that of the larva of anadromous parasitic species which likewise lives in fresh water. By the completion of metamorphosis, the AMRCs have disappeared and well-developed chloride cells have been produced, the latter cell type being essential for osmoregulation by its closely related anadromous species in hypertonic environments. By the attainment of sexual maturity, the chloride cells have been lost. Such changes in the timing of chloride cell representation could help account for the ability of some metamorphosing, but not mature individuals of another nonparasitic species ( (Bloch, 1784)), to osmoregulate in up to 70% of seawater. The well-developed chloride cells in the nonparasitic L. appendix represent the retention of an ancestral character. [ABSTRACT FROM AUTHOR]

Many animals undergo annual migrations. These movements are well studied at proximate levels, but their fundamental causes are poorly understood. Among tropical frugivorous birds, annual migration is thought to have evolved in the context of exploiting reciprocal peaks in fruit abundance among locations and seasons, yet previous tests of this hypothesis have yielded equivocal results. In this paper, I tested whether protein and (or) fruit limitation explain both uphill and downhill migratory movements in a tropical frugivorous bird, the White-ruffed Manakin (Corapipo altera Hellmayer, 1906). While White-ruffed Manakins likely migrate uphill to exploit peaks in fruit abundance, I found no evidence that elevational differences in fruit abundance explain the downhill portion of the migratory cycle. This result challenges long-standing ideas regarding the causes of altitudinal migration because it implies that birds seeking to maximize fruit intake should remain sedentary at higher elevations. Data are also inconsistent with the hypothesis that White-ruffed Manakins migrate (either uphill or downhill) to exploit arthropod prey. Future studies should consider how variation in weather, predators, or parasites could help explain altitudinal migrations of birds from breeding areas to nonbreeding areas. [ABSTRACT FROM AUTHOR]

The Southern Giant Petrel (Macronectes giganteus (Gmelin, 1789); Aves, Procellariiformes), ranging from New Zealand to the Graham Peninsula and Patagonia and also from coastal Antarctica to Gough Island, displays significant geographic variation throughout its range. Six breeding provinces were identified, which show significant interpopulational variation. The formerly proposed subspecies Macronectes giganteus giganteus and Macronectes giganteus solanderi were confirmed. Macronectes giganteus solanderi has smaller homologuous parts than M. g. giganteus. Two of the provinces belong to the subspecies M. g. solanderi. Females are smaller and have shorter bills than males. In M. g. giganteus, outer appendages are longer in the sub-Antarctic than in the Antarctic, which is consistent with Allen’s rule. Moreover, an east-to-west cline shows a gradual decrease in body size. Within M. g. solanderi, the Chubut River Estuary (Argentina) and the Falkland Islands form the southern province, and Gough Island the northern province. The birds have shallower bills in Argentina than in the Falklands or Gough, but tarsi are longest in Gough. Macronectes giganteus giganteus is morphologically polymorphic but taxonomically stable, whereas M. g. solanderi, which is biometrically less variable, could undergo taxonomical differentiation. This paper gives arguments for further morphometric and genetic studies on the taxon. [ABSTRACT FROM AUTHOR]

In this paper we explore the cyclic interactions of prey-predator systems by examining the relationship between cycle lengths of both species and the strength of their interaction. As a probe of interaction strength, we use the degree of counter-clockwise rotation in phase plots with the prey on the x axis and the predator on the y axis. We compare the results from a 25-year time series from the Hudson’s Bay Company data on American mink (Neovison vison (Schreber, 1777)) and muskrat (Ondatra zibethicus (L., 1766)) with results from three simulation models. We found that the strength of interaction (rotation range: -0.4 to 1.1 rad/year) was strongest when the two cycle lengths were similar and that it increased with the amplitude of the cycles (cycle range: 4-10 years). The time difference between prey and predator cycles that corresponded to the highest interaction strength was 2-3 years. Similar results were obtained with simulation models; the most complex Hanski model showing the overall best fit with observations. However, none of the models were able to reproduce long ranges of stable cycles by only changing one of their parameters at a time (ranges 2-4 years), whereas the observed range of stable cycles was 4-10 years. Nous examinons dans notre recherche les interactions cycliques des cycles proies-prédateurs par l’étude de la relation entre les longueurs des cycles des deux espèces et l’intensité de leur interaction. Comme mesure de l’intensité de l’interaction, nous utilisons le degré de rotation dans le sens inverse des aiguilles d’une montre dans des diagrammes de phase sur lesquels les prédateurs sont placés en abscisse et les prédateurs en ordonnée. Nous comparons les résultats d’une série chronologique de 25 ans de données de la Compagnie de la baie d’Hudson sur les visons (Neovison vison (Schreber, 1777)) et les rats musqués (Ondatra zibethicus (L., 1766)) avec les résultats de trois modèles de simulation. L’intensité de l’interaction (étendue de la rotation : -0,4 à 1,1 rad/année) est la plus grande quand les deux longueurs de cycles sont semblables et elle augmente en fonction de l’amplitude des cycles (étendue des cycles : 4-10 ans). Les différences temporelles entre les cycles de la proie et du prédateur qui correspondent à l’intensité d’interaction la plus grande sont de 2 à 3 ans. Les modèles de simulation produisent des résultats semblables et le modèle de Hanski le plus complexe présente le meilleur ajustement aux observations. Cependant, aucun des modèles n’est capable de reproduire des cycles stables à long terme par le changement successif des variables une seule à la fois (étendues 2-4 ans), alors que l’étendue observée des cycles stables est de 4 à 10 ans. [ABSTRACT FROM AUTHOR]

Although many ecological studies of wild animal populations rely on capturing individuals at least once, few have investigated either the immediate stress responses of capture, restraint, and handling, or the longer term consequences on reproductive success. In this paper, we assume that the degree of stress increase with the time taken to capture and process an animal prior to release. The influence of time since onset of capture on body temperature and blood chemistry indicators of stress was investigated in 137 adult female Svalbard reindeer (Rangifer tarandus platyrhynchus Vrolik, 1829) and 63 calves of both sexes captured by net in late-winter 2004 and 2005. In addition, we looked for evidence of negative effects of capture stress on reproductive success in marked animals over the period from 1995 to 2006. Body temperature increased with both chase time and the time the animals were restrained. In the latter case, body temperature increased twice as fast in nonpregnant animals (0.13 °C/min) compared with pregnant animals. Cortisol, glutamate dehydrogenase, and γ-glutamyltransferase all increased with time from onset of capture. However, the relationship for glucose with time since onset of capture increased initially before declining again. We found no evidence of a lower calving success in animals captured the previous winter when compared with animals that had not been captured the previous winter. Likewise, there was no relationship between the strength of the acute stress response (measured as cortisol concentrations) and the probability of pregnant females having a calf at foot the subsequent summer. Bien que plusieurs études écologiques de populations d’animaux sauvages dépendent de la capture d’individus à au moins une reprise, peu d’entre elles ont examiné soit les réactions immédiates au stress de la capture, du confinement et de la manipulation, soit les conséquences à plus long terme sur le succès de la reproduction. Dans notre travail, nous présumons que l’intensité du stress augmente en fonction du temps requis pour la capture et l’étude de l’animal avant sa libération. Nous avons examiné l’influence du temps écoulé depuis le début de la capture sur la température corporelle et les indicateurs sanguins chimiques du stress chez 137 rennes de Svalbard (Rangifer tarandus platyrhynchus Vrolik, 1829) femelles et 63 petits des deux sexes capturés au filet en fin d’hiver 2004 et 2005. Nous avons, de plus, recherché des signes d’effets négatifs du stress de la capture sur le succès de la reproduction chez des animaux marqués durant la période de 1995 à 2006. La température corporelle augmente tant en fonction de la durée de la poursuite que de celle du confinement des animaux. Dans ce dernier cas, la température corporelle croît deux fois plus rapidement chez les femelles non enceintes (0,13 °C/min) que chez celles qui le sont. Le cortisol, la glutamate déshydrogénase et la γ-glutamyltransférase augmentent tous avec le temps à partir du début de la capture. Cependant, la relation entre le glucose et le temps écoulé depuis le début de la capture montre un accroissement initial suivi d’un déclin. Il n’y a aucune indication d’un succès réduit de la mise bas chez les animaux capturés l’hiver précédent par comparaison aux animaux non capturés durant l’hiver précédent. De même, il n’y a pas de relation entre l’intensité de la réaction aiguë au stress (mesurée par le dosage des concentrations de cortisol) et la probabilité qu’une femelle enceinte possède un petit sur pied l’été suivant. [ABSTRACT FROM AUTHOR]

Food-caching by arctic foxes (Vulpes lagopus (L., 1758)) is a behavioural adaptation thought to increase winter survival, especially in bird colonies where a large number of eggs can be cached during a short nesting season. In this paper, we measured the energy content of greater snow goose (Chen caerulescens atlantica Kennard, 1927) eggs and evaluated their perishability when cached in tundra soil for a whole summer. We estimated that eggs lost only ~8% of their dry mass over 60 days of storage in the ground. We used published estimates on digestibility of nutrients by arctic foxes to estimate that fresh and stored goose eggs contained 816 and 730 kJ of metabolizable energy, respectively, a difference of 11%. Using information on arctic fox energetics, we evaluated that 145 stored eggs were required to sustain the growth of one pup from the age of 1 to 3 months (nutritional independence). Moreover, 23 stored eggs were energetically equivalent to the average fat deposit of an arctic fox during winter. Finally, we calculated that an adult arctic fox would need to recover 160-220 stored eggs to survive 6 months in resting conditions during cold winter temperatures. This value increased to 480 when considering activity cost. Based on egg acquisition and caching rates observed in many goose colonies, we conclude that cached eggs represent an important source of energy relative to the needs of an arctic fox during winter, and have thus a high fitness value. [ABSTRACT FROM AUTHOR]

Isotopic models are increasingly used to determine the relative contribution of different food sources to an animal’s diet. However, these models are based on restrictive assumptions and provide estimates rather than exact values of contributions to consumer diet. The sources of inaccuracies in isotopic models are not well understood and laboratory experiments may be useful to evaluate model performance. In this paper we assess the accuracy of the three main isotopic models in controlled laboratory experiments, involving a breed of Norway rats (Rattus norvegicus (Berkenhout, 1769)), in which the isotopic values of resources are known. At the same time, we measure errors resulting from the use of fixed or specific discrimination factor values for each resource and tissue. We show that the results of the three main isotopic models deviate considerably from the correct values in some cases. Estimations obtained using specific discrimination factors (corresponding to each experimental diet and tissue) were more accurate than those obtained using fixed discrimination factors (obtained from the literature). In addition, estimations varied depending on the tissue used, with the liver giving more accurate results than muscle or hair. We discuss the assumptions and limitations of isotopic models and highlight the importance of taking these assumptions into account when the most accurate results are sought. Finally, we propose some recommendations for the correct use of isotopic models, emphasizing the need to use specific discrimination factors for each species, tissue, and diet isotopic value. [ABSTRACT FROM AUTHOR]

Male alternative reproductive tactics have been described in many mating systems. In fishes, these tactics typically involve a territorial male that defends a spawning site or nest and a parasitic male that uses sneaking or female mimicry to steal fertilizations from the territorial male. In this paper, we use molecular genetic markers to examine the success of males that adopt alternative reproductive tactics in two sunfishes, comprising the bluegill (Lepomis macrochirus Rafinesque, 1819) and the pumpkinseed (Lepomis gibbosus (L., 1758)). In sunfishes, the tactics are referred to as parental (territorial male) and cuckolder (parasitic male). We show that cuckoldry rates peak in the second trimester of the breeding season in bluegill, whereas cuckoldry rates are lowest during this period in pumpkinseed. We also show that paternity of parental male bluegill is positively correlated with body condition, but not body length or mass. No relationship between these phenotypic variables and paternity in pumpkinseed was found. We discuss the patterns of cuckoldry in relation to differences between the species in mating opportunities, parental male defence ability, and cuckolder density. Finally, we discuss how the paternity data can be used to differentiate between two mechanisms underlying the expression of alternative reproductive tactics, comprising the condition strategy and alternative strategies. [ABSTRACT FROM AUTHOR]

The proboscis of male elephant seals (Mirounga Gray, 1827) has been suggested as an example of a secondary sexual trait since Darwin. There has been much speculation about its social function (e.g., optical signal of breeding status, amplification of vocalizations, cue for female choice). However, it has never been studied in detail, probably because its fleshy nature makes measurement difficult. In this paper, we employ photogrammetry to measure the proboscis and facial morphology of a large sample of wild, unrestrained, displaying male southern elephant seals (Mirounga leonina (L., 1758)). We describe ontogeny and allometry of the proboscis and analyze current phenotypic selection pressures on proboscis traits. We discuss the potential role of the proboscis in optical and acoustic signaling of male resource-holding potential and status. We demonstrate that proboscis size is positively correlated with age and body size independently, and that it is currently under a positive sexual selection pressure when the effect of selection on body size is removed. We suggest that selection on proboscis size is functionally related to the emission of agonistic vocalizations. [ABSTRACT FROM AUTHOR]

Predictive habitat models have become important research and management tools for monitoring the spatial distribution and abundance of wildlife species. In this paper we develop and evaluate statistical habitat models for presence of territorial Svalbard rock ptarmigan (Lagopus muta hyperborea Sundevall, 1845) cocks in spring and apply the best model to assess ptarmigan habitat selection in a larger extrapolated region. Terrain variables were extracted at detailed (10 m digital elevation model (DEM)) and coarse (50 m DEM) scales to compare model performance. Sets of candidate environmental variables related to terrain and vegetation cover were developed and explanatory variables were calculated at increasing distances from the count site to well above the typical size of ptarmigan territory. We used ecological niche factor analysis to describe the difference between used and available sites. Survey sites used by cocks were characterized by a restricted range of altitude, a high degree of terrain heterogeneity, and dense vegetation cover compared with overall site availability in the survey region. We then used model selection criteria (AICc) to find the most parsimonious logistic regression models estimating habitat resource selection functions for cocks. Detailed terrain variables were better predictors than coarse terrain variables. The normalized difference vegetation index (NDVI) was a good predictor of presence of territorial cocks, but not as good as the most preferred habitat type. Owing to limited availability of high-quality vegetation maps, the best model containing NDVI and 10 m DEM variables was used for extrapolation of male ptarmigan habitat. Our results show that it is possible to obtain a model with a high ability to rank habitats using a low number of map-derived variables. Such rankings can then be used to improve field sampling designs and are therefore a useful tool for management and conservation of ptarmigan and wildlife in Arctic and alpine areas. [ABSTRACT FROM AUTHOR]

Feeding by uloborid spiders is unusual in several respects: cheliceral venom glands are absent; prey wrapping is extensive (up to several hundred metres of silk line) and severely compresses the prey; the spider’s mouthparts usually never touch the prey; and the entire surface of the prey is covered with digestive fluid. This paper presents observations on Philoponella vicina O. Pickard-Cambridge, 1899, which provide possible causal links between these traits. The spider begins ingesting soon after it wets the prey, gaining access to the prey’s interior through a broken cuticle that was broken during wrapping and by digestion of the prey’s membranes. The more abundant of the two types of wrapping lines is also digested, but the remaining shroud of wrapping silk is dense and filters digested prey particles. Robust setae on the palpal tarsus and the spread position of the anterior legs during feeding probably protect the spider from contact with the digestive fluid. Spiders extracted about 65% of the wet contents of the prey, but feeding was slow and involved substantial water evaporation. We propose that selection in uloborid ancestors to recover wrapping silk led to increased wetting of the prey’s surface and that compressive wrapping facilitated this wetting. These traits could have led to loss of the now superfluous cheliceral poison glands. [ABSTRACT FROM AUTHOR]

We measured the rate of water loss and pore density of eggs of spruce grouse (Canachites canadensis canace (L., 1766)) and ruffed grouse (Bonasa umbellus togata (L., 1766)) from different parts of their range in Ontario. Eggs were dried in enclosed glass jars over Drierite® and in paper trays in open air at room temperature and humidity. Eggs were weighed to the nearest 0.01 g every 2–4 days and the change in mass was measured as water loss. Pores of shells were counted (pores/cm2) in the blunt, middle, and pointed sections of the egg. Eggs of spruce grouse lost water at a faster rate in Drierite® and in open air and had a greater density of pores than eggs of ruffed grouse. Rates of water loss were constant and varied inversely with ambient humidity, with the difference between species greatest in open air. Eggs late in incubation of ruffed grouse dried at a faster rate than those early in incubation in Drierite®. The adaptations of eggs of each grouse to the moisture of the nest may help explain their distribution, density, and habitat and nest-site selections, as well as behavioural aspects of the nesting hen. Both, especially the spruce grouse, may be good indictors of climate change. [ABSTRACT FROM AUTHOR]

The directional movements of the male European Quail, Coturnix coturnix (L., 1758), during the breeding season and autumn migration were studied using Emlen orientation cages. The characteristics and evolution of the habitat in which males were captured and the sexual behaviour shown at capture indicate that these birds move in search of mating partners rather than of suitable habitats. These displacements are known as “gypsy movements” but are better described, as argued in this paper, as “movements in search of females”. A majority of caged birds (59%) showed a preferred direction (α = 238.5°), which coincided almost exactly with that observed in recoveries of ringed birds during autumn migration (α = 251.3°) but not with results from cage experiments during the same migratory period (α = 187.8°). Therefore, we conclude that displacements of the male European Quail, as shown in ringing recoveries, are much more influenced by “movements in search of females” than by migration. These movements are clearly towards the southwest, the males taking short flights towards suitable breeding grounds and driven by river-course habitats. In addition, we confirm that Emlen funnels are suitable for controlled experiments on the orientation of males in demes of European Quail. [ABSTRACT FROM AUTHOR]

This paper reports on an intimate association of a cnidarian with glass sponges. Hexactinellid sponges of the genus Heterochone were found to regularly contain numerous tiny hydroids in their tissue. The hydroid belongs to a new genus and species and is here named Brinckmannia hexactinellidophila. Brinckmannia hexactinellidophila is a reduced form, lacking tentacles and gonophores, which certainly is an adaptation to its endobiotic mode of life. The possession of desmonemes allows it to be classified as a member of the suborder Filifera of the order Anthoathecata. The shape of the hydranth reveals some clear affinities with the Proboscidactylidae, a relationship which is also strongly suggested by a comparison of 16S gene sequences. Because a closer relationship to some other families cannot be excluded at this stage, the new genus is nevertheless not assigned to any known family and classified as Filifera incertae sedis. [ABSTRACT FROM AUTHOR]

Stable-isotope ratios are increasingly being used to examine ecological questions pertaining to dietary choices, physiological status, and animal migration. It has been shown that animal tissues reflect the isotopic signature present in food, altered by a small reproducible fractionation value. The average diet–tissue discrimination for δ13C and δ15N is approximately 1‰and 3‰, respectively, although the degree of diet–tissue discrimination may be affected by a range of factors and vary between organisms and tissue types. Although the average δ34S is approximately zero, the sulfur diet–tissue discrimination values have only been determined for a few organisms. It is necessary to determine accurate diet–tissue discrimination values between tissue and dietary components to have confidence in any food-web study or determination of diet quality. In this paper, we determine carbon, nitrogen, and sulfur diet–tissue discrimination values for whole blood, liver, skeletal muscle, heart, brain, and fat (carbon only) from adult mice (Mus musculus L., 1758) equilibrated on three diets with unique isotopic signatures for carbohydrate carbon and for protein carbon, nitrogen, and sulfur. These data will aid researchers in choosing tissues to be used to examine food-web changes over time. [ABSTRACT FROM AUTHOR]

We investigated thermoregulation and energetics in female big brown bats, Eptesicus fuscus (Beauvois, 1796). We exposed bats to a range of ambient temperatures (Ta) and used open-flow respirometry to record their metabolic responses. The bats were typically thermoconforming and almost always entered torpor at Tas below the lower critical temperature Tlc of 26.7 °C. Basal metabolic rate (BMR, 16.98 ± 2.04 mL O2·h–1, mean body mass = 15.0 ± 1.4 g) and torpid metabolic rate (TMR, 0.460 ± 0.207 mL O2·h–1, mean body mass = 14.7 ± 1.3 g) were similar to values reported for other vespertilionid bats of similar size and similar to a value for E. fuscus BMR calculated from data in a previous paper. However, we found that big brown bats had a lower Tlc and lower thermal conductance at low Ta relative to those measured in the previous study. During torpor, the minimum individual body temperature (Tb) that we recorded was 1.1 °C and the bats began defending minimum Tb at Ta of approximately 0 °C. BMR of big brown bats was 76% of that predicted for bats based on the relationship between BMR and body mass. However, the Vespert ilionidae have been under-represented in previous analyses of the relationship between BMR and body mass in bats. Our data, combined with data for other vespertilionids, suggest that the family may be characterized by a lower BMR than that predicted based on data from other groups of bats. [ABSTRACT FROM AUTHOR]

The last comprehensive reviews of ecology and natural history of ascidians were included in the excellent 1971 publication by Millar on the biology of ascidians and the 1991 treatise on New Caledonia ascidians by Monniot, Monniot, and Laboute. Several hundred papers have been published since that time, greatly expanding our knowledge of environmental tolerances and responses to increasing levels of anthropogenically derived toxins in marine waters, energetics and feeding strategies, predator–prey relationships, competition both intra- and inter-specific that include many studies of self–nonself recognition in colonial species, modes and environmental regulation of reproduction and development, symbionts, natural-product chemistry as antifouling and antipredator defenses, and dispersal mechanisms. The relatively new field of molecular genetics is revealing the presence of cryptic species and is helping to determine the origin of anthropogenically transported individuals, an important and growing problem that affects natural ecological relationships in marine communities worldwide. We are learning more about the difficult-to-study abyssal and Antarctic species. There have been great advances in our understanding of the importance in open-ocean food webs of the planktonic Appendicularia and Thaliacea. Also included in this review is a brief discussion of recent work on the Cephalochordata and Hemichordata. [ABSTRACT FROM AUTHOR]

Four chordate characters — dorsal hollow nerve cord, notochord, gill slits, and endostyle — are compared morphologically, molecularly, and functionally with similar structures in hemichordates to assess their putative homologies. The dorsal hollow nerve cord and enteropneust neurocord are probably homoplasies. The neurocord (= collar cord) may be an autapomorphy of Enteropneusta that innervates a unique pair of muscles, the perihemal coelomic muscles. Despite the apparent lack of organ-level homology, chordates and enteropneusts share a common pattern of neurulation that preserves a "contact innervation" between neuro- and myo-epithelia, which may be the primitive deuterostome pattern of neuromuscular innervation. The chordate notochord and hemichordate stomochord are probably homoplasies. Other potential notochord antecedents in hemichordates are examined, but no clear homolog is identified. The comparative morphology of notochords suggests that the "stack-of-coins" developmental stage, retained into adulthood only by cephalochordates, is the plesiomorphic notochord form. Hemichordate and chordate gill slits are probably homologs, but only at the level of simple ciliated circular or oval pores, lacking a skeleton, as occur in adults of Cephalodiscus spp., developmentally in some enteropneusts, and in many urochordates. Functional morphology, I125-binding experiments, and genetic data suggest that endostylar function may reside in the entire pharyngeal lining of Enteropneusta and is not restricted to a specialized midline structure as in chordates. A cladistic analysis of Deuterostomia, based partly on homologs discussed in this paper, indicates a sister-taxon relationship between Urochordata and Vertebrata, with Cephalochordata as the plesiomorphic clade. [ABSTRACT FROM AUTHOR]

Morphometric measurements or biochemical methods are often required to differentiate deer mice, Peromyscus maniculatus (Wagner, 1845), from white-footed mice, Peromyscus leucopus (Rafinesque, 1818), particularly when they are found in sympatry. However, these approaches cannot easily be applied to juveniles, or to degraded or ancient museum specimens. In this paper, we propose a rapid and non-invasive molecular approach to discriminate these cryptic species from one another. This technique relies on species-specific primers designed in the COIII mitochondrial region to amplify fragments of different lengths in each species. The method developed proved useful for the identification of ethanol-preserved, frozen, degraded, or dry museum specimens. [ABSTRACT FROM AUTHOR]

This paper presents the results of observations concerning the phenomenon of parthenogenesis among European mites of the suborder Uropodina. An analysis of the sex ratios of 66 Polish species revealed that 18 of them (more than one fourth of the examined species) consisted only of females. The authors observed no significant relationship between geographical distribution and the lack of males in the population. Populations consisting entirely of females were observed among widely distributed species as well as among species characterized by narrow geographical ranges. Nonetheless, an increase in the number of parthenogenetic species, especially as a percentage of Middle European and Scandinavian fauna, was also discernible. Species that reproduced without males were associated with forest litter and soil, whereas bisexual species "eagerly" inhabited various relatively unstable and temporary microenvironments (for instance, dead wood, birds' or small mammals' nests). The authors aim to define the biological role of occasionally appearing males for the species consisting almost entirely of females and discuss ecological and evolutionary aspects of parthenogenesis in mites of the suborder Uropodina. [ABSTRACT FROM AUTHOR]

Prey often respond to predator presence by increasing refuge use. However, some types of refuges may expose prey to other types of predators. In addition, in selecting refuges ectothermic animals may have a conflict between safety and thermal suitability. In this paper we examined in the laboratory whether common wall lizards, Podarcis muralis (Laurenti, 1768), (i) prefer to use warm refuges to cold ones, (ii) prefer safe refuges to those with chemical cues of a saurophagous snake, and (iii) whether lizards face a trade-off between using a warm but snake-scented refuge or a cold but odorless one. Results did not show differences in refuge use in relation to refuge temperature, because common wall lizards only entered to investigate it, but they were not forced to hide. So, common wall lizards did not have to be at suboptimal temperatures for longer times. Common wall lizards avoided the use of predator-scented refuges, regardless of thermal conditions, and they also increased their movement rate, trying to escape from the terrarium. Because snakes are inconspicuous inside refuges, an avoidance response to their chemicals may enhance the survival possibilities of common wall lizards. We conclude that in common wall lizards, predation-risk costs are more important than thermal costs in determining refuge use. [ABSTRACT FROM AUTHOR]

There is controversy over whether uneven sex ratios observed in mature dragonfly populations are a mere artifact resulting from the higher observability of males. Previous studies have at best made indirect inference about sex ratios by analysis of survival or recapture rates. Here, we obtain direct estimates of sex ratio from capture–recapture data based on the Cormack–Jolly–Seber model. We studied Orthetrum coerulescens (Fabricius, 1798) at three sites in the Swiss Jura Mountains over an entire activity period. Recapture rates per 5-day interval were 3.5 times greater for males (0.67, SE 0.02) than for females (0.19, SE 0.02). At two sites, recapture rate increased over the season for males and was constant for females, and at one site it decreased with precipitation for both sexes. In addition, recapture rate was higher with higher temperature for males only. We found no evidence for higher male survival rates in any population. Survival per 5-day interval for both sexes was estimated to be 0.77 (95% CI 0.75–0.79) without significant site-or time-specific variation. There were clear effects of temperature (positive) and precipitation (negative) on survival rate at two sites. Direct estimates of sex ratios were not significantly different from 1 for any time interval. Hence, the observed male-biased sex ratio in adult O. coerulescens was an artifact resulting from the better observability of males. The method presented in this paper is applicable to sex ratio estimation in any kind of animal. [ABSTRACT FROM AUTHOR]