Movement activity and habitat use of Carabus ullrichii (Coleoptera: Carabidae): The forest edge as a mating site?

Some carabid species are not restricted to a single habitat only, but use various types of habitats. In these species, relatively little is known about the utilization of occupied habitats and factors affecting their movement within these habitats. In this study, we focus on the movement activity of ubiquitous Carabus ullrichii during its reproductive period at the border of two types of habitats, a meadow and a forest. We tracked 21 adult individuals using radio telemetry and recorded in total 1,687 position fixes. Movement activity was associated with the type of habitat and specific environmental conditions such as time of the day and air temperature. Both sexes activated preferably at dusk and during the night, although males were most active at temperatures around 15°C, while females showed no preference for temperature. Males were able to walk as fast as females, but they were more associated with forest edge. We assume that the inner edge of the forest could be used as a mating site and after mating males stay there and wait for new females with which to mate, while fertilized females disperse into the surroundings. They moved further into the closed forest where they were likely looking for oviposition sites and food resources to support reproduction. Exclusively females were recorded to visit the meadow at a greater distance from the forest edge and their movements there were almost always direct.     

Pollinator aggregative and functional responses to flower density: does pollinator response to patches of plants accelerate at low‐densities?

Plant reproduction is often reduced at low densities, due to reduced pollinator visitation rates. Recent theory suggests that a disproportionate increase in pollinator visits to patches of plants as heterospecific plant density increases (i.e. if visitation is a sigmoid function of patch density) can rescue sparse populations of a focal plant species from reduced reproductive success or population decline. A field experiment was performed to determine the shape of the pollinator visitation response to patches of differing density of the common weed Brassica rapa . Both the aggregative and functional response for the entire pollinator community were saturating rather than sigmoid, indicating that pollinator response does not accelerate when density increases. The results for the entire pollinator community were consistent among temporal and spatial replicates. Aggregative response curves for specific pollinator taxa were either linear (bombyliid flies) or saturating (syrphid flies, solitary bees, and Lepidoptera). Functional responses for these taxa were saturating (syrphid flies and solitary bees) or flat (bombyliid flies and Lepidoptera). Individual pollinators visited more plants during foraging bouts in high-density patches, but visits per plant decreased. Seeds per fruit and seeds per flower increased with increasing density. There is no evidence that pollinators disproportionately visit denser patches, or that the conditions for this mechanism of pollination facilitation are likely to be met in this generalist pollinator system.     

Male mating success and risk of predation in a wolf spider: a balance between sexual and natural selection?

1. Traits that benefit males through sexual selection are simultaneously expected to impair males by provoking costs through natural selection. If we consider the two male fitness components, mating success and viability, then we may expect that the increase in male mating success resulting from a larger trait size will be counterbalanced by an increase in viability costs.
2. We studied the benefits and costs of male mate searching and sexual signalling activity in the wolf spider Hygrolycosa rubrofasciata . In the field, males search females actively and court them by drumming dry leaves with their abdomen. Females have been shown to prefer males with high drumming rate. Male moving and especially drumming is energetically highly demanding and drumming results in significant mortality costs.
3. Our objective in this study was to determine whether male mate-searching activity or drumming activity affect male mating success and the risk of males being predated.
4. It was evident that both higher mate-searching activity and higher drumming activity benefited males by increasing their mating success. Higher mate-searching activity clearly impaired males by causing direct increase in predation risk. There was also a slight tendency that more actively drumming males had higher risk of predation and from all of the predated males 13.3% were caught directly after they had drummed. Furthermore, male drumming activity decreased drastically in the presence of the predator.
5. We conclude that in H. rubrofasciata both increased mate-searching activity and drumming activity benefit males through sexual selection, but at the same time natural selection provokes direct balancing costs on the same traits.     

Male territoriality and mating system in the European beewolf Philanthus triangulum F. (Hymenoptera: Crabronidae): evidence for a “hotspot” lek polygyny

The evolution of the mating system of a species is strongly influenced by the spatial and temporal distribution of females and/or resources. Here, we describe aspects of the territorial behavior of males of a solitary digger wasp, the European beewolf (Philanthus triangulum) and characterize the mating system. We show that beewolf males establish small territories that do not contain any resources essential to females. These territories are intensively scent-marked with a pheromone from a cephalic gland and are defended against intruders in combat flights. We provide evidence that scent-marking constitutes a chemical display and that the pheromone serves to attract receptive females and, thus, represents a sex pheromone. Using spatial statistics, we show that beewolf territories are clumped in space both with respect to other male territories and, more importantly, with respect to female nesting sites. Additionally, the proportion of days a territory is occupied by a male is correlated with the number of female nests in the vicinity. Taking into account that beewolf males do not defend or provide resources essential to females, but merely display chemically to attract females for mating in an aggregation of territories close to female nesting sites, we conclude that the European beewolf exhibits a hotspot lek polygyny with female nesting sites constituting “hotspots” for lek formation.     

Male three‐spined sticklebacks Gasterosteus aculeatus make antibiotic nests: a novel form of parental protection?

The egg nest of male three‐spined sticklebacks Gasterosteus aculeatus is constructed with a glue‐like secretion that this study demonstrates has antimicrobial properties. Glue collected from reproductively active males decreased the growth rate of bacteria and opportunistic fungi, and eggs were more likely to mature and hatch after exposure to their father’s glue. This phenomenon may represent a direct physiological contribution from a male towards protecting his offspring from pathogens, and if so is a novel form of parental protection.     

How common is common? Rapidly assessing population size and structure of the frog Mantidactylus betsileanus at a site in east‐central Madagascar

Population‐level data are urgently needed for amphibians in light of the ongoing amphibian extinction crisis. Studies focused on population dynamics are not only important for rare species but also for common species which shape ecosystems to a greater degree than those that are rare. Some of the greatest global amphibian species diversity is found in Madagascar, yet there are few studies on the ecology of frog species on the island. We carried out a mark‐recapture study on the widespread frog Mantidactylus betsileanus (Mantellidae: Mantellinae: Mantidactylus) at two adjacent rainforest sites in east‐central Madagascar to assess its population size and structure. To do so, we validated and implemented an individual identification protocol using photographs of the ventral patterns of frogs and identified individuals with photographic‐matching software. Using this rapid, non‐invasive survey method, we were able to estimate a density of 26 and 28 frogs per 100 m² at each of the two sites sampled. Our results show the rainforests near the village of Andasibe, Madagascar support remarkably high amphibian abundance, helping illustrate the significant ecological role of frogs in this ecosystem. Further, individual frog markings allowed us to develop more precise estimates than traditional survey methods. This study provides a blueprint to augment existing population studies or develop new monitoring programs in Madagascar and beyond.     

Thermal habitat segregation among morphotypes of whitefish (Coregonus lavaretus: Salmonidae) and invasive vendace (C. albula): a mechanism for co‐existence?

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Do differences in life‐history traits and the timing of peak mating activity between host‐associated populations of Chilo suppressalis have a genetic basis?

The development of host races, genetically distinct populations of the same species with different hosts, is considered to be the initial stage of ecological speciation. Ecological and biological differences consistent with host race formation have been reported between water‐oat and rice‐associated populations of Chilo suppressalis. In order to confirm whether these differences have a genetic basis, we conducted experiments to determine the extent to which various life‐history traits and the time of peak mating activity of these populations were influenced by the species of host plant larvae were raised on. Individuals from each population were reared for three consecutive generations on either water‐oat fruit pulp or rice seedlings. Descendants of both populations had higher larval survival rates, shorter larval developmental periods, higher pupal weight, and longer adult forewings, when reared on water‐oats than when reared on rice. The time of peak of mating activity differed between the descendants of each population, irrespective of whether they were raised on water‐oats or rice. These results indicate that although some life‐history traits of host‐associated populations of C. suppressalis are influenced by the host plant larvae are raised on, time of peak mating activity is not. Because it is a stable, objective, phenotypic trait, further research on difference in the time of peak mating activity between host‐associated populations of C. suppressalis should be conducted to clarify the mechanism responsible for host race formation in this species.     

Dermis‐derived stem cells: a source of epidermal melanocytes and melanoma?

Human multipotent dermal stem cells (DSCs) have been isolated and propagated from the dermal region of neonatal foreskin. DSCs can self-renew, express the neural crest stem cell markers NGFRp75 and nestin, and are capable of differentiating into a wide variety of cell types including mesenchymal and neuronal lineages and melanocytes, indicative of their neural crest origin. When placed in the context of reconstructed skin, DSCs migrate to the basement membrane zone and differentiate into melanocytes. These findings, combined with the identification of NGFRp75-positive cells in the dermis of human foreskin, which are devoid of hair, suggest that DSCs may be a self-renewing source of extrafollicular epidermal melanocytes. In this review, we discuss the properties of DSCs, the pathways required for melanocyte differentiation, and the value of 3D reconstructed skin to assess the behavior and contribution of DSCs in the naturalized environment of human skin. Potentially, DSCs provide a link to malignant melanoma by being a target of UVA-induced transformation.     

Visual conditions and habitat shape the coloration of the Eurasian perch (Perca fluviatilis L.): a trade‐off between camouflage and communication?

In theory, selection for effective camouflage (i.e. dull coloration) in fish should be strongest when the conditions for visual predation are most favourable, such as in structurally simple pelagic habitats. By contrast, in more sheltered (e.g. littoral) habitats, selection may favour effective intra‐specific communication (i.e. bright coloration) (at the expense of crypsis). Poor transparency, as in highly humic waters, should constrain colour adaptations. We investigated phenotypic variation in body coloration of Eurasian perch (Perca fluviatilis L.) in littoral and pelagic habitats of four humic boreal lakes. Perch from the most transparent lake had the lightest and less coloured belly and perch were more colourful in the littoral habitats than in the pelagic areas, with the pattern being clearest in the most transparent lake. In addition, perch in the most transparent lake exhibited sexual dichromatism, with males having a more colourful belly than the females, whereas no indications of sexual dichromatism were found in more humic lakes. Moreover, in the most transparent lake, the condition of fish correlated with bright belly coloration in the littoral, but with dull belly coloration in the pelagic habitat. The results obtained in the present study suggest that selection on perch coloration may differ between lakes as a result of visual properties of the water, and within lakes as a result of divergent selection for camouflage and communication in pelagic and littoral habitats. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 47–59.     

Was god ever a ‘boss’ at Wujal Wujal? Lutherans and Kuku‐Yalanji: A socio‐historical analysis

Lutheran missionaries from Germany arrived in 1887 to ‘care for’ and to evangelise to the Kuku‐Yalanji people of the Bloomfield River area of the north Queensland rainforests. They left fifteen years later without having converted a single soul. Was this failure the result of inept missionisation? Was Lutheranism at odds with Kuku‐Yalanji religious beliefs? This paper argues that the answer lies rather at the core of the Kuku‐Yalanji worldview and social universe. Using rich historical sources, this paper demonstrates that Kuku‐Yalanji people—who have particular socio‐territorial ties to the mission lands—instigated an experiment with the missionaries. Their assumption was that the missionaries held a role that was structurally equivalent to that of ‘majamaja’ in their own system—key focal individuals with religious knowledge, power and achieved status operating at the node of a social network on a particular area of ‘country’. The missionaries failed to live up to this expectation and for this and other reasons, Kuku‐Yalanji left and the mission failed with no lasting Christian impact.     

Comparison of X‐ray and NMR structures: Is there a systematic difference in residue contacts between X‐ray‐ and NMR‐resolved protein structures?

We have compared structures of 78 proteins determined by both NMR and X-ray methods. It is shown that X-ray and NMR structures of the same protein have more differences than various X-ray structures obtained for the protein, and even more than various NMR structures of the protein. X-ray and NMR structures of 18 of these 78 proteins have obvious large-scale structural differences that seem to reflect a difference of crystal and solution structures. The other 60 pairs of structures have only small-scale differences comparable with differences between various X-ray or various NMR structures of a protein; we have analyzed these structures more attentively. One of the main differences between NMR and X-ray structures concerns the number of contacts per residue: (1) NMR structures presented in PDB have more contacts than X-ray structures at distances below 3.0 A and 4.5-6.5 A, and fewer contacts at distances of 3.0-4.5 A and 6.5-8.0 A; (2) this difference in the number of contacts is greater for internal residues than for external ones, and it is larger for beta-containing proteins than for all-alpha proteins. Another significant difference is that the main-chain hydrogen bonds identified in X-ray and NMR structures often differ. Their correlation is 69% only. However, analogous difference is found for refined and rerefined NMR structures, allowing us to suggest that the observed difference in interresidue contacts of X-ray and NMR structures of the same proteins is due mainly to a difference in mathematical treatment of experimental results.     

Are urban habitats ecological traps for a native songbird? Season‐long productivity,apparent survival,and site fidelity in urban and rural habitats

The northern mockingbird Mimus polyglottos is a native species that is more abundant in urban than non‐urban habitats (i.e. an urban‐positive species). Abundance alone, however, is not an accurate index of habitat quality because urban habitats could represent ecological traps (attractive sink habitat) for urban‐positive species. We compared mockingbird nesting productivity, apparent survival, and decision rules governing site fidelity in urban and rural habitats. If the higher abundance of mockingbirds in urban habitats is driven by higher quality urban habitat, then we predicted that productivity of urban mockingbirds would exceed the estimated source‐sink threshold and productivity of non‐urban mockingbirds. If, on the other hand, urban habitats act as ecological traps, productivity would be lower in urban habitats and would fall below the estimated source‐sink threshold. Productivity of urban pairs exceeded that of non‐urban pairs and more than offset estimated adult mortality, which makes urban habitat a likely source habitat. Apparent adult survival was higher in urban habitats than in non‐urban habitats, although this could be driven by dispersal more than mortality. Decision rules also appeared to differ between urban and non‐urban populations. Females in urban habitats with successful nests were more likely to return than those with unsuccessful nests, whereas return rates of females in nonurban habitats were unrelated to nesting success and may be more related to nesting habitat availability. We conclude that urban habitats do not act as ecological traps that lure mockingbirds into sink habitat and that increased breeding productivity contributes to their success in urban habitats.     

Species of the genus Lamachus F?rster (Hymenoptera,Ichneumonidae) parasitizing diprionid sawflies (Hymenoptera,Diprionidae) with descriptions of two?new species and a key to Chinese species

Four species of the genus Lamachus Förster 1869 belonging to the tribe Mesoleiini of the subfamily Ctenopelmatinae (Hymenoptera, Ichneumonidae) are reported from China. Two of them are new to science, Lamachus nigrus Li, Sheng & Sun, sp. n. and Lamachus rufiabdominalis Li, Sheng & Sun, sp. n. were reared from Neodiprion huizeensis Xiao & Zhou, in Guizhou Province of the Oriental part of China. The biology of Lamachus rufiabdominalis is described. A key to the species of Lamachus known from China is provided.     

Sex differences in settlement behaviour and condition of chiffchaffs Phylloscopus collybita at a wintering site in Portugal. Are females doing better?

In passerine birds, males are generally larger and dominant over females. In line with the dominance theory, in all known differential migrant passerines, females migrate further than males. However, there are alternative explanations to the dominance hypothesis, including the specialisation hypothesis, predicting that females should do better than males in habitats and/or regions to which they are specially adapted, and where they predominate in numbers. Few studies have aimed at comparing the behaviour and condition of males and females wintering in locations largely dominated by female birds. We studied a partly nomadic species, the common chiffchaff Phylloscopus collybita, at a wintering site in Portugal. Most individuals caught at this site were transients. The only consistent and relatively powerful predictor of settlement behaviour was sex. Almost all the birds that settled in the study area were female, while there was an almost even sex ratio in the transient sample. Females had higher muscle and post-juvenile moult scores when first captured. In addition, there was a significant sex-based difference in mass trajectories, with females maintaining body mass and males losing body mass when settled at the study site. Results from this study suggest that the poor performance of males was either due to inferior male competitive ability in a region/habitat where females predominate and/or it resulted from the fact that males that reach these wintering grounds are of inferior individual quality.     

Plant species richness and composition of heathland relics in north‐western Belgium: evidence for a rescue‐effect?

Aim To study the effects of the degree of fragmentation of heathland patches on their species richness and species composition, and to infer the ecological mechanisms behind the observed patterns. Location The heathland patches of the north‐western part of Flanders, Belgium. During the last 200 years, the heathland area in this study area has been reduced from c. 10,000 to c. 40 ha, yielding c. 150 small and highly isolated relic fragments. Methods Different isolation measures were calculated for each of the 153 inventoried heathland patches. The influence of isolation, area and habitat diversity on species richness was investigated using correlation techniques. Community composition of the patches was tested for nestedness, and the mechanisms potentially underlying this pattern were determined. Results and main conclusions Both the analyses at the species richness and community composition level yielded evidence for a positive species–area relation. This relation was not caused by higher habitat heterogeneity in larger patches. Patch isolation, measured in different ways, however seemed much more important in explaining species richness and community composition than fragment area. Our results indicate that area effects are overcompensated by the rescue‐effect: if a patch is close to other patches, species can disperse between them and prevent the species from going extinct. Species having a short living seed bank were also more sensitive to isolation than species with a long living seed bank, indicating that the latter most probably depend on the seed bank to survive periods when environmental conditions are harsh. Analogously to the spatial rescue‐effect, the existence of a persistent seed bank may lead to a sort of temporal rescue‐effect, where the extinction of a plant species is prevented through survival in the seed bank of a patch.     

Pair‐living in the Absence of Obligate Biparental Care in a Lizard: Trading‐off Sex and Food?

A pair‐living social organisation can typically be explained by obligate biparental care. We investigated pair‐living in the absence of biparental care in the Australian sleepy lizard, Tiliqua rugosa, which forms exceptionally strong pair bonds. We fitted 10 lizards, five male–female pairs, with Global Positioning System (GPS) recorders and continuously monitored social associations and separations between active pair partners, based on location records taken every 10 min over 3 mo. Males temporarily separated and reunited the pair more frequently than females, but females also contributed to the maintenance of the pair bond. These behavioural data were consistent with the hypothesis that females successfully coerce males into associations with one female. Lower frequencies of social association between pair partners once mating had finished support this interpretation. Males that are coerced into pair associations appear to experience higher costs of pair‐living than females, because males initiated temporary separations of the pair more frequently than females. Males showed higher movement activity and remained active later each day. This sex bias in activity may be an important mechanism to mitigate the higher costs of pair‐living for males. Costs for males might include within‐pair competition for food as females appear more competitive. Our study provides detailed empirical data on a lizard pair bond and provides important insights into pair‐living in the absence of biparental care.     

Fragmentation in the clouds? The population genetics of the native bee <Emphasis Type="Italic">Partamona bilineata</Emphasis> (Hymenoptera: Apidae: Meliponini) in the cloud forests of Guatemala

Habitat fragmentation and loss are important drivers of genetic differentiation, often leading to a decrease in genetic diversity. Yet, natural populations of tropical bees often show a lack of differentiation, even in fragmented landscapes, suggesting resilience to deal with unfavourable land use. It is not clear what leads to this lack of differentiation, but large population sizes, high rates of dispersal and stable demography likely play important roles. Here, we investigate the population genetic structure and infer the present and historic demography of the eusocial stingless bee Partamona bilineata from tropical montane cloud forests in Guatemala. We used microsatellites and mitochondrial DNA to test for genetic differentiation, to infer migration rates, and to evaluate the effects of landscape. We also used demographic modelling to trace population sizes over time. We found that six populations of P. bilineata exhibited only subtle differentiation, with the exception of one site at the edge of the cloud forest, which was clearly distinct from all others. Effective population sizes (number of colonies) appeared to be rather small (18?±?6 colonies) compared to the original sample size (N?=?51?±?9), but stable over time, and inferred rates of gene flow were low; yet, no genetic bottleneck was detected. A statistical model including elevation was the best in explaining the observed pattern of differentiation. We find that P. bilineata does not exhibit strong genetic structure, making it a resilient species for provision of pollination services. But, at the same time, our data point to the potential vulnerability of this and similar species, as effective population sizes appear to be low and hence populations may be easily affected by future environmental change. As such, P. bilineata may be representative of many other tropical stingless bees, for which lack of differentiation has been invoked.     

Macro and Microhabitat Associations of the Peter's Tent‐Roosting Bat (Uroderma bilobatum): Human‐Induced Selection and Colonization?

Understanding species‐specific habitat selection is essential to identify how natural systems are assembled and maintained, and how emerging natural and anthropogenic disturbances will affect ecosystem function. In the Neotropics, Peter's tent‐roosting bat (Uroderma bilobatum), known to roost in forests, has become abundant in human‐modified areas. To understand how habitat characteristics in both intact forest and human‐modified areas influence the presence and density of U. bilobatum, we characterized habitat use at two scales (macrohabitat and microhabitat) and used logistic and poisson regressions to determine which habitat characteristics best predicted the presence and density of U. bilobatum within each scale. Moreover, we performed a redundancy analysis to determine which habitat scale explained more variation. As these bats are obligate tent roosters, we used tent as a surrogate for bat presence and density. We found that both macrohabitat and microhabitat scales explained variation in presence and density. Characteristics of the microhabitat scale, however, had higher predictive power, revealing that U. bilobatum preferentially inhabits areas with high density of coconut palms. Coconut palms were introduced recently in the Neotropics and are found only in human‐modified areas. Therefore, we hypothesize that U. bilobatum is expanding its range into these areas following the expanded distribution of this exotic plant species.