Scale‐dependent effects of forest restoration on Neotropical fruit bats

Neotropical fruit bats (family Phyllostomidae) facilitate forest regeneration on degraded lands by dispersing shrub and tree seeds. Accordingly, if fruit bats can be attracted to restoration sites, seed dispersal could be enhanced. We surveyed bat communities at 10 sites in southern Costa Rica to evaluate whether restoration treatments attracted more fruit bats if trees were planted on degraded farmlands in plantations or island configurations versus natural regeneration. We also compared the relative influence of tree cover at local and landscape spatial scales on bat abundances. We captured 68% more fruit bat individuals in tree plantations as in controls, whereas tree island plots were intermediate. Bat activity also responded to landscape tree cover within a 200‐m radius of restoration plots, with greater abundance but lower species richness in deforested landscapes. Fruit bat captures in controls and tree island plots declined with increasing landscape tree cover, but captures in plantations were relatively constant. Individual species responded differentially to tree cover measured at different spatial scales. We attribute restoration effects primarily to habitat structure rather than food resources because no planted trees produced fruits regularly eaten by bats. The magnitude of tree planting effects on fruit bats was less than previous studies have found for frugivorous birds, suggesting that bats may play a particularly important role in dispersing seeds in heavily deforested and naturally regenerating areas. Nonetheless, our results show that larger tree plantations in more intact landscapes are more likely to attract diverse fruit bats, potentially enhancing seed dispersal.     

Enriching agroecosystems with fruit-producing tree species favors the abundance and richness of frugivorous and nectarivorous bats in Veracruz, Mexico

We evaluated how the abundance and richness of frugivorous and nectarivorous bat species differs among three types of common agroecosystems (diversified coffee plantations, simple coffee plantations and pastures) in Veracruz, Mexico, that represent a gradient of structural and floristic complexity. Using mixed effects models we demonstrated that both the richness and the total abundance of bats was higher in the diversified coffee plantations. We detected similar patterns on comparing the abundance of the four most abundant bat species. Neither season nor the season-agroecosystem interaction had any effect on the comparisons made. Using multiple regressions we found that the richness of plants that are useful to both people and bats had the most explanatory power for the richness and total abundance of frugivorous and nectarivorous bats, as well as for the abundance of Carollia sowelli, Glossophaga soricina and Sturnira spp. Our results indicate that agroecosystems value for conservation of fruit and nectar-eating bats increases as the fruit-bearing trees increases. For the effective conservation of these guilds of bats in tropical agroecosystems, a strategy of diversification with fruit-bearing species is highly recommended; such a strategy would benefit both agricultural producers and wildlife.     

New records of ectoparasitic Acari (Arachnida) and Streblidae (Diptera) from bats in Jalisco,Mexico

Ectoparasites of bats in the Neotropics are diverse and play numerous ecological roles as vectors of microbial pathogens and endoparasites and as food sources for other cave fauna living both on their hosts and in bat roosts. The ectoparasites of bats in Jalisco State of western Mexico have not been as well described as those of other states with recent checklists that have focused primarily on the Yucatan Peninsula. We captured bats from 2011–2015 on the south coast and Sierra de Amula, Jalisco using mist nets, and we removed ectoparasites by hand. We identified 24 species of streblid bat flies and six ectoparasitic mites from bats caught in mist nets. There were an additional eight possibly undescribed species of Streblidae. Our collections extend the known range of species into Jalisco.     

Connecting behaviour and performance: the evolution of biting behaviour and bite performance in bats

Variation in behaviour, performance and ecology are traditionally associated with variation in morphology. A neglected part of this ecomorphological paradigm is the interaction between behaviour and performance, the ability to carry out tasks that impact fitness. Here we investigate the relationship between biting behaviour and performance (bite force) among 20 species of ecologically diverse bats. We studied the patterns of evolution of plasticity in biting behaviour and bite force, and reconstructed ancestral states for behaviour and its plasticity. Both behavioural and performance plasticity exhibited accelerating evolution over time, and periods of rapid evolution coincided with major dietary shifts from insect‐feeding to plant‐feeding. We found a significant, positive correlation between behavioural plasticity and bite force. Bats modulated their performance by changing their biting behaviour to maximize bite force when feeding on hard foods. The ancestor of phyllostomids was likely a generalist characterized by high behavioural plasticity, a condition that also evolved in specialized frugivores and potentially contributed to their diversification.     

Intraspecific variation in body size and sexual size dimorphism,and a test of Rensch's rule in bats

The magnitude and direction of sexual size dimorphism (SSD) may vary considerably within and among taxa, and the primary causes of such variation have not been thoroughly elucidated. For example, the effect of abiotic factors is frequently attributed to explain intra‐ and interspecific variation in SSD. Rensch's rule, which states that males vary more in size than females when body size increases, has rarely been tested in bats. Therefore, whether bats follow Rensch's rule remains unclear, particularly when females are larger than males. We investigated whether four bat species presented SSD, as well as whether their body sizes varied within each sex across localities, testing the hypothesis that intraspecific SSD varies substantially depending of sampling localities. We finally examined whether bats followed Rensch's rule by simultaneously using intraspecific and interspecific approaches. Although SSD was not observed for most bat species within each locality, the females of three of the four captured species exhibited differences in body size between particular localities. Usually the females varied more in size than did males across localities, mostly exhibiting a female‐biased SSD. Significant differences in SSD were observed (i.e. mean values of the sexual dimorphism index), even though Rensch's rule was not followed.     

Phylogenetic signal,feeding behaviour and brain volume in Neotropical bats

Comparative correlational studies of brain size and ecological traits (e.g. feeding habits and habitat complexity) have increased our knowledge about the selective pressures on brain evolution. Studies conducted in bats as a model system assume that shared evolutionary history has a maximum effect on the traits. However, this effect has not been quantified. In addition, the effect of levels of diet specialization on brain size remains unclear. We examined the role of diet on the evolution of brain size in Mormoopidae and Phyllostomidae using two comparative methods. Body mass explained 89% of the variance in brain volume. The effect of feeding behaviour (either characterized as feeding habits, as levels of specialization on a type of item or as handling behaviour) on brain volume was also significant albeit not consistent after controlling for body mass and the strength of the phylogenetic signal (λ). Although the strength of the phylogenetic signal of brain volume and body mass was high when tested individually, λ values in phylogenetic generalized least squares models were significantly different from 1. This suggests that phylogenetic independent contrasts models are not always the best approach for the study of ecological correlates of brain size in New World bats.     

Phylogenetics and biogeography of the broad-nosed bats, genus Platyrrhinus (Chiroptera: Phyllostomidae)

The Neotropical broad-nosed bats, genus Platyrrhinus, represent a well-defined monophyletic group of 14 recognized species. A recent study of morphological characters confirmed Platyrrhinus monophyly and species diagnosis, but offered little support to their intra-specific relationships. We conducted phylogenetic analyses of the genus, using dense taxonomic sampling in combination with four gene sequences representing both mitochondrial and nuclear DNA transmission systems. Our aim was to elucidate the phylogenetic structure among species, using the resulting 3341 bp of DNA. Maximum parsimony, maximum likelihood, and Bayesian inference analyses produced similar topologies that confirm the monophyly of the genus Platyrrhinus and strongly support many previously unrecognized groups. Paraphyly of Platyrrhinus helleri and the unclear position of P. brachycephalus in the clades were also apparent in the data. Our biogeographical analysis suggests a Brazilian Shield origin for Platyrrhinus, followed by subsequent radiations of lineages in the Amazon Basin and Andes. Secondary dispersal from Amazonian and Andean centers is responsible for the Platyrrhinus inhabiting the Guianan Shield and the Pacific lowlands and Central America, respectively.     

Dietary hardness, loading behavior, and the evolution of skull form in bats

The morphology and biomechanics of the vertebrate skull reflect the physical properties of diet and behaviors used in food acquisition and processing. We use phyllostomid bats, the most diverse mammalian dietary radiation, to investigate if and how changes in dietary hardness and loading behaviors during feeding shaped the evolution of skull morphology and biomechanics. When selective regimes of food hardness are modeled, we found that species consuming harder foods have evolved skull shapes that allow for more efficient bite force production. These species have shorter skulls and a greater reliance on the temporalis muscle, both of which contribute to a higher mechanical advantage at an intermediate gape angle. The evolution of cranial morphology and biomechanics also appears to be related to loading behaviors. Evolutionary changes in skull shape and the relative role of the temporalis and masseter in generating bite force are correlated with changes in the use of torsional and bending loading behaviors. Functional equivalence appears to have evolved independently among three lineages of species that feed on liquids and are not obviously morphologically similar. These trends in cranial morphology and biomechanics provide insights into behavioral and ecological factors shaping the skull of a trophically diverse clade of mammals.     

The comparative phylogeography of neotropical mammals: patterns of intraspecific mitochondrial DNA variation among bats contrasted to nonvolant small mammals

The major aim of this study was to compare the phylogeographic patterns of codistributed bats and small nonvolant Neotropical mammals. Cytochrome b sequences (mitochondrial DNA) were obtained for a total of 275 bats representing 17 species. The tissue samples were collected in coastal Brazil, and were available from Mexico and the Guyana. The study concentrates on four species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Glossophaga soricina) which were well represented. The other 13 species were sequenced to test the generality of the patterns observed. In general, sequence divergence values within species were low, with most bat species presenting less than 4% average sequence divergence, and usually between 1 and 2.5%. Clades of highly similar haplotypes enjoyed broad distribution on a continental scale. These clades were not usually geographically structured, and at a given locality the number of haplotypes was high (8-10). As distance increased, some moderately divergent clades were found, although the levels of divergence were low. This suggests a geographical effect that varied depending on species and scale. Small nonvolant mammals almost invariably have high levels of sequence divergence (> 10%) for cytochrome b over much shorter distances (< 1000 km). The grain of intraspecific variation found in small nonvolant mammals is much finer than in bats. Low levels of geographical structuring cannot be attributed to a slower evolutionary rate of bat DNA in relation to other mammalian taxa. The phylogeographic pattern of bats contrasts sharply with the pattern found for Neotropical rodents and marsupials.     

Pollination of the understorey palm Calyptrogyne ghiesbreghtiana by hovering and perching bats

Inflorescences of the Central American understorey palm Calyptrogyne ghiesbreghtiana offer bats fruit-like flower tissue as reward for visitation. Bats visited the inflorescences in two different modes: frugivores (Phyllostomidae: Stenodermatinae, Carolliinae) foraged on the inflorescence while perched, whereas bats that were primarily nectarivores (Phyllostomidae: Glossophaginae) also consumed flower tissue, but did so while hovering. Fruit set was significantly lower in inflorescences that had received only hovering visits, indicating that perching behaviour offers better possibilities for pollen transfer. The pollination system of C. ghiesbreghtiana is probably adapted to perching frugivorous bats with nectar-specialist Glossophagines as non-optimal participants. Seen in an evolutionary perspective the C. ghiesbreghtiana– glossophagine bat interactions may demonstrate recruitment of new pollinators from non-destructive visitors.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 281–288.     

塔里木沙拐枣果实刺毛对果实扩散及萌发的影响

塔里木沙拐枣（Calligonum roborowskii A.Los.）是仅分布于我国西北地区荒漠环境的特有种,其果实为不开裂而周围有椭圆形刺毛的瘦果,以果实为单元进行扩散和萌发。本文采用野外观察与室内控制实验相结合的方法,对塔里木沙拐枣刺毛在果实扩散、吸水、脱水及萌发中的作用进行研究。结果显示：不同贮藏时间的果实颜色、大小、重量及刺毛长度存在显著差异。完整果实在水面漂浮时间及水媒扩散能力比去除刺毛的果实更强。完整果实在1 m/s和4 m/s风速下的扩散距离比无刺毛果实的扩散距离长。10 mmol/L赤霉素（AG₃）及不同干藏时间处理的完整果实与无刺毛果实在20℃/30℃光照和黑暗条件下的萌发率间存在显著差异,其中无刺毛果实的萌发率要高于完整果实的萌发率。室外盆栽实验显示,无刺毛果实的萌发率比完整果实高,说明果实刺毛对果实萌发有抑制作用。研究结果表明果实刺毛对塔里木沙拐枣在塔克拉玛干沙漠边缘荒漠环境中的扩散、萌发及种群更新具有重要的辅助作用。     

Echolocation calls of free-flying common vampire bats Desmodus rotundus (Chiroptera: Phyllostomidae) in Chile

We recorded and characterized the echolocation calls emitted by the common vampire bat Desmodus rotundus during foraging in natural habitats in Chile. Signal design typically shows multiple harmonics consisting of a brief quasi-constant frequency (QCF) component at the beginning of the pulse followed by a downward frequency modulated component. Calls are characterized by long durations (5.5 ms) and emitted as single pulses or in groups of 2–3 pulses at a repetition rate of 29 Hz. The higher frequency ranges (85–35 kHz) and the unusual QCF component that characterized multiharmonic signals of free-flying D. rotundus in Chile is a remarkable feature for acoustic identification with other Chilean bats.     

How aphids find their host plants,and how they don't

There is a considerable interest in trying to understand how aphids find their host plants because they are a major cause of economic losses in agricultural and horticultural production systems. Indeed, the specific behavioural sequences during host finding by aphids are one of the main reasons for their prominent role as vectors of plant pathogenic viruses. This paper reviews the visual and olfactory stimuli involved in host‐finding behaviour of aphids, both basic and applied aspects are covered. Although controlling aphids by manipulation of visual and olfactory stimuli involved in host finding and host selection can be highly successful, as shown by research, most of these measures can still be further optimised and adoption in practice is currently limited. Research therefore needs to address some critical open questions, including (a) the effects of visual contrasts on aphid behaviour; (b) the specific responses of aphids to ultraviolet (UV) light during different stages in host finding; (c) the quantification of behavioural sequences in the field and (d) the response of aphid behaviour to plant diversity at varying spatial scales; further, (e) a much more comprehensive coverage of aphid taxa and aphid ecological groups is needed in host‐finding related research to uncover ecological principles underlying this critical behaviour.     

The role of fruit traits of bird-dispersed plants in invasiveness and weed risk assessment

Aim  Birds play a major role in the dispersal of seeds of many fleshy-fruited invasive plants. The fruits that birds choose to consume are influenced by fruit traits. However, little is known of how the traits of invasive plant fruits contribute to invasiveness or to their use by frugivores. We aim to gain a greater understanding of these relationships to improve invasive plant management.
Location  South-east Queensland, Australia.
Methods  We measure a variety of fruit morphology, pulp nutrient and phenology traits of a suite of bird-dispersed alien plants. Frugivore richness of these aliens was derived from the literature. Using regressions and multivariate methods, we investigate relationships between fruit traits, frugivore richness and invasiveness.
Results  Plant invasiveness was negatively correlated to fruit size, and all highly invasive species had quite similar fruit morphology [smaller fruits, seeds of intermediate size and few (< 10) seeds per fruit]. Lower pulp water was the only pulp nutrient trait associated with invasiveness. There were strong positive relationships between the diversity of bird frugivores and plant invasiveness, and in the diversity of bird frugivores in the study region and another part of the plants' alien range.
Main conclusions  Our results suggest that weed risk assessments (WRA) and predictions of invasive success for bird-dispersed plants can be improved. Scoring criteria for WRA regarding fruit size would need to be system-specific, depending on the fruit-processing capabilities of local frugivores. Frugivore richness could be quantified in the plant's natural range, its invasive range elsewhere, or predictions made based on functionally similar fruits.     

Sex differences in movement between natural feeding and mating sites and tradeoffs between food consumption,mating success and predator evasion in Mediterranean fruit flies (Diptera: Tephritidae)

Summary Systematic quantitative observations of the location and diel pattern of adult Mediterranean fruit fly, Ceratitis capitata (Wiedemann), activities were carried out in an orange grove and surroundings on the island of Chios in Greece. Natural fly foods were assessed for their contribution to fly longevity, fecundity and fertility. There were diel shifts in male and female location. Females required a substantial and varied diet to realize peak fecundity. This diet was acquired away from the primary host, orange. Foraging for food throughout most of the day on fig and non-host foliage (including feeding on bird droppings) as well as on fig fruit and grapes, females dispersed and fed more than males. A diet of grapes alone did not support any fecundity, contributing only to longevity. A diet of figs alone, on the other hand, sustained both longevity and egg production. Bird feces alone supported neither egg production nor longevity. However, when added to a diet of figs, bird feces significantly increased fly fecundity. Throughout most of the day, males aggregated in leks within the inner canopy of the primary host, orange. The arrival here during the warmest hours of the day of receptive females, followed by pair formation, reinforced the lek mating system on host foliage. In the afternoon, females shifted to orange fruit where they suffered from high predation mortality while ovipositing. Soon after, males also shifted to orange fruit, where they attempted matings with non-receptive ovipositing females. Male feeding on fig fruit occurred late in the day, a time when they were least likely to find a mate. Male survival did not differ between the natural diets. Tradeoffs between food consumption, mating success and predator evasion are discussed for each sex and related to fruit fly mating systems.     

Nitrogen and energy requirements of the short-tailed fruit bat (Carollia perspicillata): fruit bats are not nitrogen constrained

 Nitrogen (N) and energy (E) requirements were measured in adult Carollia perspicillata which were fed on four experimental diets. Bats ate 1.3–1.8 times their body mass ⋅ day^-1 and ingested 1339.5–1941.4 kJ ⋅ kg^-0.75 ⋅ day^-1. Despite a rapid transit time, dry matter digestibility and metabolizable E coefficient were high (83.3% and 82.4%, respectively), but true N digestibility was low (67.0%). Mass change was not correlated with E intake, indicating that bats adjusted their metabolic rate to maintain constant mass. Bats were able to maintain constant mass with digestible E intake as low as 1168.7 kJ ⋅ kg^-0.75 ⋅ day^-1 or 58.6 kJ ⋅ . Metabolic fecal N and endogenous urinary N losses were 0.87 mg N ⋅ g^-1 dry matter intake and 172.5 mg N ⋅ kg^-0.75 ⋅ day^-1, respectively, and bats required 442 mg N ⋅ kg^-0.75 ⋅ day^-1 (total nitrogen) or 292.8 mg N ⋅ kg^-0.75 ⋅ day^-1 (truly digestible nitrogen) for N balance. Based on E and N requirements and digestibilities, it was calculated that non-reproductive fruit bats were able to meet their N requirements without resorting to folivory and without over-ingesting energy. It was demonstrated that low metabolic fecal requirements allowed bats to survive on low-N diets. Accepted: 23 June 1996