An analysis of Bat Hawk Macheiramphus alcinus diet in the Melaky Region of lowland western Madagascar

We present information on the prey taken by the Bat Hawk Macheiramphus alcinus in two different areas of lowland western central Madagascar. These are the first dietary data from Madagascar for this widespread Old World species. The recovered remains were almost exclusively of bats and birds, with a few examples of reptiles and insects. In total, 178 pellets were analysed. On the basis of minimum number of individuals and biomass, bats accounted for 58.3% and 30.3%, respectively, and birds 36.1% and 69.7%, respectively. Amongst the nine species of bats recovered from the pellets, four were represented by multiple individuals, particularly taxa belonging to the families Molossidae and Vespertilionidae that fly in open areas, and for the 11 species of identified birds, all were represented by a single individual. These patterns are interpreted as a specialisation of feeding on bats during a narrow window of time at dusk, as they leave day roost sites, and then using birds in a more general manner to fill in nutritional needs.     

Convergent evolution of strigiform and caprimulgiform dark-activity is supported by phylogenetic analysis using the arylalkylamine N-acetyltransferase (Aanat) gene

Alternative hypotheses propose the sister order of owls (Strigiformes) to be either day-active raptors (Falconiformes) or dark-active nightjars and allies (Caprimulgiformes). In an effort to identify molecular characters distinguishing between these hypotheses we examined a gene, arylalkylamine N-acetyltransferase (Aanat), potentially associated with the evolution of avian dark-activity. Partial Aanat coding sequences, and two introns, were obtained from the genomic DNA of 16 species: Strigiformes (four species), Falconiformes (four species), Caprimulgiformes (five species), with outgroups: Ciconiiformes (one species), Passeriformes (one species), and Apterygiformes (one species). Phylogenetic trees derived from aligned, evolutionarily conserved Aanat regions did not consistently recover clades corresponding to orders Strigiformes and Falconiformes but did place a caprimulgiform clade more distant from the strigiform and falconiform species than the latter two groups are to each other. This finding was supported by spectral analysis. The taxonomic distribution of seven intronic indels is consistent with the Aanat derived phylogenetic trees and supports conventional family-level groupings within both Strigiformes and Caprimulgiformes. The phylogenetic analyses also indicate that Caprimulgiformes is a polyphyletic grouping. In conclusion the data support, but do not conclusively prove, the proposal that Falconiformes is the sister order to Strigiformes and therefore, that the dark-activity characteristic of Strigiformes and Caprimulgiformes arose by convergent evolution.     

Evolution of the climatic niche in scaly tree ferns (Cyatheaceae,Polypodiopsida)

Although climatic niche conservatism has been assumed by a large number of studies focused on climatic niche evolution, there are examples of climatic niche diversification and adaptation to changing climates. In this article, we reconstruct a climatic niche of scaly tree ferns (Cyatheaceae) using a rigorous analytical procedure which combines climatic niche modelling with reconstruction of continuous characters given a phylogenetic hypothesis. To estimate the limits to climatic niches of species, we used climate envelope modelling and ordination. Ancestral climatic niches of species were reconstructed by maximum likelihood and least‐squares analyses. We observed a trend towards niche conservatism with occasional events of niche transformations in scaly tree ferns. We discuss the implications of our study with respect to the potential and limitations for applications of niche modelling to evolutionary studies. We suggest that future studies of evolution of climatic niches could be considerably improved by employing approaches enabling reconstruction of continuous response to climatic gradients. Further progress may also be achieved by exploring models of character evolution other than the Brownian motion model. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165 , 1–19.     

海南变色树蜥个体发育中形态和食性的变化

研究变色树蜥（Calotes versicolor)头,尾大小和食性在个体发育过程中的变化,以及头,尾大小两性异性的个体发生,成体体长（SVL）无显著的两性差异,两性异形主要表现为雄性个体有较大的头部（头长和头宽）和尾部。头,尾大小的两性异形在初生幼体就已存在,并随个体发育的进行变得更加显著。不同年龄组两性个体头长以及雌体头宽随SVL呈同速增长;雄性头宽随SVL呈异速增长,表现为雄性头宽的增长速率在个体发育过程中逐渐增大。头,尾部的相对大小在个体发育过程中有显著的变化,初生幼体头部相对较大,尾部相对较小,这种形态特征是胚胎优先保证生态学意义更为显著的部分（如头部）生长的结果,有利于初生幼体的早期生存和生长,不同性别和年龄组的变色树蜥摄入食物的种类及各种食物在摄入食物中所的比例有一定程度的差别,因而食物生态位宽度和重叠度有一定程度的差别,然而没有直接的证据表明头部大小的两性异形能导致两性食物生态位的明显分离。     

Evidence for ram suspension feeding by the piscivore, Seriola dumerili (Carangidae)

Synopsis We have quantitatively analyzed a videotape of Seriola dumerili (Carangidae) displaying ram suspension-feeding behavior and ram ventilation in the field. This is the first report of facultative suspension feeding by a piscivorous carangid. The intraoral morphology of S. dumerili is not typical of ram suspension-feeding fishes in that closely-spaced, long gill rakers are lacking. While the mechanism of particle retention is not known for any ram suspension-feeding fish species, scanning electron microscopy revealed denticles on the branchial surfaces of S. dumerili that could play a role in particle entrapment.     

Isolation and characterization of 10 microsatellite DNA markers in the oriental honey buzzard (Pernis ptilorhyncus)

We designed 10 new microsatellite markers for the oriental honey buzzard (Pernis ptilorhyncus) and tested them on 44 individuals. The number of alleles ranged from two to 12 with an average of five, while the observed heterozygosity ranged from 0.273 to 1.0. Linkage disequilibrium was not found. These markers are being used in a study of the ecology of this species in Taiwan. We also tested their utility on eight other raptor species.     

Isolation of microsatellite loci from the common buzzard,Buteo buteo (Aves: Accipitridae)

We isolated 56 common buzzard (Buteo buteo) microsatellite loci from (AC)_n‐ and (AAAG)_n‐enriched genomic libraries. Eleven loci were tested on 90 individuals from Eastern Westphalia in Germany, yielding two to 17 alleles per locus (average 5.7) and expected heterozygosities ranging from 0.11 to 0.93 (average 0.53). These highly variable microsatellite markers provide a powerful means for investigating population genetic diversity in the common buzzard, a little‐understood aspect of this widespread species.     

Morphology and feeding in tadpoles of Ceratophrys cranwelli (Anura: Leptodactylidae)

This paper provides data on the skeleton, musculature, buccal apparatus, buccopharyngeal cavity and diet of Ceratophrys cranwelli tadpoles, and attempts to contribute to the knowledge of relations between morphology and ecology in anuran larvae. Both in morphological characters and feeding habits, these tadpoles are very similar to other species within the genus. They possess many of the structural features usually found in predaceous tadpoles: strong, keratinized jaw sheaths and keratodonts, reduced buccal papillation, high values of in‐lever arm proportion and buccal floor area, well‐developed ceratohyals, and hypertrophied jaw muscles. Food sources consist of other tadpoles, microcrustaceans, larvae of insects, plant fragments, as well as rotifers and microalgae. As facultative carnivores, they are likely to play an important role in regulating the aquatic communities of the ephemeral ponds where they develop.     

Ultrastructure and Comparative Morphology of Mouth-part Sensilla in Ground Beetle Larvae (Insecta, Coleoptera, Carabidae)

Labial and maxillary palps in 22 species of ground beetle larvae revealed the presence of four different types of sensilla: sensilla digitiformia, sensilla campaniformia, sensilla basiconica and sensilla chaetica. Using transmission electron microscopy techniques, the role of most of them was defined: sensilla campaniformia and sensilla chaetica are mechanoreceptors; while sensilla basiconica are chemoreceptors. Sensilla digitiformia can be both mechanoreceptors and chemoreceptors, though hygroreception may also be postulated on the basis of their abundance on the mouthparts of some hygrophilous species that depend on damp or wet patchy biotopes/seasons. The number and location of the sensory structures has been found to vary among the investigated taxa. The differences are related to the larval behavioural types, and are an adaptive response to different lifestyles, feeding habits and use of space.     

Gonad Morphology, Colony Demography and Evidence for Hermaphroditism in Gobiodon Okinawae (Teleostei, Gobiidae)

Gobiodon okinawae is a small-sized, obligate coral-dwelling goby. The majority of species in this Indo-Pacific genus exhibit an obligatory association with branching live corals and a number have been shown to be bi-directional hermaphrodites in which adults have the capacity to shift between male and female function. Gonadal histology in G. okinawae demonstrated that all individuals had either an ovotestis or an ovary. Some females had an ovary with vitellogenic oocytes, indicating adult female function. Hermaphrodites having an ovotestis were either functionally male, as evidenced by the presence of spermatozoa or, in one instance, functionally female so judged by the presence of vitellogenic oocytes. No individuals were found to have mature gametes of both sexes, although a number of hermaphrodites had an inactive ovotestis with no mature gametes of either sex. Based on size ranges for fish having different gonad morphologies, individuals in this species appear to develop first as a female. They then either mature and function solely as a female, or become hermaphroditic. Findings based on experimentally maintained individuals suggests that adult hermaphrodites can shift sexual function in either direction. Accessory gonadal structures (AGS) were found in both sexes. These consisted of two fully differentiated pairs of lobes, each compartmentalized internally by lumina and containing PAS+secretions. The secretions of the dorsally located AGS were colloidal while those of the ventrally located AGS were fibrillar and granular in nature. The presence of two sets of AGS among males appears to be characteristic of both Gobiodon and its putative sister genus, Paragobiodon. However, the occurrence of fully developed AGS in both females and males has not previously been reported and may be unique to G. okinawae.     

Evidence for an endogenous circadian rhythm of feeding in the trout (Oncorhynchus mykiss)

Abstract

The possible endogenous circadian rhythm in the feeding activity of rainbow trout (Oncorhynchus mykiss) was investigated using individual fish previously trained for self‐feeding. Under LD 12:12 conditions, the fish showed a diurnal behaviour, in many cases with a feeding rhythm with two main peaks of food demand at dawn and dusk, with an 8h interval of low feeding activity, and the actograms showed an expected 24 h rhythm. Fish kept under constant conditions (L : L, 15°±0.5°C), showed free‐running feeding activity for about 12 days. Food demands were concentrated at dawn, with a periodogram of 25.3 hour, under continuous environmental conditions. Results showed evidence for the endogenous origin of the circadian rhythm of feeding in this species.     

Variation in Prey-resource Utilization and Oral Jaw Gape Between two Populations of Largemouth Bass, Micropterus Salmoides

Ontogenetic changes in diet and jaw gape were compared between two indigenous populations of largemouth bass, Micropterus salmoides, to test the hypothesis that ecomorphology varies among broadly distributed fish populations. Two hundred seventy-two temperate (southwestern Michigan) M. salmoides and 265 subtropical (east-central Florida) conspecifics were analyzed for food habits and oral jaw gape height and width. Percent volumetric contributions of four functional prey categories (plankton, insect, crustacean, and fish) were compared among fish-size classes to determine if interval-specific differences in prey consumption existed between populations. Subtropical M. salmoides shifted from feeding on plankton and macroinvertebrates to fish by 20mm standard length (SL); and stopped consuming plankton by 29mm SL. Temperate largemouth bass did not become piscivorous until 37mm SL and continued utilizing plankton up to 69mm SL. Following the onset of piscivory, 100–260mm SL subtropical largemouth bass began utilizing more crustaceans than fish. In contrast, temperate M. salmoides consistently fed on fish following the onset of piscivory. Variations in food habits were associated with differences in gape size between temperate and subtropical populations. Temperate largemouth bass had significantly larger gape height (ANCOVA: F = 103.4; df = 1,536; p < 0.001) and width (ANCOVA: F = 47.0; df = 1,536; p < 0.001) than subtropical bass. Although piscivory is a well-known feature of M. salmoides, the ontogeny of piscivory may vary between populations. We hypothesize that interpopulation differences in jaw gape may be related to variations in prey-resource utilization.     

The relationship between introduced European Starlings and the reproductive activities of Mountain Bluebirds and Tree Swallows in British Columbia,Canada

The European Starling Sturnus vulgaris is an introduced species in North America and is an aggressive competitor for tree cavity nest‐sites. Starlings are commonly considered to influence nest‐site selection and reproductive success of native cavity‐nesting species negatively. We examined the relationship between Starling nest density and the fecundity of two native secondary cavity‐using passerines, Mountain Bluebird Sialia currucoides and Tree Swallow Tachycineta bicolor. We monitored a total of 622 nests (approximately equal numbers for each of the three species) in woodpecker‐excavated and naturally occurring cavities in 29 small forest groves in central British Columbia, Canada, between 2000 and 2009. The dimensions of cavities used and the timing of nest initiation overlapped for all species, although Starlings initiated clutches earliest. Mixed‐effects models were used to assess whether nest abundance, clutch size or nest success were affected directly by Starling nest abundance, or indirectly via a shift in cavity selection or timing of breeding. Starlings and Mountain Bluebirds showed inverse trends in nest abundance. Mountain Bluebird clutch sizes were smaller if they were initiated later in the breeding season. There was weak evidence that Tree Swallow clutch size decreased with cavity depth when Starling nests were abundant, and increased with cavity depth where there were few Starling nests. We conclude that despite the aggressive nature of this exotic cavity‐nester, the influence of Starlings on native secondary cavity‐nesting passerines is modest where cavities are abundant.     

Mother-Infant Communication in the Lesser Spear-nosed Bat Phyllostomus discolor (Chiroptera,Phyllostomidae) — Evidence for Acoustic Learning

When mother-offspring couples of Phyllostomus discolor (lesser spear-nosed bat) are reunited after separation, an intensive exchange of infants' isolation calls and mothers' directive calls can be observed. The directive calls of each mother show a distinctive frequency-time structure, which appears to represent her individual vocal signature. During ontogenesis the isolation calls of the young change gradually, adapting increasingly to the mother's call type. A comparison of calls of separated pups at different ages with their mothers' directives demonstrated the individually distinct call characteristics of the mother also to be characteristic of the isolation calls of her young by about 50 days of age. This suggests that acoustic signals may be learned in Phyllostomus discolor.     

Development and multiplex PCR amplification of novel microsatellite markers in the White‐tailed Sea Eagle,Haliaeetus albicilla (Aves: Falconiformes,Accipitridae)

We report the development of 14 novel polymorphic microsatellite markers cloned from the White‐tailed Sea Eagle, Haliaeetus albicilla, a formerly threatened raptor that has received much conservation attention throughout Eurasia. We also present a protocol for multiplex polymerase chain reaction (PCR) amplification of the loci. Among 40 unrelated H. albicilla individuals from southern Sweden, the markers produced two to eight alleles per locus, and average observed and expected heterozygosities were 0.463 and 0.468, respectively. We further present five microsatellite markers that appeared monomorphic in H. albicilla, but which may be of interest for use in other raptor species.     

Evolution of the realized climatic niche in the genus Arabidopsis (Brassicaceae)

The evolution of the realized climatic niche in the genus Arabidopsis was studied using an almost complete phylogenetic tree based on DNA sequences of the ribosomal internal transcribed spacers. The realized climatic niche (climate space) was determined by the intersections of the distribution ranges of the taxa with climate data and is presented in temperature/precipitation diagrams. A positive correlation exists between the climate spaces of the taxa and their range sizes. The diagrams revealed a core climate; that is, a climate space in which all taxa co-exist. This core climate is almost identical to the most parsimonious reconstruction of the genus' ancestral climate space and may be considered an ancestral state of these characters. Mapping the evolutionary changes occurring in the realized climatic space on the phylogenetic tree from the core climate proved to be the most parsimonious procedure. The character complex is homoplastic; that is, many parallel evolutionary events have occurred in the subclades. With the exception of A. thaliana, which is sister to the other species of the genus and occupies a very large climate space, the late-diverged taxa of the other subclades experienced great evolutionary changes whereas the realized climate space of the taxa that diverged earlier resembles the core climate. The latter also show some parallel contractions in the climate space. It is hypothesized that the diversification of Arabidopsis may have started from small to midsized ranges in a temperate climate.