Foraging by Nightjars Caprimulgus europaeus away from their nesting areas

Radio-tagged Nightjars Caprimulgus europaeus nesting in conifer plantation clearings and on lowland heath in Dorset travelled an average of 3.1 km away from their nesting areas at night to atypical habitats, presumably to feed. Comparison of habitat availability with use showed that Nightjars preferred deciduous or mixed woodland habitats, while they avoided conifer plantations and arable or improved grassland. Absence from the nesting area was recorded on 72 % of bird-nights and birds were least likely to be away during the middle third of the night. The use of atypical habitats may have implications for Nightjar conservation.     

Morphometric analysis and taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) – an integrative approach

We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of species) and all available published data on morphology, karyology, behaviour, host associations and geographic distribution. We demonstrate that the analysis of quantitative characters using MRA plays a major role for the integration of name‐bearing types and thus for the association of taxa with names. Six species are recognized, of which two are new: A. cornis Baur sp.n. and A. quinarius Gokhman & Baur sp.n. For Anisopteromalus calandrae (Howard), a well‐known, cosmopolitan parasitoid of stored‐product pests, we have selected a neotype to foster continuity and stability in the application of this important name. The species was sometimes confused with the related A. quinarius sp.n. , another cosmopolitan species that is frequently encountered in similar environments. We also show that several species originally described or later put under Anisopteromalus actually belong to different genera: Cyrtoptyx camerunus (Risbec) comb.n. ; Meraporus glaber (Szelényi) comb.n. ; Dinarmus schwenkei (Roomi, Khan & Khan) comb.n. Neocatolaccus indicus Ayyar & Mani is confirmed as a junior synonym of Oxysychus sphenopterae (Ferrière) syn.n. and Anisopteromalus calandrae brasiliensis (Domenichini) stat.rev. must be considered as a valid but doubtful taxon. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:BDFE96D3‐D0F4‐4012‐90F5‐9A087F7F5864 .     

Phylogeny of Labidodemas and the Holothuriidae (Holothuroidea: Aspidochirotida) as inferred from morphology

The Holothuriidae is one of the three established families within the large holothuroid order Aspidochirotida. The approximately 185 recognized species of this family are commonly classified in five nominal genera: Actinopyga , Bohadschia , Holothuria , Pearsonothuria and Labidodemas. Maximum parsimony analyses on morphological characters, as inferred from type and nontype material of the five genera, revealed that Labidodemas comprises highly derived species that arose from within the genus Holothuria . The paraphyletic status of the latter, large (148 assumed valid species) and morphologically diverse genus has recently been recognized and is here confirmed and discussed. Nevertheless, we adopt a Darwinian or eclectic classification for Labidodemas , which we retain at generic level within the Holothuriidae. We compare our phylogeny of the Holothuriidae with previous classifications of its genera and subgenera, and make suggestions concerning possible systematic changes.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 103−120.     

Sequential colonization by river periphyton analysed by microscopy and molecular fingerprinting

1. An artificial glass substratum was incubated in the River Danube for a period of 28 days in order to detect the sequential colonization of microorganisms.
2. Light and fluorescent microscopy showed that microalgae and the picoalgal fraction on the slides increased rapidly over the first 2 weeks of colonization. Diatoms were numerically the most abundant component of the periphyton and their species richness and diversity increased rapidly in the early phase of colonization whereas diversity subsequently increased moderately.
3. Evenness of the diatom community was initially high, lower in the intermediate phase and again higher later on. Succession involving early, intermediate and late colonizer species was observed. Community composition during the first 5 days of colonization was very different from later stages whereas there were only minor changes subsequently.
4. Molecular community analysis by means of terminal restriction fragment length polymorphism analysis of PCR amplified 16S rRNA and 18S rRNA genes pointed to even larger differences between the composition of samples obtained early and late in the period.
5. The number of 18S rRNA and 16S rRNA terminal restriction fragments (T-RF-s) was variable over the colonization period and the fragment patterns of both the bacterial and eukaryotic portion of the microbial community were variable, with most T-RF-s unique to a single sample, suggesting a wide diversity and dynamic properties of periphytic organisms.     

Carotenoid pigments in male American goldfinches: what is the optimal biochemical strategy for becoming colourful?

Studies of brilliant carotenoid‐based coloration in birds have traditionally centred on the role that these colours play in attracting mates. More recently, biologists have begun to take a biochemical approach to understanding the types of pigments found in feathers and how these relate to the expression of ornamental coloration. Nevertheless, surprisingly few studies have assessed the types and amounts of carotenoids present in the diet or blood of animals in relation to season, sex, condition or sexually attractive colour traits, particularly for wild birds. It is conceivable not only that the total concentration of pigments available is an important predictor of sexual attractiveness and mate quality, but also that specific pigments vary among individuals and play more important physiological and pigmenting roles than others. We investigated the carotenoid content of blood and feathers in wild‐caught, yellow‐pigmented male American goldfinches (Carduelis tristis) throughout the year to determine the optimal biochemical strategy for becoming colourful. We found that birds acquired two main yellow hydroxycarotenoids (lutein and zeaxanthin) from the diet during both moulting and non‐moulting periods. Blood concentrations of both pigments changed significantly over time, with moulting birds accumulating higher levels of both lutein and zeaxanthin, but proportionally more zeaxanthin, than non‐moulting birds. Moulting birds that acquired more lutein and more zeaxanthin in blood deposited a higher concentration of carotenoid pigments (canary xanthophylls A and B) into plumage and acquired more colourful feathers. In sum, these results indicate that (a) the types of dietary carotenoids available across seasons do not change in American goldfinches, (b) seasonal fluctuations in plasma‐carotenoid signatures may result from differences in dietary access or pigment processing, and (c) the best biochemical strategy for becoming a colourful, wild male goldfinch is to accumulate as many dietary/blood pigments as possible during moult. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83 , 273–280.     

Epigenetic regulation of trophic morphology through feeding behaviour in Arctic charr, Salvelinus alpinus

Several models of speciation suggest that in species that are phenotypically plastic, selection can act on phenotypic variation that is environmentally induced in the earliest stages of divergence. One trait that could be subject to this process is foraging behaviour, where discrete foraging strategies are common. One species which is highly plastic in the expression of phenotype, the Arctic charr, Salvelinus alpinus (L.), is characterized by discrete variation in the anatomy of the head and mouthparts. These traits have been shown to have a functional significance, but the expression of which is thought to be at least partly phenotypically plastic. Here we test the hypothesis that foraging behaviour may regulate the anatomy of the head and mouthparts in Arctic charr. In a dyad experiment, size‐matched pairs of fish from a mixed family group were fed a diet of either Mysis (a hard‐bodied shrimp) or Chironomid larvae. Nine morphometric measures of head dimensions that describe wild trophic morphs were measured at the start of the experiment and 24 weeks later. Principal component scores of size‐corrected morphometric measures showed highly significant differences between fish exposed to the two diets. Univariate ANOVA analysis of the head morphometric variables showed that fish fed on Chironomids developed longer, wider jaws, longer heads and a larger eye for a given body length than did those fish fed upon Mysis. We conclude that foraging anatomy in Arctic charr is phenotypically plastic and that variation in foraging behaviour that results in feeding specialization in the wild could induce variation in head anatomy. This in turn could reinforce foraging specialization. Very rapid epigenetic divergence into distinct feeding morphs (as demonstrated here) would allow selection to act at more than one mode and thus could promote rapid evolutionary divergence, initially prior to genetic segregation, in species which are highly plastic. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78 , 43–49.     

The impact of salinity exposure on survival and temperature tolerance of the Antarctic collembolan Cryptopygus antarcticus

The collembolan Cryptopygus antarcticus Willem is potentially exposed to habitat salinities equal to (or greater than) sea water, as a result of sea spray, drying of littoral habitats, dispersal or temporary entrapment on the surface of sea water, or exposure to localized salt deposits from dense vertebrate populations on terrestrial habitats. To test the impact of this exposure on C. antarcticus, the tolerance of the collembolan to being placed on the surface of sea water and solutions of higher salt concentrations is investigated. The effects of acclimation to exposure to liquids of different salinities [44, 100 and 200 parts per thousand (ppt) sea salt] on cold and heat tolerance, as well as thermal activity thresholds, are also explored. Cryptopygus antarcticus shows > 75% survival after 10 days of exposure to both sea water and 100‐ppt salt, whereas it exhibits significantly lower survival after 5 days (60% survival) and 10 days (40%) of exposure to a 200‐ppt solution. Body water content also decreases after exposure to all salinities, and particularly to the 200‐ppt solution, in which > 50% of body water is lost after 10 days. Acclimation results in greater cold tolerance, although heat tolerance at 33, 35 and 37 °C is either unaltered or reduced. The thermal activity thresholds of C. antarcticus at both high and low temperatures are also negatively affected by saline exposure. The data demonstrate the capacity of C. antarcticus to tolerate periods of exposure to saline conditions, and also show that this exposure can enhance cross‐tolerance to low temperatures. The present study also demonstrates that salinity‐associated stress at moderately low and high temperatures narrows the thermal range of activity, thus reducing the ability of collembolans to forage, develop and reproduce. © 2013 The Royal Entomological Society     

Adaptation in the skulls and cranial muscles of South American characinoid fish

The skulls and cranial muscles of the primitive characins Creatochanes and Brycon are described. Other Characinoidei, which have been selected to illustrate the remarkable adaptive radiation of the suborder, are compared with them in detail. They are: Myleus , a deep-bodied herbivore specialized for biting pieces from plants; Serrasalmus , the piranha, a predator which bites pieces of flesh from large prey; Pyrrhulina , a surface feeder; Leporinus , a herbivore with jaws and teeth suited for nibbling rather than biting; Hoplias , a long-jawed predator; and Anisitsia , a detritus feeder which is convergent with the grey mullets.