The environmental impacts of biomass crops: use by birds of miscanthus in summer and winter in southwestern England

We compared birds in a group of established and well‐managed miscanthus (Miscanthus x giganteus) fields in Somerset and East Devon, southwestern England, with plots of short rotation coppice (SRC) willow, arable crops and grassland in two winters and one summer. Following early spring cutting, 19 miscanthus fields grew taller, initially produced greater cover and were less weedy than SRC. As stubble in May, the miscanthus contained broadly similar species at similar densities to arable and grassland comparison plots. By July, at 2‐m‐tall, miscanthus held higher densities of birds but of fewer species, most of them characteristic of woodland and scrub. SRC, previously identified as being a beneficial crop for many birds, always contained more species and individuals than miscanthus. Throughout each of two winters, 15 miscanthus plots remained unharvested and contained more wood/scrub species such as Blackbirds Turdus merula, tits, Reed Buntings Emberiza schoeniclus and Woodcock Scolopax rusticola than the comparison plots, which held more corvids and Skylarks Alauda arvensis amongst others. Similar overall mean densities of birds in the miscanthus and the comparison plots masked relatively low density variance in miscanthus and very high variance in the comparison plots. Unharvested miscanthus crops grown in place of habitat types supporting flocks of wintering birds would displace these flocks. Miscanthus plantations with open patches attracted more finches and waders in winter. The two previous studies of birds in miscanthus in the UK found more species and more individuals than we did in summer and winter. Both these studies documented high levels of weediness and patchy crop growth. In the context of this previous work our data suggest that bird use of miscanthus in summer and winter is likely to be variable, affected by region, weediness, crop structure and patchiness. While large‐scale cropping of SRC in England is likely to have a positive overall impact on a suite of common farmland and woodland birds, our data suggest that miscanthus in the southwest of England may have an approximately neutral effect. However, some open farmland specialist species may be lost when planting either crop.     

Oldest known Varanus (Squamata: Varanidae) from the Upper Eocene and Lower Oligocene of Egypt: support for an African origin of the genus

Abstract: A large collection of lizard vertebrae from northern Africa represents the oldest unambiguous occurrence of the genus Varanus. The fossils come from late Eocene and early Oligocene freshwater deposits of the Fayum, Egypt, an area noted for many significant primate finds. The recovery and identification of this material indicate that the genus Varanus arose in Africa, before dispersing to Australia and Asia. This dispersal occurred prior to the early to mid‐Miocene, by which time fossil Varanus are known from Australia and Eurasia. Although the dispersal route remains unknown, the lizard material reported here supports the hypothesis that a corridor existed allowing freshwater and terrestrial organisms to cross from Africa to Asia.     

The Role of Minerals in Food Selection in a Black Howler Monkey (Alouatta Pigra) Population in Belize Following a Major Hurricane

As plants may contain low levels of some minerals including sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. In 2001, Hurricane Iris hit the Monkey River Forest in Belize causing substantial damage to the food supply of the black howler monkey population (Alouatta pigra) living there. This included an 18‐month absence in fruit production and a complete loss of figs that are high in calcium. In this article, we describe the post‐hurricane diet of this monkey population and compare the mineral content of food items to each other and to recommendations for non‐human primates [NRC 2003]. We also investigate food selection in relation to potentially limiting minerals. Behavioral data from four groups of howlers (2002–2006) and samples of all ingested food items were collected and a sample of 99 plant from 18 food species was analyzed for mineral content. Unexpectedly, the post‐hurricane diet contained more mature leaves than new leaves despite the availability of new leaves. Leaves contained higher amounts of minerals than reproductive parts and with the exception of Cecropia peltata stems, plant parts were low in sodium. Cecropia peltata is a pioneer species that grows following habitat disturbance thus the ingestion of these stems may be a potential mechanism to avoid sodium deficiency in this damaged forest. Calcium and zinc were found above recommended values in most food items; however, both positively predicted food selection, which may reflect a difference between their abundance and their bioavailability. However, as mature leaves contained more calcium than other plant parts, their high post‐hurricane consumption may also be a response to the absence of figs and the need to find an alternate calcium source. This study highlights how habitat disturbance may affect mineral abundance and the dietary choices of primates. Am. J. Primatol. 74:1054‐1063, 2012. © 2012 Wiley Periodicals, Inc.     

Oral deformities in tadpoles (Ranacatesbeiana) associated with coal ash deposition: effects on grazing ability and growth

1. Tadpoles of the bullfrog ( Rana catesbeiana ) collected in a coal ash deposition basin (contaminated with As, Cd, Cr, Cu, Se and other elements) and a downstream drainage swamp had a reduced number of labial teeth and deformations of labial papillae when compared with tadpoles from reference areas. Tadpoles from the coal ash-affected areas had 90% fewer teeth in anterior tooth row number 2 and 40% fewer teeth in posterior row number 1 than reference animals. In the deposition basins, drainage swamp and reference ponds, respectively, 96.2, 85.1 and 2.9% of tadpoles had oral deformities.
2. Tadpoles with deformities were less able to graze periphyton than were normal tadpoles, when tested in the laboratory. When presented with periphyton as a sole food source, tadpoles with deformed teeth had lower (negative) growth rates than those with normal teeth, which had slightly positive growth rates. When particulate food was also available, tadpoles grew well regardless of deformities.
3. It appears that the morphological deformities associated with this coal ash-polluted environment can have ecological ramifications for the affected organisms by limiting the type of food that can be consumed and the ability to grow when multiple food types are unavailable.     

End-products of behaviour versus behavioural characters: a phylogenetic investigation of pupal cocoon construction and form in some North American black flies (Diptera: Simuliidae)

Cocoon spinning was analysed, using video recording and playback, in eighteen Nearctic black fly species, comparing nine Simulium species, six Eusimulium species, Stegopterna mutata, Cnephia dacotensis and Prosimulium mixtum. Fourteen behavioural characters were revealed that produced twenty-two equally parsimonious trees (CI = 0.93, RI = 0.96). Another tree was constructed on the basis of five characters relating to the cocoon structure (end-product characters). The goal of the study was to determine whether characters relating to behavioural components of black fly cocoon spinning or those based on end-products of the behaviour are superior for revealing phylogenetic relationships. This was accomplished by comparing both data sets to a phylogeny constructed with the use of cytological and morphological characters. If taxa are grouped according to end-products (the cocoons) there are some spurious groupings. The behavioural analysis only required one extra step to duplicate the morphological and cytological tree. In the case of black flies, it is more informative to use characters resulting from the analysis of the cocoon spinning behaviour than cocoon morphology.     

The effect of dispersal ability in winter and summer stoneflies on their genetic differentiation

Abstract.  1. Plecopteran species disperse less than most other aquatic insects. Within stoneflies, members of different families vary in the degree of wing morphology and season of adult emergence.
2. Dispersal limitations were tested to determine if there were increased differences among the nearby, Chagrin and Grand River populations in north-eastern Ohio, by comparing genetic variation within the 16s rRNA region of mitochondrial DNA in two stoneflies. Allocapnia recta emerges in winter and often has rudimentary wings, and Leuctra tenuis emerges in summer with fully developed wings.
3. There was significant genetic variability between the samples of A. recta from two adjacent rivers (FST = 0.20), but not between samples of L. tenuis (FST = 0.07).
4. Distinct clades in A. recta were found to occur within the minimum spanning tree specific to the Chagrin River, which contributed to a significant difference in gene diversity between the two rivers. Haplotypes in L. tenuis appeared randomly distributed between the two rivers; however, nucleotide diversity was significantly less in samples from the Grand River.
5. Shared haplotypes of both species illustrate the inter-connectedness of the Chagrin and Grand River populations, and the lower genetic variability of L. tenuis between the two rivers is indicative of its greater dispersal capability.     

Ecological opportunity and the origin of adaptive radiations

Ecological opportunity – through entry into a new environment, the origin of a key innovation or extinction of antagonists – is widely thought to link ecological population dynamics to evolutionary diversification. The population‐level processes arising from ecological opportunity are well documented under the concept of ecological release. However, there is little consensus as to how these processes promote phenotypic diversification, rapid speciation and adaptive radiation. We propose that ecological opportunity could promote adaptive radiation by generating specific changes to the selective regimes acting on natural populations, both by relaxing effective stabilizing selection and by creating conditions that ultimately generate diversifying selection. We assess theoretical and empirical evidence for these effects of ecological opportunity and review emerging phylogenetic approaches that attempt to detect the signature of ecological opportunity across geological time. Finally, we evaluate the evidence for the evolutionary effects of ecological opportunity in the diversification of Caribbean Anolis lizards. Some of the processes that could link ecological opportunity to adaptive radiation are well documented, but others remain unsupported. We suggest that more study is required to characterize the form of natural selection acting on natural populations and to better describe the relationship between ecological opportunity and speciation rates.     

An apparatus for pulse and pulse-chase experiments with 14CO2 on attached leaves with known, steady-state rates of photosynthesis

Abstract. An apparatus is described to carry out pulse and pulse-chase experiments with ¹⁴CO₂ on intact, attached leaves with known, steady-state rates of photosynthesis under defined conditions of temperature, vapour pressure deficit and photon flux density. Data are presented which show that the pattern of distribution of ¹⁴C between compounds in extracts of such leaves is a true reflection of the pathways of photosynthetic carbon metabolism in the leaf during steady-state photosynthesis.     

Characterization of simple sequence repeat markers derived in silico from Brassica rapa bacterial artificial chromosome sequences and their application in Brassica napus

A collaborative Brassica rapa genome sequencing project is currently in progress to aid the identification of agronomically important traits in Brassica species. As an initial stage, the ends of over 110 000 bacterial artificial chromosome clones were sequenced and mined for simple sequence repeats (SSRs). We present the characterization of 40 of these SSRs and their application in Brassica napus. The markers were screened against six Brassica species and Arabidopsis, and demonstrated reliable amplification, genome specificity, cross‐amplification and significant polymorphism. These SSRs will be useful for genetic analysis of Brassica germplasm.     

The swarming behaviour of the Scottish biting midge, Culicoides impunctatus (Diptera: Ceratopogonidae)

Abstract.

• 1 Swarms of Culicoides impunctatus males were examined in the field in Scotland. Most swarms were close to midge emergence/breeding grounds over a variety of vegetation, some of which clearly acted as swarm markers. Low light (0–1000 lux) and still/humid conditions favoured swarming.
• 2 Swarm size ranged between less than 10 and more than one thousand midges. The modal size was 200 individuals. The smallest swarms were usually columnar in shape and the larger swarms ovoid.
• 3 Midges behaved individually within swarms, moving in an elliptical manner characteristic of other dipterans in swarms.
• 4 Swarms were classified as either ‘persistent’ or ‘transient’ in terms of their shape, size and stability. Wind was the most influential factor in disrupting swarms.
• 5 Swarms were confirmed as mating sites for C.impunctatus.