El Niño,grazers and fisheries interact to greatly elevate extinction risk for Galapagos marine species

Comparisons between historical and recent ecological datasets indicate that shallow reef habitats across the central Galapagos Archipelago underwent major transformation at the time of the severe 1982/1983 El Niño warming event. Heavily grazed reefs with crustose coralline algae (‘urchin barrens’) replaced former macroalgal and coral habitats, resulting in large local and regional declines in biodiversity. Following recent threat assessment workshops, a total of five mammals, six birds, five reptiles, six fishes, one echinoderm, seven corals, six brown algae and nine red algae reported from coastal environments in Galapagos are now recognized as globally threatened. The 2008 International Union for the Conservation of Nature (IUCN) Red List includes 43 of these species, while two additional species (Galapagos damsel Azurina eupalama and 24‐rayed sunstar Heliaster solaris) not seen for > 25 years also fulfil IUCN threatened species criteria. Two endemic species (Galapagos stringweed Bifurcaria galapagensis and the damselfish A. eupalama) are now regarded as probably extinct, while an additional six macroalgal species (Dictyota galapagensis, Spatoglossum schmittii, Desmarestia tropica, Phycodrina elegans, Gracilaria skottsbergii and Galaxaura barbata) and the seastar H. solaris are possibly extinct. The removal of large lobster and fish predators by artisanal fishing probably magnified impacts of the 1982/1983 El Niño through a cascade of indirect effects involving population expansion of grazing sea urchins. Marine protected areas with adequate enforcement are predicted to ameliorate but not eliminate ecosystem impacts caused by increasing thermal anomalies associated with El Niño and global climate change.     

Systematic revision of the genus Psithyristria Stål (Hemiptera: Cicadidae) with seven new species and a molecular phylogeny of the genus and higher taxa

The cicada genus Psithyristria Stål (Hemiptera: Cicadidae), endemic to Luzon, the Philippines, is reviewed, and its higher taxonomic affiliations are determined using morphology and molecular phylogenetics. Seven new Psithyristria species, P. grandis, sp.n. , P. albiterminalis, sp.n. , P. incredibilis, sp.n. , P. paraspecularis, sp.n. , P. peculiaris, sp.n. , P. moderabilis, sp.n. and P. genesis, sp.n. , are described. A key to the 12 known species is provided. The molecular phylogenetic analyses of Psithyristria and putatively related taxa showed some unexpected generic relationships, leading to changes in higher taxonomic placement for a number of Asian cicada genera. Psithyristria falls within the tribe Cicadini Latreille, 1802, and the tribe Psithyristriini Distant, 1905 syn.n. is therefore synonymized with Cicadini. The subtribe Psithyristriina Distant, 1905 stat.n. is recognized within Cicadini and defined for the genera Psithyristria, transferred from Psithyristriini, and Basa Distant, Pomponia Stål and Semia Matsumura, transferred from Cicadina, synonymizing Pomponiina Kato, 1932 syn.n. with Psithyristriina. The Cicadini subtribe Leptopsaltriina Moulton, 1923 is redefined to include the genera Terpnosia Distant, Euterpnosia Matsumura, Leptosemia Matsumura, Neocicada Kato, Puranoides Moulton, Leptopsaltria Stål, Tanna Distant, Purana Distant, Formosemia Matsumura, Maua Distant, Nabalua Moulton, Taiwanosemia Matsumura, Gudaba Distant and Calcagninus Distant, synonymizing Terpnosiina Kato, 1932 syn.n. The tribe Cicadatrini Distant, 1905 is recognized and redefined to include the genera Cicadatra Kolenati, Psalmocharias Kirkaldy, Mogannia Amyot & Audinet‐Serville, Nipponosemia Kato and Emathia Stål, synonymizing Moganniini Distant, 1905 syn.n. The nine Psithyristria species included in the molecular analyses have an uncorrected mitochondrial genetic distance of 2–9%, and most species appear to be related through a single radiation event that occurred approximately 5–10 Ma. No phylogenetic structure was found in two unusually divergent characters, the forewing venation and the shape of the uncal lobes. Psithyristria is found in the northern Luzon mountains and is closely related to Semia of Taiwan and eastern China, Pomponia of east Asia and the Indonesian/Malaysian islands, and probably most closely to Basa of India. Psithyristria may be a cicadid example of a small number of Philippine organisms that trace their ancestry directly back to the temperate Asian mainland, rather than through the island chains to the south of the country.     

Glacial refugia in a maritime temperate climate: Cicada (Kikihia subalpina) mtDNA phylogeography in New Zealand

Understanding the biological significance of Pleistocene glaciations requires knowledge of the nature and extent of habitat refugia during glacial maxima. An opportunity to examine evidence of glacial forest refugia in a maritime, Southern Hemisphere setting is found in New Zealand, where the extent of Pleistocene forests remains controversial. We used the mitochondrial phylogeography of a forest-edge cicada ( Kikihia subalpina ) to test the hypothesis that populations of this species survived throughout South Island during the Last Glacial Maximum. We also compared mitochondrial DNA phylogeographic patterns with male song patterns that suggest allopatric divergence across Cook Strait. Cytochrome oxidase I and II sequences were analyzed using network analysis, maximum-likelihood phylogenetic estimation, Bayesian dating and Bayesian skyline plots. K. subalpina haplotypes from North Island and South Island form monophyletic clades that are concordant with song patterns. Song divergence corresponds to approximately 2% genetic divergence, and Bayesian dating suggests that the North Island and South Island population-lineages became isolated around 761 000 years bp . Almost all South Island genetic variation is found in the north of the island, consistent with refugia in Marlborough Sounds, central Nelson and northwest Nelson. All central and southern South Island and Stewart Island haplotypes are extremely similar to northern South Island haplotypes, a 'northern richness/southern purity' pattern that mirrors genetic patterns observed in many Northern Hemisphere taxa. Proposed southern South Island forest habitat fragments may have been too small to sustain populations of K. subalpina , and/or they may have harboured ecological communities with no modern-day analogues.     

High light decreases xylem contribution to fruit growth in tomato

Recently, contradicting evidence has been reported on the contribution of xylem and phloem influx into tomato fruits, urging the need for a better understanding of the mechanisms involved in fruit growth. So far, little research has been performed on quantifying the effect of light intensity on the different contributors to the fruit water balance. However, as light intensity affects both transpiration and photosynthesis, it might be expected to induce important changes in the fruit water balance. In this study, tomato plants (Solanum lycopersicum L.) were grown in light and shade conditions and the fruit water balance was studied by measuring fruit growth of girdled and intact fruits with linear variable displacement transducers combined with a model‐based approach. Results indicated that the relative xylem contribution significantly increased when shading lowered light intensity. This resulted from both a higher xylem influx and a lower phloem influx during the daytime. Plants from the shade treatment were able to maintain a stronger gradient in total water potential between stem and fruits during daytime, thereby promoting xylem influx. It appeared that the xylem pathway was still functional at 35 days after anthesis and that relative xylem contribution was strongly affected by environmental conditions.     

Patterns and Mechanisms for Age-dependent Reproduction and Survival in Birds

SYNOPSIS. The majority of bird species exhibit age-dependentsurvival and reproduction. In almost all cases, first time breedersor young individuals perform at a lower and slower rate thanolder individuals. This review highlights the importance ofage-dependent effects and urges further study of the proximateand ultimate mechanisms involved. Age effects show substantivevariation across life history stage, breeding season, year,cohort, habitat types and environmental conditions both withinand across taxons. In some populations or years, age effectsdisappear. Despite the variable patterns, age effects show amazingpersistence in a variety of extreme ecological and environmentalconditions. Experimental manipulations of food, predation pressureand breeding experience do not usually remove age effects. Age-dependenteffects may be maintained or accumulate through the breedingseason and profoundly influence fitness, or they may be washedout or reversed by events later in the breeding season. Recently,we have amassed substantive information about the patterns ofvariation in age-dependent reproduction and survival among individuals,but we have made little progress toward understanding the proximatemechanisms responsible for this variation. Proximate and ultimateprocesses are inextricably linked, and thus the study of age-dependenceis highly relevant to the further development of life historytheory. Studies of age-dependent performance have general relevanceto population management and conservation issues as age sub-structuringmay contribute substantially to annual or inter-populationalvariation in reproductive success.     

Ontogeny and life-history strategy of Barycrinus (Crinoidea, Mississippian)

Discovery of an encrusting juvenile holdfast assigned to the Mississippian crinoid Barycrinus demonstrates that this stalked crinoid had a complex life history. The free-swimming larva settled to become a hard substratum encrusting juvenile, which broke free to become a free-living adult rooted into an unconsolidated substratum. Furthermore, additional small, encrusting holdfast types suggest that this was a common life-history strategy among Mississippian crinoids and, perhaps, blastoids.     

On the use of DNA sequences for determining the species limits of a polymorphic new species in the stink bug genus Halys (Heteroptera: Pentatomidae) from Pakistan

Abstract.  We describe a new species of Halys Fabricius (Pentatomidae: Pentatominae: Halyini) based on morphological and DNA sequence data, and demonstrate the value of DNA sequences for taxonomic problems that are difficult to resolve on the basis of morphology alone. Halys sindillus Memon, Meier & Manan, sp.n. varies with regard to characters that are usually constant within the genus (spermathecal bulb of females; blade of male clasper; ratio between the second and third antennomeres; length of labium). The surprising levels of variation raised the question as to how many species were represented in three series of specimens from Pakistan. Because the morphological variability was largely continuous, we hypothesized the presence of one new species, and confirm this result here using sequence data from two mitochondrial markers. The data reveal very little molecular variation within the newly described species (COI: 730 bp: 0–0.16%; COI/tRNA_Leu/COII: 563 bp: 0–0.36%), that is, morphology and DNA sequences show very different patterns of variability. The new species is compared with the closely related Halys sulcatus (Thunberg) whose sequences are distinctly different and whose spermathecal bulbs are largely invariable (I: 2.87–3.28%; II: 2.13–2.49%). We discuss the shortcomings of mitochondrial data in taxonomy and compare the genetic distances in Halys with frequency distributions of intra- and interspecific distances obtained for all 878 Hemiptera COI sequences in GenBank. We conclude that the observed distances for Halys are consistent with our taxonomic conclusions, thus demonstrating the usefulness of DNA sequences for Halys taxonomy. However, the observed overlap between intra- and interspecific sequence variability in Hemiptera is so wide that it questions the feasibility of approaches to taxonomy based predominantly on DNA sequences (e.g. DNA taxonomy, DNA barcoding).     

Response of Brown Treesnakes to Reduction of Their Rodent Prey

ABSTRACT Trapping brown treesnakes (Boiga irregularis; BTS) with live-mouse (Mus domesticus) lures is the principal control technique for this invasive species on Guam. Lure-based trapping is also used on other islands as a precaution against undetected arrivals and in response to verified BTS sightings. However, the effectiveness of lure-based trapping on other islands is questionable, as it has yielded no BTS despite other evidence of their presence. Some evidence suggests that high rodent numbers may interfere with BTS control. To test the relationship between rodent abundance and snake trappability, we conducted a controlled, replicated field experiment incorporating a rodenticide treatment during a BTS mark-recapture study. Using open population modeling in Program MARK, we estimated BTS apparent survival and recapture probabilities. Rodent reduction increased BTS recapture probabilities by 52–65% in 2002 and 22–36% in 2003, and it decreased apparent survival by < 1% both years. This appears to be the first published instance of manipulating wild prey to influence snake behavior. Rodent reduction may enhance detection and control of BTS with traps on Guam and other islands. It may also amplify the effectiveness of oral toxicants against BTS.     

Wind Energy Development and Wildlife Conservation: Challenges and Opportunities

ABSTRACT Wind energy development represents significant challenges and opportunities in contemporary wildlife management. Such challenges include the large size and extensive placement of turbines that may represent potential hazards to birds and bats. However, the associated infrastructure required to support an array of turbines—such as roads and transmission lines—represents an even larger potential threat to wildlife than the turbines themselves because such infrastructure can result in extensive habitat fragmentation and can provide avenues for invasion by exotic species. There are numerous conceptual research opportunities that pertain to issues such as identifying the best and worst placement of sites for turbines that will minimize impacts on birds and bats. Unfortunately, to date very little research of this type has appeared in the peer-reviewed scientific literature; much of it exists in the form of unpublished reports and other forms of gray literature. In this paper, we summarize what is known about the potential impacts of wind farms on wildlife and identify a 3-part hierarchical approach to use the scientific method to assess these impacts. The Lower Gulf Coast (LGC) of Texas, USA, is a region currently identified as having a potentially negative impact on migratory birds and bats, with respect to wind farm development. This area is also a region of vast importance to wildlife from the standpoint of native diversity, nature tourism, and opportunities for recreational hunting. We thus use some of the emergent issues related to wind farm development in the LGC—such as siting turbines on cropland sites as opposed to on native rangelands—to illustrate the kinds of challenges and opportunities that wildlife managers must face as we balance our demand for sustainable energy with the need to conserve and sustain bird migration routes and corridors, native vertebrates, and the habitats that support them.     

Ecological Studies of Seaweeds in McMurdo Sound, Antarctica

Three species of benthic marine macroalgae comprise the chiefcomponents of the seaweed flora of McMurdo Sound, Antarctica.Quantitative studies at Cape Evans demonstrate a depth-relateddistribution pattern, with Iridaea cordata (Turner) Bory inshallow water, Phyllophora antarctica A. and E. S. Gepp abundantand fertile at intermediate depths, and Leptophytum coulmanicum(Foslie) Adey dominant below 20 m. The vertical distributionof species is correlated with irradiance levels. At sites withthinner annual sea ice and less snow accumulation (e.g., CapeEvans, Cape Royds, and Granite Harbor), vertical distributionsare shifted downward relative to those at sites that remaincovered most of the year with thick or snow-covered fast ice(e.g., Cape Armitage and New Harbor). Disturbance caused byice scour and anchor ice probably determines the upper limitof algal distribution; herbivory is apparently absent. There is a disproportionate representation of cystocarpic femalegametophytes in populations of I. cordata and P. antarctica.Perennation via persistent basal crusts and apogamic recyclingof gametophytes are suggested as factors structuring phase distribution.Although the overall size of I. cordata blades is greater (andcystocarpic plants more abundant) at Cape Royds than at CapeEvans, cystocarpic blades are similar in minimum size at bothsites, indicating a threshhold size or age for the onset ofreproduction in this species.