Longnose leopard lizard (Gambelia wislizenii) home range and habitat use on Cannonball Mesa, Colorado

November 2006.Includes bibliographical references

Thermal conditions predict intraspecific variation in senescence rate in frogs and toads

Variation in temperature is known to influence mortality patterns in ectotherms. Even though a few experimental studies on model organisms have reported a positive relationship between temperature and actuarial senescence (i.e., the increase in mortality risk with age), how variation in climate influences the senescence rate across the range of a species is still poorly understood in free-ranging animals. We filled this knowledge gap by investigating the relationships linking senescence rate, adult lifespan, and climatic conditions using long-term capture-recapture data from multiple amphibian populations. We considered two pairs of related anuran species from the Ranidae (Rana luteiventris and Rana temporaria) and Bufonidae (Anaxyrus boreas and Bufo bufo) families, which diverged more than 100 Mya and are broadly distributed in North America and Europe. Senescence rates were positively associated with mean annual temperature in all species. In addition, lifespan was negatively correlated with mean annual temperature in all species except A. boreas. In both R. luteiventris and A. boreas, mean annual precipitation and human environmental footprint both had negligible effects on senescence rates or lifespans. Overall, our findings demonstrate the critical influence of thermal conditions on mortality patterns across anuran species from temperate regions. In the current context of further global temperature increases predicted by Intergovernmental Panel on Climate Change scenarios, a widespread acceleration of aging in amphibians is expected to occur in the decades to come, which might threaten even more seriously the viability of populations and exacerbate global decline.Peer reviewe

Coastline responses to changing storm patterns

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 33 (2006): L18404, doi:10.1029/2006GL027445.Researchers and coastal managers are pondering how accelerated sea-level rise and possibly intensified storms will affect shorelines. These issues are most often investigated in a cross-shore profile framework, fostering the implicit assumption that coastline responses will be approximately uniform in the alongshore direction. However, experiments with a recently developed numerical model of coastline change on a large spatial domain suggest that the shoreline responses to climate change could be highly variable. As storm and wave climates change, large-scale coastline shapes are likely to shift—causing areas of greatly accelerated coastal erosion to alternate with areas of considerable shoreline accretion. On complex-shaped coastlines, including cuspate-cape and spit coastlines, the alongshore variation in shoreline retreat rates could be an order of magnitude higher than the baseline retreat rate expected from sea-level rise alone.The Andrew W. Mellon Foundation, the National Science Foundation Biocomplexity Program, and the Duke University Center on Global Change supported this work

Crop Updates 2007 - Weeds

This session covers thirty two papers from different authors: 1. ACKNOWLEDGEMENTS, Alexandra Douglas CONVENOR – WEEDS DEPARTMENT OF AGRICULTURE AND FOOD WILD RADISH MANAGEMENT 2. Decimate a wild radish seed bank in five years, Peter Newman, Sally Peltzer, Abul Hashem and Aik Cheam, Department of Agriculture and Food 3. High level of seed-set control in wild radish is achievable, Aik Cheam and Siew Lee,Department of Agriculture and Food 4. Wild radish: Best management practice, Aik Cheam and Siew Lee, Department of Agriculture and Food 5. Control of phenoxy resistant wild radish through the combined effects of wheat competition and phenoxy herbicides, Natalie Maguire and Michael Walsh, WAHRI, School of Plant Biology, University of Western Australia 6.Efficacy of florasulam on chlorsulfuron resistant and susceptible wild radish populations in Western Australia, Michael Walsh1 and Dan Cornally2, 1WAHRI, School of Plant Biology, University of Western Australia, 2Dow Agrosciences Australia 7. Does liming to increase soil pH limit the growth and development of wild radish (Raphanus raphanistrum)Matt Willis and Michael Walsh, WAHRI, School of Plant Biology, University of Western Australia IWM TECHNIQUES AND SEEDBANKS 8. Weed trimming – a potential technique to reduce weed seed set, Glen Riethmuller, Abul Hashem and Shahab Pathan, Department of Agriculture and Food 9. Burn narrow windrows in the wind, Peter Newman1and Michael Walsh2, 1Department of Agriculture and Food, 2Research Fellow, WA Herbicide Resistance Initiative 10. Winning the Weed War with the Weed Seed Wizard! Michael Renton, Sally Peltzer and Art Diggle, Department of Agriculture and Food HERBICIDE RESISTANCE AND GENE FLOW 11. Frequency of herbicide resistance in wild oat (Avena fatua) across the Western Australian wheatbelt, Mechelle Owen and Stephen Powles, WA Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia 12. Pollen mediated gene flow of herbicide resistance can occur over long distances doe annual ryegrass (Lolium rigidum): Results of two years with different meteorological conditions, Roberto Busi, Robert Barrett-Lennard and Stephen B. Powles, Western Australian Herbicide Resistance Initiative, School of Plant Biology – University of Western Australia 13. Doublegee has developed resistance to metsulfuron-methyl within WA wheatbelt, Dr Abul Hashem1and Dr Shahab Pathan2, 1Senior Research Officer, and 2Research Officer, Department Agriculture and Food 14. Another case of glyphosate resistance in annual ryegrass confirmes within Western Australia, Dr Abul Hashem1and Dr Shahab Pathan2, 1Senior Research Officer, and 2Research Officer, Department Agriculture and Food 15. Glyphosate resistance in the northern NSW – implications for Western Australian farming systems, Andrew Storrie, Tamworth Agricultural Institute, NSW Department of Primary Industries ALTERNATIVES TO TRIFLURALIN, KNOCKDOWNS, TANK MIXES AND NOVEL USES 16. Alternative pre-emergent herbicides to trifluralin for annual ryegrass control, Mr David Minkey and Dr Abul Hashem, Department of Agriculture and Food, 17. Evaluation of a new pre-emergent herbicide alternative dor the control of trifluralin resistant Lolium rigidum Gaudin (annual ryegrass) in wheat and barley, Craig A. Ruchs, Syngenta Crop Protection Australia Pty Ltd and Dr Peter Boutsalis, University of Adelaide 18. Novel knockdown tank mixes: Results from 12 trials over four years, Shahab Pathan1, Abul Hashem2, Catherine Borger3, Nerys Wilkins and Julie Roche, Department of Agriculture and Food, Western Australia, and 3the University of Western Australia 19. Alternative herbicides for weed control in lupins, Peter Newman and Martin Harries, Department of Agriculture and Food 20. Novel use application of clopyealid in lupins, John Peirce, and Brad Rayner, Department of Agriculture and Food 21. A model to predict grass selective herbicide rates, John Moore, Department of Agriculture and Food CROP AND WEED MANAGEMENT 22. Inter-row weed control in wide row lupin using knockdown-based tank mixes, Dr Abul Hashem1, Ray Fulwood2 and Chris Roberts3, 1Senior Research Officer, Department of Agriculture and Food, 2Farmer, Meckering, WA, 3Technical Officer, Department of Agriculture and Food 23. Timing of weed removal in wide-row lupins, Sally Peltzer, Shahab Pathan and Paul Matson, Department of Agriculture and Food 24. The effect of row spacing and crop density on competitiveness of lupins with wild radish, Bob French and Laurie Maiolo, Department of Agriculture and Food 25. Is delayed sowing a good strategy for weed management in lupins? Bob French, Department of Agriculture and Food 26. Delayed sowing as a strategy to manage annual ryegrass, Department of Agriculture and Food HERBICIDE TOLERANCE 27. The effect of herbicides on nodulation in lupins, Lorne Mills1, Harmohinder Dhammu2 and Beng Tan1, 1Curtin University of Technology, and 2Department of Agriculture and Food 28. Response of new wheat varieties to herbicides, Harmohinder Dhammu, Department of Agriculture and Food 29. Herbicide tolerance of new barley varieties, Harmohinder Dhammu, Vince Lambert and Chris Roberts, Department of Agriculture and Food 30. Herbicide tolerance of new oat varieties, Harmohinder Dhammu, Vince Lambert and Chris Roberts, Department of Agriculture and Food OTHER WEEDY MATTERS 31. Research and extension need for wild radish and other cruciferous weeds, Aik Cheam, Department of Agriculture and Food 32. e-weed – an information resource of seasonal weed management issues, Vanessa Stewartand Julie Roche, Department of Agriculture and Foo

Sex-related differences in aging rate are associated with sex chromosome system in amphibians

Sex-related differences in mortality are widespread in the animal kingdom. Although studies have shown that sex determination systems might drive lifespan evolution, sex chromosome influence on aging rates have not been investigated so far, likely due to an apparent lack of demographic data from clades including both XY (with heterogametic males) and ZW (heterogametic females) systems. Taking advantage of a unique collection of capture-recapture datasets in amphibians, a vertebrate group where XY and ZW systems have repeatedly evolved over the past 200 million years, we examined whether sex heterogamy can predict sex differences in aging rates and lifespans. We showed that the strength and direction of sex differences in aging rates (and not lifespan) differ between XY and ZW systems. Sex-specific variation in aging rates was moderate within each system, but aging rates tended to be consistently higher in the heterogametic sex. This led to small but detectable effects of sex chromosome system on sex differences in aging rates in our models. Although preliminary, our results suggest that exposed recessive deleterious mutations on the X/Z chromosome (the "unguarded X/Z effect") or repeat-rich Y/W chromosome (the "toxic Y/W effect") could accelerate aging in the heterogametic sex in some vertebrate clades.Peer reviewe

Drivers of site fidelity in ungulates

1. While the tendency to return to previously visited locations—termed ‘site fidelity’—is common in animals, the cause of this behaviour is not well understood. One hypothesis is that site fidelity is shaped by an animal's environment, such that animals living in landscapes with predictable resources have stronger site fidelity. Site fidelity may also be conditional on the success of animals’ recent visits to that location, and it may become stronger with age as the animal accumulates experience in their landscape. Finally, differences between species, such as the way memory shapes site attractiveness, may interact with environmental drivers to modulate the strength of site fidelity. 2. We compared inter‐year site fidelity in 669 individuals across eight ungulate species fitted with GPS collars and occupying a range of environmental conditions in North America and Africa. We used a distance‐based index of site fidelity and tested hypothesized drivers of site fidelity using linear mixed effects models, while accounting for variation in annual range size. 3. Mule deer Odocoileus hemionus and moose Alces alces exhibited relatively strong site fidelity, while wildebeest Connochaetes taurinus and barren‐ground caribou Rangifer tarandus granti had relatively weak fidelity. Site fidelity was strongest in predictable landscapes where vegetative greening occurred at regular intervals over time (i.e. high temporal contingency). Species differed in their response to spatial heterogeneity in greenness (i.e. spatial constancy). Site fidelity varied seasonally in some species, but remained constant over time in others. Elk employed a ‘win‐stay, lose‐switch’ strategy, in which successful resource tracking in the springtime resulted in strong site fidelity the following spring. Site fidelity did not vary with age in any species tested. 4. Our results provide support for the environmental hypothesis, particularly that regularity in vegetative phenology shapes the strength of site fidelity at the inter‐annual scale. Large unexplained differences in site fidelity suggest that other factors, possibly species‐specific differences in attraction to known sites, contribute to variation in the expression of this behaviour. 5. Understanding drivers of variation in site fidelity across groups of organisms living in different environments provides important behavioural context for predicting how animals will respond to environmental change

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo