Coyotes as Sentinels for Monitoring Bovine Tuberculosis Prevalence in White-Tailed Deer

Abstract: Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is endemic in free-ranging white-tailed deer (Odocoileus virginianus) in 5 counties (Alcona, Alpena, Montmorency, Oscoda, and Presque Isle) in the northeastern Lower Peninsula of Michigan, USA. The presence of a wildlife reservoir of tuberculosis in Michigan and the incidence of bTB in cattle (Bos taurus) resulted in Michigan losing its bTB accredited-free status. Subsequent wildlife surveillance programs identified relatively high disease prevalence in coyotes (Canis latrans), generating interest in their potential to serve as a sentinel species to detect bTB prevalence in white-tailed deer. Our goal was to develop an empirical basis for generating hypotheses about the spatial epidemiology of bTB infection in coyotes for future surveillance, management, and modeling efforts. Though variation in coyote home-range size may confound attempts to spatially correlate the incidence of disease in the sentinel and host species at a fine scale, overlap zones (OZs) between adjacent coyote home ranges may be the appropriate sample unit for spatially correlating disease prevalence in coyotes and white-tailed deer. Because overlapping home ranges are generally configured around resource rich (e.g., small mammals and white-tailed deer) timber management patches, the OZ concentrates spatial interaction between adjacent groups in a relatively small area. Furthermore, there is a direct relationship between interaction probabilities and the spatial dispersion of those patches. The latter finding provides a useful metric to incorporate into future efforts to develop spatially explicit models of bTB dynamics. Modeling efforts can then be used as a foundation to predict the epidemiological ramifications of alterations in intensively managed forested landscapes. (JOURNAL OF WILDLIFE MANAGEMENT 71(5):1545-1554; 2007)     

Species interactions and habitat associations of birds inhabiting urban areas of Sydney,Australia

Abstract The absence of small birds from many suburban areas may be due to adverse garden characteristics, interspecific aggression or human behaviour such as supplementary food provisioning that encourages predators. We investigated the relationship between these factors and the presence of seven small bird species in Sydney through a community‐based survey. The survey was conducted by participants over a 7‐day period between 7 am and 10 am in November and early December 2000. Three dominant species, the noisy miner (Manorina melanocephala), pied currawong (Strepera graculina) and common myna (Acridotheres tristis) were each present in over 59% of gardens. Each small bird species was present in less than 40% of gardens. All small birds were negatively associated with noisy miners, but only the silvereye (Zosterops lateralis) was negatively associated with pied currawongs. None of the species of small birds was negatively associated with common mynas. Four species of small birds were associated with at least one habitat variable, notably the proportion of native vegetation. Although more birds were recorded in gardens in which meat was provided, there were significantly fewer small birds in these gardens. There were also more birds recorded in gardens where seed was provided, with red‐browed finches (Neochmia temporalis) positively associated with seed provisioning in most regions of Sydney. The presence of dogs and cats was not related to the total abundance of birds overall or small birds in gardens. While garden characteristics may influence the presence of small birds to some degree, the presence of noisy miners, a species that are thought to aggressively exclude other species from their territories, is likely to be an important influence on these species in suburban areas. Furthermore, supplementary feeding by people is likely to negatively influence some small birds. The presence of carnivorous pets does not seem to influence the presence of small birds at the scale of the individual garden.     

PROVISION OF COMMUNITY‐WIDE BENEFITS IN PUBLIC HEALTH INTERVENTION RESEARCH: THE EXPERIENCE OF INVESTIGATORS CONDUCTING RESEARCH IN THE COMMUNITY SETTING IN SOUTH ASIA

Background: This article describes the types of community‐wide benefits provided by investigators conducting public health research in South Asia as well as their self‐reported reasons for providing such benefits. Methods: We conducted 52 in‐depth interviews to explore how public health investigators in low‐resource settings make decisions about the delivery of ancillary care to research subjects. In 39 of the interviews respondents described providing benefits to members of the community in which they conducted their study. We returned to our narrative dataset to find answers to two questions: What types of community‐wide benefits do researchers provide when conducting public health intervention studies in the community setting, and what reasons do researchers give when asked why they provided community‐wide benefits? Findings: The types of community‐wide benefits delivered were directed to the health and well‐being of the population. The most common types of benefits delivered were the facilitation of access to health care for individuals in acute medical need and emergency response to natural disasters. Respondents' self‐reported reasons when asked why they provided such benefits fell into 2 general categories: intrinsic importance and instrumental importance.     

CO2 enrichment predisposes foliage of a eucalypt to freezing injury and reduces spring growth

Seedlings of Eucalyptus pauciflora, were grown in open-top chambers fumigated with ambient and elevated [CO₂], and were divided into two populations using 10% light transmittance screens. The aim was to separate the effects of timing of light interception, temperature and [CO₂] on plant growth. The orientation of the screens exposed plants to a similar total irradiance, but incident during either cold mornings (east-facing) or warm afternoons (west-facing). Following the first autumn freezing event elevated CO₂-grown plants had 10 times more necrotic leaf area than ambient CO₂ plants. West-facing plants had significantly greater (25% more) leaf damage and lower photochemical efficiency (F_v/F_m) in comparison with east-facing plants. Following a late spring freezing event east-facing elevated CO₂ plants suffered a greater sustained loss in F_v/F_m than west-facing elevated CO₂- and ambient CO₂-grown plants. Stomatal conductance was lower under elevated CO₂ than ambient CO₂ except during late spring, with the highest leaf temperatures occurring in west-facing plants under elevated CO₂. These higher leaf temperatures apparently interfered with cold acclimation thereby enhancing frost damage and reducing the ability to take advantage of optimal growing conditions under elevated CO₂.     

Studies in the Principles of Phytotoxicity: V. INTERRELATIONSHIPS BETWEEN SPECIFIC DIFFERENCES IN SPRAY RETENTION AND SELECTIVE TOXICITY

In a detailed study of the factors which control spray retentionby the shoot, five species with markedly different morphologicalcharacteristics have been examined (Helianthus annuus, Brassicaatha, Linum usitatisrnnwn, Hordeum vulgare, and Pisum sativum).The amount of spray retained, expressed as volume per unit weightof shoot or unit leaf area, is dependent on the stage of developmentof each species, the volume of spray applied, and the surfacetension of the spray solution. The interrelationships betweenthese factors are complex for all the second-order interactionsproved to be highly significant. Under one set of condi tionsthere may be a tenfold difference in retention between two specieswhile under another set the corresponding difference may beas little as twofold. Between a spray output of 14 and 143 ml./m.³ the level of retentionby P. sativum and H. vulgare is linearly related to output butfor H. annuus and B. alba the relationship is curvilinear. Whenthe surface tension is reduced below 40 dynes/cm. retentionby P. sativum and H. vulgare is increased, but for B. alba andH. annuus retention is decreased if the output exceeds 50 ml./m.For a given output, a reduction in the mean droplet size augmentsretention by H. vulgare but not by H. annuus. Differences in retention either between species or between stagesof develop ment are linked with the ratio of leaf area to shootweight, the nature of the leaf surfaces, the angle of incidenceat which the droplets strike the leaf, and localized accumulation.Retention is maximal when the leaf-area ratio is high, the surfacescompletely wetted, and the laminae set in a horizontal plane:once this maximum value is reached any additional spray receivedruns off the shoot. The relationship between retention and the concentration ofthe spray solution required to bring about some standard biologicalresponse has been examined for two groups of compounds—thosewhich are freely translocated (triethanolarnine salts of 2:4-dichloro-,2:4:5-trichloro-, and z-methyl-4-chloro-phenoxyacetic acids)and those which are not (arnrnonium 2:4-dinitro-6-sec-butylphenate).For the first group the equi-effective concentration is inverselyand linearly related to retention since the total amount receivedis of primary importance in determining the inhibition of growth,though the position of the droplets must be taken into account.Placing micro-drops containing the growth regulator on the cotyledonsof L. usitatimmwn inhibits the growth of the shoot less thana spray application of the same amount over the whole shoot:for H. annuus placing the growth regulator on either the firstor second pair of leaves or on the first internode induces moreinhibition of growth than application to the cotyledons. With ammonium dinitro-sec-butylphenate the relationship betweenretention and concentration is also inverse but approximatelylogarithmic for L. usitatisrimum. For some other species thechanges in retention consequent upon a reduction in the surfacetension are not matched by comparable changes in the equi-effectiveconcentration. For B. alba and H. annuus though lowering thesurface tension may decrease retention it may also Himiniahthe concentration because the fall in retention is more thanoffset by a greater penetration of the compound into the shoot. It is concluded that differences in spray retention betweenspecies can play a major role in determining selective actionand the conditions under which this factor may operate mosteffectively are discussed.     

Using digital images to reconstruct three‐dimensional biological forms: a new tool for morphological studies

We examined two image‐based methods, photogrammetry and stereo vision, used for reconstructing the three‐dimensional form of biological organisms under field conditions. We also developed and tested a third ‘hybrid’ method, which combines the other two techniques. We tested these three methodologies using two different cameras to obtain digital images of museum and field sampled specimens of giant tortoises. Both the precision and repeatability of the methods were assessed statistically on the same specimens by comparing geodesic and Euclidean measurements made on the digital models with linear measurements obtained with caliper and flexible tape. We found no substantial difference between the three methods in measuring the Euclidean distance between landmarks, but spatially denser models (stereo vision and ‘hybrid’) were more accurate for geodesic distances. The use of different digital cameras did not influence the results. Image‐based methods require only inexpensive instruments and appropriate software, and allow reconstruction of the three‐dimensional forms (including their curved surfaces) of organisms sampled in the field. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 425–436.     

Elevated CO2 and nutrient addition after soil N cycling and N trace gas fluxes with early season wet-up in a California annual grassland

We examined the effects of growth carbon dioxide (CO₂)concentration and soil nutrient availability on nitrogen (N)transformations and N trace gas fluxes in California grasslandmicrocosms during early-season wet-up, a time when rates of Ntransformation and N trace gas flux are high. After plant senescenceand summer drought, we simulated the first fall rains and examined Ncycling. Growth at elevated CO₂ increased root productionand root carbon:nitrogen ratio. Under nutrient enrichment, elevatedCO₂ increased microbial N immobilization during wet-up,leading to a 43% reduction in gross nitrification anda 55% reduction in NO emission from soil. ElevatedCO₂ increased microbial N immobilization at ambientnutrients, but did not alter nitrification or NO emission. ElevatedCO₂ did not alter soil emission of N₂O ateither nutrient level. Addition of NPK fertilizer (1:1:1) stimulatedN mineralization and nitrification, leading to increased N₂Oand NO emission from soil. The results of our study support a mechanisticmodel in which elevated CO₂ alters soil N cycling and NOemission: increased root production and increased C:N ratio in elevatedCO₂ stimulate N immobilization, thereby decreasingnitrification and associated NO emission when nutrients are abundant.This model is consistent with our basic understanding of how C availabilityinfluences soil N cycling and thus may apply to many terrestrial ecosystems.     

The Place of "Others" in Hunter-Gatherer Intensification

Archaeologists are interested in understanding the conditions under which hunter-gatherer intensification occurs. Typically, most models assign primacy to population pressure or social relations and address intensification as it occurs among foragers inhabiting arid or temperate environments. In this article, I explore episodes of resource intensification and "deintensification" on the subarctic island of Newfoundland. Correlating periods of resource intensification and "deintensification" with changes in the social landscape, I argue that the presence or absence of "Others" played a significant role in informing hunter-gatherer subsistence strategies and settlement patterns.     

Influence of Vegetation on Bat Use of Riparian Areas at Multiple Spatial Scales

ABSTRACT Research on habitat use by bats typically occurs at a single fine spatial scale, despite recent work demonstrating the importance of considering multiple spatial scales when investigating vertebrate habitat selection. We assessed bat use of 118 stream reaches located throughout the Oregon Coast Range, USA, and measured vegetation characteristics at 3 spatial scales surrounding each of these locations. We used an information-theoretic approach to determine vegetation characteristics most closely related to bat activity and a multilevel modeling approach to evaluate variation in bat activity at different spatial scales. Characteristics of vegetation at the finest spatial scale explained more variation in bat activity than did characteristics of vegetation at broader spatial scales, suggesting that fine-scale anthropogenic or natural disturbance events that alter cover of shrubs or trees in riparian areas are likely to influence bat habitat use. The influence of vegetation on activity varied by species of bat and appeared to operate more strongly through constraints imposed by vegetation architecture than through influences on abundance of insect prey. This diversity of responses to vegetation characteristics among bat species suggests that the best strategy for biodiversity conservation over broad spatial scales is maintenance or creation of a diversity of riparian vegetation conditions. We recommend that land managers planning to manipulate riparian vegetation strive to create diversity in shrub coverage, canopy coverage, and open space above the stream channel to promote foraging habitat for all species.     

Effects of elevated CO2 on the protein concentration of food crops: a meta-analysis

Meta‐analysis techniques were used to examine the effect of elevated atmospheric carbon dioxide [CO₂] on the protein concentrations of major food crops, incorporating 228 experimental observations on barley, rice, wheat, soybean and potato. Each crop had lower protein concentrations when grown at elevated (540–958 μmol mol^?1) compared with ambient (315–400 μmol mol^?1) CO₂. For wheat, barley and rice, the reduction in grain protein concentration was ～10–15% of the value at ambient CO₂. For potato, the reduction in tuber protein concentration was 14%. For soybean, there was a much smaller, although statistically significant reduction of protein concentration of 1.4%. The magnitude of the CO₂ effect on wheat grains was smaller under high soil N conditions than under low soil N. Protein concentrations in potato tubers were reduced more for plants grown at high than at low concentrations of ozone. For soybean, the ozone effect was the reverse, as elevated CO₂ increased the protein concentration of soybean grown at high ozone concentrations. The magnitude of the CO₂ effect also varied depending on experimental methodology. For both wheat and soybean, studies performed in open‐top chambers produced a larger CO₂ effect than those performed using other types of experimental facilities. There was also indication of a possible pot artifact as, for both wheat and soybean, studies performed in open‐top chambers showed a significantly greater CO₂ effect when plants were rooted in pots rather than in the ground. Studies on wheat also showed a greater CO₂ effect when protein concentration was measured in whole grains rather than flour. While the magnitude of the effect of elevated CO₂ varied depending on the experimental procedures, a reduction in protein concentration was consistently found for most crops. These findings suggest that the increasing CO₂ concentrations of the 21st century are likely to decrease the protein concentration of many human plant foods.