A comparison of North American avian conservation priority ranking systems

The need to prioritize species based on their perceived endangerment has led to the development of systems for categorizing and assessing their degree of vulnerability. Systems with divergent biological and geographical scopes can result in conflicting lists of high-priority species, potentially confusing conservationists and hampering the efficient allocation of resources. To assess conservation priorities for North American birds, we compare three priority-setting systems; those of the International Union for the Conservation of Nature (IUCN), NatureServe, and Partners in Flight (PIF). We found highest correspondence among the three systems in the highest and lowest categories of the respective systems with lower levels of correspondence in intermediate categories. We suggest that this is because the systems, while using different formulations of criteria, are based on the major factors known to be correlated with extinction risk. The few examples of species listed as a high conservation priority by one group but not one or both of the others appear to be the result of differences in availability or interpretation of data. Better communication and collaboration among those responsible for compiling the priority lists for each system is needed.A primary difference among the systems was the total number of species identified as conservation priorities. IUCN identified the fewest species (47) and PIF the most (157). This difference is the result of differences in geographic and taxonomic scope of each system. However, when considered as the percent of the total number of taxa evaluated by each system, all systems identified approximately 20% of species as of conservation concern. To reconcile disparate lists, we urge that conservationists use a hierarchical approach that first considers species that meet thresholds for endangerment under global systems, followed by species considered most vulnerable relative to all continental biota.     

Effect of cultivation and within-field differences in soil conditions on feral Helianthus annuus growth in ridge-tillage maize

Differences in weed population dynamics with respect to within-field heterogeneity are not well documented despite increasing interest in site-specific management of agro-ecosystems. The focus of this study was to determine if mechanical weed management (cultivation) and/or soil factors help to explain observed within-field distributions of feral common sunflower (Helianthus annuus L.). The ridges and furrows created by the ridge–tillage system adds additional microsites to existing spatial heterogeneity for soil characteristics such as soil organic carbon (SOC) concentration. Experimental areas were selected on the basis of naturally high or low SOC concentration. Cultivation resulted in 100% mortality of H. annuus seedlings growing in the middle of furrows. Cultivation of pre-emergence herbicide treated and no-herbicide ridges resulted in small but statistically significant ( = 0.05) reductions in seedling survival. No differences were detected in H. annuus canopy height, stem diameter, stem length, or vegetative biomass between high and low SOC environments. Neither total reproductive biomass (P = 0.49) nor the biomass of flowers near physiological maturity (an estimate of fecundity; P = 0.59) were affected by SOC environment. Late season H. annuus lodging was observed to reduce reproductive biomass. Juvenile plants that survived mechanical weed control efforts grew and produced reproductive biomass similarly across SOC environments. The lack of difference in vegetative and reproductive characteristics between high and low SOC environments suggests that SOC (or the edaphic conditions associated with greater or lesser SOC level) was not critical in contributing to the observed distribution of H. annuus from juvenile to flowering stages of growth within well-fertilized, irrigated agricultural habitats.     

Vegetational changes associated with recreational use and fire suppression in the Eagle Cap Wilderness, Oregon: Some management implications

Construction and use of trails and campsites, grazing by recreational packstock, and suppression of fires have altered the vegetation of the Eagle Cap Wilderness Area in northeastern Oregon, USA. The amount and type of alteration has varied among vegetation types and with the kind of activity. Changes attributed to intensive recreational use are localised but severe, particularly in more densely forested areas. Suppression of fires has produced subtle but widespread changes. Current attempts to minimise these changes are often inadequate due to the lack of ecological information and the difficulties of implementing regulations. Management suggestions are offered.     

Adsorption of bacteria on soils: Experiments,thermodynamic rationale,and application

A model for the adsorption of bacteria to soil particles is described using the physical-chemical Langmuir isotherm and the van't Hoff equation. An example of the use of the model for assessing bacterial movement through soil is provided.Staphylococcus aureus was the sorbate with sorbents of activated charcoal, kaolinite clay, Mendon silt loam, and silica sand. Competitive agents sodium lauryl sulfate, sodium chloride, and peptone were also studied. Peptone was the most successful competitor with the bacteria for sites on the sorbent.     

Semicarbazide formation in azodicarbonamide-treated flour: a model study

Semicarbazide was previously found in foods that were in contact with rubber gaskets foamed at high temperatures with a blowing agent azodicarbonamide. Because azodicarbonamide is an approved flour additive in certain countries, we set out to ascertain if semicarbazide is formed during the baking process from flours containing that additive. The levels of semicarbazide in baking flour treated with azodicarbonamide and bread baked from such flours were determined by isotope dilution (13C15N2-semicarbazide) liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS). The samples were homogenized with HCl, extracted with n-pentane, derivatized with 2-nitrobenzaldehyde, and the derivative was extracted with ethyl acetate. After solvent exchange to 10% acetonitrile in water containing 0.1% acetic acid, the samples were analyzed using a 2.1 mm x 150 mm C18 column eluted with 2 mM ammonium formate in water/methanol (40:60). Semicarbazide was formed during the dry heating of commercial azodicarbonamide-containing flours at temperatures of 150-200 degrees C reaching levels of 0.2 mg/kg. Similar levels of semicarbazide were found in the crusts of breads made from azodicarbonamide-treated flour.     

Volatile emissions of navel oranges as predictors of freeze damage

Volatile emissions of navel orange (Citrus sinensis L. Osbeck cv. Washington) fruit were evaluated as a means for predicting and gauging freeze damage. The fruits were subjected to -5 or -7 degrees C treatments in a laboratory freezer for various time periods of 2-9.5 h and stored at 23 degrees C for 1, 2, or 7 days, after which time the emission of volatiles from the fruit was measured. Following the final day of volatile measurements the fruits were stored at 5 degrees C for an additional 2-3 weeks and then evaluated for fruit quality characteristics. Peel injury in the form of brown lesions, drying of the juice vesicles, a decline in acidity, and a loss of flavor were observed to occur as a result of freezing. Corresponding to the loss in fruit quality were large increases in the emissions of ethanol, ethyl butanoate, methyl hexanoate, and ethyl octanoate. With the exception of methyl hexanoate, for which volatile emissions decreased during storage for 7 days at 23 degrees C, all of the other volatiles were relatively unchanged in amount by storage. Treatment at -7 degrees C caused greater injury, quality loss, and more volatile emanation than did freezing at -5 degrees C. The measurement of volatile emissions appears to be a useful approach to identify freeze-damaged navel oranges.     

Marking of deer fences to reduce frequency of collisions by woodland grouse

Recent studies of the effects of deer fences on tetraonids have concluded that fences are an important cause of mortality in woodland grouse. This 2-year study involving 16 sections of fences in the Scottish Highlands evaluates the effectiveness of making fences highly visible by using orange netting to reduce bird collisions with fences. A total of 437 collisions involving 13 bird species were recorded. Red grouse (Lagopus lagopus scoticus) formed 42% of all collisions, with black grouse (Tetrao tetrix) 29% and capercaillie (T. urogallus) 20%. Allowing for corpse removal by scavengers, an estimated 70% of red grouse and 29% of black grouse collisions were fatal. Black grouse and capercaillie both collided with 11 of the 16 fences at mean rates of 1.3 and 0.9 collisions km⁻¹ year⁻¹, red grouse collisions occurred at 13 fences, with a mean rate of 1.6 collisions km⁻¹ year⁻¹. Fewer grouse collisions occurred in the summer. Three quarters of black grouse collisions were by males. Collision rates were positively correlated with indices of black grouse and capercaillie abundance. Fence marking reduced capercaillie collisions by 64%, black grouse by 91% and red grouse by 49%. Although marked fences reduced capercaillie collision rates, they still remained an important cause of mortality. To conserve capercaillie, fences need to be removed altogether pending increased deer culls that would allow woodland regeneration without fences, or “grouse friendly” fences designed.     

Concentration and deposition of trace metals in Ontario-1982

Results of trace metal concentrations in air and precipitation and the corresponding wet and dry deposition in Ontario in 1982 arc reported. In terms of the spatial patterns, in general, there was a decreasing gradient from south-to-north in both concentration and deposition. Patterns differed with each parameter although certain groups of metals (e.g., Fe and Al; Pb, Zn, and Mn) displayed similar patterns. In general, wet deposition was greater than dry deposition at all sites. Geographically, the variability in the wet to dry deposition ratio for coarse particles (MMD > 2.5 μm) was small. However, it increased from the south to the north for fine particles (MMD < 2.5 μm), being higher away from the source areas. Scavenging ratios (W) have been derived from the precipitation and air concentrations of trace metals. The scatter in W is quite large for all trace metals, up to 2 orders of magnitude. There was little seasonal variability in W for fine particles (Pb, Mn, Zn, and Cd). However, coarse particles (Fe, Al, and Cu) were more efficiently scavenged by snow than by rain.     

Chronic effects of reduced dissolved oxygen on Daphnia magna

Daphnia magna, initially exposed when less than 48 h old, were maintained at reduced dissolved oxygen (DO) concentrations for 26 days. Exposure was accomplished in a continuous flow recirculating water system. Number of days to first brood, number of young in the first brood, total number of young produced, and dry weight were parameters measured. Statistical analyses show the Daphnia exposed to the lowest DO concentration tested (1.8 mg l^?1) had significantly reduced responses for all parameters measured. In addition, the organisms exposed to 2.7 mg l^?1 O₂ gained less weight than did the controls.     

Ecology of otters in Northern Scotland IV. A model scheme for otter Lutra lutra L. conservation in a freshwater system in aberdeenshire

Habitats for inclusion within otter havens are illustrated from a case-history study on the middle part of the Aberdeenshire River Dee. The environment is divided into breeding and rearing areas and places for non-breeding otters. One good location for a haven incorporating all three habitats includes 12–13 km of river and two nearly lochs. In this area, part of the river bank is inaccessible, and there are secluded islands and deep woods. Havens should include tiny tributaries leading to shelter where otters are likely to have their young. An otter haven in mid-Deeside planned to incorporate all these habitats may be regarded as a model for conservation that could be followed in other similar environments elsewhere.