Assessment and management of risk to wildlife from cadmium

Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction.     

Response of aquatic macroinvertebrate density and diversity to wetland management and structure in the Montezuma Wetlands Complex,New York

We investigated how water management and other covariates affected aquatic macroinvertebrate density and diversity of wetlands in the Montezuma Wetlands Complex (MWC) of the Lake Ontario watershed, New York, USA. We conducted aquatic macroinvertebrate sampling during May–July in 2016–2018 to coincide with when juvenile wetland birds require these protein foods. Models that best explained aquatic macroinvertebrate density and taxon richness included water drawdown treatment, water depth, and water drawdown treatment from the prior year. Predicted mean density of aquatic macroinvertebrates was 117.2% greater in partial drawdown than passive wetlands (i.e., wetlands without active water removal) and increased by 516.2% with 15.5–48 cm increase in water depth. Density of aquatic macroinvertebrates also was ≥ 2.6 times greater in wetlands with a full drawdown the year prior. Taxon richness and Shannon Wiener Diversity Index (H′) varied positively with water depth, and there was greater diversity in partial drawdown than passive wetlands. Taxon richness was nearly 2 times greater in areas with full drawdown the year prior than those with partial drawdowns and passive wetlands. Other competing models for H′ also included negative effects of percentage monotypic cattail and invasive plant taxa. These findings are consistent with aquatic macroinvertebrate adaptation to dynamic wetland hydrology, and we recommend that managers actively manipulate hydrology to provide abundant and diverse food resources for birds at managed wetlands in the Great Lakes region.     

The study of terrestrial vertebrates of the Ob River basin

The paper describes the 300-year history of studying the terrestrial vertebrates in the Ob basin and the current state of researches into amphibians, reptiles, birds and mammals. We examine the role of the research centres in Western Siberia in studying the terrestrial vertebrates in the Ob basin, from the steppe in the south to the tundra in the north and the uplands of the Altai, Kuznetsky Alatau and Salair. We describe the degree of exploration of the terrestrial vertebrates in 11 Russian regions located in the area. The paper includes discussions of rare species, population, spatial distribution and man’s impact on the animals. We also indicate areas where there is insufficient study.     

The avifauna of Western Siberia taiga zone wetlands (Tomsk oblast)

Wetland landscapes are widely spread in the Western Siberia taiga zone. Wetlands serve climatic and hydrological global functions, as well as many others. They also form the habitats for many species of animals. Dynamic development of Western Siberia wetlands and human influence on them demand the investigation of the wetlands’ bird population. This study aims to determine the wetland avifauna species diversity and to evaluate bird abundance and current state of rare species listed in Red Data Book. The study was carried out in the southern and middle taiga zones and in subtaiga. The study is based on the surveys that authors made in 2007–2013 in Tomsk oblast and also on the data gathered by the scientists in the Western Siberia forest zone. Counts were made according to Y.S. Ravkin’s methods. Counts of bird density are based on mean discovery distance on the routes. A total of 600?km walking and 150 water counting routes (by boats) were covered. It was found that 225 bird species inhabit Western Siberia wetland landscapes (196 – Tomsk oblast). Near 80% of birds inhabiting wetlands nest here.     

Artificial Swarm System: Boundedness, Convergence, and Control

An artificial swarm system consisting of multiagents is considered in this paper. The agents may interact with each other based on their relative position. Each agent exhibits a repulsion/attraction behavior toward another agent, which mimics some biological swarm systems. The performance of each individual agent is the accumulation of these respective considerations toward other agents. The overall performance of the swarm system is analyzed, which includes uniform boundedness, uniform ultimate boundedness, and convergence. This mimics aggregation and formation in biological systems. The control design for each agent toward achieving the performance is then proposed. The control is a mimic of nature’s strategy in constraining mechanical systems.     

Human activity and potential impacts on dune breeding birds in the Alexandria coastal Dunefield

Human use of coasts has increased considerably with increasing demand for recreational experiences, increased availability of off-road vehicles (ORVs) and population increase. Besides impacts on dune morphology and flora, humans and ORVs also affect the fauna. The Alexandria Dunefield in Algoa Bay comprises a 50 km sandy beach backed by a 2.1 km wide strip of dunefield. The dunefield is largely conserved, but access to the beach is allowed under permit, and the beach is heavily utilised by fishermen and recreational ORV drivers. The area is also important for dune breeding birds. Beach and dune use by fishermen and other users was quantified by recording their position relative to the high water mark and along a 20 km stretch of beach, and through analysis of access permits and angling competition data. An increase in vehicle use in the area was observed. An indication of human perception of the area was obtained by questionnaires. Eighty percent of human activity was concentrated in 50% of the study site where the highest concentration of dune breeding birds nest. Sixty percent of the vehicles recorded, were on or above the high water mark (in the dunes). Of the beach-users interviewed, 74% suggested that only registered vehicles should be allowed on the beach. Most (80%) anglers had no problem determining the position of the high water mark. There is an overlap in area and seasonal use between beach-users and breeding birds. With specific areas along the beach being heavily impacted and vehicles utilising the area above the high water mark the potential for impact on the fauna and flora of these areas is high. There is a need to educate beach users as to the vulnerability of dune systems and to develop appropriate management guidelines to minimise the impacts of beach users on the dune fauna.     

Consideration of grain and extent in landscape studies of terrestrial vertebrate ecology

The choice of scale (both grain and extent) of a research project can directly affect the results of the project itself, and the comparability of those results to similar research. This paper reviews 149 self-described landscape studies published between 1987 and 2001. From each paper, data for several variables were gathered that we proposed may influence the choice of scale. These variables included the taxa the research considered, the characteristics of the landscape of interest, the species response variables measured, the type of methodology employed by the study, the habitat type(s) surveyed, and the technique(s) used to create habitat maps. Our results demonstrated that only 61% of the papers identified both the grain and extent at which the research was conducted. Taxonomic group, landscape characteristics, and study type all appeared to influence both the choice of grain and extent for the study. Wide variation (standard deviation) in grain and extent among studies suggests that researchers either used some factor not considered here to select scale, or made decisions of the scale on pragmatic grounds, rather than on the appropriateness of the scale to the variables. Finally, 24 of the 149 studies reviewed researched the same combination of categories of the six variables that we considered, yet only for one combination was the grain and extent used within the same order of magnitude. This review highlights the need for more structured choice of scale in landscape studies, and in particular the need for more standardized size of grain and extent for greater comparability among studies.     

The importance for birds of the riparian woodlands within the alluvial corridor of the river garonne,S.W. France

Communities of nesting birds were studied in four distinct biotopes within the alluvial corridor of the River Garonne: 50 terrace woodlands, 17 riparian woodlands, one poplar plantation, and one slope woodland. A total of 400 stations were investigated, consisting of eight distinct classes of forest size for the terrace woodlands and four for the riparian woodlands. The distribution of 64 species of birds, observed by means of 20 minute listening point surveys, was related to three main factors: forest size, site wetness, and the wooded space marginality (forests, woods, copses, hedges, trees). Indices of mean richness and of mean abundance show that the riparian woodlands were the richest and the most densely populated. The surface area of woodlands has a strong effect on the structure of the bird community on terraces but less in the riparian environment. Multivariate analysis contrasted the species from the open islands within closed environments with the species from the closed islands within an open environment. The effect upon the nesting bird communities of the fragmentation of the original forest within the alluvial corridor of the River Garonne is demonstrated by a grouping of two characteristics: the connectivity of the riparian woodlands and the insularity of the terrace woodlands. The conservation of a continuous ribbon of riparian woodlands is shown to be an important condition for maintaining a rich community of nesting birds.     

A conceptual model for assessing risks in a Mediterranean Natura 2000 Network site

Every year millions of tons of chemical products are disposed to the environment as a result of human activities, with deleterious consequences to biodiversity. In Europe the biodiversity policy basis for action is provided by the Birds and the Habitats Directives. According to these directives a network of protected areas is being built across EU countries encompassing the Natura 2000 Network. But the management plans of these protected areas do not require an ecotoxicological assessment of chemicals used within its limits. As for risk assessment protocols described in EC pieces of legislation and technical guidance documents, they are generic guidelines that not take into consideration regional particularities, e.g. the Mediterranean ecoregion specificities, and its local ecological values. Herewith we present a conceptual model for the assessment of risks posed by agriculture to bird species of conservationist concern from Natura 2000 Network sites; an example is set in a cereal steppe of the Iberian Peninsula. Hazards identified are related to the utilization of herbicides, disposal of sewage sludge to be used as fertilizer, and the input of veterinary pharmaceuticals that can be found in livestock dung and urine. This innovative model, to be used in high tier risk assessment, takes into account the biotic parameters of the protected bird species: great bustard (Otis tarda), lesser kestrel (Falco naumanni), and montagu's harrier (Circus pygargus). The transfer of chemicals is considered to occur mainly through a realistic trophic chain scenario according to the different feeding behaviour among different species and even within the same species when having different feeding habits (e.g. adults and juveniles). Moreover, the probabilistic approach is proposed in order to perform a transparent risk assessment and clearer risk communication.     

Distribution and habitat selection of wintering birds in urban environments

Habitat selection of wintering land-birds was studied in 31 human settlements in Finland. A total of 26 wintering bird species representing 5155 individuals were observed. Between-year variation (CV_B%) and short-term fluctuation within one winter (CV_W%) in species richness (CV_B=10% CV_W=15%) were low, as were total numbers of birds (CV_B=22% CV_W=24%) and populations of the most common bird species (CV_B=20–40% CV_W=15–47%). The most abundant bird species (e.g., Passer domesticus, Parus major and Pica pica) occurred in most of the study sites. The total densities of omnivorous birds, sedentary birds and bird species that commonly use feeding tables were higher in a heavily urbanized areas than in moderately or less urbanized areas. According to the Canonical Correspondence Analysis, three corvid species populations, P. domesticus and Columba livia domestica were positively related to human population density. Corvus corone cornix and P. domesticus populations correlated positively with the proportion of the built-up areas in the study plots. The omnivorous diet of these species was a possible reason for their success in urban environments. Dendrocopus major, Parus montanus, Parus cristatus, Parus ater and Certhia familiaris were negatively related to the urbanization axis. These species live mainly in coniferous forest habitats and are probably unable to use deciduous-dominated urban parks in winter time. To attract these species, coniferous trees and shrubs should also be used in park management and planning in northern latitudes. Many species, like Pic. pica, Carduelis chloris and Parus caeruleus, were located at an intermediate place on an urban–forest gradient axis. We suppose that these species are the most probable candidates for colonizing or increasing their abundances in European towns and cities in near the future. All of these species use feeding tables, which help them to adapt to urban environments.