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Chlamydial infections in free-living birds

Most studies of chlamydial infections in free-living wild birds have been limited to surveys for the presence of Chlamydia psittaci or antibody to C psittaci and have largely been done in association with the identification of chlamydiosis in human beings, commercial fowl, or pet birds. The emphasis of these studies has been to determine the prevalence of infection and the potential role of wild birds in the spread of chlamydiae to domestic birds and human beings. Little is known about the epizootiology of chlamydiosis in free-living birds or its affect on their population dynamics. The following article is a summary of reported studies of chlamydiosis in free-living wild birds in relation to host range, ecologic aspects of transmission and maintenance, and the prevalence of disease.

Journal of the American Veterinary Medical Associa↗

Satellite telemetry and wildlife studies in India: Advantages, options and challenges

Greater spatial coverage, accuracy and non-invasiveness of satellite technology make it one of the best tools to track long-distance migrants, which is otherwise difficult using conventional radio telemetry. In this article, we review the evolution of satellite telemetry and its application. We provide examples of three recent studies in India that have demonstrated and created a widespread appreciation of the use and benefits of satellite telemetry among biologists and managers. We also discuss the future prospects of this technology vis-a-vis benefits and challenges in the Indian subcontinent.

Current Science↗

What records have we been breaking?

"Today was another record-breaking day," the evening radio or television declares. High temperatures, low temperatures, floods, drought - take your choice. But how can we put these pronouncements in perspective? What do they really mean? We present two types of information in this article: 1) an analysis of daily air temperature and precipitation for Fort Collins and 2) an analysis of annual precipitation for Fort Collins. Each analysis provides a different meaning to the statement about a record-breaking day or year.

Colorado↗

Parentage and relatedness in polyandrous comb-crested jacanas using ISSRs

In this article we present the first analysis of parentage and relatedness in a natural vertebrate population, using Intersimple Sequence Repeat (ISSR) markers. Thus, 28 ISSR markers were used in a study of a sex-role reversed, simultaneously polyandrous shorebird from northeastern Australia, the comb-crested jacana (Irediparra gallinacea). Assessment of parentage was based on comparison of field observations, novel bands, individual-specific bands found in 7/9 males and 4/6 females, and a 99% CI exclusion criteria. Integrating results from these approaches resulted in confirmation of paternity in all 36 chicks. In only one case (2.8% of chicks) was a co-mate assigned paternity. Thus, comb-crested jacanas appear to be genetically monogamous. These results showed resemblance to sequentially polyandrous birds but differed from the simultaneously polyandrous wattled jacana ( Jacana jacana; Emlen et al. 1998). A significant relationship between relatedness and ISSR similarity resulted in recognition that 14/15 adults sampled may be related to at least one other adult by 0.25 or more. Lack of dispersal may be explained by physical limitations and adequate regional habitat. ISSRs proved to be simple and helpful in resolving these issues.

Journal of Heredity↗

Supervised classification of Landsat thematic mapper imagery in a semi-arid rangeland by nonparametric discriminant analysis

In this article the authors used a nonparametric discriminant function in a supervised classification of Landsat Thematic Mapper satellite imagery of a ~240,000-ha semi-arid region in the Snake River Plains, southwestern Idaho. First, agriculture pixels were classified by distance from the soil baseline and water pixels by the thermal band value. Next, successive nonparametric discriminant functions were used to separate grassland and shrubland categories with subsequent classifications of vegetation within major classes. Accuracy in separating grasslands and shrublands was 80 percent and remained consistent relative to different thresholds in minimum percent ground cover defining shrublands. Within major grassland shrubland groups, researchers achieved 64 percent accuracy in separating dominant vegetation classes.

Photogrammetric Engineering and Remote Sensing↗

Relationship between chemical structure and rat repellency

Repellent activity is defined as the activity of a compound in preventing consumption of, or gnawing attacks upon, foodstuffs or articles containing or treated with the candidate substance. Data are presented on repellency indices of 2700 compounds, and it is shown that repellency is associated with specific functional groups attached to alkyl, aryl, or heterocyclic nuclei. Functional groups containing nitrogen, sulfur or halogens are most active, with amines, imides, thiocyanates and thiocarbamates forming some of the most active classes. Activity of any functional group may be affected by molecular weight, unsaturation, or spatial configuration of the nucleus, or by the presence of additional substituent groups.

National Research Council, Chemical-Biological Coo↗

Interactions of wolves and dogs in Minnesota

This article reports on the nature and extent of wolf-dog interactions in Minnesota, based on investigations of complaints received by personnel of the federal government dealing with wolf-depredation control. Findings may indicate the wolf-dog interactions that can be expected in other recovery areas.

Wildlife Society Bulletin↗

Type specimens and basic principles of avian taxonomy

"Ornithology" may be defined as the scientific study of birds. No aspect of avian biology, including management and conservation, can be carried out without reference by name to birds at some taxonomic level. Thus, the names of species of birds, and of groups of species, can fairly be considered to be of primary importance in ornithology. To be useful, these names themselves must be defined and related to biological entities. The definition of a name is accomplished by the designation of a "type." The International Code of Zoological Nomenclature, in paragraph (C) of Article 72 (third edition, 1985), establishes criteria for eligibility of a name-bearing type. The type of a species or sub-species name is the biological specimen defined by the name, and later use of the name implies specific or subspecific identity with the type. It is imperative, therefore, that a type be available for study and comparison so that the identity of other material with it can be established.

The Auk↗

May the forethought (and studies) be with your campsite-protection planning!

Visitation has reached record levels along the Appalachian Trail, a 2000+ mile footpath extending from Maine to Georgia along the crest of the Appalachian Mountains. Camping impacts associated with this use have also expanded rapidly in recent years, particularly in popular National Parks and at attraction features such as lakes and ponds. This article reviews recreation ecology research on camping impacts and their relationship to amount of use and environmental attributes. Management options for responding to camping management problems are described, including the manipulation of use-related, environmental, and managerial factors.

Register↗

Questions about Thayer's Gull

In response to recently published articles about the taxonomic status of Thayer's Gull, Larus thayeri, we pose several questions that should be answered before a taxonomic decision can be made.

Ontario Birds↗

FrogwatchUSA

full text: Frogs and toads are perhaps the most approachable and available of all our wildlife. In many, if not most places, they are abundant. In wetter parts of the East, almost anyone outside on a warm rainy night in spring will hear their dream-like calls, bellows, trills and snores. Even in the deserts of the Southwest, a nocturnal trip after a summer monsoon will yield toads moving across the roads toward a cacophonous orgy of mating and calling in the roadside ditches and desert pools. Birds share with frogs and toads this same sense of presence in our daily lives. But the difference is that birds are like the attractive neighbor who just never gives you the time of day, while frogs are more like the troglodyte who appears regularly to chat, philosophize, and have a beer. Uninvited, frogs appear in our water gardens, toads are on our stoops in the morning, we catch them when we are kids, raise their babies in the aquarium, and feel sorry when we find we have run them over with the lawnmower. When concerns about declining populations of amphibians reached the mass media, the Secretaries' office became involved. In addition to using traditional research mechanisms to investigate the problem, the Secretary also wanted to involve the public directly. The combination of high public appeal and the relative ease with which frog calls can be learned made a large-scale monitoring program for frogs and toads possible. What emerged was a program called Frogwatch USA, modeled after a successful Canadian program with a similar name. A web site was created (www.frogwatch.org) that presented potential frogwatchers with directions and a way to register their site online as well as enter their data. Observers chose where to count frogs depending on what they felt was important. For some it was their backyard, others chose vulnerable wetlands in their neighborhoods, or spots on local refuges and parks. Initially funded at $8,000 a year and then after two years increased to $25,000, most of the first part of this program's life was spent developing the tools and web site to document counts of frogs online. Despite the lack of time available to promote the program, send out press releases and recruit observers, news of the program quickly spread by word of mouth and the electronic media. Many newspaper articles later, we found a large number of people had become involved with counting frogs in their neighborhoods and backyards. Current figures show 1,456 observers who have registered at 1,683 sites logging almost 5,000 visits. These visits yield information on when and what species are calling from wetlands throughout the United States. These records are usually the only records of information about frogs and toads for those sites and become a permanent record that can be revisited in future years. Additionally, when observers make a lot of visits or there are many sites in a region, a phenology of calls can be created that documents when it is most likely in that year for each species to be recorded. Finally, even for those observers whose data we may mistrust and therefore are likely to eliminate from analyses, these people have taken the time to leave their televisions, go outside, and directly experience frogs, toads, and all that occur in Nature. In 1999 it was decided that FrogwatchUSA needed to work with another group that specifically focused on environmental education and outreach. After talking to a number of organizations we found that the National Wildlife Federation, with their Backyard Wildlife Habitat, Endangered Species, and other programs along with their four million members who are interested in nature, would be an excellent match. Thus a partnership was born. After over a year of work between Interior and National Wildlife Federation biologists and lawyers, an agreement has been created that places the Federation as the lead of Frogwatch USA. It will now take care of res

People, Land, and Water↗

Trekking poles: Can you save your knees and the environment?

The increasing use of trekking poles has stimulated a growing awareness of some environmental and social impacts associated with their use. These impacts have not been documented in the scientific literature. This article reviews the impacts of trekking pole use to provide a basis for further dialogue, and suggests how they may be altered or used in ways that will minimize impact.

Register↗

Schizochromism in a Peregrine Falcon from Arizona

Herein, we report the first record of schizochromism in the Peregrine Falcon (Falco peregrinus). Our example is a nestling from southern Arizona. The lack of dark brown pigment in this bird made it closely resemble the blue-gray plumage of an adult. Near fledging time, the bird was eaten by its nestmates, so this article also documents cannibalism.

Journal of Raptor Research↗

Pesticide-laced predator baits: considerations for prosecution and sentencing

The illegal use of pesticide-laced baits for predator control is a wildlife crime that is underreported, inadequately documented, and insufficiently punished. The crime occurs when some ranchers, farmers, and hunting groups illegally lace baits with pesticides to control avian and mammalian predators. The activity has poisoned birds protected by the Endangered Species Act, Migratory Bird Treaty Act, and the Bald and Golden Eagle Protection Act. However, because of difficulties in discovering, reporting, and confirming the baitings and the wildlife kills, the crimes often appear inconsequential. The limited knowledge of these crimes in the public, regulatory, and judicial arenas distorts their importance .for some prosecutors and judges. The United States pesticide regulatory system has positioned federal and state prosecutors and judges in a critical role for protecting wildlife from the illegal practice of lacing baits with pesticides. In this article, the authors provide an overview of the crime and describe the ways in which the crime is investigated. They then present investigative and experimental evidence on the extent of the illegal practice and the magnitude of the kills in order to elucidate their importance with respect to prosecution and sentencing. The authors conclude by recommending that sufficient resources be made available, public awareness and education increased, and persistent prosecution occur in order to improve the effectiveness of all federal wildlife enforcement.

Environmental Lawyer↗

Site occupancy models with heterogeneous detection probabilities

Models for estimating the probability of occurrence of a species in the presence of imperfect detection are important in many ecological disciplines. In these ?site occupancy? models, the possibility of heterogeneity in detection probabilities among sites must be considered because variation in abundance (and other factors) among sampled sites induces variation in detection probability (p). In this article, I develop occurrence probability models that allow for heterogeneous detection probabilities by considering several common classes of mixture distributions for p. For any mixing distribution, the likelihood has the general form of a zero-inflated binomial mixture for which inference based upon integrated likelihood is straightforward. A recent paper by Link (2003, Biometrics 59, 1123?1130) demonstrates that in closed population models used for estimating population size, different classes of mixture distributions are indistinguishable from data, yet can produce very different inferences about population size. I demonstrate that this problem can also arise in models for estimating site occupancy in the presence of heterogeneous detection probabilities. The implications of this are discussed in the context of an application to avian survey data and the development of animal monitoring programs.

Biometrics↗

Hierarchical models of animal abundance and occurrence

Much of animal ecology is devoted to studies of abundance and occurrence of species, based on surveys of spatially referenced sample units. These surveys frequently yield sparse counts that are contaminated by imperfect detection, making direct inference about abundance or occurrence based on observational data infeasible. This article describes a flexible hierarchical modeling framework for estimation and inference about animal abundance and occurrence from survey data that are subject to imperfect detection. Within this framework, we specify models of abundance and detectability of animals at the level of the local populations defined by the sample units. Information at the level of the local population is aggregated by specifying models that describe variation in abundance and detection among sites. We describe likelihood-based and Bayesian methods for estimation and inference under the resulting hierarchical model. We provide two examples of the application of hierarchical models to animal survey data, the first based on removal counts of stream fish and the second based on avian quadrat counts. For both examples, we provide a Bayesian analysis of the models using the software WinBUGS.

Journal of Agricultural, Biological, and Environme↗

Mortality of Mississippi Sandhill Crane chicks

Mississippi sandhill cranes (Grus canadensis pulla) are a highly endangered species that live in the wild in 1 county in Mississippi. As part of a large effort to restore these endangered cranes, we are conducting a project to look at the causes of mortality in crane chicks on the Mississippi Sandhill Crane National Wildlife Refuge in Gautier, MS, USA. This includes surgically implanting miniature radio transmitters in crane chicks to gather data on mortality. This article describes some of the practical difficulties in conducting this type of project in a savannah and swamp location along the Gulf Coast of the USA.

Journal of Avian Medicine and Surgery↗

Modeling individual effects in the Cormack-Jolly-Seber Model: A state-space formulation

In population and evolutionary biology, there exists considerable interest in individual heterogeneity in parameters of demographic models for open populations. However, flexible and practical solutions to the development of such models have proven to be elusive. In this article, I provide a state-space formulation of open population capture-recapture models with individual effects. The state-space formulation provides a generic and flexible framework for modeling and inference in models with individual effects, and it yields a practical means of estimation in these complex problems via contemporary methods of Markov chain Monte Carlo. A straightforward implementation can be achieved in the software package WinBUGS. I provide an analysis of a simple model with constant parameter detection and survival probability parameters. A second example is based on data from a 7-year study of European dippers, in which a model with year and individual effects is fitted.

Biometrics↗