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At least 793 records · Page 44Linked to original sources
USGS2024

Control of introduced American bullfrogs and support of Chiricahua leopard frog conservation in southeast Arizona

1. This report summaries field surveys conducted during July 2023 through April 2024 to control introduced American bullfrogs ( Lithobates [ Rana ] catesbeianus ; hereafter bullfrog) and support Chiricahua leopard frog ( Lithobates [ Rana ] chiricahuensis ) conservation in southeast Arizona. We conducted 394 field surveys across 141 sites in Chiricahua leopard frog Recovery Units 1 and 2 during this survey period. 2. During these surveys, we detected bullfrogs at 36 sites and removed a total of 452 bullfrogs. Bullfrog reproduction was only observed during this survey period at sites on private property where we did not have landowner permission to remove bullfrogs. We found bullfrogs and Chiricahua leopard frogs co-occurring at only a single site (Chulo Tank). Only a single bullfrog was present at this site, and it was removed. 3. Within the Cobre Ridge/Recovery Unit 1 region, we detected Chiricahua leopard frogs at 15 sites, with reproductive activity confirmed at two sites. We performed or assisted with Chiricahua leopard frog translocations at five sites. We detected Chiricahua leopard frog overwinter survival at two sites in this region although moribund and dead frogs were observed at one of these two sites. 4. We did not detect Chiricahua leopard frog within our Canelo Hills Buffer Zone or stock tanks along the foothills of the San Rafael Valley. We detected Chiricahua leopard frogs at four sites on the Appleton-Whittell Research Ranch with reproduction documented at two sites. We also removed two adult bullfrogs from a single site. 5. We detected Chiricahua leopard frogs at 17 sites on the Las Cienegas National Conservation Area (LCNCA). While Chiricahua leopard frog reproduction was not confirmed during July–November of 2023, as of 24 April 2025 we detected Chiricahua leopard frog reproduction at three sites. We did detect a moribund Chiricahua leopard frog at Lower Empire Gulch in March 2024. No bullfrogs were detected on the LCNCA and a single adult bullfrog was removed from one site in the Elgin Buffer Zone. 6. We began bullfrog removal efforts at a new eradication site along the Babocomari River on the Babacomari Ranch. This planned four-year eradication project will remove a significant non-urban bullfrog source population that threatens existing Chiricahua leopard frog metapopulations.

Arizona↗
USGS2018

Landscape conservation design for enhancing the adaptive capacity of coastal wetlands in the face of sea-level rise and coastal development

Coastal wetlands provide many valuable benefits to people and wildlife, including critical habitat, improved water quality, reduced flooding impacts, and protected coastlines. However, in the 21st century, accelerated sea-level rise and coastal development are expected to greatly alter coastal landscapes across the globe. The future of coastal wetlands is uncertain, challenging coastal environmental managers to develop conservation strategies that will increase the resilience of these valuable ecosystems to change and preserve the benefits they provide. One strategy for preparing for the effects of sea-level rise is to ensure that there is space available for coastal wetlands to migrate inland. In a recent study, we identified areas where coastal wetlands may move inland along the northern Gulf of Mexico coast, one of the most wetland-rich and sea-level rise sensitive regions of the world. Building on these findings, this project produced customized landscape conservation-design products focused on identifying landward migration routes for coastal wetlands. The resulting products provide environmental managers with information to make decisions to enhance the capacity of coastal wetlands to adapt to sea-level rise and coastal development, protecting these ecosystems and the critical economic and ecological benefits that they provide.

Alabama, Florida, Louisiana, Mississippi, Texas↗
USGS2013

Resilience thinking and a decision-analytic approach to conservation: strange bedfellows or essential partners?

There has been some tendency to view decision science and resilience theory as opposing approaches, or at least as contending perspectives, for natural resource management. Resilience proponents have been especially critical of optimization in decision science, at least for those cases where it is focused on the aggressive pursuit of efficiency. In general, optimization of resource systems is held to reduce spatial, temporal, or organizational heterogeneity that would otherwise limit efficiency, leading to homogenization of a system and making it less able to cope with unexpected changes or disturbances. For their part, decision analysts have been critical of resilience proponents for not providing much practical advice to decision makers. We believe a key source of tension between resilience thinking and application of decision science is the pursuit of efficiency in the latter (i.e., choosing the “best” management action or strategy option to maximize productivity of one or few resource components), vs. a desire in the former to keep options open (i.e., maintaining and enhancing diversity). It seems obvious, however, that with managed natural systems, there must be a principle by which to guide decision making, which at a minimumallows for a comparison of projected outcomes associated with decision alternatives. This is true even if the primary concern of decision making is the preservation of system resilience. We describe how a careful framing of conservation problems, especially in terms of management objectives and predictive models, can help reduce the purported tension between resiliencethinking and decision analysis. In particular, objective setting in conservation problems needs to be more attuned to the dynamics of ecological systems and to the possibility of deep uncertainties that underlie the risk of unintended, if not irreversible, outcomes. Resilience thinking also leads to the suggestion that model development should focus more on process rather than pattern, on multiple scales of influence, and on phenomena that can create alternative stability regimes. Although we acknowledge the inherent difficulties in modeling ecological processes, we stress that formulation of useful models need not depend on a thorough mechanistic understanding or precise parameterization, assuming that uncertainty is acknowledged and treated in a systematic manner.

Ecology and Society↗
USGS2023

A hierarchical approach to fish conservation in semiarid landscapes: A need to understand multiscale environmental relationships

A multiscale perspective is essential for conservation planning of riverine fishes. Coarse-scale habitat (e.g., basis) can influence both finer-scale habitat characteristics (e.g., reaches and microhabitat) and associated species distributions. Finer-scale management and habitat rehabilitation efforts can fail without the consideration of coarser-scale constraints. We provide a conceptual hierarchical framework for multiscale fish conservation strategies in the semiarid Great Plains. The Great Plains stream network is highly fragmented due to dam construction, water withdrawals, and increased drought severity. Our framework uses relationships with basin-scale connectivity and streamflow and reach-scale physicochemical characteristics in the context of aiding species reintroduction and stream habitat improvements.

Book chapter↗
USGS2018

Evaluating outcomes of management targeting the recovery of a migratory songbird of conservation concern

Assessing outcomes of habitat management is critical for informing and adapting conservation plans. From 2013 – 2019, a multi-stage management initiative aims to create >25,000 ha of shrubland and early-successional vegetation to benefit Golden-winged Warblers (Vermivora chrysoptera) in managed forested landscapes of the western Great Lakes region. We studied a dense breeding population of Golden-winged Warblers at Rice Lake National Wildlife Refuge (NWR) in Minnesota, USA, where shrubs and young trees were sheared during the winter of 2014-2015 in a single treatment supported in part by the American Bird Conservancy (ABC) and in part by other funding source(s) to benefit Golden-winged Warblers and other species associated with young forest [e.g., American Woodcock (Scalopax minor)] and as part of maintenance of early successional forest cover on the refuge.

Minnesota↗
USGS1999

Picking up the pieces: Conserving remnant natural areas in the post-industrial landscape of the Calumet Region

The Calumet Region was shaped by geologic forces, succession, and interacting biomes converging on a unique natural landscape. Over the past 4500 years, a strand plain has formed to the north of a geologic area called Toleston Beach. Sequential and differential primary succession of dune and swale communities in this region allowed species from different biomes to interact freely. In the mid-nineteenth century, commerce and settlement drastically changed the area, and natural areas were fragmented, manipulated, and degraded by cultural intrusions and industrialization. Despite the near obliteration of dune and swale habitat, small fragments of natural land escaped destruction. These native fragments maintained some semblance of the landscape that once covered the region. Currently, these native fragments are threatened by the lingering intrusion of historic contamination and the continuing presence of industry and commerce. Restoration and conservation of these remnants will need to be a process of integrating biological diversity goals into the landscape of the industrialized region through planning and design. We outline here the natural history of the region, the philosophical rationale for conservation, and possible approaches for integrating and maintaining these valuable remnant resources and processes.

Illinois, Indiana, Michigan↗
USGS1994

A glossary for avian conservation biology

This glossary provides standard definitions for many of the terms used in avian conservation biology. We compiled these definitions to assist communication among researchers, managers, and others involved in the Neotropical Migratory Bird Conservation Program, also known as Partners in Flight. We used existing glossaries and recent literature to prepare this glossary. The cited sources were not necessarily the first ones to use the terms. Many definitions were taken verbatim from the cited source material. Others were modified slightly to clarify the meaning. Definitions that were modified to a greater extent are indicated as being adapted from the originals. Terms that have been used in more than one way by different authors are listed with numbered alternative definitions if the definitions differ substantially.

The Wilson Bulletin↗
USGS1995

Contributions of the Conservation Reserve Program to populations of breeding birds in North Dakota

Previous studies have shown that habitat provided by the Conservation Reserve Program (CRP), a feature of the 1985 farm bill, is used by many birds. The present study quantitatively assesses the importance of the CRP by estimating changes in breeding-bird populations of North Dakota projected if CRP land would revert to cultivation. Of 18 species that were common in CRP or crop fields or both, 12 were more abundant in CRP habitats. Six of these species had suffered significant population declines during 1967-1990, according to the North American Breeding Bird Survey. In contrast, none of the six species that were more common in cropland than in CRP fields had declined significantly. Termination of the Conservation Reserve Program and a return of enrolled land to cultivation is projected to cause population declines in North Dakota exceeding 17% for Sedge wren (Cistothorus platensis), Grasshopper sparrow (Ammodramus savannarum), Savannah Sparrow (Passerculus sandwichensis), Dickcissel (Spiza americana), and Lark Bunting (Calamospiza melanocorys).

The Wilson Bulletin↗
USGS1993

The Conservation Reserve Program: habitat for grassland birds

The Conservation Reserve Program (CRP) has effected major changes to the landscape, especially in the northern Great Plains. Breeding birds have responded dramatically to habitat changes by colonizing CRP fields, often in large numbers. The vegetation in most CRP fields consists of introduced grasses and legumes, along with a variety of weedy species. This paper describes the bird populations found during three years of surveys on more than 300 CRP fields in western Minnesota, North Dakota, South Dakota, and eastern Montana. We relate densities of selected species to geographic location, annual effects, conservation practice adopted, and vegetation features.

Great Plains Research↗
USGS2003

Review of techniques to prevent introduction of zebra mussels (Dreissena polymorpha) during native mussel (Unionoidea) conservation activities

Because of the declines in diversity and abundance of native freshwater mussels (superfamily Unionoidea), and the potential decimation of populations of native mussels resulting from the rapid spread of the exotic zebra mussel Dreissena polymorpha, management options to eliminate or reduce the threat of the zebra mussel are needed. Relocating native mussels to refugia (artificial and natural) has been proposed to mitigate the threat of zebra mussels to native species. Relocation of native mussels to refugia such as fish hatchery facilities or natural habitats within their historic range. Which are unlikely to be infested by zebra mussels, necessitates that protocols be developed to prevent the inadvertent introduction of zebra mussels. Several recent studies have developed Such protocols, and have assessed their effectiveness on the health and survival of native mussels during subsequent relocation to various refugia. The purpose of this project is to synthesize and evaluate the current protocols and to develop a set of procedures that resource managers and researchers should consider before conducting conservation activities in zebra mussel infested waters. We found that the existing protocols have many common points of concern, such as facility modification and suitability, zebra mussel risk assessment and management procedures, and health and disease management procedures. These conservation protocols may have broad applicability to other situations and locations. A summary and evaluation of the information in these main areas, along with recommended guidelines, are presented in this article.

Journal of Shellfish Research↗
USGS2003

Status assessment and conservation plan for the Western Burrowing Owl in the United States

The Western Burrowing Owl ( Athene cunicularia hypugaea ) is a grassland specialist distributed throughout w. North America, primarily in open areas with short vegetation and bare ground in desert, grassland, and shrub-steppe environments. Burrowing Owls are dependent on the presence of fossorial mammals (primarily prairie dogs and ground squirrels), whose burrows are used for nesting and roosting. Burrowing Owls are protected by the Migratory Bird Treaty Act in the United States and Mexico. They are listed as Endangered in Canada and Threatened in Mexico. They are considered by the U.S. Fish and Wildlife Service (USFWS) to be a Bird of Conservation Concern at the national level, in three USFWS regions, and in nine Bird Conservation Regions . At the state level, Burrowing Owls are listed as Endangered in Minnesota, Threatened in Colorado, and as a Species of Concern in California, Montana, Oklahoma, Oregon, Utah, Washington, and Wyoming.

Biological Technical Publication↗
USGS2000

Grassland bird use of Conservation Reserve Program Fields in the Great Plains

The area enrolled in the Conservation Reserve Program in the Great Plains is enormous: nearly 18 million acres, or more than 7 million hectares, in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use has had a huge influence on grassland bird populations. Many, but certainly not all, grassland species flourish in CRP habitats. Responses to the program vary not only by species, but by region, year, vegetation composition in a field, and whether or not a field was hayed or grazed. Further, the large scale of CRP has allowed researchers to begin to address other important conservation questions, such as the effect of the size of habitat patch and the influences of landscape features. Although the CRP provisions of farm bills have been beneficial to grassland birds, it is critical that gains in grassland habitat induced by the program not be offset by losses due to sodbusting.

Technical Report↗
USGS1985

An overview of raptor biology and conservation in Latin America

Prior to the last decade, biological studies of raptorial birds in Latin America were, with a few exceptions, nonexistent. For many species all that was known was the general range and habitat type. While the logistical and political challenges are still present, the last few years has seen the opening of a door to what will almost surely be a flood of scientific investigations. From over 40,000 ground miles traveled in 16 countries, field contact with over two thirds of the raptor species, and interviews with conservation officers in 10 nations, I will report on some raptor concentration areas, identify topics for future research, and generalize on raptor conservation issues. I will also briefly mention some recent biological studies and touch briefly on the challenges awaiting the biologist who tries his or her hand at reaping the rewards that are present in abundance for those who engage in raptor studies in Latin America.

Book chapter↗
USGS2001

Evaluation of the major histocompatibility complex (Mhc) in cranes: applications to conservation efforts

Although there have been heated discussions concerning the relative importance of using Mhc diversity as a basis for selecting breeders in conservation projects, most parties agree that the genetic variability residual in an endangered species should be maintained through genetic management, if at all possible. Substantial evidence exists (particularly in birds) documenting the influences of specific Mhc haplotypes on disease outcome and also that those individuals which are heterozygous for Mhc alleles appear to have an advantage for survival over those that are homozygous. Thus, conservation of genetic variability of the Mhc is likely important for the preservation of fitness, especially in small breeding populations. More than half of the world's crane species are listed as endangered. Members of all 15 known species are represented among breeding animals for captive propagation at the International Crane Foundation (Wisconsin) and the USGS Patuxent Wildlife Research Center (Maryland). Collaborative multi-organization efforts and the availability of extensive pedigree records have allowed the study of Mhc variability in several species of cranes. We have found, for example, that Mhc diversity in the captive Florida sandhill crane (Grus canadensis pratensis) population appears high, whereas in the captive whooping crane (Grus americana), which has undergone a severe 'genetic bottleneck,? both the number of alleles and the levels of heterozygosity appear to be substantially reduced.

Book chapter↗
USGS2005

Post-harvest field manipulations to conserve waste rice for waterfowl

Rice seeds escaping collection by combines during harvest (hereafter, waste rice) provide quality forage for migrating and wintering waterfowl in the Lower Mississippi Alluvial Valley (MAV) and other rice growing regions in the United States. Recent sample surveys across the MAV have revealed abundance of waste rice in fields declined an average of 71% between harvest and late autumn. Thus, we evaluated the ability of common post-harvest, field-management practices to conserve waste rice for waterfowl until early winter via controlled experiments in Mississippi rice test plots in 2001 and 2003 and analyses of data from MAV-wide surveys of waste rice in rice production fields in 2000-2002. Our experiments indicated test plots with burned rice stubble that were not flooded during autumn contained more waste rice than other treatments in 2001 (P?0.10). Waste-rice abundance in test plots did not differ among postharvest treatments in 2003 (P = 0.97). Our analyses of data from the MAV sample surveys did not detect differences in abundance of waste rice among fields burned, rolled, disked, or left in standing stubble post-harvest (P?0.04; Bonferroni corrected critical ( a= 0.017). Because results from test-plot experiments were inconclusive, we based our primary inference regarding best post-harvest treatments on patterns of rice abundance identified from the MAV surveys and previously documented environmental and agronomic benefits of managing harvested rice fields for wintering waterfowl. Therefore, we recommend leaving standing stubble in rice fields after harvest as a preliminary beneficial management practice. We suggest future research evaluate potential of postharvest practices to conserve waste rice for waterfowl and reduce straw in production rice fields managed for wintering waterfowl throughout the MAV.

Proceedings of the Annual Conference of the Southe↗
USGS2003

Developing a general conceptual framework for avian conservation science

Avian conservation science in North America has produced a variety of monitoring programs designed to provide information on population status of birds. Waterfowl surveys provide population estimates for breeding ducks over most of the continent, the North American Breeding Bird Survey (BBS) provides indexes to population change for >400 breeding bird species, and many other surveys exist that index bird populations at a variety of scales and seasons. However, many fundamental questions about bird population change remain unanswered. I suggest that analyses of monitoring data provide limited understanding of causes of population change, and that the declining species paradigm (Caughley 1994) is sometimes an inefficient approach to increasing our understanding of causes of population change. In North America, the North American Bird Conservation Initiative (NABCI) provides an opportunity to implement alternative approaches that use management, modeling of population responses to management, and monitoring in combination to increase our understanding of bird populations. In adaptive resources management, modeling provides predictions about consequences of management, and monitoring data allow us to assess the population consequences of management. In this framework, alternative hypotheses about response of populations to management can be evaluated by formulating a series of models with differing structure, and management and monitoring provide information about which model best predicts population response.

Ornis Hungarica↗
USGS2011

Secretion of anti-Müllerian hormone in the Florida manatee Trichechus manatus latirostris , with implications for assessing conservation status

Environmental and anthropogenic stressors can affect wildlife populations in a number of ways. For marine mammals (e.g. the Florida manatee Trichechus manatus latirostris ), certain stressors or conservation risk factors have been identified, but sublethal effects have been very difficult to assess using traditional methods. The development of 'biomarkers' allows us to correlate effects, such as impaired reproduction, with possible causes. A recently developed biomarker (anti-Müllerian hormone, AMH) provides an enzyme-linked immunosorbent assay of gonadal function. The study objective was to determine AMH levels in wild manatees. In total, 28 male and 17 female manatee serum samples were assayed. Animal demographics included collection date, body weight (kg) and total length (cm). In certain cases, age of individuals was also known. AMH levels ranged from 160 to 2451.85 ng ml -1 (mean = 844.65 ng ml -1 ) in males and 0.00 to 0.38 ng ml -1 (mean = 0.10 ng ml-1) in females. Linear regression analyses revealed a significant relationship between male AMH levels and body weight (R 2 = 0.452; p < 0.001) and length (R 2 = 0.338; p < 0.001). Due to the small sample size, regression analyses for female AMH and body weight and length were not significant. This represents the first report of AMH detection in a marine mammal. AMH levels in male manatees are the highest of any species observed to date, whereas levels in females are within reported ranges. Further studies will promote improved conservation decision by assessing AMH levels in the manatee as a function of various stressors including, but not limited to, nutritional status, serious injuries (e.g. watercraft collisions), exposure to biotoxins or contaminants, or disease.

Florida↗
USGS1995

Simulation models for conservative and nonconservative solute transport in streams

Solute transport in streams is governed by a suite of hydrologic and chemical processes. Interactions between hydrologic processes and chemical reactions may be quantified through a combination of field-scale experimentation and simulation modeling. Two mathematical models that simulate conservative and nonconservative solute transport in streams are presented. A model for conservative solutes that considers One Dimensional Transport with Inflow and Storage (OTIS) may be used in conjunction with tracer-dilution methods to quantify hydrologic transport processes (advection, dispersion, lateral inflow and transient storage). For nonconservative solutes, a model known as OTEQ may be used to quantify chemical processes within the context of hydrologic transport. OTEQ combines the transport mechanisms in OTIS with a chemical equilibrium sub-model that considers complexation, precipitation/dissolution and sorption. OTEQ has been used to quantify processes affecting trace metals in two streams in the Rocky Mountains of Colorado, USA.

Effects of scale on interpretation and management ↗