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At least 973 records · Page 54Linked to original sources

USGS2015

Climate-induced lake drying causes heterogeneous reductions in waterfowl species richness

Context Lake size has declined on breeding grounds for international populations of waterfowl. Objectives Our objectives were to (1) model the relationship between waterfowl species richness and lake size; (2) use the model and trends in lake size to project historical, contemporary, and future richness at 2500+ lakes; (3) evaluate mechanisms for the species–area relationship (SAR); and (4) identify species most vulnerable to shrinking lakes. Methods Monte Carlo simulations of the richness model were used to generate projections. Correlations between richness and both lake size and habitat diversity were compared to identify mechanisms for the SAR. Patterns of nestedness were used to identify vulnerable species. Results Species richness was greatest at lakes that were larger, closer to rivers, had more wetlands along their perimeters and were within 5 km of a large lake. Average richness per lake was projected to decline by 11 % from 1986 to 2050 but was heterogeneous across sub-regions and lakes. Richness in sub-regions with species-rich lakes was projected to remain stable, while richness in the sub-region with species-poor lakes was projected to decline. Lake size had a greater effect on richness than did habitat diversity, suggesting that large lakes have more species because they provide more habitat but not more habitat types. The vulnerability of species to shrinking lakes was related to species rarity rather than foraging guild. Conclusions Our maps of projected changes in species richness and rank-ordered list of species most vulnerable to shrinking lakes can be used to identify targets for conservation or monitoring.

Landscape Ecology↗

USGS2015

Environmental predictors of shrubby cinquefoil ( Dasiphora fruticosa ) habitat and quality as host for Maine’s endangered Clayton’s copper butterfly ( Lycaena dorcas claytoni )

Population size of habitat-specialized butterflies is limited in part by host plant distribution and abundance. Effective conservation for host-specialist species requires knowledge of host-plant habitat conditions and relationships with the specialist species. Clayton’s copper butterfly ( Lycaena dorcas claytoni ) is a Maine state-endangered species that relies exclusively on shrubby cinquefoil ( Dasiphora fruticosa ) as its host. Dasiphora fruticosa occurs in 28 wetlands in Maine, ten of which are occupied by L. d. claytoni. Little is known about environmental conditions that support large, persistent stands of D. fruticosa in Maine. We evaluated the environment (hydrology, pore water and peat nutrients) associated with D. fruticosa distribution, age, and condition in Maine wetlands supporting robust stands of D. fruticosa to compare with L. d. claytoni occurrence. Although dominant water source in D. fruticosa —containing wetlands included both groundwater discharge and surface-flow, D. fruticosa coverage was greater in wetlands with consistent growing season water levels that dropped into or below the root zone by late season, and its distributions within wetlands reflected pore water hydrogen ion and conductivity gradients. Flooding magnitude and duration were greatest during the L.d. claytoni larval feeding period, whereas, mean depth to water table and upwelling increased and were most variable following the L. d. claytoni egg-laying period that precedes D. fruticosa senescence. Oldest sampled shrubs were 37 years, and older shrubs were larger and slower-growing. Encounter rates of L. d. claytoni were greater in wetlands with larger D. fruticosa plants of intermediate age and greater bloom density. Wetland management that combines conditions associated with D. fruticosa abundance (e.g., non-forested, seasonally consistent water levels with high conductivity) and L. d. claytoni occurrence (e.g., drawdown below the root zone following egg-laying, abundant blooms on intermediate-aged D. fruticosa, nearby D. fruticosa -containing wetlands) will aid L. d. claytoni conservation.

Wetlands Ecology and Management↗

USGS2023

A global ecological signal of extinction risk in marine ray-finned fishes (class Actinopterygii)

Many marine fish species are experiencing population declines, but their extinction risk profiles are largely understudied in comparison to their terrestrial vertebrate counterparts. Selective extinction of marine fish species may result in rapid alteration of the structure and function of ocean ecosystems. In this study, we compiled an ecological trait dataset for 8,185 species of marine ray-finned fishes (class Actinopterygii) from FishBase and used phylogenetic generalized linear models to examine which ecological traits are associated with increased extinction risk, based on the International Union for the Conservation of Nature Red List. We also assessed which threat types may be driving these species toward greater extinction risk and whether threatened species face a greater average number of threat types than non-threatened species. We found that larger body size and/or fishes with life histories involving movement between marine, brackish, and freshwater environments are associated with elevated extinction risk. Commercial harvesting threatens the greatest number of species, followed by pollution, development, and then climate change. We also found that threatened species, on average, face a significantly greater number of threat types than non-threatened species. These results can be used by resource managers to help address the heightened extinction risk patterns we found.

Cambridge Prisms: Extinction↗

USGS2009

Estimation of avian population sizes and species richness across a boreal landscape in Alaska

We studied the distribution of birds breeding within five ecological landforms in Yukon-Charley Rivers National Preserve, a 10,194-km 2 roadless conservation unit on the Alaska-Canada border in the boreal forest zone. Passerines dominated the avifauna numerically, comprising 97% of individuals surveyed but less than half of the 115 species recorded in the Preserve. We used distance-sampling and discrete-removal models to estimate detection probabilities, densities, and population sizes across the Preserve for 23 species of migrant passerines and five species of resident passerines. Yellow-rumped Warblers (Dendroica coronata) and Dark-eyed Juncos (Junco hyemalis) were the most abundant species, together accounting for 41% of the migrant passerine populations estimated. White-winged Crossbills (Loxia leucoptera), Boreal Chickadees (Poecile hudsonica), and Gray Jays (Perisoreus canadensis) were the most abundant residents. Species richness was greatest in the Floodplain/Terrace landform flanking the Yukon River but densities were highest in the Subalpine landform. Species composition was related to past glacial history and current physiography of the region and differed notably from other areas of the northwestern boreal forest. Point-transect surveys, augmented with auxiliary observations, were well suited to sampling the largely passerine avifauna across this rugged landscape and could be used across the boreal forest region to monitor changes in northern bird distribution and abundance. ?? 2009 The Wilson Ornithological Society.

Wilson Journal of Ornithology↗

USGS2024

Ohi'a lehua (Metrosideros polymorpha): A most resilient and persistent foundation species in Hawaiian forests

Metrosideros polymorpha (‘ōhi‘a, ‘ōhi‘a lehua) is an important foundation species in Hawaiian forest habitats. The genus originated in New Zealand and was dispersed to the Hawaiian archipelago approximately 3.9 million years ago. It evolved into five distinct endemic species and one of these, Metrosideros polymorpha , further differentiated into eight varieties across what are now the main Hawaiian Islands. ‘Ōhi‘a is a tree that has great significance in indigenous Hawaiian culture. It is considered a physical manifestation of several principal Hawaiian deities, and serves a broad range of uses in Hawaiian material culture. It occupies a wide diversity of habitats, extending from sea level to over 2,200 m elevation, occupying habitats that range from extremely wet to dry rainfall zones. It is the dominant or co-dominant tree species in wet and mesic forests and is also one of the first woody species to become established on young lava flows. Although ‘ōhi‘a is a dominant forest tree it also exhibits many characteristics of a pioneer species. ‘Ōhi‘a provides the matrix for a wide diversity of endemic plants and animals found in these habitats and functions as the primary vegetation cover on native Hawaiian watersheds, facilitating groundwater recharge and regulating surface runoff. ‘Ōhi‘a has shown remarkable resilience by recolonizing forests that were opened up by disturbance, such as the widespread ‘ōhi‘a canopy dieback that occurred on East Maui in the 1900s and on the east side of the Island of Hawai‘i in the 1970s. Several human-related conditions threaten the continued stability of Hawaii’s native ecosystems, including invasive plants, plant diseases, introduced animals, and changing climate. The research and conservation legacy of Dr. Dieter Mueller-Dombois helped to expand our knowledge of the ecology and importance of ‘ōhi‘a forests, and to increase awareness and appreciation of the remarkable Hawaiian ecosystems that are unique to the world.

Hawaii↗

USGS2020

Predicting multi-species foraging hotspots for marine turtles in the Gulf of Mexico

Quantifying the distribution of animals and identifying underlying characteristics that define suitable habitat are essential for effective conservation of free-ranging species. Prioritizing areas for conservation is important in managing a geographic extent that has a high level of disturbance and limited conservation resources. We examined the potential use of a species distribution model ensemble for multi-species conservation in marine habitats. Using satellite telemetry locations during foraging as input data, and ensemble ecological niche models, we predicted foraging areas for 2 nesting marine turtle species within the Gulf of Mexico (GoM): Kemp’s ridley Lepidochelys kempii (n = 63) and loggerhead Caretta caretta (n = 63). We considered 7 geophysical, biological, and climatic variables and compared contributing factors for each species’ foraging habitat selection. For both species, predicted suitable foraging habitats encompassed large areas along the GoM coast, but only intersected with each other in relatively small areas. Highly parameterized models resulted in overall greater fits, suggesting that multiple factors influence habitat selection by these species. Model validation results were mixed: cross-validation resulted in high prediction accuracy for both species, but an evaluation against independent data resulted in a low omission rate (5%) for Kemp’s ridleys and a high omission rate (72%) for loggerheads. The relatively small intersection of model-predicted foraging areas for these 2 species within the study area may indicate possible niche differentiations. The high omission rate for loggerheads indicates our samples likely underrepresent the population and illustrates the challenges in predicting suitable foraging extents for species that make dynamic movements and have greater individual variability.

Gulf of Mexico↗

USGS2007

Seabirds as indicators of marine ecosystems: Introduction: A modern role for seabirds as indicators

A key requirement for implementing ecosystem-based management is to obtain timely information on significant fluctuations in the ecosystem (Botsford et al. 1997). However, obtaining all necessary information about physical and biological changes at appropriate temporal and spatial scales is a daunting task. Intuitively, one might assume that physical data are more important for the interpretation of ecosystem changes than biological data, but analyses of time series data suggest otherwise: physical data are more erratic and often confusing over the short term compared to biological data, which tend to fluctuate less on annual time scales (Hare & Mantua 2000). Even so, biological time-series may also be confusing when coexisting marine species respond differently to ecosystem variability. For example, while warming temperatures in the Gulf of Alaska following the 1976 to 1977 regime shift favored an increase in gadoids and flatfish, a variety of forage fish and pandalid shrimp species virtually disappeared (Anderson & Piatt 1999). Zooplankton communities in the Gulf of Alaska also demonstrated similar patterns of response (Francis et al. 1998). At the basin scale, favorable conditions for salmon in Alaska following the regime shift were matched inversely by poor conditions in the California Current (Francis et al. 1998). In marine birds, subtropical species increased, while subarctic ones decreased during a warming phase in the southern California Bight. Clearly, no single index can tell the whole story accurately. Multi-species, multi-region, and multi-trophic level approaches are needed to quantify fluctuations in marine ecosystem processes and in the distribution and abundance of its inhabitants, to determine critical parameter thresholds and to use this information in management and marine conservation.

Marine Ecology Progress Series↗

USGS2014

Spawning behavior in Atlantic cod: analysis by use of data storage tags

Electronic data storage tags (DSTs) were implanted into Atlantic cod captured in Icelandic waters from 2002 to 2007 and the depth profiles recovered from these tags (females: n = 31, males: n = 27) were used to identify patterns consistent with published descriptions of cod courtship and spawning behavior. The individual periods of time that males spent exhibiting behavior consistent with being present in a spawning aggregation—i.e. periods consisting of a clear tidal signature in the DST depth profile associated with an individual remaining on or near the substrate—were longer than those of females. Over the course of a spawning season, male cod spent approximately twice the amount of time in spawning aggregations than females, but female cod visited more aggregations per unit time. On average, males participated in approximately 57% more putative spawning events, i.e. vertical ascents potentially corresponding to gamete release, than did females. However, males <85 cm total length participated in the same number of putative spawning events as females of comparable size. In both sexes, larger individuals and/or individuals that spent a longer period of time within an aggregation participated in a larger number of putative spawning events. Although further validation and refinement is necessary, particularly in the identification of spawning events, the ability offered by DSTs to quantify cod spawning behavior may aid in the development of management and conservation plans.

Marine Ecology Progress Series↗

USGS2017

Inequity in ecosystem service delivery: Socioeconomic gaps in the public-private conservation network

Conservation areas, both public and private, are critical tools to protect biodiversity and deliver important ecosystem services (ES) to society. Although societal benefits from such ES are increasingly used to promote public support of conservation, the number of beneficiaries, their identity, and the magnitude of benefits are largely unknown for the vast majority of conservation areas in the United States public-private conservation network. The location of conservation areas in relation to people strongly influences the direction and magnitude of ES flows as well as the identity of beneficiaries. We analyzed benefit zones, the areas to which selected ES could be conveyed to beneficiaries, to assess who benefits from a typical conservation network. Better knowledge of ES flows and beneficiaries will help land conservationists make a stronger case for the broad collateral benefits of conservation and help to address issues of social-environmental justice. To evaluate who benefits the most from the current public-private conservation network, we delineated the benefit zones for local ES (within 16 km) that are conveyed along hydrological paths from public (federal and state) and private (easements) conservation lands in the states of North Carolina and Virginia, USA. We also discuss the challenges and demonstrate an approach for delineating nonhydrological benefits that are passively conveyed to beneficiaries. We mapped and compared the geographic distribution of benefit zones within and among conservation area types. We further compared beneficiary demographics across benefit zones of the conservation area types and found that hydrological benefit zones of federal protected areas encompass disproportionately fewer minority beneficiaries compared to statewide demographic patterns. In contrast, benefit zones of state protected areas and private easements encompassed a much greater proportion of minority beneficiaries (~22–25%). Benefit zones associated with private conservation lands included beneficiaries of significantly greater household income than benefit zones of other types of conservation areas. Our analysis of ES flows revealed significant socioeconomic gaps in how the current public-private conservation network benefits the public. These gaps warrant consideration in regional conservation plans and suggest that private conservation initiatives may be best suited for responding to the equity challenge. Enhancing the ecosystem benefits and the equity of benefit delivery from private conservation networks could build public and political support for long-term conservation strategies and ultimately enhance conservation efficacy.

North Carolina, Virginia↗

USGS1995

Sea otters in the northern Pacific Ocean

About 250 years ago sea otters ( Enhydra lutris ) were distributed continuously from central Baja California, north and west along the Pacific Rim to Machatka Peninsula in Russia, and south along the Kuril Island to northern Japan (Kenyon 1969; Fig. 1a). Several hundred thousand sea otters may have occurred in the north Pacific region when commercial hunting began in the 18th century (Riedman and Estes 1990). At least two attributes of the sea otter have influenced humans, likely for as long as they have resided together along the coast of the north Pacific Ocean. First, sea otters rely on a dense fur, among the finest in the world, for insulation in the cold waters of the Pacific Ocean. The demand for sea otter fur led to their near extinction in the 19th century. The fur harvest, begun about 1740 and halted by international treaty in 1911, left surviving colonies, each likely numbering less than a few hundred animals, in California, south-central Alaska, and the Aleutian, Medney, and Kuril Islands (Fig. 1a). These individuals provided the nucleus for the recovery of the species. Today more than 100,000 sea otters occur throughout about 75% of their original range (fig. 1b). Immigration has resulted in near-complete occupation of the Aleutian and Kuril archipelagos and the Alaska peninsula. Successful translocations have resulted in viable populations in southeast Alaska, Washington, and British Columbia. Large amounts of unoccupied habitat remain along the coasts of Russia, Canada, the United States, and Mexico. The second potential source of conflict between sea otters and humans is that sea otters prey on and often limit some benthic invertebrate populations. Because some of these invertebrates are aso used by humans (Estes and VanBlaricom 1985), human perceptions about the effects of sea otter foraging on invertebrates sometimes differ. By limiting populations of herbivorous invertebrates ( e.g. , sea urchins [Echinoidea]) otters help maintain the integrity of kelp forest communities. At the same time, sea otter predation on other marine invertebrates can lead to direct competition with humans for resources. These interactions add complex dimensions to the conservation and management of sea otters, in large part because of wide-ranging social, ecological, and economic consequences of sea otter foraging. Long-term data on abundance and distribution are available for relatively few sea otter populations. Here we summarize such data from three populations: Being Island, Russia; Prince William Sound, Alaska; and Olympic Peninsula, Washington. The Bering Island population resulted from natural emigration and represents complete recovery. Prince William Sounds represents near recovery of a remnant population, whereas the Washington population was established via translocations from Alaska and is just beginning to recover. We will compare growth rates and current status among these populations. Because of its unique status and growth characteristics, the California sea otter is not treated in this article.

Book chapter↗

USGS2015

Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa . Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

Endangered Species Research↗

USGS2020

Northern Goshawk (Accipiter gentilis) home range, movement and forays revealed by GPS-tracking

The Northern Goshawk ( Accipiter gentilis ) is an apex predator occurring across North America and Eurasia. The species has received considerable conservation focus in late-seral conifer forests of western North America, where its habitat has been substantially reduced and altered by timber harvest and is increasingly at risk from high severity fire, drought, and forest pathogens. In the Sierra Nevada range of California, management and conservation of goshawks are hampered by a lack of knowledge of their basic space use and movement ecology. We used global positioning system (GPS) loggers to investigate space use of 20 resident, adult Northern Goshawks over 3 yr (2015–2018) in the Plumas National Forest, California. Median home range sizes of male goshawks were more than twice as large as those of females, and nonbreeding-season home ranges were three times larger than breeding-season home ranges. High resolution GPS data (location interval 1–6 min) allowed quantification of daily transit distances up to 60 km for individual goshawks and revealed long-distance forays into adjacent territories and surrounding areas. Four goshawks (three males, one female) undertook forays >8 km from their nest locations, with forays lasting up to 6 d; these forays occurred during both breeding and nonbreeding seasons for both sexes. Comparing our results to current conservation approaches, we determined that USDA Forest Service goshawk Protected Activity Centers protected <25% of both the roost locations and the area used during the daytime. Conservation efforts for Northern Goshawks in the Sierra Nevada would benefit from consideration of year-round habitat needs at larger scales than previously thought.

California↗

USGS2024

Assessing and implementing the concept of Blue Economy in Laurentian Great Lakes fisheries: Lessons from coupled human and natural systems

Inland fisheries often receive little to no attention in global discussions about sustainable development. The consequences of overlooking inland fisheries in sustainability dialogues are increasingly problematic as fisheries stressors (e.g., overharvest, species invasion, climate change, habitat modification) intensify. Elevating the global profile of inland fisheries requires an approach for quantifying and clearly conveying the ecological, economic, and societal values of these systems. One such approach involves the Blue Economy, a multifaceted concept initially used to describe the intersection of marine conservation and sustainable use of marine resources for economic growth. Although conceptually powerful, the Blue Economy has rarely been applied to inland waters and fisheries. To address this knowledge gap, we conceptualized Laurentian Great Lakes fisheries from a Blue Economy perspective. In particular, we evaluated the utility of the coupled human and natural systems (CHANS) framework for characterizing the ecological, economic, and societal values of Laurentian Great Lakes fisheries and associated contributions to the Blue Economy (e.g., human livelihoods, food security, recreation, conservation, economic prosperity). There are numerous opportunities to leverage CHANS methods (e.g., metacoupling, telecoupling) and associated mathematical models to advance fisheries science, inform fisheries management, and ultimately move toward a Blue Economy in the Laurentian Great Lakes. To that end, we demonstrated applications of CHANS methods, discussed strategies for communicating with stakeholders, and provided insights for navigating challenges to developing a Blue Economy in the Laurentian Great Lakes—a model that could be used in the African Great Lakes and other large ecosystems in the world.

Laurentian Great Lakes↗

USGS2012

Preliminary investigations of the winter ecology of Long-billed Curlews in coastal Texas

Since the early 1900s, the distribution of the Long-billed Curlew ( Numenius americanus ) has contracted dramatically in the eastern one-half of its historic range. The species has been designated as a "Bird of Conservation Concern" and focal species by the U.S. Fish and Wildlife Service, a species of concern by several states, and a "Highly Imperiled" species in the U.S. Shorebird Conservation Plan. The uncertain outlook for this species has contributed to a plethora of research on Long-billed Curlews, most of which have focused on breeding and nesting ecology of the species. Gaps remain in information about factors affecting population dynamics on the winter grounds and the linkages between Long-billed Curlew populations on the breeding range, migration routes, and winter range. To begin filling those gaps, a pilot study was done to evaluate (1) curlew use of nocturnal roost sites, (2) use of public outreach to locate curlews and contribute to preliminary assessment of foraging habitat use, (3) six different methods to capture curlews, and (4) movements by curlews on wintering areas. The study area includes the lower Texas coast, which harbors the eastern-most dense populations of Long-billed Curlews in North America. Use of historical winter roost sites was not observed; however, there was documented limited use (up to 150 curlews) of several new roost sites, some of which were used on an intermittent or erratic basis. Reports elicited from the public indicated Long-billed Curlews wintering in coastal Texas often forage in open, grass-covered lots of partially developed residential areas, golf courses, and public parks within urban and suburban zones. Curlews were reported to use these sites in developed areas as far as 100 kilometers inland. Other reports indicated Long-billed Curlews foraging in farm fields, shallow coastal marsh, and on the beaches of Gulf of Mexico barrier islands. The effectiveness of six techniques for capture of Long-billed Curlews was evaluated in the study. Seven curlews were captured and banded with four of six methods attempted. At least one curlew each was captured with (1) noose ropes, (2) baited bow net, (3) Coda Netgun, and (4) whoosh net; no curlews were caught with a cast net or Super Talon netgun. The Coda Netgun proved to be the most effective methodology examined. Captured birds (7) were weighed, measured, and banded. Body masses (mean = 518 grams) were low compared to data previously published on body mass of Long-billed Curlews. There were 22 observations recorded of banded curlews. Resightings confirmed that birds were not harmed during capture. All of the 22 resightings occurred within two kilometers of the banding locations, suggesting that birds remained near their chosen foraging areas. Results from this 1-year pilot study yielded an intriguing combination of findings that warrant further investigation. Observations include reduced numbers of roosting birds along the Texas coast during dry conditions, highly dynamic use of nocturnal roost sites, use of widely divergent habitat types for foraging, low body mass of most captured birds, and apparent fidelity to general feeding areas. Future investigations of this eastern winter population of curlews would benefit from larger sample sizes and monitoring of individual birds.

Texas↗

USGS2017

Population characteristics and the influence of discharge on Bluehead Sucker and Flannelmouth Sucker

Rivers are among some of the most complex and important ecosystems in the world. Unfortunately, many fishes endemic to rivers have suffered declines in abundance and distribution suggesting that alterations to lotic environments have negatively influenced native fish populations. Of the 35 fishes native to the Colorado River basin (CRB), seven are considered either endangered, threatened, or species of special concern. As such, the conservation of fishes native to the CRB is a primary interest for natural resource management agencies. One of the major factors limiting the conservation and management of fishes endemic to the CRB is the lack of basic information on their ecology and population characteristics. We sought to describe the population dynamics and demographics of three populations of Bluehead Suckers ( Catostomus discobolus ) and Flannelmouth Suckers ( C. latipinnis ) in Utah. Additionally, we evaluated the potential influence of altered flow regimes on the recruitment and growth of Bluehead Suckers and Flannelmouth Suckers. Mortality of Bluehead Suckers and Flannelmouth Suckers from the Green, Strawberry, and White rivers was comparable to other populations. Growth of Bluehead Suckers and Flannelmouth Suckers was higher in the Green, Strawberry, and White rivers when compared to other populations in the CRB. Similarly, recruitment indices suggested that Bluehead Suckers and Flannelmouth Suckers in the Green, Strawberry, and White rivers had more stable recruitment than other populations in the CRB. Models relating growth and recruitment to hydrological indices provided little explanatory power. Notwithstanding, our results indicate that Bluehead Suckers and Flannelmouth Suckers in the Green, Strawberry, and White rivers represent fairly stable populations and provide baseline information that will be valuable for the effective management and conservation of the species.

Utah↗

USGS2014

Predicting foundation bunchgrass species abundances: Model-assisted decision-making in protected-area sagebrush steppe

Foundation species are structurally dominant members of ecological communities that can stabilize ecological processes and influence resilience to disturbance and resistance to invasion. Being common, they are often overlooked for conservation but are increasingly threatened from land use change, biological invasions, and over-exploitation. The pattern of foundation species abundances over space and time may be used to guide decision-making, particularly in protected areas for which they are iconic. We used ordinal logistic regression to identify the important environmental influences on the abundance patterns of bluebunch wheatgrass ( Pseudoroegneria spicata ), Thurber's needlegrass ( Achnatherum thurberianum ), and Sandberg bluegrass ( Poa secunda ) in protected-area sagebrush steppe. We then predicted bunchgrass abundances along gradients of topography, disturbance, and invasive annual grass abundance. We used model predictions to prioritize the landscape for implementation of a management and restoration decision-support tool. Models were fit to categorical estimates of grass cover obtained from an extensive ground-based monitoring dataset. We found that remnant stands of abundant wheatgrass and bluegrass were associated with steep north-facing slopes in higher and more remote portions of the landscape outside of recently burned areas where invasive annual grasses were less abundant. These areas represented only 25% of the landscape and were prioritized for protection efforts. Needlegrass was associated with south-facing slopes, but in low abundance and in association with invasive cheatgrass ( Bromus tectorum ). Abundances of all three species were strongly negatively correlated with occurrence of another invasive annual grass, medusahead ( Taeniatherum caput-medusae ). The rarity of priority bunchgrass stands underscored the extent of degradation and the need for prioritization. We found no evidence that insularity reduced invasibility; annual grass invasion represents a serious threat to protected-area bunchgrass communities. Our study area was entirely within the Wyoming big sagebrush ecological zone, understood to have inherently low resilience to disturbance and resistance to weed invasion. However, our study revealed important variation in abundance of the foundation species associated with resilience and resistance along the topographic-soil moisture gradient within this zone, providing an important foothold for conservation decision-making in these steppe ecosystems. We found the foundation species focus a parsimonious strategy linking monitoring to decision-making via biogeographic modeling.

Ecosphere↗

USGS2006

Conceptual ecological model for management of breeding grassland birds in the Mid-Atlantic Region

The status of grassland birds has become an increasingly important conservation issue. These species exhibit the most consistent population declines of any group of North American birds during the past 40 years. Anecdotal evidence suggests these declines have been occurring for nearly a century (Peterjohn and Sauer 1999). While the widespread conversion of grasslands into other habitats contributed to these declining populations, other factors such as habitat fragmentation and mowing regimes are also implicated (Vickery et al. 1999a). This plight of grassland birds has heightened awareness of the need for concerted conservation actions to reverse these seriously declining population trends. The National Park Service (NPS) is positioned to potentially contribute to grassland bird conservation in the Mid-Atlantic Region. The NPS maintains a number of historic sites and former battlefields that are managed for their cultural significance but also support wildlife populations. Many of these “cultural parks” maintain open landscapes to recreate land use patterns that existed at the times of the historical events. These open landscapes are primarily managed grasslands which could be maintained to benefit grassland birds. In 2005, the NPS initiated a project exploring the potential of “cultural parks” to support significant breeding grassland bird communities. This project involved parks within three NPS Inventory and Monitoring Program (I&M) networks, Mid-Atlantic, National Capital, and Eastern Rivers and Mountains. Five parks were selected for the initial focus of this study, all of which maintain open landscapes for interpretation of historic events. Most parks were selected because they represent the most extensive grassland habitats within their networks, with the rationale that if these parks cannot support significant breeding grassland bird communities, then parks with smaller acreages cannot support these communities either. The five parks included in this study are: Antietam National Battlefield, Fort Necessity National Battlefield, Gettysburg National Battlefield, Manassas National Battlefield, and Monocacy National Battlefield. This conceptual ecological model is one product of this project. The information presented below allows NPS Network Coordinators to understand the factors to consider when making decisions concerning grassland management within their networks. This model provides park Resource Managers with information on grassland ecology in the Mid-Atlantic Region, the ecological requirements of grassland birds likely to occur in their parks, and management issues that influence whether significant breeding populations can be expected to occupy grasslands created and maintained in the parks. The Resource Managers can then make informed decisions concerning their ability to create and maintain grassland habitats. The emphasis of this conceptual model is restricted to management of breeding grassland birds. Additional species may occur in this region during migration and winter, while habitat requirements of all grassland birds during nonbreeding seasons will differ from those described for the breeding season.

Natural Resource Report↗

USGS2001

Comparison of marine and terrestrial protected areas under federal jurisdiction in the United States

There is a significant disparity in the protection of terrestrial and marine environments in the United States. Despite the considerable literature dedicated to the subject of protected areas, both terrestrial and marine, in the United States, we are not aware of work explicitly describing this dichotomy. We compared marine and terrestrial areas under federal jurisdiction to provide a quantitative assessment of the differences between the conservation of land and sea in the United States. Specifically, we compared national marine sanctuaries (including sanctuary preservation areas and ecological reserves) with national parks, national forests, and national wildlife refuges (including national wilderness preservation areas). Our results suggest that marine sanctuaries are fewer in number, smaller in total area, and smaller in percentage of area covered than are terrestrial protected areas.

Conservation Biology↗