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At least 217 records · Page 12Linked to original sources
USGS2020

U.S. Geological Survey sagebrush ecosystem research annual report for 2020

The sagebrush ( Artemisia spp.) ecosystem extends across 251,473 square miles over portions of 13 western States. Affected by multiple stressors, including interactions among fire, invasive plants, and human land uses, this ecosystem has experienced significant loss, fragmentation, and degradation of landscapes once dominated by sagebrush. In turn, wildlife populations have declined following these deleterious conditions. Federal, State, local, and Tribal agencies, nongovernmental organizations, and industry have been galvanized by declining wildlife populations to implement management actions to confront the impacts of these stressors and ensure the long-term availability of the sagebrush ecosystem for the broad range of uses critical to stakeholders in the Western United States. The sagebrush ecosystem provides habitat for more than 350 species of plants and animals that are dependent on sagebrush for all or part of their annual life history. The greater sage-grouse ( Centrocercus urophasianus ) stands out as an iconic species of this ecosystem. Sage-grouse populations occur in 11 States, and 2 Canadian Provinces and require relatively large expanses of sagebrush-dominated habitat to meet all their seasonal habitat needs. Recent management actions to conserve and maintain the sagebrush ecosystem have focused on the protection and restoration of sage-grouse habitat; however, each of the 350 species has a unique life history and differing area requirements (for example, large areas for mule deer [ Odocoileus hemionus ] and small areas for pygmy rabbit [ Brachylagus idahoensis ]), and some species, such as migratory birds, rely on various parts of the sagebrush ecosystem but only for part of the year (for example, Brewer’s sparrow [ Spizella breweri ]). The U.S. Geological Survey (USGS) has a broad research program focused on the sagebrush ecosystem, wildlife species within the ecosystem, and the species’ response to stressors and management actions. The program provides a foundation of scientific information for use in major land and resource management decisions in the sagebrush ecosystem. By providing the science to inform these decisions, the USGS is assisting land and resource managers at the Federal, State, Tribal, and local levels working towards the goal of sustainable wildlife populations and restored landscapes. This information can inform planning and management conducted by nongovernmental organizations as well. USGS research is tailored specifically to inform adaptive management, improve strategies for maintaining existing areas of intact sagebrush, and restoring degraded landscapes. Examples of research support for partners include providing information for actions such as the preclusion of the need to list the greater sage-grouse under the Endangered Species Act and recent revisions to Bureau of Land Management and U.S. Department of Agriculture Forest Service resource management plans and land use. The USGS continues to provide foundational science to inform science-based decisions within the U.S. Department of the Interior and other Federal, State, and local agencies and their continued conservation, management, and restoration of the sagebrush ecosystem to help support local economies.

Arizona, California, Colorado, Idaho, Montana, Nev↗
USGS2001

`Akohekohe response to flower availability: seasonal abundance, foraging, breeding, and molt

We studied the relationship of flower availability to the seasonality of life history events of the `Akohekohe (Palmeria dolei), a primarily nectarivorous and endangered Hawaiian honeycreeper from montane rain forests on Maui, Hawai`i. For comparison, we also investigated temporal bird density and foraging behavior of three other competing Hawaiian honeycreepers: `Apapane (Himatione sanguinea), `I`iwi (Vestiaria coccinea), and Hawai`i `Amakihi (Hemignathus virens). All species except `Amakihi fed primarily on nectar of `Ohi?a-lehua (Metrosideros polymorpha), which produced flowers year-round but had an annual flowering peak in January. Flowers of several subcanopy shrubs and trees were important components of the diet for all nectarivores, and these were available seasonally depending upon the species. `Akohekohe densities did not change temporally, suggesting a relatively stable population residing above 1,700 m. Monthly densities of `Apapane, `I`iwi, and Hawai`i `Amakihi were positively correlated with monthly `Ohi?a-lehua flower abundance, and 50-80% of these populations departed temporarily from our high-elevation site in July. There was a positive correlation with the timing of Akohekohe breeding and high abundance of `Ohi?a-lehua bloom. Molt followed breeding. From a conservation perspective, these results show that `Akohekohe maintain a relatively stable population above the mid-elevation zone of disease transmission, particularly during the fall when `Ohi?a-lehua bloom decreases and mosquitoes increase. `Akohekohe remain on their territories partly by switching their foraging to subcanopy trees and shrubs, most of which require protection from feral pigs (Sus scrofa).

Hawaii↗
USGS2002

Individual covariation in life-history traits: Seeing the trees despite the forest

We investigated the influence of age on survival and breeding rates in a long-lived species Rissa tridactyla using models with individual random effects permitting variation and covariation in fitness components among individuals. Differences in survival or breeding probabilities among individuals are substantial, and there was positive covariation between survival and breeding probability; birds that were more likely to survive were also more likely to breed, given that they survived. The pattern of age-related variation in these rates detected at the individual level differed from that observed at the population level. Our results provided confirmation of what has been suggested by other investigators: within-cohort phenotypic selection can mask senescence. Although this phenomenon has been extensively studied in humans and captive animals, conclusive evidence of the discrepancy between population-level and individual-level patterns of age-related variation in life-history traits is extremely rare in wild animal populations. Evolutionary studies of the influence of age on life-history traits should use approaches differentiating population level from the genuine influence of age: only the latter is relevant to theories of life-history evolution. The development of models permitting access to individual variation in fitness is a promising advance for the study of senescence and evolutionary processes.

Brittany↗
USGS2017

Nest predation risk explains variation in avian clutch size

Questions about the ecological drivers of, and mechanistic constraints on, productivity have driven research on life-history evolution for decades. Resource availability and offspring mortality are considered among the 2 most important influences on the number of offspring per reproductive attempt. We used a factorial experimental design to manipulate food abundance and perceived offspring predation risk in a wild avian population (red-faced warblers; Cardellina rubrifrons ) to identify the mechanistic cause of variation in avian clutch size. Additionally, we tested whether female quality helped explain the extant variation in clutch size. We found no support for the Food Limitation or Female Quality Hypotheses, but we did find support for both predictions of the Nest Predation Risk Hypothesis. Females that experienced an experimentally heightened perception of offspring predation risk responded by laying a smaller clutch than females in the control group. Additionally, predation rates at artificial nests were highest where red-faced warbler clutch size was smallest (at high elevations). Life-history theory predicts that an individual should invest less in reproduction when high nest predation risk reduces the likely benefit from that nesting attempt and, indeed, we found that birds exhibit phenotypic plasticity in clutch size by laying fewer eggs in response to increasing nest predation risk.

Behavioral Ecology↗
USGS2019

Large-scale tree mortality from Rapid Ohia Death negatively influences avifauna in lower Puna, Hawai‘i Island, USA

‘Ōhi’a lehua ( Metrosideros polymorpha ) is the principle tree species in forests across the Hawaiian Islands and provides critical foraging and nesting habitat for native passerines. Rapid Ohia Death (ROD), caused by the vascular wilt fungus Ceratocystis lukuohia and the canker pathogen C. huliohia , was first detected in the Puna District of Hawaii Island in 2010. It affects all life stages of ‘ōhi’a and as of July 2018 had spread to an estimated 40,469 ha across Hawaii Island. To determine the impact of ROD on the forest bird community we conducted point counts in lowland ‘ōhi’a forest in 2016 and compared them to counts from 2003 to 2004, before the appearance of ROD. We found an increase in species diversity and a significant decrease in the densities of a native Hawaiian honeycreeper, the Hawaii Amakihi ( Chlorodrepanus virens ), and the nonnative Japanese White-eye ( Zosterops japonicus ). Yellow-fronted Canary ( Crithagra mozambica ) and Saffron Finch ( Sicalis flaveola ), 2 nonnative passerines associated with the shrub layer and more open habitats, were only detected in 2016. Proportion of survey points occupied were comparable between survey periods, but relative abundances were generally lower. Hawaii Amakihi densities declined by 79% and Japanese White-eye densities declined by 33%. Our findings suggest that the loss of ‘ōhi’a canopy due primarily to ROD has adversely affected populations of native Hawaii Amakihi and nonnative Japanese White-eye, 2 of the most abundant species of lowland Hawaiian forests.

Hawaii↗
USGS2009

Does influenza A affect body condition of wild mallard ducks, or vice versa?

Low pathogenic avian influenza (LPAI) viruses are well documented to circulate within wild waterfowl populations (Olsen et. al. 2006 ). It has been assumed that these infections are benign with no subsequent effects on life-history parameters. The study by Latorre-Margalef et al. (2009 ; hereafter L.-M. et al. ) represents an important step, as they attempt to test this assumption in wild birds. L.-M. et al. captured migrating mallards ( Anas platyrhynchos ) at a staging area and tested them for the presence of avian influenza A virus (IAV). They related IAV infection status to body mass and duration of time spent on the staging area. Overall, the study is well designed with impressive sample sizes and the analyses are carefully conducted and presented. However, in discussing these results, the authors assume causation based upon correlation and, although they acknowledge the possibility of immunosuppression during migration due to reduced energy stores, they do not discuss it as a possible explanation for their findings. Below, we consider several of the major findings by L.-M. et al. , providing alternative explanations for the results. Because the L.-M. et al. study design is correlational, it is not possible to use their data to distinguish between their interpretations and our alternative explanations.

Proceedings of the Royal Society B: Biological Sci↗
USGS2011

Status and distribution of the Kittlitz's Murrelet Brachyramphus brevirostris along the Alaska Peninsula and Kodiak and Aleutian Islands, Alaska

The Kittlitz's Murrelet Brachyramphus brevirostris is adapted for life in glacial-marine ecosystems, being concentrated in the belt of glaciated fjords in the northern Gulf of Alaska from Glacier Bay to Cook Inlet. Most of the remaining birds are scattered along coasts of the Alaska Peninsula and Aleutian Islands, where they reside in protected bays and inlets, often in proximity to remnant glaciers or recently deglaciated landscapes. We summarize existing information on Kittlitz's Murrelet in this mainly unglaciated region, extending from Kodiak Island in the east to the Near Islands in the west. From recent surveys, we estimated that ~2400 Kittlitz's Murrelets were found in several large embayments along the Alaska Peninsula, where adjacent ice fields feed silt-laden water into the bays. On Kodiak Island, where only remnants of ice remain today, observations of Kittlitz's Murrelets at sea were uncommon. The species has been observed historically around the entire Kodiak Archipelago, however, and dozens of nest sites were found in recent years. We found Kittlitz's Murrelets at only a few islands in the Aleutian chain, notably those with long complex shorelines, high mountains and remnant glaciers. The largest population (~1600 birds) of Kittlitz's Murrelet outside the Gulf of Alaska was found at Unalaska Island, which also supports the greatest concentration of glacial ice in the Aleutian Islands. Significant populations were found at Atka (~1100 birds), Attu (~800) and Adak (~200) islands. Smaller numbers have been reported from Unimak, Umnak, Amlia, Kanaga, Tanaga, Kiska islands, and Agattu Island, where dozens of nest sites have been located in recent years. Most of those islands have not been thoroughly surveyed, and significant pockets of Kittlitz's Murrelets may yet be discovered. Our estimate of ~6000 Kittlitz's Murrelets along the Alaska Peninsula and Aleutian Islands is also likely to be conservative because of the survey protocols we employed (i.e. early seasonal timing of surveys, strip transects).

Alaska↗
USGS1960

The trumpeter swan: its history, habits, and population in the U.S

This report on the trumpeter evolved from studies made from 1948 to 1957 when I served first as an assistant and later as manager, of the Red Rock Lakes Refuge. I have also drawn extensively on the records of the National Park Service, the U. S. Fish and Wildlife Service, and the National Museum in Washington, D. C. Other pertinent information bearing on the life history of the trumpeter swan in the United States has been extracted from published articles, unpublished reports and records, firsthand accounts and correspondence. This account includes a historical record of this bird in the United States and Alaska, an outline of its habits and characteristics in its native Rocky Mountain environment, and furnishes information necessary to guide its future.

North American Fauna↗
USGS2008

Effects of environmental factors on incubation patterns of Greater Sage-Grouse

Birds in which only one sex incubates the eggs are often faced with a direct conflict between foraging to meet metabolic needs and incubation. Knowledge of environmental and ecological factors that shape life-history strategies of incubation is limited. We used continuous videography to make precise measurements of female Greater Sage-Grouse ( Centrocercus urophasianus ) incubation constancy (percentage of time spent at the nest in a 24-hour period) and recess duration. We used an information-theoretic approach to evaluate incubation patterns in relation to grouse age, timing of incubation, raven abundance, microhabitat, weather, and food availability. Overall, sage-grouse females showed an incubation constancy of 96% and a distinctive bimodal distribution of brief incubation recesses that peaked at sunset and 30 min prior to sunrise. Grouse typically returned to their nests during low light conditions. Incubation constancy of yearlings was lower than that of adults, particularly in the later stages of incubation. Yearlings spent more time away from nests later in the morning and earlier in the evening compared to adults. Video images revealed that nearly all predation events by Common Ravens ( Corvus corax ), the most frequently recorded predator at sage-grouse nests, took place during mornings and evenings after sunrise and before sunset, respectively. These were the times of the day when sage-grouse typically returned from incubation recesses. Recess duration was negatively related to raven abundance. We found evidence that incubation constancy increased with greater visual obstruction, usually from vegetation, of nests. An understanding of how incubation patterns relate to environmental factors will help managers make decisions aimed at increasing productivity through successful incubation.

The Condor↗
USGS2003

Survival of female Lesser Scaup: Effects of body size, age, and reproductive effort

In birds, larger females generally have greater breeding propensity, reproductive investment, and success than do smaller females. However, optimal female body size also depends on how natural selection acts during other parts of the life cycle. Larger female Lesser Scaup (Aythya affinis) produce larger eggs than do smaller females, and ducklings from larger eggs survive better than those hatching from smaller eggs. Accordingly, we examined patterns of apparent annual survival for female scaup and tested whether natural selection on female body size primarily was stabilizing, a frequent assumption in studies of sexually dimorphic species in which males are the larger sex, or was directional, counter-acting reproductive advantages of large size . We estimated survival using mark-recapture methods for individually marked females from two study sites in Canada (Erickson, Manitoba; St. Denis, Saskatchewan). Structurally larger (adults) and heavier (ducklings) females had lower survival than did smaller individuals in Manitoba; no relationship was detected in adults from Saskatchewan. Survival of adult females declined with indices of increasing reproductive effort at both sites; consequently, the cost of reproduction could explain age -related patterns of breeding propensity in scaup . Furthermore, if larger females are more likely to breed than are smaller females, then cost of reproduction also may help explain why survival was lower for larger females. Overall, we found that advantages of large body size of female scaup during breeding or as young ducklings apparently were counteracted by natural selection favoring lightweight juveniles and structurally smaller adult females through higher annual survival .

Condor↗
USGS1990

[Book review] Return of the Whooping Crane

Fewer than 40 years ago, Life magazine ran an article decrying the plight of Whooping Cranes ( Grus americana ) on their wintering grounds at Aransas National Wildlife Refuge (Aransas) along the Gulf Coast. The small flock of approximately 20 birds that summered at Wood Buffalo National Park (Wood Buffalo) in Canada and wintered on the Texas coast at Aransas comprised the entire wild population of the species-a population that at the time seemed to be drifting inexorably to- ward extinction. Today, the Aransas/Wood Buffalo flock numbers more than 140 birds, there are more than 30 birds in captivity at the Patuxent Wildlife Research Center (Patuxent), and another 20-plus birds at the International Crane Foundation in Baraboo, Wisconsin. There are also a dozen wild birds in an experimental flock (termed the Rocky Mountain flock by Doughty) that winters at Bosque Del Apache National Wildlife Refuge (NWR) in New Mexico and summers in the mountain valleys centered on Grays Lake NWR in Idaho.

The Auk↗
USGS2007

Mercury in precipitation in Indiana, January 2001–December 2003

Mercury in precipitation was monitored during 2001 through 2003 at four locations in Indiana as part of the National Atmospheric Deposition Program-Mercury Deposition Network (NADP-MDN). Monitoring stations were operated at Roush Lake near Huntington, Clifty Falls State Park near Madison, Monroe County Regional Airport near Bloomington, and Indiana Dunes National Lakeshore near Porter. At these monitoring stations, precipitation amounts were measured and weekly samples were collected for analysis of total mercury and methylmercury by low-level methods. Wet deposition was computed with the total mercury and methylmercury concentrations and the precipitation amounts. In 3 years of weekly samples collected at the four monitoring stations, the volume-weighted total mercury concentration was 11.5 ng/L (nanograms per liter). As a reference for comparison, the total mercury concentration in 47 percent of the samples analyzed was greater than the Indiana water-quality standard for mercury (12 ng/L, protecting aquatic life) and nearly all of the concentrations exceeded the Indiana water-quality standards for mercury in the Great Lakes system (1.8 ng/L, protecting human health, and 1.3 ng/L, protecting wild mammals and birds). The precipitation-weighted concentrations at three of the monitoring stations in Indiana in 2003 were in the top 40 percent of all monitoring stations in the NADP-MDN and the concentration at Indiana Dunes was the eighth highest in the NADP-MDN for 2003. At the four monitoring stations during the study period, the mean weekly total mercury deposition was 243 ng/m 2 (nanograms per square meter) and mean annual total mercury deposition was 12,623 ng/m 2 . The annual mercury deposition at the four monitoring stations in Indiana in 2003 was in the top 40 percent of all monitoring stations in the NADP-MDN and the annual mercury deposition at the Clifty Falls station was the tenth highest in the NADP-MDN for 2003. For the 3-year period, the median methylmercury concentration in weekly samples was 0.058 ng/L with a maximum of 5.77 ng/L. Normalized methylmercury deposition was 2.09 ng/m 2 per inch of precipitation and methylmercury deposition was 0.7 percent of the total mercury deposition. The annual and mean weekly methylmercury deposition was highest at the Roush Lake station. Among the monitoring stations in the NADP-MDN with methylmercury data, methylmercury deposition at the monitoring stations in Indiana appeared to be higher than at eight stations in Wisconsin and Minnesota for that same time period, although methylmercury concentrations in Indiana were similar to or lower than those in Wisconsin and Minnesota. Geographically, the weekly total mercury concentrations at Indiana Dunes and Clifty Falls were statistically higher than concentrations at Bloomington, although a statistical difference in weekly total mercury deposition was not found among the four monitoring stations. Annual mercury emissions from sources in the vicinity of Indiana Dunes and Clifty Falls in 2001 were more than 10 times those at Bloomington, although other factors may help explain the differences in total mercury concentrations, such as the types of mercury emissions, mercury transport from sources outside Indiana, and meteorological conditions. Mercury concentrations and deposition varied at the four monitoring stations during the 3-year period. Total mercury concentrations in weekly samples ranged from 1.54 to 77 ng/L and weekly mercury deposition ranged from 0.8 to 2,456 ng/m 2 . Data from weekly samples exhibited seasonal patterns. Total mercury concentrations and deposition were highest in spring and summer and lowest in winter. Methylmercury concentrations were highest in winter and methylmercury deposition was highest in spring. Annual precipitation at the four monitoring stations was highest in 2003, exceeding the precipitation normals in spring and summer 2003. Annual mercury deposition in 2003 at the Roush Lake, Clifty Falls, and Indiana Dunes was as much as 41 to 67 percent higher in 2003 than in 2001 or in 2002 at those stations. Total mercury deposition that was more than 10 percent of the mean annual deposition (1,262 ng/m 2 ) was recorded in 11 of 551 weekly samples from the study period. These samples contained approximately 3 inches or more of rain and most were collected in spring and summer 2003. The highest deposition (2,456 ng/m 2 in a sample from Roush Lake) was 15.7 percent of the annual deposition at that station and approximately 10 times the mean weekly deposition for Indiana. High deposition recorded in three weekly samples at Clifty Falls contributed 31 percent of the annual deposition at that station in 2003. Weekly samples with high mercury deposition may help to explain the differences in annual mercury deposition among the four monitoring stations in Indiana.

Indiana↗
USGS2009

Synthesis of ground and remote sensing data for monitoring ecosystem functions in the Colorado River Delta, Mexico

The delta of the Colorado River in Mexico supports a rich mix of estuarine, wetland and riparian ecosystems that provide habitat for over 350 species of birds as well as fish, marine mammals, and other wildlife. An important part of the delta ecosystem is the riparian corridor, which is supported by agricultural return flows and waste spills of water originating in the U.S. and Mexico. These flows may be curtailed in the future due to climate change and changing land use practices (out-of-basin water transfers, increased agricultural efficiency, and more optimal management of dams) in the U.S. and Mexico, and resource managers need to monitor the effects of their water management practices on these ecosystems. We developed ground-validated, remote sensing methods to monitor the vegetation status, habitat value, and water use of wetland and riparian ecosystems using multi-temporal, multi-resolution images. The integrated methodology allowed us to project species composition, leaf area index, fractional cover, habitat value, and evapotranspiration over seasons and years throughout the delta, in response to variable water flows from the U.S. to Mexico. Waste spills of water from the U.S. have regenerated native cottonwood and willow trees in the riparian corridor and created backwater and marsh areas that support birds and other wildlife. However, the main source of water supporting the riparian vegetation is the regional aquifer recharged by underflow from U.S. and Mexico irrigation districts. Native trees have a short half-life in the riparian zone due to human-set fires and harvesting for timber. Active management, monitoring, and restoration programs are needed to maintain the habitat value of this ecosystem for the future.

Colorado River Delta↗
USGS2015

Book review: Flight ways: Life and loss at the edge of extinction.

In less than 200 pages, Thom van Dooren aims in his ambitious book, Flight Ways , to reconnect humans empathetically with the rest of the planet's inhabitants, but especially vanishing species. This is asking a lot, but he succeeds—or at least makes great strides—using evocative storytelling and compelling discourse. A number of themes are carefully woven together with the goal of awakening sensitivities, building understanding, and motivating commitment to stopping the decline of populations and species. As one who works in the field of endangered Hawaiian bird research, I found this book illuminating, thought-provoking, and insightful. It probes deeply into the evolution, ecology, and ethics of our interactions with other species and offers useful lessons for thinking about endangered species and extinction in more meaningful ways. It will likely spur self-examination and further inquiry by readers, which can open new lines of communication with the general public about conservation. Review info: Flight Ways: Life and Loss at the Edge of Extinction . By Thom van Dooren, 2014. ISBN 978-0231166188, 193 pp.

Journal of Field Ornithology↗
USGS2009

U.S. Geological Survey (USGS) Western Region: Seabirds coastal and ocean science

From the cold, high Arctic area of Alaska to the warm, tropical Pacific area of Hawai'i, a diverse array of seabird species numbering in the millions of individuals live off the bounty of the Pacific Ocean. Many come to land only to nest and raise their young - these are species supremely adapted for life on the water, whether it be near the coast or hundreds of miles at sea. Those seabirds that reside in the North Pacific year-round are joined each summer by millions of migrant birds that leave the southern hemisphere in winter for better feeding conditions in the north. Seabirds in the Pacific remain one of the great wildlife spectacles on the earth. Yet, seabirds face a number of threats such as oil spills, introduction of predators to their nesting islands, and conflicts with fisheries. State and Federal agencies require increasingly sophisticated information on population dynamics, breeding biology, and feeding ecology to successfully manage these species and their ecosystems. Within the Western Region of the USGS, scientists from the Alaska Science Center (ASC), Western Ecological Research Center (WERC), and Pacific Islands Ecosystems Research Center are leading the way in conducting research on many of these little known species. Their aim is to improve our understanding of seabirds in the Pacific and to provide information to support informed management of the birds and their ecosystems.

Fact Sheet↗
USGS2012

Time-specific patterns of nest survival for ducks and passerines breeding in North Dakota

In many bird species, survival can vary with the age of the nest, with the date a nest was initiated, or among years within the same nesting area. A literature review showed that patterns of survival vary in relation to nest age and date and are often contradictory. Inconsistencies could be a result of temporal variation in the environment or life-history differences among species. We examined patterns of nest survival in relation to nest age, date, and year for several duck and passerine species nesting at a single location in North Dakota during 1998–2003. We predicted that if environment shaped nest survival patterns, then temporal patterns in survival might be similar among three species of upland nesting ducks, and also among three species of grassland passerines nesting at the same site. We expected that survival patterns would differ between ducks and passerines because of relatively disparate life histories and differences in predators that prey on their nests. Nest survival was rarely constant among years, seasonally, or with age of the nest for species that we studied. As predicted, the pattern of survival was similar among duck species, driven mainly by differences in nest survival associated with nest initiation date. The pattern of survival also was similar among passerine species, but nest survival was more influenced by nest age than by date. Our findings suggest that some but not all variation in temporal patterns of nest survival in grassland birds reported in the literature can be explained on the basis of temporal environmental variation. Because patterns of survival were dissimilar among ducks and passerines, it is likely that mechanisms such as predation or brood parasitism have variable influences on productivity of ducks and passerines nesting in the same area. Our results indicate that biologists and managers should not assume that temporal environmental variations, especially factors that affect nest survival, act similarly on all grassland birds.

North Dakota↗
USGS2014

Pharmacokinetics of buprenorphine hydrochloride following intramuscular and intravenous administration to American kestrels ( Falco sparverius )

Objective —To determine the pharmacokinetics of buprenorphine hydrochloride after IM and IV administration to American kestrels ( Falco sparverius ). Animals —13 healthy 3-year-old captive-bred American kestrels. Procedures —Buprenorphine hydrochloride (0.6 mg/kg) was administered IM to all birds. Blood samples were collected at 9 times, ranging from 5 minutes to 9 hours after drug administration. Plasma buprenorphine concentrations were measured by use of tandem liquid chromatography–mass spectrometry. Pharmacokinetic parameters were determined by use of least squares linear regression and noncompartmental analysis of naïve pooled data. After a washout period of 2 weeks, the same dose of buprenorphine was administered IV to all birds and blood samples were collected at the same times after drug administration. Results —Maximum plasma buprenorphine concentration was achieved within 5 minutes after IM administration. For IM administration, bioavailability was 94.8% and elimination half-life was 92.1 minutes. For IV administration, steady-state volume of distribution was 4,023.8 mL/kg, plasma clearance was 49.2 mL/min/kg, and elimination half-life was 105.5 minutes. Conclusions and Clinical Relevance —Buprenorphine was rapidly absorbed, and bioavailability was good after IM administration to American kestrels. Plasma buprenorphine concentrations were > 1 ng/mL for 9 hours after both IM and IV administration. These results, in combination with those of a pharmacodynamic study, suggested that the analgesic effects of buprenorphine could last at least 6 to 9 hours in this species. Further investigations of the duration of analgesic effects, multiple-dose protocols, and potential adverse effects of buprenorphine are warranted in American kestrels and other raptors.

American Journal of Veterinary Research↗
USGS2011

Strategy to control the invasive alien tree Miconia calvescens in Pacific islands: Eradication, containment or something else?

Miconia calvescens (Melastomataceae) is a notorious plant invader in the tropical islands of French Polynesia, Hawaii and New Caledonia. A small tree native to Central and South America, it was first introduced as an ornamental in private botanic gardens in Tahiti (1937), Honolulu (1961), and Nouméa (1970s) where it escaped, became naturalised, and formed dense monospecific stands. More than 80,000 ha are currently invaded in French Polynesia, 10,000 ha in the Hawaiian Islands and 140 ha in New Caledonia. Control programmes have been under way in the Hawaiian Islands (Oahu, Maui, Hawaii, Kauai) and French Polynesia (Raiatea, Tahaa, Nuku Hiva, Fatu Hiva) since the early 1990s, and in New Caledonia (Province Sud) since 2006. Despite more than 15 years of intensive control efforts and millions of plants destroyed, eradication has not been achieved in any of these islands, mainly because the species has multiple features that thwart its elimination (e.g., prolific seed production, active dispersal by alien and native frugivorous birds, large and persistent soil seed bank, shade-tolerance), combined with the difficulty of detecting and destroying plants on rough terrain and steep slopes, insufficient control frequency, and limited financial and human resources. Miconia’s life cycle requires at least four years growth from seedling to fruiting. Consequently, prevention of fruit production may be an effective management strategy for small populations. This “juvenilization” process may allow the eradication of small populations when carefully conducted over a quarter century.

French Polynesia, Hawai'i, New Caledonia↗