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At least 109 records · Page 6Linked to original sources
USGS1991

Capture myopathy in an endangered sandhill crane (Grus canadensis pulla)

Despite precautions to protect cranes, a 3-year-old endangered Mississippi sandhill crane ( Grus canadensis pulla ) was found caught in a leghold trap in Gautier, Mississippi, on 11 November 1987. The bird could have been in the trap for up to 16 hr and was standing and struggling to escape when it was discovered. Serum chemistries of the crane on 12 November revealed elevated lactic dehydrogenase (2,880 IU/L), alanine aminotransferase (ALT) (152 IU/L), and aspartate aminotransferase (AST) (>1,000 IU/L) values. Following surgical amputation of a fractured toe, the bird never attempted to stand and was unable to stand even when manually supported. Radiographic and physical examination of both legs did not reveal any anatomical abnormalities. Despite medical care, including supportive therapy, no improvement was observed in the bird's ability to stand and to support itself, and the bird died on 19 November. Serum chemistries and the postmortem and histopathologic findings were compatible with capture myopathy described in other species. Because of the possible susceptibility of long-legged birds such as the Mississippi sandhill crane to capture myopathy, special care must be taken when trapping, handling, chemically immobilizing, and transporting these species. In addition, precautions must be taken when conducting a predator-control program to ensure that nontarget wildlife are unlikely to encounter traps. Capture myopathy has only rarely been observed in wild birds, and this case represents the first report in a Mississippi sandhill crane.

Mississippi↗
USGS2008

Responses in bird communities to wildland fires in southern California

There is a growing body of literature covering the responses of bird species to wildland fire events. Our study was unique among these because we investigated the effects of large-scale wildland fires on entire bird communities across multiple vegetation types. We conducted avian point counts during the breeding seasons for two years before and two years after the Cedar and Otay Fires in 2003 in southern California. Our balanced sampling effort took place at two sites, one low-elevation and one high-elevation, each containing replicate stations (burned and unburned) within five vegetation types: chaparral, coastal sage scrub, grassland, oak woodland, and riparian. Although fire caused some degree of change in the vegetation structure at all of our impacted survey points, we found that the post-fire shrub and tree cover was significantly lower in only two of the vegetation types within the low-elevation site, coastal sage scrub and chaparral. We found no significant changes in cover at the high-elevation site. Using univariate and multivariate analyses, we tested whether the fires were associated with a change in bird species diversity, community structure, and the relative abundance of individuals within a species. We found that species diversity changed in only one circumstance: it increased in coastal sage scrub at the low-elevation site. Multivariate analyses revealed significant differences in the post-fire bird community structure in the low-elevation chaparral, low-elevation coastal sage scrub, and the high-elevation grassland communities. Vegetation characteristics altered by fire, such as decreases in shrub and tree cover, influenced the changes we observed in the bird communities. The relative abundance of some species (lazuli bunting [ Passerina amoena ] and horned lark [ Eremophila alpestris ]) significantly increased after the fires, while other species declined significantly (Anna's hummingbird [ Calypte anna ], wrentit [ Chamaea fasciata ], and bushtit [ Psaltriparus minimus ]). We detected mixed results for the spotted towhee ( Pipilo maculatus ), which increased in burned chaparral and declined in burned coastal sage scrub within the low-elevation site. We suggest that the observed responses of birds to these fires may be attributed to: (1) the availability of nearby unburned refugia, (2) the continued suitability of post-fire vegetation at the study sites, and (3) the generally high mobility of this taxon.

California↗
USGS2005

Efficient statistical mapping of avian count data

We develop a spatial modeling framework for count data that is efficient to implement in high-dimensional prediction problems. We consider spectral parameterizations for the spatially varying mean of a Poisson model. The spectral parameterization of the spatial process is very computationally efficient, enabling effective estimation and prediction in large problems using Markov chain Monte Carlo techniques. We apply this model to creating avian relative abundance maps from North American Breeding Bird Survey (BBS) data. Variation in the ability of observers to count birds is modeled as spatially independent noise, resulting in over-dispersion relative to the Poisson assumption. This approach represents an improvement over existing approaches used for spatial modeling of BBS data which are either inefficient for continental scale modeling and prediction or fail to accommodate important distributional features of count data thus leading to inaccurate accounting of prediction uncertainty.

Environmental and Ecological Statistics↗
USGS1981

The role of observer bias in the North American Breeding Bird Survey

Ornithologists sampling breeding bird populations are subject to a number of biases in bird recognition and identification. Using Breeding Bird Survey data, these biases are examined qualitatively and quantitatively, and their effects on counts are evaluated. Differences in hearing ability and degree of expertise are the major observer biases considered. Other, more subtle influences are also discussed, including unfamiliar species, resolution, imagination, similar songs and attitude and condition of observers. In most cases, welltrained observers are comparable in ability and their differences contribute little beyond sampling error. However, just as hearing loss can affect results, so can an unprepared observer. These biases are important because they can reduce the credibility of any bird population sampling effort. Care is advised in choosing observers and in interpreting and using results when observers of variable competence are involved.

Book chapter↗
USGS2015

User’s guide to the North Pacific Pelagic Seabird Database 2.0

The North Pacific Pelagic Seabird Database (NPPSD) was created in 2005 to consolidate data on the oceanic distribution of marine bird species in the North Pacific. Most of these data were collected on surveys by counting species within defined areas and at known locations (that is, on strip transects). The NPPSD also contains observations of other bird species and marine mammals. The original NPPSD combined data from 465 surveys conducted between 1973 and 2002, primarily in waters adjacent to Alaska. These surveys included 61,195 sample transects with location, environment, and metadata information, and the data were organized in a flat-file format. In developing NPPSD 2.0, our goals were to add new datasets, to make significant improvements to database functionality and to provide the database online. NPPSD 2.0 includes data from a broader geographic range within the North Pacific, including new observations made offshore of the Russian Federation, Japan, Korea, British Columbia (Canada), Oregon, and California. These data were imported into a relational database, proofed, and structured in a common format. NPPSD 2.0 contains 351,674 samples (transects) collected between 1973 and 2012, representing a total sampled area of 270,259 square kilometers, and extends the time series of samples in some areas—notably the Bering Sea—to four decades. It contains observations of 16,988,138 birds and 235,545 marine mammals and is available on the NPPSD Web site. Supplementary materials include an updated set of standardized taxonomic codes, reference maps that show the spatial and temporal distribution of the survey efforts and a downloadable query tool.

Open-File Report↗
USGS1981

Sampling in rugged terrain

Work in rugged terrain poses some unique problems that should be considered before research is initiated. Besides the obvious physical difficulties of crossing uneven terrain, topography can influence the bird species? composition of a forest and the observer's ability to detect birds and estimate distances. Census results can also be affected by the slower rate of travel on rugged terrain. Density figures may be higher than results obtained from censuses in similar habitat on level terrain because of the greater likelihood of double-recording of individuals and of recording species that sing infrequently. In selecting a census technique, the researcher should weigh the efficiency and applicability of a technique for the objectives of his study in light of the added difficulties posed by rugged terrain. The variable circular-plot method is probably the most effective technique for estimating bird numbers. Bird counts and distance estimates are facilitated because the observer is stationary, and calculations of species? densities take into account differences in effective area covered amongst stations due to variability in terrain or vegetation structure. Institution of precautions that minimize the risk of injury to field personnel can often enhance the observer?s ability to detect birds.

Book chapter↗
USGS2007

Modeling tradeoffs in avian life history traits and consequences for population growth

Variation in population dynamics is inherently related to life history characteristics of species, which vary markedly even within phylogenetic groups such as passerine birds. We computed the finite rate of population change (??) from a matrix projection model and from mark-recapture observations for 23 bird species breeding in northern Arizona. We used sensitivity analyses and a simulation model to separate contributions of different life history traits to population growth rate. In particular we focused on contrasting effects of components of reproduction (nest success, clutch size, number of clutches, and juvenile survival) versus adult survival on ??. We explored how changes in nest success or adult survival coupled to costs in other life history parameters affected ?? over a life history gradient provided by our 23 Arizona species, as well as a broader sample of 121 North American passerine species. We further examined these effects for more than 200 passeriform and piciform populations breeding across North America. Model simulations indicate nest success and juvenile survival exert the largest effects on population growth in species with moderate to high reproductive output, whereas adult survival contributed more to population growth in long-lived species. Our simulations suggest that monitoring breeding success in populations across a broad geographic area provides an important index for identifying neotropical migratory populations at risk of serious population declines and a potential method for identifying large-scale mechanisms regulating population dynamics. ?? 2007 Elsevier B.V. All rights reserved.

Ecological Modelling↗
USGS1980

A variable circular-plot method for estimated bird numbers

A bird census method is presented that is designed for tall, structurally complex vegetation types, and rugged terrain. With this method the observer counts all birds seen or heard around a station, and estimates the horizontal distance from the station to each bird. Count periods at stations vary according to the avian community and structural complexity of the vegetation. The density of each species is determined by inspecting a histogram of the number of individuals per unit area in concentric bands of predetermined widths about the stations, choosing the band (with outside radius x) where the density begins to decline, and summing the number of individuals counted within the circle of radius x and dividing by the area (Bx2). Although all observations beyond radius x are rejected with this procedure, coefficients of maximum distance.

Condor↗
USGS1981

Growth of mallards fed phosphamidon for 13-day periods during three different developmental stages

Mallard ducklings ( Anas platyrhynchos ) were exposed to a 13-day dietary treatment of 0, 0·5 or 5·0 ppm phosphamidon at one of three successive age intervals (5–17 days, 18–30 days, or 31–43 days) during a 10-week growth period. Weekly measurements of body weight, wing length, primary feather length, and bill length revealed slower development of primary feathers in those birds treated from 5 to 17 days; treatment effects on body weight and wing length from 6 to 8 weeks of age were observed among those birds treated from 18 to 30 days of age. Some differences in growth patterns among birds treated with the same phosphamidon level, but at different growth stages, were attributed to the varying size of the group with which a duckling was housed at different times in the growth process. No brain cholinesterase depression was observed in any group either 24h after phosphamidon treatment was terminated or at 10 weeks of age.

Environmental Pollution (Series A)↗
USGS2015

Estimating wind-turbine-caused bird and bat fatality when zero carcasses are observed

Many wind-power facilities in the United States have established effective monitoring programs to determine turbine-caused fatality rates of birds and bats, but estimating the number of fatalities of rare species poses special difficulties. The loss of even small numbers of individuals may adversely affect fragile populations, but typically, few (if any) carcasses are observed during monitoring. If monitoring design results in only a small proportion of carcasses detected, then finding zero carcasses may give little assurance that the number of actual fatalities is small. Fatality monitoring at wind-power facilities commonly involves conducting experiments to estimate the probability ( g ) an individual will be observed, accounting for the possibilities that it falls in an unsearched area, is scavenged prior to detection, or remains undetected even when present. When g < 1, the total carcass count ( X ) underestimates the total number of fatalities ( M ). Total counts can be 0 when M is small or when M is large and g ≪1. Distinguishing these two cases is critical when estimating fatality of a rare species. Observing no individuals during searches may erroneously be interpreted as evidence of absence. We present an approach that uses Bayes' theorem to construct a posterior distribution for M , i.e., P ( M | X , ĝ ), reflecting the observed carcass count and previously estimated g . From this distribution, we calculate two values important to conservation: the probability that M is below a predetermined limit and the upper bound ( M * ) of the 100(1 &minus; &alpha;)% credible interval for M . We investigate the dependence of M * on &alpha;, g , and the prior distribution of M , asking what value of g is required to attain a desired M * for a given &alpha;. We found that when g < ~0.15, M * was clearly influenced by the mean and variance of ĝ and the choice of prior distribution for M , but the influence of these factors is minimal when g > ~0.45. Further, we develop extensions for temporal replication that can inform prior distributions of M and methods for combining information across several areas or time periods. We apply the method to data collected at a wind-power facility where scheduled searches yielded X = 0 raptor carcasses

Ecological Applications↗
USGS2024

Mercury concentrations in Seaside Sparrows and Marsh Rice Rats differ across the Mississippi River Estuary

Mercury (Hg) concentrations and their associated toxicological effects in terrestrial ecosystems of the Gulf of Mexico are largely unknown. Compounding this uncertainty, a large input of organic matter from the 2010 Deepwater Horizon oil spill may have altered Hg cycling and bioaccumulation dynamics. To test this idea, we quantified blood concentrations of total mercury (THg) in Seaside Sparrows ( Ammospiza maritima ) and Marsh Rice Rats ( Oryzomys palustris ) in marshes west and east of the Mississippi River in 2015 and 2016. We also tested for a difference in THg concentrations between oiled and non-oiled sites. To address the potential confounding effect of diet variation on Hg transfer, we used stable nitrogen (δ 15 N) and carbon (δ 13 C) isotope values as proxies of trophic position and the source of primary production, respectively. Our results revealed that five to six years after the spill, THg concentrations were not higher in sites oiled by the spill compared to non-oiled sites. In both species, THg was higher at sites east of the Mississippi River compared to control and oiled sites, located west. In Seaside Sparrows but not in Marsh Rice Rats, THg increased with δ 15 N values, suggesting Hg trophic biomagnification. Overall, even in sites with the most elevated THg, concentrations were generally low. In Seaside Sparrows, THg concentrations were also lower than previously reported in this and other closely related passerines, with only 7% of tested birds exceeding the lowest observed effect concentration associated with toxic effects across bird species (0.2 µg/g ww ) . The factors associated with geographic heterogeneity in Hg exposure remain uncertain. Clarification could inform risk assessment and future restoration and management actions in a region facing vast anthropogenic changes.

Ecotoxicology↗
USGS2013

Arsenic induced toxicity in broiler chicks and its alleviation with ascorbic acid: a toxico-patho-biochemical study

To find out toxico-pathological effects of arsenic (As) and ameliorating effect of ascorbic acid (Vit C), broilers birds were administered 50 and 250 mg/kg arsenic and Vit C, respectively alone/in combination. As-treated birds exhibited severe signs of toxicity such as dullness, depression, increased thirst, open mouth breathing and watery diarrhea. All these signs were partially ameliorated with the treatment of Vit C. As-treated birds showed a significant decrease in serum total proteins while serum enzymes, urea and creatinine were significantly increased. Alkaline phosphatase and lactate dehydrogenase completely whereas proteins, aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea and creatinine were partial ameliorated in birds treated with As+Vit C as compared to As-treated and control birds. Pale and hemorrhagic liver and swollen kidneys were observed in As-treated birds. Histopathologically, liver exhibited congestion and cytoplasmic vacuolation while in kidneys, condensation of tubular epithelium nuclei, epithelial necrosis, increased urinary spaces, sloughing of tubules from basement membrane and cast deposition were observed in As-treated birds. Pathological lesions were partially ameliorated with the treatment of Vit C. It can be concluded that arsenic induces biochemical and histopathological alterations in broiler birds; however, these toxic effects can be partially attenuated by Vit C.

International Journal of Agriculture & Biology↗
USGS2020

Avian community responses to management of vegetation and water levels in restored wetlands at the Humacao Nature Reserve, Puerto Rico

Coastal wetlands of the Caribbean have been greatly reduced in area and quality, and information on wildlife responses to management is lacking. We applied wetland management practices (disking, control of water levels) in a site historically disturbed by Saccharum spp. (sugarcane) cultivation at the Humacao Nature Reserve, southeastern Puerto Rico, and evaluated avian community response. We conducted weekly bird surveys and nest searches on disked and non-disked plots within recently constructed impoundments. The avian community shifted from 16 upland dominated species pre-restoration, to 67 wetland-dependent species at the end of our study (2001–2002). Ordination analysis indicated avian guild use of plots varied with environmental variables. Bird species diversity was not influenced by treatment, month, or salinity levels but was influenced by water depth and vegetation cover. Bird abundance was influenced by water depth, but not by treatment, month, salinity or vegetation cover. Furthermore, water depths of 0.10–0.20 m and salinity of ≤15 ppt promoted habitat conditions suitable for a diverse wetland avian community. We located 268 nests of 8 wetland bird species and observed adults with young of various other waterbirds, including species of conservation concern such as Dendrocygna arborea (West Indian Whistling Duck) and Porzana flaviventer (Yellow-breasted Crake). Bird community responses suggest that management practices (i.e., soil disturbance and control of water levels) can improve wetland biodiversity in abandoned sugarcane fields of Puerto Rico. Moreover, these practices may benefit wetland biodiversity in other Caribbean islands with a similar history of land use and habitat degradation.

Humacao Nature Reserve↗
USGS2008

North American Bird Banding and quantitative population ecology

Early bird-banding programs in North America were developed to provide descriptions of bird migration and movement patterns. This initial interest in description quickly evolved into more quantitative interests in two ways. There was (1) interest in quantifying migration and movement patterns, and (2) rapid recognition that re-observations of marked birds provided information about other parameters relevant to population dynamics. These included survival rate, recruitment rate, and population size. The evolution of methods for estimating population size, survival, recruitment, and movement is reviewed and we show it to be closely tied to bird-banding data. These estimation methods have been used with bird-banding data to draw important inferences about evolutionary ecology, population ecology, and population management. Illustrative examples of such inferences are provided.

Book chapter↗
USGS2012

Changes in avian and plant communities of aspen woodlands over 12 years after livestock removal in the northwestern Great Basin

Riparian and quaking aspen (Populus tremuloides) woodlands are centers of avian abundance and diversity in the western United States, but they have been affected adversely by land use practices, particularly livestock grazing. In 1990, cattle were removed from a 112,500-ha national wildlife refuge in southeastern Oregon. Thereafter, we monitored changes in vegetation and bird abundance in years 1&ndash;3 (phase 1) and 10&ndash;12 (phase 2) in 17 riparian and 9 snow-pocket aspen plots. On each 1.5-ha plot, we sampled vegetation in 6 transects. Three times during each breeding season, observers recorded all birds 50 m to each side of the plot's 150-m centerline for 25 minutes. We analyzed data with multivariate analysis of variance and paired t tests with p values adjusted for multiple comparisons. In both periods, riparian and snow-pocket aspen produced extensive regeneration of new shoots (x̄ = 2646 stems/ha and 7079 stems/ha, respectively). By phase 2, a 64% increase in medium-diameter trees in riparian stands indicated successful recruitment into the overstory, but this pattern was not seen in snow-pocket stands, where the density of trees was over 2 times greater. By phase 2 in riparian and snow-pocket stands, native forb cover had increased by 68% and 57%, respectively, mesic shrub cover had increased by 29% and 58%, and sagebrush cover had decreased by 24% and 31%. Total avian abundance increased by 33% and 39% in riparian and snow-pocket aspen, respectively, ground or understory nesters increased by 133% and 67% and overstory nesters increased by 34% and 33%. Similarly, ground or understory foragers increased by 25% and 32%, aerial foragers by 55% and 57%, and overstory foragers by 66% and 43%. We interpreted the substantial regeneration of aspen shoots, increased densities of riparian forbs and shrubs, and increased avian abundances as a multitrophic-level response to the total removal of livestock and as substantial movement toward recovery of biological integrity.

Aspen Woodlands;Great Basin↗
USGS1998

Natal and breeding philopatry in a black brant, Branta bernicla nigricans , metapopulation

We estimated natal and breeding philopatry and dispersal probabilities for a metapopulation of Black Brant ( Branta bernicla nigricans ) based on observations of marked birds at six breeding colonies in Alaska, 1986–1994. Both adult females and males exhibited high (>0.90) probability of philopatry to breeding colonies. Probability of natal philopatry was significantly higher for females than males. Natal dispersal of males was recorded between every pair of colonies, whereas natal dispersal of females was observed between only half of the colony pairs. We suggest that female-biased philopatry was the result of timing of pair formation and characteristics of the mating system of brant, rather than factors related to inbreeding avoidance or optimal discrepancy. Probability of natal philopatry of females increased with age but declined with year of banding. Age-related increase in natal philopatry was positively related to higher breeding probability of older females. Declines in natal philopatry with year of banding corresponded negatively to a period of increasing population density; therefore, local population density may influence the probability of nonbreeding and gene flow among colonies.

Alaska, Northwest Territories↗
USGS2025

Module 4: Basic biology of wetland animals

An assortment of animals inhabit wetlands, with many invertebrates, amphibians and reptiles, fishes, birds, and some mammals being wetland specialists. Wetlands provide ample water, food, and cover that benefits resident animals, but periodic high floods, frequent drying, and harsh water qualities (low-oxygen, acidic, saline) can stress wetland animals. Animals that rely on wetlands have developed numerous adaptations to cope with these stresses. The animal biodiversity in wetlands is particularly valued by people, from deep historical and cultural connections, to modern ecotourists and bird watchers who observe it and hunters and anglers who appreciate the consumptive resources they provide. Animals such as alligators and beavers create or physically-modify wetland environments; this activity is called ecosystem engineering and makes these animals among the most important organisms to wetland ecology. Wetlands are high in biodiversity and support rich communities of wetland invertebrates, are primary breeding habitats for most amphibians, and nearly all migratory birds rely on wetlands during some part of their annual cycle. The interactions of animals with plants (herbivory, cutting) and each other (predation) strongly shape wetland environments and affect nutrient cycling. Human impacts on wetlands can negatively affect many animals through habitat loss and degradation, resulting in many wetland amphibians, reptiles, and birds being listed as threatened and endangered species. Thus, wetland conservation is vital to conserve many animal species.

Wetland Science & Practice↗