Geology ReportsSearch

SEARCH · Geology Reports

Results for “Zoological Studies”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Type specimens and basic principles of avian taxonomy

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

The Auk

Estimation of the bottleneck size in Florida panthers

We have estimated the extent of genetic variation in museum (1890s) and contemporary (1980s) samples of Florida panthers Puma concolor coryi for both nuclear loci and mtDNA. The microsatellite heterozygosity in the contemporary sample was only 0.325 that in the museum samples although our sample size and number of loci are limited. Support for this estimate is provided by a sample of 84 microsatellite loci in contemporary Florida panthers and Idaho pumas Puma concolor hippolestes in which the contemporary Florida panther sample had only 0.442 the heterozygosity of Idaho pumas. The estimated diversities in mtDNA in the museum and contemporary samples were 0.600 and 0.000, respectively. Using a population genetics approach, we have estimated that to reduce either the microsatellite heterozygosity or the mtDNA diversity this much (in a period of c. 80years during the 20th century when the numbers were thought to be low) that a very small bottleneck size of c. 2 for several generations and a small effective population size in other generations is necessary. Using demographic data from Yellowstone pumas, we estimated the ratio of effective to census population size to be 0.315. Using this ratio, the census population size in the Florida panthers necessary to explain the loss of microsatellite variation was c .41 for the non-bottleneck generations and 6.2 for the two bottleneck generations. These low bottleneck population sizes and the concomitant reduced effectiveness of selection are probably responsible for the high frequency of several detrimental traits in Florida panthers, namely undescended testicles and poor sperm quality. The recent intensive monitoring both before and after the introduction of Texas pumas in 1995 will make the recovery and genetic restoration of Florida panthers a classic study of an endangered species. Our estimates of the bottleneck size responsible for the loss of genetic variation in the Florida panther completes an unknown aspect of this account. ?? 2008 The Authors. Journal compilation ?? 2008 The Zoological Society of London.

Animal Conservation

The relationship between annual survival rate and migration distance in mallards: An examination of the time-allocation hypothesis for the evolution of migration

Predictions of the time-allocation hypothesis were tested with several a posteriori analyses of banding data for the mallard (Anas platyrhynchos). The time-allocation hypothesis states that the critical difference between resident and migrant birds is their allocation of time to reproduction on the breeding grounds and survival on the nonbreeding grounds. Residents have higher reproduction and migrants have higher survival. Survival and recovery rates were estimated by standard band-recovery methods for banding reference areas in the central United States and central Canada. A production-rate index was computed for each reference area with data from the U.S. Fish and Wildlife Service May Breeding Population Survey and July Production Survey. An analysis of covariance was used to test for the effects of migration distance and time period (decade) on survival, recovery, and production rates. Differences in migration chronology were tested by comparing direct-recovery distributions for different populations during the fall migration. Differences in winter locations were tested by comparing distributions of direct recoveries reported during December and January. A strong positive relationship was found between survival rate, and migration distance for 3 of the 4 age and sex classes. A weak negative relationship was found between recovery rate and migration distance. No relationship was found between production rate and migration distance. During the fall migration, birds from the northern breeding populations were located north of birds from the southern breeding populations. No pattern could be found in the relative locations of breeding and wintering areas. Although our finding that survival rate increased with migration distance was consistent with the time-allocation hypothesis, our results on migration chronology and location of wintering areas were not consistent with the mechanism underlying the time-allocation hypothesis. Neither this analysis nor other recent studies of life-history characteristics of migratory and resident birds supported the timeallocation hypothesis.

Canadian Journal of Zoology

Bulletin of the United States Geological and Geographical Survey of the Territories: No. 6, second series

Table of Contents I.----An account of the various publications relating to the travels of Lewis and Clarke, with a commentary on the zoological results of their expedition. By Dr. Elliott Coues, U.S.A. II.---Notice of a very large Goniatite from eastern Kansas. By F.B. Meek III.--Fossil orthoptera from the Rocky Mountajn tertiaries. By Samuel H. Scudder IV.--Studies of the American Falconidae: Monograph of the Polybori. By Robert Ridgway

Report

The adrenocortical response of greater sage grouse (Centrocercus urophasianus) to capture, ACTH injection, and confinement, as measured in fecal samples

Investigators of wildlife populations often utilize demographic indicators to understand the relationship between habitat characteristics and population viability. Assessments of corticosterone may enable earlier detection of populations at risk of decline because physiological adjustments to habitat disturbance occur before reproductive diminutions. Noninvasive methods to accomplish these assesments are important in species of concern, such as the greater sage grouse (GRSG). Therefore, we validated a radioimmunoassay that measures immunoreactive corticosterone metabolites (ICM) in fecal samples and used it to characterize the adrenocortical response of 15 GRSG exposed to capture, intravenous injection of 50 IU/kg adrenocorticotrophic hormone (ACTH) or saline, and 22 h of confinement. Those animals injected with ACTH exhibited a more sustained (P = 0.0139) and less variable (P = 0.0012) response than those injected with saline, indicating different levels of adrenocortical activity. We also found that potential field-collection protocols of fecal samples did not alter ICM concentrations: samples held at 4??C for up to 16 h contained similar levels of ICM as those frozen (-20??C) immediately. This study demonstrates a multiphasic adrenocortical response that varied with the level of stimulation and indicates that the assay used to measure this phenomenon is applicable for studies of wild GRSG. ?? 2009 by The University of Chicago. All rights reserved.

Oregon

Influence of land use and climate on wetland breeding birds in the Prairie Pothole region of Canada

Bird populations are influenced by a variety of factors at both small and large scales that range from the presence of suitable nesting habitat, predators, and food supplies to climate conditions and land-use patterns. We evaluated the influences of regional climate and land-use variables on wetland breeding birds in the Canada section of Bird Conservation Region 11 (CA-BCR11), the Prairie Potholes. We used bird abundance data from the North American Breeding Bird Survey, land-use data from the Prairie Farm Rehabilitation Administration, and weather data from the National Climatic Data and Information Archive to model effects of regional environmental variables on bird abundance. Models were constructed a priori using information from published habitat associations in the literature, and fitting was performed with WinBUGS using Markov chain Monte Carlo techniques. Both land-use and climate variables contributed to predicting bird abundance in CA-BCR11, although climate predictors contributed the most to improving model fit. Examination of regional effects of climate and land use on wetland birds in CA-BCR11 revealed relationships with environmental covariates that are often overlooked by small-scale habitat studies. Results from these studies can be used to improve conservation and management planning for regional populations of avifauna. ?? 2007 NRC.

Canadian Journal of Zoology

Relative abundance of coyotes (Canis latrans) influences gray fox (Urocyon cinereoargenteus) occupancy across the eastern United States

Gray fox ( Urocyon cinereoargenteus (Schreber, 1775)) populations in portions of the eastern United States have experienced declines whose trajectories differ from those of other mesocarnivore populations. One hypothesis is that gray fox declines may result from interspecific interactions, particularly competition with abundant coyotes ( Canis latrans Say, 1823). Alternatively, gray foxes may respond negatively to increased urbanization and reduced forest cover. To evaluate these hypotheses, we used single-species occupancy models of camera trap data to test the effects of habitat covariates, such as the amount of urbanization and forest, on coyote and gray fox occupancy. Additionally, we test the effect of an index based on an N -mixture model of the number of coyotes at each camera trap site on gray fox occupancy. Results indicate that occupancy probabilities of coyote and gray fox relate positively to the amount of forest, but they provided no evidence urban cover impacts gray foxes. Additionally, gray fox occupancy was negatively related to the index of the number of coyotes at each site. Our models support the idea that interactions with coyotes impact gray fox occupancy across the eastern United States. These results illustrate how large-scale studies can relate mechanisms identified within specific landscapes to phenomena observed at larger scales.

Canadian Journal of Zoology

Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus)

Knowledge of diet-tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared ??13C and ??15N of paired serum and vibrissal roots with those of ingested milk (n = 52) from free-ranging Steller sea lion (Eumetopias jubatus (Schreber, 1776)) pups (1-11 months) and juveniles (14-27 months) to estimate diet-tissue discrimination. Mean 15N enrichment from ingested milk to serum was 2.1??? ?? 0.6%??? and ??15N at the root of the vibrissae (representing current growth) were not significantly different from serum values. Milk was enriched for mean 13C by 5.0??? ?? 1.0%??? and 7.3??? ?? 1.2??? relative to serum and vibrissal roots, respectively, which was due to the presence of 13C-depleted lipids in milk. This was confirmed by lipid extraction from a subset of milk and serum samples, resulting in a 5.8??? ?? 1.0??? change only in milk. This study established that vibrissal roots and serum are reflective of a milk diet with approximately 2.0??? 15N enrichment, and vibrissal roots reflect serum and lipid-extracted milk values with approximately 2.0??? 13C enrichment. These discrimination factors are important to establish for stable isotope studies assessing diet shifts. ?? 2008 NRC.

Canadian Journal of Zoology

Effects of fasting and refeeding on body composition of captive gray wolves (Canis lupus)

We examined the effects of fasting and refeeding on body composition in 9 captive adult gray wolves, Canis lupus (6 males, 3 females), during May-June 1995. Body composition was estimated by the technique of tritiated water dilution. Wolves were immobilized and weighed, baseline blood samples were taken, tritiated water was injected, and additional blood samples were taken before fasting, after 10 d of fasting, and again after 2 d of refeeding. Male wolves lost 8% (P = 0.0001) and females lost 7% body mass (P = 0.01) during the 10 d. Males lost 54% of this mass in water, 28% in fat, and 18% in protein/ash; females lost 58% in water, 20% in fat, and 22% in protein/ash. Upon refeeding, male wolves consumed an average of 6.8 kg (15.3% body mass) of deer meat per day and females consumed 6.4 kg (18.7% body mass). All wolves regained their initial mass. Males regained 24% of this mass in water, 70% in fat, and 6% in protein/ash; females regained 35% in water, 51% in fat, and 14% in protein/ash. This study provided evidence that after prolonged fasting, captive wolves could quickly and efficiently regain lost body mass after refeeding.

Canadian Journal of Zoology

Testing whether adrenal steroids mediate phenotypic and physiologic effects of elevated salinity on larval tiger salamanders

Salinity (sodium chloride, NaCl) from anthropogenic sources is a persistent contaminant that negatively affects freshwater taxa. Amphibians can be susceptible to salinity, but some species are innately or adaptively tolerant. Physiological mechanisms mediating tolerance to salinity are still unclear, but changes in osmoregulatory hormones such as corticosterone (CORT) and aldosterone (ALDO) are prime candidates. We exposed larval barred tiger salamanders ( Ambystoma mavortium ) to environmentally relevant NaCl treatments (<32–4000 mg·L −1 ) for 24 days to test effects on growth, survival, and waterborne CORT responses. Of those sampled, we also quantified waterborne ALDO from a subset. Using a glucocorticoid antagonist (RU486), we also experimentally suppressed CORT signaling of some larvae to determine if CORT mediates effects of salinity. There were no strong differences in survival among salinity treatments, but salinity reduced dry mass, snout–vent length, and body condition while increasing water content of larvae. High survival and sublethal effects demonstrated that salamanders were physiologically challenged but could tolerate the experimental concentrations. CORT signaling did not attenuate sublethal effects of salinity. Baseline and stress-induced (after an acute stressor, shaking) CORT were not influenced by salinity. ALDO was correlated with baseline CORT, suggesting it could be difficult to decouple the roles of CORT and ALDO. Future studies comparing ALDO and CORT responses of adaptively tolerant and previously unexposed populations could be beneficial to understand the roles of these hormones in tolerance to salinity. Nevertheless, our study enhances our understanding of the roles of corticosteroid hormones in mediating effects of a prominent anthropogenic stressor.

Integrative Zoology

A 4-year study of invasive and native spider populations in Maine

Invasive spiders pose potential threats to native spiders. In 2002, the European spider Linyphia triangularis (Clerck, 1757) (Araneae: Linyphiidae) was discovered in all but one county in Maine. At Acadia National Park, we conducted a 4-year study of L. triangularis and three native linyphiid species of a similar size ( Frontinella communis (Hentz, 1850), Pityohyphantes subarcticus Chamberlin and Ivie, 1943, and Neriene radiata (Walckenaer, 1842)). Using line-transect surveys, we measured population densities in coastal and forest habitat. The density of L. triangularis varied across years but was always significantly higher on the coast than in the forest. In contrast, only one native species was present on the coast and at very low numbers. Coastal L. triangularis were larger and in better condition than those in the forest, and numbers and biomass of insect prey were also higher on the coast. In 2 years, we also conducted transects at a second coastal location in Maine where the invader was at low density. At that site, native densities were substantially higher than at either Acadia site. Our data are consistent with the hypothesis that L. triangularis is reducing populations of native spiders. Companion studies suggest that L. triangularis negatively impacts natives by usurping both web sites and webs.

Maine

Heightened immune system function in polar bears using terrestrial habitats

Climate change is altering the distribution of some wildlife species while warming temperatures are facilitating the northward expansion of pathogens, potentially increasing disease risk. Melting of Arctic sea ice is causing polar bears ( Ursus maritimus ) of the Southern Beaufort Sea (SBS) to increasingly spend summer on land, where they may encounter novel pathogens. Here, we tested whether SBS polar bears on shore during summer exhibited greater immune system activity than bears remaining on the sea ice. In addition, we tested whether the type of immune response correlated with body condition, because adaptive responses (slowly-developing defenses against specific pathogens) often require less energy than innate responses (rapid defenses not based on pathogen identity). After accounting for body condition, we found that polar bears on shore exhibited higher total white blood cell counts, neutrophils, and monocytes than bears on the ice, suggesting greater infections. Lymphocytes, eosinophils, basophils and globulins did not differ. C-reactive protein, an indicator of inflammation, also did not differ between habitats. Body condition was associated with variables indicative of both innate and adaptive immunity, suggesting that neither response was uniquely limited by energy resources. Our data indicate that as more polar bears spend longer periods of time on shore, they may experience more infections. We encourage continued health monitoring of this species and studies of the long-term fitness consequences from disease.

Physiological and Biochemical Zoology

Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size

Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.

Current Zoology

Evaluating potential artefacts of photo-reversal on behavioral studies with nocturnal invasive sea lamprey ( Petromyzon marinus )

Sea lampreys ( Petromyzon marinus L., 1758) are nocturnal, so experiments evaluating their behaviour to chemosensory cues have typically been conducted at night. However, given the brief timeframe each year that adult P. marinus are available for experimentation, we investigated whether P. marinus exposed to a 12 h shifted diurnal cycle (reversed photoperiod) could be tested in a darkened arena during the day and show the same response to chemosensory cues as natural photoperiod P. marinus that were tested during the night. Ten replicates of 10 P. marinus , from each photoperiod, were exposed to deionized water (negative control), 2-phenylethylamine hydrochloride (PEA HCl, putative predator cue), or P. marinus whole-body extract (conspecific alarm cue). All P. marinus demonstrated a significant avoidance response to both cues. No significant differences were found in avoidance to PEA HCl between photoperiods. Avoidance of P. marinus whole-body extract was significantly stronger in natural compared with reversed photoperiod P. marinus . The use of reversed photoperiod subjects is suitable for examining the presence or absence of avoidance in response to novel chemosensory alarm cues, or the change in the magnitude of antipredator response. Studies investigating the natural magnitude of antipredator response should use natural photoperiod experimental subjects.

Canadian Journal of Zoology

Diving and foraging patterns of Marbled Murrelets (Brachyramphus marmoratus): Testing predictions from optimal-breathing models

The diving behavior of Marbled Murrelets (Brachyramphus marmoratus) was studied using telemetry along the Oregon coast during the 1995 and 1996 breeding seasons and examined in relation to predictions from optimal-breathing models. Duration of dives, pauses, dive bouts, time spent under water during dive bouts, and nondiving intervals between successive dive bouts were recorded. Most diving metrics differed between years but not with oceanographic conditions or shore type. There was no effect of water depth on mean dive time or percent time spent under water even though dive bouts occurred in depths from 3 to 36 m. There was a significant, positive relationship between mean dive time and mean pause time at the dive-bout scale each year. At the dive-cycle scale, there was a significant positive relationship between dive time and preceding pause time in each year and a significant positive relationship between dive time and ensuing pause time in 1996. Although it appears that aerobic diving was the norm, there appeared to be an increase in anaerobic diving in 1996. The diving performance of Marbled Murrelets in this study appeared to be affected by annual changes in environmental conditions and prey resources but did not consistently fit predictions from optimal-breathing models.

Canadian Journal of Zoology

Estimating abundance, temporary emigration and the pattern of density dependence in a cyclic snowshoe hare population in Yukon, Canada

Estimates of demographic parameters based on capture-mark-recapture (CMR) methods may be biased when some individuals in the population are temporarily unavailable for capture (temporary emigration). We estimated snowshoe hare abundance, apparent survival, and probability of temporary emigration in a population of snowshoe hares (Lepus americanus Erxleben 1777) in the Yukon using Pollock’s robust design CMR model, and population density using spatially-explicit CMR models. Survival rates strongly varied among cyclic phases, seasons, and across five population cycles. We found strong evidence that temporary emigration was Markovian (i.e., non-random), suggesting that it varied among individuals that were temporary emigrant in the previous sampling period and those that were present in the sampled area. The probability of temporary emigration for individuals that were in the study area during the previous sampling occasion (γ´´) varied among cycles. Probability that individuals that were temporarily absent from the sampled area would remain temporary emigrants (γ´) showed strongly seasonal pattern, low in winter and high during summers. Snowshoe hare population density ranged from 0.017 (0.015–0.05) hares/ha to 4.43 (3.90–5.00) hares/ha and large-scale cyclical fluctuation. Autocorrelation functions and autoregressive analyses revealed that our study population exhibited statistically significant cyclic fluctuations, with a periodicity of 9-10 years.

Yukon

Gray wolf (Canis lupus) predation patterns following recent recolonization in a multi-predator, multi-prey system

Predator–prey interactions are among the most fundamental of ecological relationships. Recolonizing gray wolf ( Canis lupus Linnaeus, 1758) populations present new challenges for wildlife management in multi-prey, multi-carnivore systems. We documented diet composition and kill rates for wolves in a recently recolonized area over winter and summer seasons (2014–2015). Elk ( Cervus canadensis Erxleben, 1777) were the primary ungulate prey (63%) located at wolf kill sites. Deer (mule deer ( Odocoileus hemionus (Rafinesque, 1817)) and white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780))) were less prevalent than elk in wolf diets, but the amount of deer in diets (40%–50%) varied by pack and season. Juvenile elk were the most prevalent class of prey in wolf diets during summer (63.3%) and winter (36.3%), with adult elk (32.5%) observed nearly as often as juveniles in winter. Kill rates varied by season, with rates 2.3 times higher in summer (mean = 3.5 ungulates/week per pack) than winter (mean = 1.5 ungulates/week per pack), consistent with increased availability and use of neonate prey. Prey biomass acquisition did not vary by pack or season (summer = 243 kg/week per pack; winter = 182 kg/week per pack). Our study quantified predation patterns for a recolonizing wolf population, and patterns that we documented were similar to other multi-prey systems in North America.

Oregon

Regional variation in muscle metabolic enzymes in individual American shad (Alosa sapidissima)

Evaluation of the activity of metabolic enzymes is often used to assess metabolic capacity at the tissue level, but the amount of regional variability within a tissue in an individual fish of a given species is frequently unknown. The activities of four enzymes (citrate synthase (CS), phosphofructokinase, lactate dehydrogenase (LDH), and β-hydroxyacyl coenzyme A dehydrogenase (HOAD)) were assayed in red and white muscle at 10 sites along the body of adult American shad ( Alosa sapidissima ). Red and white muscle HOAD and white muscle CS and LDH varied significantly, generally increasing posteriorly. Maximal variation occurs in red muscle HOAD (~450%) and white muscle LDH (~60%) activity. Differences between the sexes also vary with sampling location. This study suggests that the variability in enzyme activity may be linked to functional differences in the muscle at different locations, and also provides guidelines for sample collection in this species.

Canadian Journal of Zoology