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United States Department of Agriculture Wildlife Services: Staff Publications

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Articles 1471 - 1500 of 1529

Full-Text Articles in Physical Sciences and Mathematics

Predation On Atlantic Salmon Smolts By Striped Bass After Dam Passage, Bradley F. Blackwell, Francis Juanes Apr 1998

Predation On Atlantic Salmon Smolts By Striped Bass After Dam Passage, Bradley F. Blackwell, Francis Juanes

United States Department of Agriculture Wildlife Services: Staff Publications

We documented predation on smolts of Atlantic salmon Salmo salar by striped bass Morone saxatilis foraging in the tailrace of the Essex Dam on the Merrimack River, Lawrence, Massachusetts, and assessed factors that may affect smolt susceptibility to predation. During 6 d of diurnal angling from 6 to 28 May, we captured 212 striped bass, 41 of which contained prey remains. More than 48% of striped bass that contained prey had consumed smolts. Atlantic salmon smolts composed more than 80% of the total mass of prey remains recovered and included both individuals of stocked-fry and stocked-smolt origin. Based on information …


Anthraquinone Protects Rice Seed From Birds, Michael L. Avery, John S. Humphrey, Thomas M. Primus, David G. Decker, Arlene P. Mcgrane Apr 1998

Anthraquinone Protects Rice Seed From Birds, Michael L. Avery, John S. Humphrey, Thomas M. Primus, David G. Decker, Arlene P. Mcgrane

United States Department of Agriculture Wildlife Services: Staff Publications

Application of bird-repellent chemicals to seed prior to planting is one possible approach to reducing bird damage to rice. Anthraquinone is a promising seed treatment compound, and in this paper we describe a sequence of tests evaluating a formulated commercial anthraquinone product. In l-cup cage tests, rice consumption by individual male red-winged blackbirds (Agelaius phoeniceus) and female boat-tailed grackles (Quiscalus major) was reduced 64-93% by 0.5 and 1.0% (g/g) anthraquinone treatments. Daily rice consumption by single male boat-tailed grackles tested in large enclosures was reduced from > 14 g in pretreatment to < 1 g by a 1.0% treatment. One of five test birds ate nothing during a 1 day post-treatment session. In a 7 day trial within a 0.2 ha flight pen, a group of four male grackles consumed 1.3% of anthraquinone-treated rice seed compared to 84.1% of sorghum, a nonpreferred alternate food. At two study sites in southwestern Louisiana, loss of rice sprouts in 2 ha plots sown with anthraquinone-treated seed was 0 and 12% compared to losses of 33% and 98% in nearby untreated plots. The formulation performed well at every stage of testing, and further development of anthraquinone products for bird-damage management is warranted.


Laboratory Evaluation Of Predator Odors For Eliciting An Avoidance Response In Roof Rats (Rattus Rattus), Michael D. Burwash, Mark E. Tobin, Anthony D. Woolhouse, Thomas P. Sullivan Apr 1998

Laboratory Evaluation Of Predator Odors For Eliciting An Avoidance Response In Roof Rats (Rattus Rattus), Michael D. Burwash, Mark E. Tobin, Anthony D. Woolhouse, Thomas P. Sullivan

United States Department of Agriculture Wildlife Services: Staff Publications

We evaluated eight synthetic predator odors and mongoose (Herpestes auropunctatus) feces for eliciting avoidance responses and/or reduced feeding by wild captured Hawaiian roof rats (Rattus rattus). In a bioassay arena, we recorded: (1) time until each rat entered the arena, (2) time elapsed until first eating bout, (3) time spent in each half of the arena, (4) number of eating bouts, and (5) consumption. Rats displayed a response to the predator odors in terms of increased elapsed time before initial arena entry and initial eating bout, a lower number of eating bouts, and less food consumption …


Determination Of Zinc Phosphide Residues In Corn (Zea Mays) Grain, Fodder, And Forage, M. J. Goodall, S. A. Volz, J. J. Johnston, D. B. Hurlbut, R. E. Mauldin, D. L. Griffin, E. E. Petty Apr 1998

Determination Of Zinc Phosphide Residues In Corn (Zea Mays) Grain, Fodder, And Forage, M. J. Goodall, S. A. Volz, J. J. Johnston, D. B. Hurlbut, R. E. Mauldin, D. L. Griffin, E. E. Petty

United States Department of Agriculture Wildlife Services: Staff Publications

Zinc phosphide (ZN3P2) is an acute rodenticide. One of its current uses employs application as a grain bait or pellet at the time of planting to reduce agricultural losses by field rodents. To mitigate rodent induced losses to corn, we hoped to expand the approved uses of zinc phosphide to include corn applications. After determining acceptable efficacy, we conducted a study to determine if potentially hazardous zinc phosphide residues in corn would result from this use. A field study was conducted in 5 corn growing states to provide samples for residue analysis of corn treated with …


Observations Of Nocturnal Foraging In The Double-Crested Cormorant, D. Tommy King, J. Brent Harrel, Brian Dorr, David Reinhold Mar 1998

Observations Of Nocturnal Foraging In The Double-Crested Cormorant, D. Tommy King, J. Brent Harrel, Brian Dorr, David Reinhold

United States Department of Agriculture Wildlife Services: Staff Publications

Double-crested Cormorants (Phalacrocorax auritus) are normally considered a diurnal species. Here we describe cormorants foraging nocturnally in an oxbow lake in Mississippi. We have observed this behavior only once during 30 capture attempts over seven years.


The National Wildlife Research Center: Providing Innovative Solutions To Human–Wildlife Conflicts Mar 1998

The National Wildlife Research Center: Providing Innovative Solutions To Human–Wildlife Conflicts

United States Department of Agriculture Wildlife Services: Staff Publications

Welcome to the National Wildlife Re search Center (NWRC), the primary research facility within the Wildlife Services (WS) program of the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS). NWRC provides scientific information on wildlife, its habitat, and its relationship to agriculture and public safety. Here at the Center and at our nine field stations, specialists conduct scientific inquiries into the problems of wildlife damage and look for solutions to these problems.


Zinc Phosphide Residues In Gray-Tailed Voles (Microtus Canicaudus) Fed Fixed Particles Of A 2% Grain Bait, R. T. Sterner, D. A. Goldade, R. E. Mauldin Jan 1998

Zinc Phosphide Residues In Gray-Tailed Voles (Microtus Canicaudus) Fed Fixed Particles Of A 2% Grain Bait, R. T. Sterner, D. A. Goldade, R. E. Mauldin

United States Department of Agriculture Wildlife Services: Staff Publications

This study measured depelted-carcass residues of zinc phosphide (Zn3P2, CAS # 1314-84-7) in 8 (4 males and 4 females) gray-tailed voles (Microtus canicaudus). Six (3 males and 3 females) voles were confined individually in 1.89 dkl (5 gal) plastic pails that contained 5,2% Zn3P2 steamrolled- oat (SRO) groats; 2 voles (1 male and 1 female) served as analytical (unbaited) controls. Four test voles (3 males and 1female) died within 7.5 h after bait exposure; whereas, 2 test voles showed no signs of toxicosis and were euthanized 7.0 h after bait exposure. …


Cytochrome P450 And Organochlorine Contaminants In Black-Crowned Night-Herons From The Chesapeake Bay Region, Usa, Barnett A. Rattner, Mark J. Melancon, Clifford P. Rice, Walter Riley Jr., John D. Eisemann, Randy K. Hines Oct 1997

Cytochrome P450 And Organochlorine Contaminants In Black-Crowned Night-Herons From The Chesapeake Bay Region, Usa, Barnett A. Rattner, Mark J. Melancon, Clifford P. Rice, Walter Riley Jr., John D. Eisemann, Randy K. Hines

United States Department of Agriculture Wildlife Services: Staff Publications

Black-crowned night-heron (Nycticorax nycticorax) offspring were collected from a relatively uncontaminated coastal reference site (next to Chincoteague National Wildlife Refuge, VA, USA) and two sites in the Chesapeake Bay watershed (Baltimore Harbor, MD and Rock Creek Park, Washington, DC, USA). Hepatic microsomal activities of benzyloxyresorufin-O-dealkylase and ethoxyresorufin-O-dealkylase were significantly elevated (up to sixfold and ninefold induction, respectively) in pipping embryos from the Baltimore Harbor colony compared to the reference site, whereas values in embryos from the Rock Creek Park colony were intermediate. Concentrations of organochlorine pesticides and metabolites in pipping embryos from both sites …


The Problem With Voles, Kim Wagner Oct 1997

The Problem With Voles, Kim Wagner

United States Department of Agriculture Wildlife Services: Staff Publications

At first glance, these small, stocky, short-tailed rodents may seem harmless, but don't let their appearance fool you! Voles (a.k.a. meadow mice) can cause w lot of damage. Voles kill trees by removing all the bark around the base of the tree (girdling), and by feeding on tree roots. Vole damage to seedlings and tree roots can significantly reduce reforestation rates and tree growth. In British Columbia, vole damage was the main reason over 40 percent of the forest plantations examined had inadequate restocking rates. Vole populations follow acyclic pattern with population levels reaching a peak every two to five …


Aerial Photography Techniques To Estimate Populations Of Laughing Gull Nests In Jamaica Bay, New York, 1992-1995, Richard A. Dolbeer, Jerrold L. Belant, Glen E. Bernhardt Aug 1997

Aerial Photography Techniques To Estimate Populations Of Laughing Gull Nests In Jamaica Bay, New York, 1992-1995, Richard A. Dolbeer, Jerrold L. Belant, Glen E. Bernhardt

United States Department of Agriculture Wildlife Services: Staff Publications

We evaluated aerial photography (full coverage, using fixed-wing aircraft) and aerial video (transects, using helicopter) surveys to estimate the population of Laughing Gull (Larus ahicilla) nests in Jamaica Bay, New York, during June 1992-1995. We counted 4,920 nests in the colony using aerial photography and estimated 5,367 nests using aerial video in 1992. In 1993-1995, we respectively counted 5,691,5,095, and 6,126 nests in the colony using aerial photography, and estimated from ground plots that our counts differed from the actual number of nests by means of -9% to 1%. Overall (1993-1995) correction factors (by which to multiply the aerial photography …


Carrion Seeking In Brown Tree Snakes: Importance Of Olfactory And Visual Cues, John A. Shivik, Larry Clark Apr 1997

Carrion Seeking In Brown Tree Snakes: Importance Of Olfactory And Visual Cues, John A. Shivik, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

We performed field experiments to examine brown tree snake (Boiga irregularis) attraction to carrion. These snakes were attracted to carrion and entered traps baited with dead mice as readily as traps baited with live mice. Using the cues arising from both live and dead prey, we examined the relative importance of visual and chemical cues to brown tree snakes. With carrion lures, chemical cues alone were sufficient for attracting and capturing snakes, but with live prey lures visual cues were required to attract and capture brown tree snakes. Our study presents the first experimental field evidence showing carrion …


Assessing The Hazard To Granivorous Birds Feeding On Chemically Treated Seeds, Michael L. Avery, David L. Fischer, Thomas M. Primus Mar 1997

Assessing The Hazard To Granivorous Birds Feeding On Chemically Treated Seeds, Michael L. Avery, David L. Fischer, Thomas M. Primus

United States Department of Agriculture Wildlife Services: Staff Publications

Current methods for evaluating hazards to seed-eating birds are based on estimated exposure per unit area and assume that birds ingest all of the chemical on a treated seed. In an earlier study, however, it was determined that red-winged blackbirds removed only about 15% of an insecticidal treatment applied to individual rice seeds. Here, we extend those findings by examining the seed-handling behavior of four granivorous bird species exposed to millet, rice, sunflower and sorghum treated with imidacloprid. Mourning doves (Zenaida macroura L.) swallowed the seed whole. House finches (Carpodacus mexicanus Muller), red-winged blackbirds (Agelaius phoeniceus L.) …


Comparison Of Three Formulations Of Alphachloralose For Immobilization Of Canada Geese, Jerrold L. Belant, Thomas W. Seamans Jan 1997

Comparison Of Three Formulations Of Alphachloralose For Immobilization Of Canada Geese, Jerrold L. Belant, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

The effectiveness of an alpha-chloralose (AC)-corn oil suspension, an AC-margarine mixture, and AC tablets were compared for immobilizing Canada geese (Branta canadensis). Responses to AC immobilization also were compared in male and female Canada geese. There was no difference in mean time to first effects or mean time to capture between male and female geese dosed with 30 mg/kg AC in orally-administered bread baits. Recovery times (≤24 hr) also were similar between sexes. Mean (±SE) time to first effects for geese immobilized with AC tablets in bread baits ( 19 ± 3 mm) was significantly less than mean …


Solid-Phase Extraction Method For The Quantitative Analysis Of Organochlorine Pesticides In Wildlife Urine, E. E. Petty, J . J . Johnston, S.A. Volz Jan 1997

Solid-Phase Extraction Method For The Quantitative Analysis Of Organochlorine Pesticides In Wildlife Urine, E. E. Petty, J . J . Johnston, S.A. Volz

United States Department of Agriculture Wildlife Services: Staff Publications

A gas chromatographic method for the analysis of nine organochlorine pesticides in wildlife urine is described. Reversedphase solid-phase extraction is utilized to extract the organochlorine pesticides from urine. The pesticides are recovered by elution with hexane-ethyl ether (1:1) and quantified by gas chromatography with electron-capture detection. Method detection limits range from 1.4 to 2.7 μg/L. Mean recoveries for all pesticides are 90.6%.


Compensation Programs For Wildlife Damage In North America, Kimberly K. Wagner, Robert H. Schmidt, Michael R. Conover Jan 1997

Compensation Programs For Wildlife Damage In North America, Kimberly K. Wagner, Robert H. Schmidt, Michael R. Conover

United States Department of Agriculture Wildlife Services: Staff Publications

Financial compensation for damages caused by wildlife is an alternative to lethal wildlife damage management techniques, but little is known about the use of these programs in North America. We conducted surveys requesting information on wildlife species and type of damage covered by compensation programs, annual cost of programs, and the monitoring and assessment of program success to the wildlife agencies of all states and Canadian provinces. We also requested information on programs providing producers with damage-abatement materials instead of or in addition to financial compensation. All states and provinces responded to our survey. Nineteen states and 7 provinces had …


Estimating Survival Of Song Bird Carcasses In Crops And Woodlots, George M. Linz, David L. Bergman, William J. Bleier Jan 1997

Estimating Survival Of Song Bird Carcasses In Crops And Woodlots, George M. Linz, David L. Bergman, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

Estimates of non-target animal mortality due to the effects of agricultural pesticides may be biased by the removal of carcasses by scavengers. We placed intact songbird carcasses in ripening sunflower fields in late-summer, and in harvested corn fields and woodlots in early spring to assess carcass removal by scavengers. Removal curves differed among the three habitats (P < 0.001). One day after placement, 58% of carcasses persisted in the sunflower fields, whereas 82% and 90% remained in the corn fields and woodlots, respectively. Our results suggest that survival times for carcasses are variable and dependent on habitat and, perhaps seasonal factors. In most cases, searches for carcasses should be conducted within one day of the pesticide application.


Age Classification Of Laughing Gulls Based On Summer Plumage, Jerrold L. Belant, Richard A. Dolbeer Oct 1996

Age Classification Of Laughing Gulls Based On Summer Plumage, Jerrold L. Belant, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

We described quantitatively 19 summer plumage characteristics and bill and foot pigmentation of 247 known-age Laughing Gulls (Larus atricilla) collected in New York during 1992-1994. There were no differences in characteristics measured for male and female Laughing Gulls. Ninety percent of 2-yr-old Laughing Gulls and 96% of ≥ 3-yr-old birds had full hoods. Fifty-seven percent of 2-yr-old Laughing Gulls possessed at least partial tail bands in contrast to 4% of 3-yr-old and 0% of ≥ 4-yr-old gulls. Thus 2-and ≥ 3-yr-old Laughing Gulls cannot be separated reliably by the presence or absence of a tail band. Pink pigmentation on the …


Distribution And Abundance Of Roof-Nesting Gulls In The Great Lakes Region Of The United States, Chris P. Dwyer, Jerrod L. Belant, Richard A. Dolbeer Sep 1996

Distribution And Abundance Of Roof-Nesting Gulls In The Great Lakes Region Of The United States, Chris P. Dwyer, Jerrod L. Belant, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

In 1994, we conducted aerial, mail, and telephone surveys to determine the distribution and abundance of roof-nesting gulls in states bordering the Great Lakes. We documented more than 7,922 nesting pairs of gulls at 30 colonies in four states; species composition was 71% ring-billed (Larus delawarensis^, 24% herring (Z. argentatus^, and 5% unknown. Colony size ranged from 1 to 1,003 nesting pairs. Proportions of ring-billed gulls nesting less that 5.0 and more than 10.0 km from the Great Lakes were 31% and 39%, in contrast to 63% and less than 1% for herring gulls, respectively. Maximum distances herring and ring-billed …


Longevity Of Woodhouse's Toad In Colorado, Richard M. Engeman, E. Marie Engeman May 1996

Longevity Of Woodhouse's Toad In Colorado, Richard M. Engeman, E. Marie Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Little is known about the longevity of amphibians in nature. Records from captive specimens have demonstrated life spans of 10 to 20 yr for a number of anuran species, including 36 yr for Bufo bufo (Duellman WE, Trueb L. 1986. Biology of Amphibians. New York: McGraw-Hill. 670 p). Here, we report on a male Woodhouse's toad (Bufo woodhousii) which appeared in 1978, and has apparently remained since, in a basement window well of a brick home in an unincorporated western suburb of Denver, Colorado (T3S, R69W, 530). In the intervening years no other toads have been observed in …


Evaluation Of Propane Exploders As White-Tailed Deer Deterrents, J. L. Belant, T. W. Seamans, C.P. Dwyer Apr 1996

Evaluation Of Propane Exploders As White-Tailed Deer Deterrents, J. L. Belant, T. W. Seamans, C.P. Dwyer

United States Department of Agriculture Wildlife Services: Staff Publications

In response to increased white-tailed deer (Odocoileus virginianus) depredation of agricultural crops and encroachment on airports, we evaluated the effectiveness of systematic and motion-activated propane exploders as deer frightening devices. We conducted three experiments in a 2200 ha fenced facility in northern Ohio with high (91/km2) deer densities during 1994-1995. Systematic exploders were calibrated to detonate once at 8 to 10 min intervals, whereas motion-activated exploders detonated 8 times/deer intrusion. Systematic propane exploders were generally ineffective, deterring deer from corn for <2 days only, whereas motion-activated exploders repelled deer for O-6 weeks. Repellency of motion-activated exploders varied seasonally, possibly in response to variations in deer density, availability of alternate food, or reproductive and social behavior. We recommend motion-activated exploders over systematic exploders as deer frightening devices for crop damage mitigation and on airports; however, systematic exploders may have utility for short-term (a few days) use.


A Comparison Of Gross Pathology, Histopathology, And Mycobacterial Culture For The Diagnosis Of Tuberculosis In Elk(Cervus Elaphus), Elizabeth B. Rohonczy, Arumuga V. Balachandran, Thomas W. Dukes, Janet B. Payeur, Jack C. Rhyan, Dennis A. Saari, Terry L. Whiting, Susan H. Wilson, Jerald L. Jarnagin Mar 1996

A Comparison Of Gross Pathology, Histopathology, And Mycobacterial Culture For The Diagnosis Of Tuberculosis In Elk(Cervus Elaphus), Elizabeth B. Rohonczy, Arumuga V. Balachandran, Thomas W. Dukes, Janet B. Payeur, Jack C. Rhyan, Dennis A. Saari, Terry L. Whiting, Susan H. Wilson, Jerald L. Jarnagin

United States Department of Agriculture Wildlife Services: Staff Publications

Using the isolation of Mycobacterium bovis as the reference standard, this study evaluated the sensitivity, specificity and kappa statistic of gross pathology (abattoir postmortem inspection), histopathology, and parallel or series combinations of the two for the diagnosis of tuberculosis in 430 elk and red deer. Two histopathology interpretations were evaluated: histopathology I, where the presence of lesions compatible with tuberculosis was considered positive, and histopathology II, where lesions compatible with tuberculosis or a select group of additional possible diagnoses were considered positive. In the 73 animals from which M. bovis was isolated, gross lesions of tuberculosis were most often in …


Black Bear Damage To Lodgepole Pine In Central Oregon, Victor G. Barnes Jr., Richard M. Engeman Oct 1995

Black Bear Damage To Lodgepole Pine In Central Oregon, Victor G. Barnes Jr., Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear (Ursus amerlcanus) damage to 108 lodgepole pine (Pinus contorta) trees was found in a mixed conifer habitat in central Oregon. No trees of three other conifer species were injured. Eighty-nine percent of the damage occurred in the same year. Nearly 20% of the freshly damaged trees had bark removed from more than 75% of the circumference and, judging from the fate of trees damaged in prior years, probably succumbed.


Foraging Behaviors Of Snowy Egrets (Egretta Thula) And Yellow-Crowned Night-Herons (Nyctanassa Violacea) In South Louisiana, D. Tommy King, Dwight Leblanc Mar 1995

Foraging Behaviors Of Snowy Egrets (Egretta Thula) And Yellow-Crowned Night-Herons (Nyctanassa Violacea) In South Louisiana, D. Tommy King, Dwight Leblanc

United States Department of Agriculture Wildlife Services: Staff Publications

We report two previously undescribed foraging techniques used by Snowy Egrets (Egretta thula) and Yellow-crowned Night-Herons (Nyctanassa violacea) to catch crawfish (Procambarus spp.). Snowy Egrets were selecting crawfish that had recently molted their shells and Yellow-crowned Sight-Herons were targeting crawfish that were emerging from their burrows. These observations were conducted on commercial crawfish ponds near Catahoula, LA, USA.


Abundance Of Gulls And Other Birds At Landfills In Northern Ohio, Jerrold L. Belant, Thomas W. Seamans, Steven W. Gabrey, Richard A. Dolbeer Jan 1995

Abundance Of Gulls And Other Birds At Landfills In Northern Ohio, Jerrold L. Belant, Thomas W. Seamans, Steven W. Gabrey, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

We estimated the abundance of birds at three landfills in northern Ohio from May 1991-July 1992 recording 699,350 individuals of 42 species. Gulls (Larus spp.) comprised 94.5% of the birds recorded followed by European starlings (Sturnus vulgaris, 5.0%) and turkey vultures (Cathartes aura, 0.3%). Gulls were primarily of two species, ring-billed (L. delawarensis, 74.49%) and herring (L. argentatus, 25.50%). The mean number of gulls per observation during July-January was at least five times the mean number observed during other months. The combined monthly mean number of gulls at the three landfills peaked in August (>4000 birds), with gulls virtually …


Birds Associated With Blackbird Spring Feeding Sites In South Dakota, George M. Linz, David L. Bergman, William J. Bleier Jan 1995

Birds Associated With Blackbird Spring Feeding Sites In South Dakota, George M. Linz, David L. Bergman, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

From 2 to 16 April 1993, we conducted road-side surveys of birds using harvested fields of small grains, soybeans, and wm within 8 km of two blackbird roosts in east central South Dakota. Blackbirds, waterfowl, killdeer, homed larks, ring-necked pheasants, and western meadowlarks were the most common buds recorded. The frequencies of blackbirds, non-game birds, terrestrial game birds, and waterfowl was not equally distributed within the three habitats (P = 0.U.23).


American Woodock Use Of A Nest Box, David L. Bergman, Joel M. Bergman Jan 1995

American Woodock Use Of A Nest Box, David L. Bergman, Joel M. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

-Lombardo et al. (1989, Condor 91 :744-747) reviewed two hypotheses for the use of nest boxes by house sparrows Passer domesticus, European starlings Sturnus vulgaris, eastern bluebirds Sialia sialis, and great tits Passer major during the nonbreeding season: (1) roosting in nest cavities may be associated with nest-cavity selection during intense competition for a limited number of usable cavities, and (2) birds use cavities during the non breeding season to decrease the rate of heat loss. We were unable to locate any prior documentation of nest box use by American woodcock (Scolopax major), therefore we report on a new behavior …


Feeding Responses To Predator-Based Repellents In The Mountain Beaver (Aplodontia Rufa), Gisela Epple, J. Russell Mason, Evgueny Aronov, Dale L. Nolte, Richard Hartz, Ron Kaloostian, Dan Campbell, Amos Smith Iii Jan 1995

Feeding Responses To Predator-Based Repellents In The Mountain Beaver (Aplodontia Rufa), Gisela Epple, J. Russell Mason, Evgueny Aronov, Dale L. Nolte, Richard Hartz, Ron Kaloostian, Dan Campbell, Amos Smith Iii

United States Department of Agriculture Wildlife Services: Staff Publications

Predator odors have potential as feeding repellents for mammalian herbivores, including Aplodontia rufa, the mountain beaver. However, the repellency of major chemical constituents of natural predator scents for this species has not been evaluated. In this study, the effects of several synthetic sulfur compounds from predator scents on feeding by mountain beavers were assessed and compared to the effects of coyote (Canis latrans) urine. Retrieval of food by mountain beavers from bowls scented with either coyote urine, diluted with water to different concentrations, synthetic components of predator scents, or control odorants was studied. The following synthetic compounds …


A Comparison Of Plotless Density Estimators Using Monte Carlo Simulation, Richard M. Engeman, Robert T. Sugihara, Larry F. Pank, William E. Dusenberry Nov 1994

A Comparison Of Plotless Density Estimators Using Monte Carlo Simulation, Richard M. Engeman, Robert T. Sugihara, Larry F. Pank, William E. Dusenberry

United States Department of Agriculture Wildlife Services: Staff Publications

We conducted an extensive simulation study to compare the performance of a large group of plotless density estimators (PDEs) to obtain clarification of their relative performance in a diversity of sampling situations. The PDEs studied included well-known ones from the literature plus some extensions and modifications introduced here. The simulations cover 96 combinations of 6 spatial patterns, 4 sample sizes, and 4 population densities. We made comparisons within classes of similar estimators, and we indicate the best-performing PDEs out of the complete set studied. Over all spatial patterns, the angle-order estimator with measurements to the third closest individual in each …


Dietary Comparisons Of Adult Male Common Grackles, Red-Winged Blackbirds, And Yellow-Headed Blackbirds In North Central North Dakota, H. Jeffrey Homan, George M. Linz, William J. Bleier, Robert B. Carlson Jan 1994

Dietary Comparisons Of Adult Male Common Grackles, Red-Winged Blackbirds, And Yellow-Headed Blackbirds In North Central North Dakota, H. Jeffrey Homan, George M. Linz, William J. Bleier, Robert B. Carlson

United States Department of Agriculture Wildlife Services: Staff Publications

We compared the esophageal contents of adult male common grackles (Quiscalus quiscula), red-winged blackbirds (Agelaius phoeniceus),and yellow-headed blackbirds (Xanthocephalus xanthocephalus) collected in north central North Dakota from July through October 1989. Temporal variation in the diets of all species was related to food availabilities, which were heavily influenced by crop phenology. Depending on species, mean percent dry weight of sunflower achenes during August increased 2-6 times over July. Yellow-headed blackbirds migrated from north central North Dakota by early September, but substantial numbers of common grackles and red-winged blackbirds remained until mid-October. Sunflower was an …


Tolerance Of Bitter Compounds By An Herbivore, Cavia Porcellus, Dale L. Nolte, J. Russell Mason, Stanley Lewis Jan 1994

Tolerance Of Bitter Compounds By An Herbivore, Cavia Porcellus, Dale L. Nolte, J. Russell Mason, Stanley Lewis

United States Department of Agriculture Wildlife Services: Staff Publications

Many plant defensive chemicals are bitter to humans. Because of this taste characteristic, and because bitter compounds are often toxic, such substances, and the plants that contain them, are regarded as generally unpalatable to wildlife. These assumptions may be unwarranted. To test the hypothesis that herbivores are indifferent to 'bitter' tastants, we investigated the responsiveness of guinea pigs (Cavia porcellus) to denatonium benzoate, denatonium saccharide, limonene, L-phenylalanine, naringin, quebracho, quinine, Ro-Pel (a commercial animal repellent containing denatonium saccharide) and sucrose octaacetate. Only quinine and sucrose octaacetate slightly but significantly reduced feeding (P < 0.05). Our findings are inconsistent with the notion that herbivores generally avoid what humans describe as bitter tastes.