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United States Department of Agriculture Wildlife Services: Staff Publications

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Disease Emergence In Birds: Challenges For The Twenty-First Century, Milton Friend, Robert G. Mclean, F. Joshua Dein Apr 2001

Disease Emergence In Birds: Challenges For The Twenty-First Century, Milton Friend, Robert G. Mclean, F. Joshua Dein

United States Department of Agriculture Wildlife Services: Staff Publications

Finch (Carpodacus mexicanus) conjunctivitis is an example of the rapid geographic spread that can result from disease emergence in naive populations. That event was neither novel nor transient relative to its occurrence or effects. Disease emergence and reemergence are hallmarks of the latter part of the twentieth century (Center for Disease Control 1994, Levins et al. 1994, DaSilva and Laccarino 1999, Gratz 1999). Current examples involving domestic animals include the problems in Europe with bovine spongiform encephalopathy (BSE, or ‘‘mad cow disease’’) (Brown 2001) and foot-and-mouth disease (FMD) (Kitching 1999). Human health has been affected by diseases caused …


Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins Apr 2001

Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas …


Compound Drc-1339 Concentrate- Feedlots Apr 2001

Compound Drc-1339 Concentrate- Feedlots

United States Department of Agriculture Wildlife Services: Staff Publications

DRC-1339 is a slow-acting avicide registered by the Animal and Plant Health Inspection Service's (APHIS) Wildlife Services (WS) program for the control of blackbirds, starlings, pigeons, crows, ravens, magpies, and gulls. Only WS certified applicators, or persons working under their direct supervision, can apply this avicide. WS has five DRC-1339 products registered with the U.S. Environmental Protection Agency (EPA) to use for bird problems that cannot be resolved by Starlicide Complete (EPA Reg. No. 67517-8) or other commercially available products. The Compound DRC-I 339 Concentrate-Feedlots (1339-FL) registration provides alternate baits for controlling blackbird and starling problems at feedlots and allows …


Compound Drc- 1339 Concentrate-Staging Areas (Epa Reg. No. 56228-30) Apr 2001

Compound Drc- 1339 Concentrate-Staging Areas (Epa Reg. No. 56228-30)

United States Department of Agriculture Wildlife Services: Staff Publications

DRC-1339 (3-chloro-4-methyl benzenamine HCI, Chemical Abstract Service Reg. No. 7745-89-3) is a slow- acting avicide that is registered with the Environmental Protection Agency (EPA) for the control of several species of pest birds including blackbirds, starlings, pigeons, crows, ravens, magpies, and gulls. Technical DRC-1339 (Starlicide Technical, EPA Reg. No. 602-1 34) contains 97 percent DRC-1339. DRC-1339 was developed jointly by Ralston Purina, Inc., Purina Mills, Inc., and the National Wildlife Research Center (NWRC) of the U. S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) Wildlife Service's (WS) program.


M-44 User Tips Apr 2001

M-44 User Tips

United States Department of Agriculture Wildlife Services: Staff Publications

CONTENTS:

The M-44 Sodium Cyanide Ejector Mechanism
M-44 Cyanide Capsules
Capsule Storage
Sealants
Carrying Capsules for Use in the Field
Checking Capsules
Ejectors
Stakes
Driving Stakes
Keeping Dirt and Sand Out
Safety
Antidote Kits
Sources of Information


Using Iophenoxic Acid Injections Of Prey To Identify Mammals That Feed On Them, Frederick F. Knowlton, Stanley R. Olmstead Mar 2001

Using Iophenoxic Acid Injections Of Prey To Identify Mammals That Feed On Them, Frederick F. Knowlton, Stanley R. Olmstead

United States Department of Agriculture Wildlife Services: Staff Publications

Identifying species or individuals that feed upon other species of animals is an important aspect of some predation studies. We evaluated the effectiveness with which the biomark associated with iophenoxic acid (IA) injections was transferred from domestic goats to coyotes (Canis latrans) that fed on them. We injected doses of 100, 300, or 1,000 mg of IA into goats to raise serum iodine levels, fed meat from the injected goats to coyotes, and monitored serum iodine levels in both species for about I20 days. Within 3 days, mean serum iodine levels in goats increased from 5.33 mcg/I 00 ml to …


Comparison Of Active Ingredients And Delivery Systems In Deer Repellents, Kimberly K. Wagner, Dale L. Nolte Mar 2001

Comparison Of Active Ingredients And Delivery Systems In Deer Repellents, Kimberly K. Wagner, Dale L. Nolte

United States Department of Agriculture Wildlife Services: Staff Publications

In some situations chemical repellents are a socially appealing nonlethal alternative to reduce deer (Odocoileus spp.) damage to plants. New products are continually becoming available, but their ability to repel deer is very variable. We tested 20 repellents representing 4 modes of action (fear, pain, taste, and aversive conditioning) and 2 delivery systems (topical applications and area repellents [scent packets]) to evaluate current products and identify trends that could be used to predict efficacy of future products. During fall 1998, we placed treated western red cedar (Thuja plicata) seedlings in pastures with black-tai led deer (Odocoileus …


Pulp Cavity-Tooth Width Ratios From Known-Age And Wild-Caught Coyotes Determined By Radiography, Frederick F. Knowlton, Susan L. Whittemore Mar 2001

Pulp Cavity-Tooth Width Ratios From Known-Age And Wild-Caught Coyotes Determined By Radiography, Frederick F. Knowlton, Susan L. Whittemore

United States Department of Agriculture Wildlife Services: Staff Publications

Although the relative sizes of pulp cavities in teeth are used frequently to identify various age classes of carnivores, validation of the technique has received little attention. We measured the pulp cavities and tooth widths based on radiographs of canine and premolar teeth from a large sample of known-age, pen-reared coyotes (Canis latrans) and from samples of wild-caught coyotes of unknown age. The ratio of pulp cavity to tooth width decreased rapidly through the first year of life. Although canine tooth ratios of juvenile, yearling, and adult coyotes differed, variations within yearling and adult groups precluded accurate assignment …


Comparison Of Primary And Secondary Repellents For Aversive Conditioning Of European Starlings, Roger W. Sayre, Larry Clark Mar 2001

Comparison Of Primary And Secondary Repellents For Aversive Conditioning Of European Starlings, Roger W. Sayre, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Secondary repellents have been demonstrated to effectively reduce avian crop depredation. However, these compounds frequently are toxins and there are concerns about environmental safety. Many primary repellents are toxicologically and environmentally safer, but these chemicals are not as effective when traditional delivery methods are used. We set out to determine whether the difference in efficacy of primary vs. secondary repellents was due to differences in potency of the chemical classes or site of action within the animal. We hypothesized that the efficacy of primary repellents could be enhanced if they could be delivered directly to the gastrointestinal system, thus by-passing …


Dogs Increase Recovery Of Passerine Carcasses In Dense Vegetation, H. Jeffrey Homan, George M. Linz, Brian D. Peer Mar 2001

Dogs Increase Recovery Of Passerine Carcasses In Dense Vegetation, H. Jeffrey Homan, George M. Linz, Brian D. Peer

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers use carcass searches to assess mortality resulting from biological (e.g., diseases) and physical (e.g., structure collisions) sources. Carcass searches may occur over large areas and need to be completed rapidly because of scavenging and decomposition. However, small carcasses are often missed when dense vegetation is searched. We placed carcasses of house sparrows (Passer domesticus) in dense cover of residual and newly grown vegetation and compared searching efficiency of humans and canines. Dogs received no special training in searching for passerine carcasses. In 36 trials conducted in 5 x 40-m plots, human searchers found 45% (SD=19) of the carcasses …


Integrated Management Tactics To Assess Risk And Reduce Damage To Conifer Reforestation By Pocket Gophers, Richard M. Engeman, Gary W. Witmer Mar 2001

Integrated Management Tactics To Assess Risk And Reduce Damage To Conifer Reforestation By Pocket Gophers, Richard M. Engeman, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

In the western United States, pocket gophers pose an acute and chronic problem for forest managers to overcome. Gophers cause extensive damage to seedlings and can delay reforestation for decades.. Here we examine the predictive factors for assessing the risk for damage and the available control tools and damage control strategies. The information is reviewed and summarized so that an integrated damage reduction plan can be developed in a logical, cost-effective, and environmentally responsible fashion..


Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins Mar 2001

Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas …


Monitoring Of Terrestrial Carnivore Populations, Eric M. Gese Mar 2001

Monitoring Of Terrestrial Carnivore Populations, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

There is increasing concern about the status and distribution of terrestrial carnivore populations throughout the world (Schaller, 1996). Changes in land-use practices, habitat loss and fragmentation, sanctioned human persecution, declines in natural prey, disease, illegal poaching, and increased competition within carnivore guilds have brought about a general decline in several carnivore populations with some species now occupying a fragment of their former range. The continued loss of suitable habitat due to an ever expanding human population has placed the issue of conservation and protection of some carnivores as a top environmental priority and/or controversy for many agencies and organizations. Paramount …


Porcine Zona Pellucida Immunocontraception: Long-Term Health Effects On White-Tailed Deer, Lowell A. Miller, Ken Crane, Stan Gaddis, Gary J. Killian Mar 2001

Porcine Zona Pellucida Immunocontraception: Long-Term Health Effects On White-Tailed Deer, Lowell A. Miller, Ken Crane, Stan Gaddis, Gary J. Killian

United States Department of Agriculture Wildlife Services: Staff Publications

As part of a 9-year study on the contraceptive effects of Porcine Zona Pellucida (PZP) on white-tailed deer (Odocoileus virginianus), we analyzed serum chemistry panels during the first 4 years. This included the first 2 years when does were being actively immunized, and 2 years post-immunization. The chemistry panel was designed to detect pathologies that might result from the immunization of the deer. Blood chemistry results did not suggest any pathological changes resulting from the immunization. Seasonal differences in serum cholesterol were similar in both the control and PZP-treated groups. Seasonal changes in the mean body weights of …


Effect Of Primary And Secondary Repellents On European Starlings: An Initial Assessment, Roger W. Sayre, Larry Clark Mar 2001

Effect Of Primary And Secondary Repellents On European Starlings: An Initial Assessment, Roger W. Sayre, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers need chemical repellents that are effective at deterring damage by birds, but these repellents must be environmentally and toxicologically safe. The number of commercially available bird repellents has been reduced because of concerns about environmental safety. Currently, there are 2 categories of avian repellents. Chemicals that are reflexively avoided by birds because they irritate the peripheral chemical senses are referred to as primary repellents. Chemicals that cause gastrointestinal illness and learned avoidance of ancillary sensory cues that are paired with the illness are known as secondary repellents. Secondary repellents most often identified as the most effective avian repellents …


Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark Mar 2001

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Because the brown treesnake (Boiga irregularis) has virtually extirpated the avifauna on Guam and is a threat to other Pacific islands, the development of alternative and efficient control methods is required. Therefore, we performed a large-scale field experiment to determine whether the acetaminophen baits we developed could be used to reduce population levels of brown treesnakes on Guam. Toxic baits were made by inserting 80 mg of acetaminophen into dead neonatal mice, and these mouse baits were used to treat plots. Reference plots were baited with unadulterated baits. We used mark-recapture methods to estimate snake abundance on plots …


Black Bear Forest Damage In Washington State, Usa: Economic, Ecological, Social Aspects, Georg J. Ziegltrum, Dale L. Nolte Mar 2001

Black Bear Forest Damage In Washington State, Usa: Economic, Ecological, Social Aspects, Georg J. Ziegltrum, Dale L. Nolte

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear (Ursus americanus) damage to coniferous forests can be detrimental to the forest products industry in Washington state. Value of timber damage, west of the Cascade Mountains is millions of dollars every year. The Washington Forest Protection Association’s (WFPA) Animal Damage Control Program (ADCP) manages bear damage in cooperation with the Washington Department of Fish and Wildlife (WDFW). Bears can significantly affect the viability of other wildlife, for example, elk (Cervus elaphus) calf predation on calving sites. Conversely, bear-damaged trees add to the snags and dead wood on the ground, which provide important habitat and …


The Other Tools For Wolf Management, John A. Shivik Mar 2001

The Other Tools For Wolf Management, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Non-lethal options are being studied by researchers at the National Wildlife Research Center. But do they really work?


Field Evaluation Of A Visual Barrier To Discourage Gull Nesting, P. A. Pochop, J.L. Cummings, R. M. Engeman Mar 2001

Field Evaluation Of A Visual Barrier To Discourage Gull Nesting, P. A. Pochop, J.L. Cummings, R. M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Ring-billed Gull Larus delawarensis and California Gull L. californicus populations have increased throughout the western United States in close association with human settlement (Conover 1983; Ryder 1993). On Upper Nelson Island in the Columbia River, the number of Ring-billed and California Gull nests increased from 4 600 in 1978 to 21 000 in 1999 (Thompson and Tabor 1981; Pochop, this manuscript). Agriculture and landfills provided food sources, and construction of reservoirs increased island nest sites for gulls (Ryder 1993). Gulls gather below hydroelectric facilities in the spring to feed on migrating juvenile salmonids (Steuber et al. 1995). Also, increased gull …


Great Egret Preference For Catfish Size Classes, Scott J. Werner, Mark E. Tobin, Paul B. Fioranelli Mar 2001

Great Egret Preference For Catfish Size Classes, Scott J. Werner, Mark E. Tobin, Paul B. Fioranelli

United States Department of Agriculture Wildlife Services: Staff Publications

Several species of fish-eating birds are commonly observed near aquaculture facilities in the southern United States. An understanding of the relationships between these birds and specific commodities is needed to interpret and manage bird impacts to aquacultural production. We conducted two foraging experiments to evaluate the preference o f Great Egrets (Ardea alba) for three specific size classes of Channel Catfish (Zctalurus punctatus). During six no-choice feeding trials, egrets consumed significantly more small (7.5-10 cm) fingerlings than medium (13- 18 cm) or large (23-23 cm) catfish. Egrets captured 19 large catfish, and ingested only two, even …


Case Study 2: Seed Treatment, Peter Edwards, Kees Romijn, Michael L. Avery, Ralf Barfknecht, Mark Clook, Wout Slob, Martin Urban Mar 2001

Case Study 2: Seed Treatment, Peter Edwards, Kees Romijn, Michael L. Avery, Ralf Barfknecht, Mark Clook, Wout Slob, Martin Urban

United States Department of Agriculture Wildlife Services: Staff Publications

General information and use pattern
Function: Insecticide seed treatment
Mode of action: Acetylcholinesterase (AChE) inhibitor
Type and composition of formulation: Cereal seed treatment with colored dye. Nominal concentration on seed is 1000 mg a.i./kg.
Crop and pest: Control of wheat bulb fly in autumn/winter-sown cereals
Application: Treated seed is drilled to a depth of approximately 2.5 cm at a sowing rate of approximately 180 kg seed/ha. Soil type, seedbed, and climatic conditions may influence the proportion of seeds left on the soil surface. The label is explicit about procedures to minimize seed left on the soil surface and collection and …


Objectives And Integrated Approaches For The Control Of Brown Tree Snakes, Richard M. Engeman, Daniel S. Vice Mar 2001

Objectives And Integrated Approaches For The Control Of Brown Tree Snakes, Richard M. Engeman, Daniel S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

The inadvertent introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island’s native terrestrial vertebrates, has presented a health hazard to small children, and also has produced an economic problem. Management of brown tree snakes is aimed at a number of objectives, the foremost of which has been to deter its dispersal through Guam’s cargo traffic to other locations. Another objective is to reclaim areas on Guam for reintroduction of native wildlife. A related objective is the protection of small sensitive sites on Guam from brown tree snake …


A Direct Comparison Of Trapping And Spotlight Searches For Capturing Brown Tree Snakes On Guam, Richard M. Engeman, D.S. Vice Mar 2001

A Direct Comparison Of Trapping And Spotlight Searches For Capturing Brown Tree Snakes On Guam, Richard M. Engeman, D.S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

Brown Tree Snake populations on Guam are controlled in the vicinities of cargo staging and transport areas to prevent their dispersal from Guam, and their populations are controlled in areas where endangered species are to be reintroduced. Trapping and night-time spotlight searches of fences are the two primary Brown Tree Snake population reduction methods used on Guam. We conducted a three month study comparing Brown Tree Snake captures by spotlighting fences to captures by trapping. Traps were placed either on the edge of the forest paralleling the fences, or they were hung on the fences. Applications of each capture method …


Repelling Sandhill Cranes From Corn: Whole-Kernel Experiments With Captive Birds, Bradley F. Blackwell, David A. Helon, Richard A. Dolbeer Mar 2001

Repelling Sandhill Cranes From Corn: Whole-Kernel Experiments With Captive Birds, Bradley F. Blackwell, David A. Helon, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Sandhill cranes (Grus canadensis) are opportunistic omnivores that incorporate both waste and unharvested cereal grains (Gramineae) in their diets. Limited hunting of cranes to reduce crop damage has had questionable results, and lethal control of depredating species is increasingly contentious. Our objectives were to evaluate anthraquinone-based Flight ControlTM and methyl anthranilate-based ReJeX-iTTM AG-36 as nontoxic avian foraging repellents in separate 2-choice pen tests with captive greater sandhill cranes (G. c. tabida) fed with whole-kernel corn (Zea mays). In both tests, crane pairs consumed, respectively, 8.6 and 9.8 times more untreated than treated …


Effect Of Feeding Stations On The Home Ranges Of American Black Bears In Western Washington, Philipp Fersterer, Dale L. Nolte, Georg J. Ziegltrum, Hartmut Gossow Mar 2001

Effect Of Feeding Stations On The Home Ranges Of American Black Bears In Western Washington, Philipp Fersterer, Dale L. Nolte, Georg J. Ziegltrum, Hartmut Gossow

United States Department of Agriculture Wildlife Services: Staff Publications

Forest managers establish feeding stations throughout coniferous forests in western Washington that are vulnerable to American black bear (Ursus americanus) damage in the spring. This study was conducted to determine whether the home ranges of bears in areas with supplemental feeding were smaller than the home ranges of bears in similar adjacent areas without supplemental feeding. Home range sizes varied among bears. However, the home range sizes of bears in feeding areas did not differ (P > 0.35) from home ranges of bears in non-feeding areas. Male bears had larger (P = 0.0002) home ranges than female …


Daily Activity Budgets And Population Size Of American White Pelicans Wintering In South Louisiana And The Delta Region Of Mississippi, D. Tommy King, Scott J. Werner Mar 2001

Daily Activity Budgets And Population Size Of American White Pelicans Wintering In South Louisiana And The Delta Region Of Mississippi, D. Tommy King, Scott J. Werner

United States Department of Agriculture Wildlife Services: Staff Publications

Twenty-one American White Pelicans (Pelecanus erythrorhynchos) were captured and fitted with radio-transmitters in South Louisiana and the delta region o f Mississippi during the winter and early spring of 1994-1997. The pelicans were monitored to determine their daily activity budgets while using different habitats such as catfish ponds, crawfish ponds, rivers, lakes, and bayous. Pelicans foraging at catfish ponds spent about 4% of their day foraging and 96% loafing, while pelicans foraging in other habitats spent about 28% of their day foraging and 72% loafing. For an individual bird, the mean number of foraging sessions per day was …


Case Study 1 : Foliar Insecticide I, Monte Mayes, John D. Eisemann, Alain Baril, Tony Hawkes, Liesbeth Heijink, Peter Lawlor Mar 2001

Case Study 1 : Foliar Insecticide I, Monte Mayes, John D. Eisemann, Alain Baril, Tony Hawkes, Liesbeth Heijink, Peter Lawlor

United States Department of Agriculture Wildlife Services: Staff Publications

A major part of the Woudschoten workshop was conducted in the form of breakout groups dealing with a case study each. A case study consists of a set of test results, data, and information on a fictitious pesticide which could be part of an application for authorization. The groups were asked to take the role of regulators assessing the risk to birds for a specified use. Basic data packages for each case containing a description of the use, standard toxicity data, and background information were prepared by the case study authors and distributed in advance. The groups were then asked …


Bear Behavior In The Vicinity Of Supplemental Feeding Stations In Western Washington, Dale L. Nolte, Timothy J. Veenendaal, Georg J. Ziegltrum, Philipp Fersterer Mar 2001

Bear Behavior In The Vicinity Of Supplemental Feeding Stations In Western Washington, Dale L. Nolte, Timothy J. Veenendaal, Georg J. Ziegltrum, Philipp Fersterer

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear can inflict severe negative Impacts on timber stands in the northwestern United States. A supplemental feeding program to provide bears an alternative food source during spring is practiced in the state of Washington, and to a lesser extent in other states. We initiated concurrent studies to assess characteristics of bear that forage at feeding stations, the interactions of bears around feeders, and impacts of the program on bear territories. Numerous bears fed at stations, including females with and without cubs, yearlings, and males. Bear feeding bouts at stations were generally short, less than 15 minutes. Bears generally fed …


Bear Behavior In The Vicinity Of Supplemental Feeding Stations In Western Washington, Dale L. Nolte, Timothy J. Veenendaal, George J. Ziegltrum, Philipp Fersterer Mar 2001

Bear Behavior In The Vicinity Of Supplemental Feeding Stations In Western Washington, Dale L. Nolte, Timothy J. Veenendaal, George J. Ziegltrum, Philipp Fersterer

United States Department of Agriculture Wildlife Services: Staff Publications

Black bear can inflict severe negative Impacts on timber stands in the northwestern United States. A supplemental feeding program to provide bears an alternative food source during spring is practiced in the stat e of Washington, and to a lesser extent in other states. We initiated concurrent studies to assess characteristics of bear that forage at feeding stations, the interactions of bears around feeders, and impacts of the program on bear territories. Numerous bears fed at stations, including females with and without cubs, yearlings. and males. Bear feeding bouts at stations were generally short, less than 15 minutes. Bears generally …


Influence Of Size Of Sporocyst Inoculum Upon The Size And Number Of Sarcocysts Of Sarcocystis Falcatula Which Develop In The Brown-Headed Cowbird, Melanie P. Hemenway, Michael L. Avery, Pam E. Ginn, Sarah Schaack, John B. Dame, Ellis C. Greiner Mar 2001

Influence Of Size Of Sporocyst Inoculum Upon The Size And Number Of Sarcocysts Of Sarcocystis Falcatula Which Develop In The Brown-Headed Cowbird, Melanie P. Hemenway, Michael L. Avery, Pam E. Ginn, Sarah Schaack, John B. Dame, Ellis C. Greiner

United States Department of Agriculture Wildlife Services: Staff Publications

The influence of the number of sporocysts in the inoculum of Sarcocystis falcatula on the morphology of the sarcocysts has not been reported in the literature. To determine if there is a relationship, different number of sporocysts were inoculated orally into wild-caught cowbirds. After 14 weeks, the cowbirds were euthanised and muscle tissue was examined grossly and by histologic sections. Sarcocysts were compared based on the numbers which developed and their sizes. There was a linear increase in the number of sarcocysts as the size of the inoculum increased, however, the size of the sarcocysts became smaller with the increase …