Abdomen - the portion of the body that lies between the thorax and the pelvis.

Abdominal cavity - the space that contains the abdominal viscera (the liver, spleen, intestines, etc.).

Abdominal wall - the layers of muscles lying between the skin and the abdominal cavity.

Absorption - to take in a substance through the pores or cells of a tissue. The substance must pass through the tissue to be absorbed.

Acanthocephalans - cylindrical, unsegmented worms that attach to the host by a retractable proboscis with sharp hooks.

Acaracides - substances, such as pesticides, that kill mites.

Acariasis - infestation of the body by mites.

Accipiters - short winged, long-tailed hawks; North American species are goshawk, Cooper's hawk, and sharp-shinned hawk.

Acute - sharp or severe, such as an illness with a sudden onset and a relatively short course.

Air sacs - thin-walled sacs that communicate with the lungs and are part of the avian respiratory system.

Airsacculitis - inflammation of the air sacs in birds.

Alcids - typically, pelagic colonial nesting seabirds, including species such as auklets, guillemots, murres, murrelets, and puffins.

Algae - a special form of plant life that lacks true roots, stems, or leaves, and that ranges in size from microscopic single cells to multicellular structures, such as seaweeds.

Alimentary canal - the digestive tract.

Allergic disease - development of a hypersensitivity of the host to substances foreign to the body, primarily antigens and other proteins.

Altricial - refers to newly hatched birds that require care in the nest for some period of time.

Ambient temperature - room or environmental temperature.

Amino acids - organic compounds of specific composition from which proteins are synthesized.

Amphibians - coldblooded animals characterized by moist, smooth skin that live both on land and in water at various life stages and that have gills at some stage of development, that is, frogs, toads, salamanders.

Amplification host - a host in which disease agents, such as viruses, increase in number.

Amyloid deposit - a complex protein material that grossly resembles starch and that in certain abnormal conditions accumulates in various body tissues causing cellular damage and injury to the affected organ.

Anaerobic - absence of oxygen; often refers to an organism that grows, lives, or is found in an environment devoid of oxygen, such as the cellular form of Clostridium botulinum, which causes avian botulism.

Analgesia - the absence of normal sensitivity to pain, typically, being in a semiconscious state induced through an anesthetic.

Anemia - a reduction in the normal number of red blood cells, or erythrocytes, in the body.

Anesthetic - a drug used to temporarily deaden pain.

Anesthetic induction time - the time between administering an anesthetic chemical and the actual time when target nerves are deadened.

Animal pathogens - organisms such as viruses, bacteria, and parasites, that are capable of invading and infecting animal hosts and causing disease.

Annelids - a group of invertebrates characterized by the segmented worms, including those in marine and freshwater and earthworms in addition to leeches.

Anorexia - lack of appetite.

Anoxia - a total lack of oxygen caused by several mechanisms that prevent oxygen from reaching the mitochondria of cells. Anoxia indicates a level of oxygen in animal tissues that is below normal in the presence of an adequate blood supply.

Antibody - a specialized serum protein produced by the immune system in response to an antigen in an attempt to counteract the effects of the antigen; antibodies in the blood indicate exposure to specific antigens or disease agents.

Antidote - substances that counteract or prevent the action of a poison.

Antigen - any foreign substance (generally proteins) to which the body reacts by producing antibodies. Antigens may be soluble substances such as toxins, particulate matter such as pollen, or microorganisms such as bacteria and viruses.

Antiserum - a serum containing antibodies to specific antigens; can be used to test biological samples for the presence of specific antigens.

Antitoxin - any substance that counteracts the action of a toxin or poison; generally, a specific type of antibody produced in experimental animals as a result of exposure to a specific toxin. Botulism antitoxin, for example, can be produced by exposing an animal to low levels of botulism toxin over a long period of time and then harvesting serum from that animal to treat other animals.

Arbovirus - a virus that is transmitted by invertebrates of the phylum Arthropoda [insects, arachnids (spiders, mites, ticks, etc.) and crustaceans].

Arthropod - members of the phylum Arthropoda (insects, arachnids, and crustaceans).

Ascites - accumulation of fluid in the abdominal cavity.

Aseptic - free from infection; sterile.

Asexual reproduction - the formation of new individuals without the union with cells of the opposite sex and usually by an individual.

Asymptomatic - without visible signs of illness; an asymptomatic carrier is an organism that harbors a disease agent, but that shows no outward signs.

Ataxia - incoordination.

Avicides - chemical substances used to kill or repel birds.

Avirulent - not virulent, does not cause disease.

Bacterin - a vaccine consisting of killed bacteria that is used for protection against infection by a specific bacterial disease.

Bacteriophage - a virus that infects a bacterium.

Bacterium - singular for bacteria. Any of a group of microscopic, unicellular organisms that have distinct cell membranes and that lack a distinct nucleus surrounded by a nuclear membrane.

Barbiturate - a type of sedative or anesthetic that is chemically derived from barbituric acid.

Bay diving ducks - typically, ducks that feed in deep bodies of water, usually in coastal bays and deep lakes. Species include canvasback, goldeneyes, redhead, and scaup.

Benign - noninvasive, that is, tumors that do not spread to other parts of the body; not malignant.

Big game - hunted species of large mammals (from deer to elephants).

Bile - yellow-brown to greenish liquid secreted by the liver and stored in the gallbladder before excretion by way of the intestine. Bile is composed of metabolic breakdown products derived from hemoglobin and other metabolic waste products.

Bioaccumulation - the accumulation of long-lived toxins, such as chlorinated hydrocarbons, as a result of repeated exposure or of exposure from a variety of sources.

Biomagnification - an increase in concentrations of long-lived contaminants in animals at higher positions in the food chain.

Biota - the plant and animal life of an area.

Biotoxins - poisons produced by and derived from the cells or secretions of a living organism, either plant or animal.

Birds of prey - synonymous with raptors; includes eagles, hawks, falcons, kites, and owls.

Biting louse - see Hippobascid flies.

Black flies - small, bloodsucking, biting flies of the genus Simulium; vectors for Leucocytozoon infections.

Blood flukes - trematode parasites that are found in the blood cells of the host.

Brine flies - species of flies whose larvae live in brine.

Brooding - care of young birds by the adult.

Buffered formalin - a 3.7 percent solution of formaldehyde (equal to 10 percent formalin) to which sodium phosphate buffers have been added. Buffered formalin is the best overall fixative for tissue for later microscopic study.

Bumblefoot - an inflammation and, often, swelling of the foot of birds as the result of a bacterial infection.

Bursa of Fabricious - a saclike outgrowth of the cloaca of birds that is part of the avian immune system.

Buteos - a subfamily of the hawks characterized by soaring behavior, broad, rounded wings, and a broad, fanned tail, such as the red-tailed hawk.

Caecum - (British; plural caeca) or cecum (American; plural ceca) - a large, blind pouch or sac (often a pair) at the junction of the small intestine and the large intestine.

Calcification - the process by which tissues become hardened by the deposition of calcium salts.

Canidia - fungal spores.

Canker - synonymous with trichomoniasis in doves and pigeons.

Capture myopathy - a state of immobility resulting from damage to skeletal and cardiac muscles caused by extreme physical exertion, struggle, or stress; may occur in wildlife as they are chased in capture attempts: may appear later when captured wildlife are under physical restraint; or may appear after they have been released.

Cardiac muscle - heart muscle.

Cardiovascular system - the heart and blood vessels by which blood is pumped and circulated through the body.

Carnivores - refers to flesheating mammals in the Order Carnivora and includes dogs, skunks, weasels, cats, raccoons, etc.

Carrion - dead and decaying flesh.

Caseous - resembling cheese or curd.

Central nervous system - the brain and spinal cord.

Ceratopogonid flies - very small, bloodsucking gnats commonly known as punkies, no-see-ums, or sand flies.

Cercaria - the final free-swimming larval stage of a trematode parasite.

Cestodes - flattened, usually segmented, parasitic worms; tapeworms.

Chelating chemical - a chemical that combines with a metal ion in a firm, ringlike band and that prevents the metallic ion from having any further biochemical effect.

Chlorinated hydrocarbons - organic compounds characterized by the presence of chlorine; commonly refers to persistent chemicals with insecticidal properties; DDT and dieldrin are common examples.

Choana - one of the paired openings on the inner side of the maxilla (upper beak), near the back of the oral cavity, that opens into the nasal cavity.

Cholinesterase enzymes - enzymes that are particularly important in the transmission of nerve impulses; the activity of these enzymes is inhibited by exposure to organophosphorus and carbamate compounds, and death results when activity is greatly reduced.

Chronic - persisting for a relatively long time.

Chronic losses - mortality of attrition; small numbers of continual losses over extended periods of time.

Clinical sign - an abnormal physiological change or behavior pattern that is indicative of illness. Signs are externally observable, as contrasted with symptoms, which are subjective.

Cloaca - a common passage for the fecal, urinary, and reproductive discharges of most lower vertebrates (birds, reptiles, and amphibians).

Coalescence - the fusion or growing together of tissue damage from a disease agent.

Coldblooded vertebrates - species such as fishes and reptiles, which have blood that varies in temperature to approximately that of the surrounding environment.

Colibacillosis - infection with the bacterium Escherichia coli.

Colon - the large intestine.

Colonial nesters - birds that nest in large groups.

Comatose - in a coma or comalike state; an abnormal state of continuous deep unconsciousness.

Congener - a member of the same taxonomic grouping, such as polychlorinated biphenyls, that possess similar chemical structures.

Congenital abnormality - usually an anatomical malformation that results from incomplete growth during embryonic development. Also refers to an abnormal biochemical pathway caused by a genetic factor.

Congestion - the abnormal accumulation of blood in a tissue or organ; often causes a reddening of the affected area.

Contagious - capable of being transmitted from animal to animal, such as a contagious disease.

Coccidiasis - the presence of coccidia, protozoa of the subphylum Sporozoa.

Coccidiosis - a disease caused by coccidia, protozoa of the subphylum Sporozoa.

Cornea - the transparent tissue on the front of the eyeball that covers the iris and pupil, through which light passes to the interior.

Coronary band - a fatty band encircling the heart; in hooved animals, the germinal layer beneath skin at the junction of the skin and hoof.

Cracker shell - a shotgun shell that is loaded to produce a visible burst and loud sound in order to frighten animals.

Crop - a dilation of the esophagus at the base of the neck of some birds.

Crustacea - a specialized group of invertebrates that includes such diverse species as lobster, shrimp, barnacles, wood lice, and water fleas.

Cygnet - a young swan.

Cyanobacteria - a genus of bacteria composed of the blue-green algae; like the dinoflagellates, cyanobacteria are important sources of environmental toxins that can cause illness and death in humans and wildlife.

Cyanosis - a bluish discoloration of the skin and mucous membranes due to an excessive concentration of deoxygenated hemoglobin in the blood.

Cystocanth - an infective juvenile stage of thorny-headed worms (acanthocephalan parasites).

Cytoplasm - the aqueous part of the cell that is outside of the nucleus but that is contained within the cell wall. The cytoplasm is the site of most of the chemical activities of the cell.

Dabbling ducks - Ducks that feed on the surface or in shallow water, including mallard, American black duck, gadwall, American wigeon, northern pintail, northern shoveler, and teal. Also referred to as puddle ducks.

Definitive host - an organism in which sexually mature stages of a parasite occur.

Dehydration - a condition that results from excessive loss of body fluids.

Depopulation - the destruction of an exposed or infected group of animals.

Dermatophytosis - a fungal infection of the skin.

Dessication - the act or process of drying a substance.

Digestive tract (alimentary canal) - the organs associated with the ingestion, digestion, and absorption of food, such as the esophagus, stomach, and intestines.

Dinoflagellates - aquatic protozoa that are an important component of plankton. These single-celled organisms may be present in vast numbers, causing discoloration of the water referred to as "red tide." Some species secrete powerful neurotoxins.

Dioxins - a chemical component of defoliants, such as agent orange, that are considered to be carcinogenic (cause cancer), teratogenic (cause fetal abnormalities), and mutagenic (cause abnormal mutation rate).

Direct life cycle - a parasitic life cycle that requires only a single host for its completion.

Diurnal - active during the day.

Diving ducks - synonymous with bay diving ducks.

Domestic duck - ducks typically raised for market, such as the white Pekin.

Drive-trapping - capture of flightless birds during the molt and of other animals by herding them into a netted or fenced containment area.

Drop nets - suspended nets used to capture animals by remote release of the nets or triggering mechanisms at the net site.

Dyspnea - labored breathing.

Ecchymotic - a hemorrhagic, irregular-shaped area in tissues that is bruise-like in appearance and, often, in color.

Ecology - the study of the interrelationships between living organisms and their environment.

Ectoparasite - a parasite that lives on the external surface, or in the integument, of its host.

Ectotherms - species that rely on sources of heat outside themselves (i.e., coldblooded species).

Edematous - swelling of tissues due to abnormal accumulation of fluid in the intercellular tissue spaces; seepage of these fluids may result in accumulations within the body cavity.

EDTA - ethylenediamine tetra-acetic acid; a chelating agent that binds with lead and that is used in the treatment of lead poisoning.

EEE - eastern equine encephalomyelitis; a viral disease.

ELISA - a molecular-based enzyme-linked immonosorbent assay; a type of test used to detect either antigen or antibody.

Emaciation - a wasted condition of the body; excessive leanness.

Emasculatome - a veterinary instrument designed for bloodless castration of cattle or sheep; has been used for euthanasia of birds by cervical dislocation.

Encrustation - forming a crust or a covering; for example, salt encrustation.

Endemic - a disease that commonly is present within a population or a geographical area.

Endogenous phase - developmental phase of the life cycle of a parasite that occurs within the host.

Endoparasite - a parasite that lives within the body of its host.

Endotherms - warmblooded vertebrates; species able to internally regulate their body temperatures.

Epicardium - the outer covering of the heart.

Epidemic - the presence of a disease in a population or in an area in a higher than expected prevalence, or rate.

Epithelial cells - cells that cover the external and internal surfaces of the body.

Epizootic - a disease affecting a greater number of animals than normal; typically, occurrences involving many animals in the same region at the same time.

Epizootiology - the study of the natural history of disease in animal populations.

Erosion - wearing away; gradual disintegration.

Erythrocytes - red blood cells; serve to transport oxygen throughout the body.

Esophagus -the passage extending from the mouth to the stomach.

Estrogenic - possessing characteristics of the hormone estrogen; estrogenic compounds may elicit the development of feminine characteristics in male animals.

Etiologic agent - any living or nonliving thing, power, or substance capable of causing a disease.

Eutrophication - the excessive growth, caused by an oversupply of nutrients, of plants and algae in bodies of water.

Exotic disease - a disease that normally does not occur within a particular area.

Exotoxin - a toxin formed and excreted by bacterial cells.

Exsanguination (bleeding out) - the draining of blood from an animal.

Fastidious - refers to the very specific requirements for the culture of some bacteria.

Fauna - the animals of an area.

"Feather edge" - a long, shallow edge of a body of water that gradually deepens offshore.

Femur - the thigh bone of humans; the upper legbone in hooved mammals and birds. The bone between the pelvis and the knee.

Feral pigeon - rock dove.

Fibrin - an insoluble protein that forms a network of fibers during clotting of the blood.

Fibrinoperitonitis - fibrin-coated inflammation of the surfaces of the peritoneal cavity.

Fibrinous - a pathologic term referring to a threadlike sheet of material that may occur on surfaces of organs in some disease conditions; clotting factors in blood contribute to the structure of this material.

Flatworms - the common name for parasites of the phylum Platyhelminthes, flukes or trematodes.

Flukes - parasitic flatworms; also referred to as trematodes.

Fly larvae - maggots.

Fomite - an object that is not in itself harmful, such as a wooden object or article of clothing, but that may harbor pathogenic microorganisms and serve to transmit an infection to a living organism.

Food chain - ascending trophic levels within an ecosystem in which species at the lower level are the primary food base for the species at the next highest level.

Formalin - a liquid solution of formaldehyde that is used as a tissue fixative, usually to prepare tissues for microscopic examination.

Fossorial - refers to digging animals that live in burrows.

Frounce - synonymous with trichomoniasis in raptors.

Fungicides - chemicals that kill fungi.

Gallinaceous birds - heavy-bodied, chickenlike land birds. Includes ring-necked pheasant, quails, grouse, and wild turkey.

Gamete - one of two cells produced by a gametocyte; the union of male and female gametes initiates the development of a new individual during sexual reproduction.

Gametocyte - an undifferentiated cell that develops into a gamete.

Gangrene - tissue death due to a failure of the blood supply to that tissue area followed by bacterial invasion and putrefication.

Gapes - see gapeworm.

Gapeworm - parasites of the trachea of birds; synonym for tracheal worms.

Gastrointestinal tract - the tubular organs that form a digestive pathway from the mouth to the vent, including the stomach and intestines.

Geographic information system - a specialized computer system for storage, manipulation, and presentation of layers of geographical information.

Gizzard - the enlarged muscular ventriculus (stomach) of many birds.

Granuloma - refers to a tumorlike mass or nodule; often associated with a response to an infection.

Haemoproteus - blood parasites transmitted by louse flies of the family Hippoboscidae and midges of the family Ceratopogonidae.

Hatchet-breast - a common term to describe the prominent, protruding breast keel seen as the result of the atrophy of the breast muscles. "The keel appears as sharp and as prominent as the back of a hatchet."

Hawaiian forest birds - native and introduced avifauna of the forested areas of the Hawaiian Islands. Includes such species as sparrows, finches, cardinals, honeycreepers, and thrushes.

Helminths - parasitic worms.

Hemosporidia - protozoan blood parasites.

Hemoglobin - the oxygen-carrying pigment of red blood cells.

Hemozoin - a dark pigment produced from the hemoglobin in the host's red blood cells by malarial parasites that collect in tissues, such as the spleen and liver, causing those organs to appear grayish to dark brown or black.

Hepatitis - inflammation of the liver.

Hepatomegaly - enlargement of the liver.

Herbicides - chemicals used to kill unwanted vegetation.

Hermaphroditic - organisms that possess both male and female functional reproductive organs.

Herpesvirus - one of the major groups of related viruses that have DNA nucleic acids and that are further characterized by similar size, shape, and physiochemical reactions.

Herpetologists - those who study the natural history and biology of reptiles.

Heterogenous organism - one that is derived from a combination of different types of parent organisms.

Hippoboscid flies - a group of wingless and winged parasitic flies found on birds and mammals.

Histoplasmosis - a disease of humans caused by inhalation of the fungus Histoplasma capsulatum.

History - as it refers to wildlife disease investigations, a record of background information and chronological events associated with a die-off.

Homeostasis - the tendency toward equilibrium; refers to the capacity of living organisms to maintain internal body environmental conditions necessary for survival.

Husbandry practice - the care and maintenance of animals.

Hydropericardium - an excessive amount of fluid within the sac surrounding the heart.

Hypersensitivity - greater than normal sensitivity to stimuli or to biological agents.

Hypothermia - greatly reduced body temperature.

Hypovalemic shock - shock resulting from insufficient blood volume to maintain adequate cardiac output and blood pressure; caused by acute hemorrhage or excessive fluid loss.

Icthyologists - those who study the natural history and biology of fishes.

Immune - being resistant to a disease.

lmmunosuppressive therapy - a medical treatment that suppresses the normal immune response.

Impaction - an abnormal accumulation of food or other ingested materials that become lodged in a section of the digestive tract.

Immune system - the combination of host body defenses that guard against infectious disease.

lnapparent - an infection in which the infectious agent exists within the host but that causes no recognizable signs of illness; the infectious agent may or may not be shed at irregular times.

Incidence - the number of new cases of a disease occurring in a population within a certain time period.

Inclusion body - a structure within the cytoplasm or nucleus of a cell; a characteristic of some viral diseases, inclussion bodies occur in only a few species.

Incubation period - the time interval required for the development of disease; the time between the invasion of the body by a disease agent and the appearance of the first clinical signs.

Indigenous - native to a particular area.

Indirect life cycle - a life cycle that requires more than one host for its completion.

Infection - the invasion and multiplication of an infectious agent in host body tissues.

Infectious agent - a living organism capable of invading another.

Infective - capable of producing infection.

Infestation - parasitic invasion of external surfaces of a host.

Insecticides - pesticides used to kill insects.

Intermediate host - an organism in which a parasite undergoes a stage of asexual development.

lntracellular parasite - a parasitic organism, usually microscopic, that lives within the cells of the host animal.

Involuntary muscle - muscle that is not under the control of the individual.

Isolate - refers to microorganisms; the separation of a population of organisms that occur in a particular sample (verb); for example, to isolate a bacterial or viral organism from a sample. As a noun, refers to the organism that was isolated; for example, a bacterial isolate was obtained from a sample.

lsopods - crustaceans with flattened bodies, such as sowbugs, pillbugs, and wood lice.

Joint capsule - the thick, fibrous capsule surrounding a joint, as around the knee.

Keel - the narrow middle portion of a bird's sternum.

Kites - hawk-like birds.

Lacrimal discharge - a discharge from the tear glands near the eye.

Laparotomy - a surgical procedure in which an incision is made into the abdominal cavity, often to determine the sex of birds for which plumage and other characteristics cannot be used for that purpose.

Larva - an immature parasitic life cycle stage; typically, the form of the parasite is unlike the mature stage.

Larynx - the musculocartilaginous structure at the upper part of the trachea; it guards the entrance to the trachea and secondarily serves as the organ of voice.

Latent - dormant or concealed; a latent infection refers to the situation in which a disease condition is not apparent.

Lentogenic - refers to a form of Newcastle disease virus that is mildly virulent as measured in chickens.

Leucocytozoon - blood parasites transmitted by black flies of the family Simulidae.

Lesion - an abnormal change in tissue or an organ due to disease or injury.

Lethargy - abnormal drowsiness or stupor.

Louse fly - see Hippoboscid flies.

Lyme disease - an infectious disease that is caused by the spirochete Borrelia burgdorferi and transmitted by ticks.

Lipophilic - having an affinity for fat; such as chemicals that accumulate in fat and fatty tissues.

Livestock - domestic animals raised for food and fiber commonly refers to animals such as hogs, sheep, cattle, and horses.

M-44 - a predator-control device that uses cyanide as the toxic component.

Macrocyst - a large cyst; a large spore case (fungi); an encapsulated reproductive cell of some slime molds.

Macrogamete - the female sexual form of the malaria parasite that is found in the gut of the mosquito vector.

Maggot - a soft-bodied larva of an insect, especially a form that lives in decaying flesh.

Malarias - infectious diseases caused by protozoan parasites that attack the red blood cells.

Malignant - spread from the location of origin to other areas; that is, tumors that are invasive and that spread throughout the body.

Marek's disease - an important infectious disease of poultry, that is caused by infection with a herpesvirus.

Marine birds - birds of the open ocean, typically pelagic, and often colonial nesters, such as alcids, shearwaters, storm petrels, gannets, boobies, and frigatebirds.

Meningoencephalitis - inflammation of the transparent covering (meninges) of the brain.

Mergansers - a group of waterfowl that are commonly referred to as "fish ducks" due to their food habits.

Meront - an asexual stage in the development of some protozoan parasites that gives rise to merozoites.

Merozoite - a stage in the life cycle of some protozoan parasites.

Mesogenic - refers to a form of Newcastle disease virus that is moderately virulent as measured in chickens.

Metabolic rate - an expression of the rate at which oxygen is used by cells of the body.

Metacercaria - the encysted resting or maturing stage of a trematode (fluke) parasite in the tissues of an intermediate host.

Microgamete - the male sexual form of the malaria parasite found in the gut of the mosquito vector.

Migratory birds - all birds listed under the provisions of the Migratory Bird Treaty Act.

Minamata disease - mercury poisoning of humans; named after an incident resulting from contamination within Minamata Bay, Japan.

Miracidium - the first larval stage of a trematode parasite, which undergoes further development in the body of a snail.

Mobilization - refers to the tendency of lipophilic chemicals [environmental contaminants, such as chlorinated hydrocarbons, that have an affinity for storage in adipose (fat) tissue] to be released into the bloodstream as fat stores are depleted.

Mollusks - species of the phylum Mollusca; includes snails, slugs, mussels, oysters, clams, octopuses, nautiluses, squids, and similar species.

Molt - the normal shedding of hair, horns, feathers, and external skin before replacement by new growth.

Moribund - a visible, debilitated state resulting from disease; appearing to be suffering from disease and close to death.

Motility/motile/nonmotile - these terms refer to whether or not a bacterial organism moves on a particular culture medium; such movement reflects the presence of flagellae. Thus, the absence or presence of motility is a useful characteristic for identifying bacteria.

Motor paralysis - paralysis of the voluntary muscles.

Mucosa - a mucous membrane.

Mucous membrane - the layer of tissue that lines a cavity or the intestinal tract and that secretes a mixture of salts, sloughed cells, white blood cells, and proteins.

Mucosal surface - a layer of cells lining the inside of the intestinal tract or other body part that secretes mucus.

Myocarditis - inflammation of heart muscle.

Myocardium - the middle and thickest layer of the heart wall; composed of cardiac muscle.

Mycosis - fungal infection.

Mycotoxin - a poison produced by various species of molds (fungi).

Myiasis - infestation of the body by fly maggots.

Nares - the external openings on the top of the bill of birds; the external orifices of the nose; the nostrils.

Nasal gland - a specialized gland of birds and some other species that serves to concentrate salt and secrete it from the body.

Nasal cavity - the forward (proximal) portion of the passages of the respiratory system, extending from the nares to the pharynx and separated from the oral cavity by the roof of the mouth.

NDV - Newcastle disease virus.

Necropsy - the methodical examination of the internal organs and tissues of an animal after death to determine the cause of death or to observe and record pathological changes.

Nematodes - unsegmented, cylindrical parasitic worms; roundworm.

Neoplasm - see tumor.

Nervous system - specialized components of vertebrates, and, to a lesser extent invertebrates, that control body actions and reactions to stimuli and the surrounding environment.

Neurotoxin - toxins that cause damage to or destroy nerve tissue.

Nictitating membrane - the so-called third eyelid, a fold of tissue connected to the medial (side closest to the midline) side of the eye, which moves across the eye to moisten and protect it.

Nocturnal - species that are active during evening (nondaylight) hours.

Nodule - a small mass of tissue that is firm, discrete, and detectable by touch.

Nontoxic shot - shotshells with shotpellets that are not made of lead or other toxic metals; typically, soft iron is used, and is referred to as steel shot.

No-see-ums - see Ceratopognid flies.

Occlusion - a blockage or obstruction; the closure of teeth.

Oligochaetes - the earthworms and aquatic forms of the class Oligochaeta.

Oocyst - the encyst or encapsulated zygote in the stage of some protozoan parasites; often highly resistant to environmental conditions.

Opisthotonos - abnormal spasm of the neck and back muscles resulting in a body position in which the head and heels are involuntarily thrown back and the body is arched forward.

Osmoregulation - adjustment of osmotic pressure in relation to the surrounding environment.

Osteoporosis - loss of bone structure.

PAH - an acronym for polycyclic aromatic hydrocarbons.

Panzootic - a disease involving animals within a wide geographic area such as a region, continent, or globally.

Parasitism - an association between two species in which one (the parasite) benefits from the other (the host), often by obtaining nutrients.

Paratenic host - a host that has been invaded by a parasite, but within which no morphological or reproductive development of the parasite takes place; a "transport" host.

Paresis - partial paralysis.

Passerines - small- to medium-sized perching birds.

Pathogenic - the ability to cause disease.

Pathological - an adjective used to describe structural or functional changes that have occurred as the result of a disease.

PCB - acronym for polychlorinated biphenyls, a group of chlorinated aromatic hydrocarbons used in a variety of commercial applications. These compounds have long environmental persistence and have been a source for various toxic effects in a wide variety of fauna.

Pelagic - refers to living in or near large bodies of water, such as oceans or seas; typically, this term refers to avian species that only come to land areas during the breeding season.

Pericardium - the fibrous sac surrounding the heart.

Pericarditis - inflammation and thickening of the sac surrounding the heart.

Peritoneal cavity - the abdominal cavity, which contains the visceral organs.

Phage - a virus that has been isolated from a prokaryote (an organism without a defined nucleus, having a single double-standard DNA molecule, a true cell wall, and other characteristics). Most phages are bacterial viruses.

Pharynx - the musculomembranous passage between the mouth and the larynx and esophagus.

Pigeon milk - the regurgitated liquid that an adult pigeon feeds its young.

Pinnipeds - aquatic mammals that include the sea lions, fur seals, walruses, and earless seals.

Plaque - a patch or a flat area, often on the surface of an organ.

Plasmodium - blood parasites transmitted by mosquitos of the family Culicidae.

Plumage - the feather covering of birds.

Postmortem - examination and dissection of animal carcasses performed after the death of the animal. Also, changes that occur in tissues after death.

Poultry - domestic avian species, such as chickens and domestic ducks, geese, and turkeys.

Prefledglings - birds of the current hatch year that have not become feathered enough to fly.

Prevalence - the number of cases of a disease occurring at a particular time in a designated or defined area; rate.

Proboscis - a tubular process or structure of the head or snout of an animal, usually used in feeding; in this Manual, the tubular process of Acanthocephalan parasites is used for attachment to the host and feeding from it.

Protoporphyrin - a component of hemoglobin; useful in the diagnosis of exposure to lead.

Protozoan - a one-celled animal with a recognizable nucleus, cytoplasm, and cytoplasmic structures.

Psittacines - parrots, parakeets, and other species within the family Psittacidae.

Puddle ducks - see dabbling ducks.

Proventriculus - the first, or "glandular," stomach of a bird.

Puddle ducks - synonymous with dabbling or surface-feeding ducks.

Punkies - small, biting midges of the genus Culicoides; vectors for Haemoproteus infections. See ceratopognid flies.

Purulent - containing pus, as in a purulent discharge.

Range - the geographic distribution of a population or the area within which an individual animal moves (as in home range).

Raptors - synonymous with birds of prey. Birds, including hawks, owls, falcons, and eagles, that feed on flesh.

Reactivation - refers to the process by which cholinesterase enzyme activity returns to normal after carbamate exposure.

Rendering - a process by which animal carcasses are converted into fats and fertilizer.

Reptiles - coldblooded vertebrates that belong to the class Reptiles; such as., snakes, turtles, lizards.

Reservoir host - the host that maintains the disease agent in nature and that provides a source of infection to susceptible hosts.

Respiratory system - the collection of organs that provide oxygen to the organism and result in the release of carbon dioxide; typically, the trachia and lungs.

Rice breast disease - synonym for sarcocystis.

Rocket nets - remotely triggered, weighted firing devices that are propelled through the air by an explosive force carrying the netting to which they are attached over the birds or other animals being captured.

Rodenticides - toxic substances used to kill rodents.

Rodents - mammals that have chisel-like, ever growing incisor teeth that are used for gnawing; i.e., mice to beavers.

Rookery - a nesting area for some colonial birds, such as herons and egrets.

Roost sites - typically, locations where birds congregate at night in trees and other locations.

Rough fish - a term given to bottom-feeding freshwater fish with large scales, such as carp, buffalo, and similar species.

Roundworms - see nematodes.

Ruminants - hooved mammals possessing a rumen or first stomach, from which food or a cud is regurgitated for further chewing. Includes deer, elk, sheep, cattle, etc.

Salivary glands - the glands of the mouth that produce saliva.

Salt gland - see nasal gland.

Sand flies - see punkies.

Scavengers - animals that feed on dead, sick or injured prey. Includes crows, vultures, gulls, eagles, hawks, etc.

Schizogony - a type of asexual reproduction in some protozoan parasites in which daughter cells are produced by multiple nuclear divisions of the parasite (schizont).

Schizonts - the multinucleate, intermediate parasite stage that develops into merozoites within a host cell.

Scoliosis - an abnormal lateral curvature of the spine.

Sea ducks - ducks that frequent open ocean, although some species may be found on coastal bays or inland waters. includes oldsquaw, eiders, scoters, and harlequin duck.

Secondary poisoning - intoxication of an animal as a result of eating a poisoned animal; for example, the poisoning of an eagle after it has fed on a duck that was poisoned by a chemical in treated grain. This differs from biomagnification, which involves increasing concentrations of toxic compounds within the body of organisms at increasing higher levels of a food chain.

Section 7 consultations - the Endangered Species Act requires discussion and evaluation of any proposed Federal activity, program, or permit that might affect an endangered species.

Sedated - chemically quieted.

Septicemia - the presence of pathogenic microorganisms or toxins in the blood.

Serosa - refers to the outside layer of an organ, such as the serosal surface of the intestine, or the lining of a body cavity.

Serosal surface - the external surface of an organ or a tissue within the body.

Serotype - a taxonomic subdivision of a microorganism, based on characteristic antigens or proteins.

Serovar - a taxonomic subdivision of a microorganism similar to serotype (above) but usually more specific.

Shorebirds - birds that feed at the edge of shallow water, along mudflats, and in shallow wetlands. Typically, these birds feed on invertebrates and include such species as American avocet, black-necked stilt, curlews, plovers, phalaropes, sandpipers, yellowlegs, and sanderling.

Signs - observable evidence of disease in animals (similar to symptoms in humans).

Sloughing - shedding of dead cells or dead tissue from living structures or tissues.

Slugs - terrestrial, snail-like mollusks that have a long, fleshy body and only a rudimentary shell.

Small mammals - mice to rabbits, racoons etc.; a general term used in wildlife management to group species of small to moderate size.

Small rodents - see rodents; rodents of small size, such as rats and mice.

Songbirds - small perching and singing birds, typically of the order Passeriformes, including sparrows, finches, and cardinals.

Sowbugs - see isopods.

Splenomegaly - enlargement of the spleen.

Spore - refers to a resistant stage, usually of bacteria or fungi, by which some microorganisms survive unfavorable environmental conditions and then develop into active life forms during favorable environmental conditions.

Sporogony - sporulation that involves multiple fission of a sporont (schizogony), resulting in the production of a sporocysts and sporozoites.

Sporont - a zygote of coccidian protozoa.

Sporozoite - the elongate nucleated infective stage of coccidian protozoan parasites.

Sporulation - the formation or libertion of spores.

Squab - a nestling pigeon that has not fledged.

Sternum - the breastbone.

Subcutaneous - under the skin.

Systemic - affecting the entire body.

Tapeworms - segmented parasitic flatworms; also referred to as cestodes.

Teal - small, swift-flying waterfowl of the genus Anas.

Tegument - the covering of an organ or the body.

Tenosynovitis - inflammation of the tendon sheath.

Teratogenic - causing embryonic deformities due to abnormal differentiation and development of cells.

Thermoregulation - regulation of the internal temperature of the body by various physiological processes.

Thorax - the part of the body between the neck and the respiratory diaphragm (in mammals), encased by the ribs.

Thorny-headed worms - acanthocephalan parasites.

Thymus gland - a lymph-gland-like organ involved in cellular immunity, located in the neck or upper thoracic cavity.

Torticollis - twisting or rotation of the neck causing an unnatural position of the head.

Toxic - poisonous.

Toxicosis - the condition of being poisoned.

Trematodes - flat, unsegmented parasitic worms; flatworms, flukes.

Trichomonids - protozoan parasites of the genus Trichomonas.

Trophic level - refers to an animal's position in the food chain. Species at higher trophic levels are, to a greater or lesser extent, dependent upon species in preceding trophic levels as sources of energy.

Tumor (neoplasm) - growths within organs and tissues of the body that result from the abnormal progressive multiplication of cells in a manner uncontrolled by the body.

Ubiquitous - found everywhere.

Ulceration - crater-like lesions in the skin and other tissues.

Ungulates - hoofed mammals.

Unthrifty appearance - an expression used in animal husbandry to describe an animal that is unkempt and dirty. Usually hair or feathers are soiled by excrement.

Upland gamebirds - game birds found in terrestrial habitats. Includes species such as ring-necked pheasant, quails, grouse, wild turkey, etc.

Upper digestive tract - the portion of the gastrointestinal tract that extends from the anterior opening of the esophagus in the region of the mouth to the stomach, but not including the intestines.

Ureter - the tubular structure that transports urates from the kidneys to the cloaca of birds.

Vascular system - blood circulation system.

Vector - an insect or other living organism that carries and transmits a disease agent from one animal to another.

Vegetative form - in bacteria, an active, growing, multiplying stage of development as opposed to a "spore," or a resistant resting stage.

Velogenic - refers to highly virulent strains of Newcastle disease virus that are capable of producing severe disease in the host.

Ventriculus - the stomach of a bird.

Verminous peritonitis - inflammation of the peritoneal cavity caused by parasites, usually nematodes.

Vertebrates - animals with backbones.

Viremia - the presence of virus in the blood.

Virulence - the disease-producing ability of a microorganism, generally indicated by the severity of the infection in the host and the ability of the agent to invade or cause damage or both to the host's tissues.

Virulent - the degree to which an infectious agent produces adverse effects on the host; a highly virulent organism may produce severe disease, including death.

Virus shedding - discharge of virus from body openings by way of exudate, excrement, or other body wastes or discharges.

Viscera - the internal organs, particularly of the thoracic and abdominal cavities.

Viscerotropic - possessing an affinity for visceral organs; a disease that acts primarily on the soft internal tissues of the body such as the heart, lungs, liver, and digestive tract.

Voluntary muscle - muscle normally under control of the individual.

Voucher specimen - specimens deposited in scientific collections that are representative of a species or a subgrouping of a species.

Wading birds - long-necked, long-legged birds that feed by wading in wetlands and catching prey with their bills. Includes egrets, herons, ibises, roseate spoonbills, flamingos, and bitterns.

Waterbirds - birds that require aquatic habitat.

Waterfowl - species of the Family Anatidae; ducks, geese, and swans. Does not include American coot.

Whistling ducks - the fulvous whistling duck or the tropical black-bellied tree duck.

Yeasts - single-celled, usually rounded fungi that produce by budding.

Zooplankton - minute animal organisms that in combination with counterparts from the plant kingdom constitute the plankton (minute free-floating organisms) of natural waters.

Zygote - a cell resulting from the union of a male and a female gamete, until it divides; the fertilized ovum.