Wildlife Physiology, Nutrition, and Harvest Management

Comprehensive practice flashcards covering wildlife nutrition, physiological indices, digestive tract adaptations, public wildlife values, sustained yield concepts, and deer harvest management strategies.

Nutrition

The process whereby an animal gets and processes portions of its external environment for the continued functioning of its internal metabolism, or the study of nutrients in food used to support maintenance, growth, and reproduction.

Nutritional Condition

The state of body components controlled by nutrition which, in turn, influences an animal's fitness; most commonly assessed through measures of body fat or energy stores.

Kidney Fat Index (KFI)

A standard physiological index of body condition calculated as $\frac{\text{Weight of adhering fat}}{\text{Weight of kidney}}$, determined after trimming fat flush at the kidney ends to allow comparisons across animals and seasons.

Bone Marrow Fat

The final lipid reserve metabolized by an animal, serving as a critical post-mortem physiological indicator of acute starvation and extreme malnutrition.

Blood Urea Nitrogen (BUN)

A measurement of urea nitrogen circulating in the blood that remains relatively unaffected by capture stress or captivity, serving as a reliable index of protein nutrition.

Abomasal Parasite Count

An indirect index of deer population density relative to carrying capacity: a mean under $500$ indicates a herd below carrying capacity, $500\text{--}1500$ indicates at carrying capacity, and over $1500$ indicates a herd above carrying capacity.

Ptilochronology

The study of avian nutritional status and feather growth rates through measurement of alternating dark and light growth bars that reflect $24\text{-hour}$ nutritional cycles.

Bobwhite Quail Sex Determination

The method of distinguishing sex in Colinus virginianus by facial plumage: males display a white throat patch, whereas females display a buff-colored throat patch.

Bobwhite Quail Age Determination

The method of aging Colinus virginianus by wing plumage: buff-tipped primary coverts identify a juvenile bird, while the complete absence of buff-tipped coverts denotes an adult.

Corpus Luteum (CL)

An endocrine ovarian structure that forms from a ruptured follicle following ovulation; it secretes progesterone essential for uterine implantation and early development.

Mast

The synchronous, large-scale production of fruits, acorns, or nuts by trees and woody plants, which serves as a major seasonal food resource hoarded by sciurids and tracked by birds.

Metabolic Water

Endogenous water released inside animal tissues through the oxidation of macronutrients ($1.1\,\text{ml/g}$ from lipids, $0.6\,\text{ml/g}$ from carbohydrates, and $0.4\,\text{ml/g}$ from proteins).

Essential Amino Acids

A group of 10 amino acids that most mammals cannot synthesize internally or at a rate sufficient to meet physiological requirements: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Crude Protein

An estimate of total protein content obtained by measuring nitrogen ($\text{N}$) concentration and multiplying by $6.25$, based on the assumption that typical protein consists of $16\%$ nitrogen.

Gross Energy

The total caloric heat released upon oxidation in a bomb calorimeter, averaging $4.0\,\text{kcal/g}$ for carbohydrates, $9.5\,\text{kcal/g}$ for lipids, $5.5\,\text{kcal/g}$ for proteins, and $0.0\,\text{kcal/g}$ for minerals.

Osteophagia

The behavioral consumption of bones, shed antlers, or shells by herbivores to satisfy high physiological demands for calcium and phosphorus.

Grass Tetany

A metabolic disorder in ruminants (also known as grass staggers) induced by poor magnesium absorption or utilization during spring grazing on fertilized pastures.

Capture Myopathy

A severe, often fatal muscle pathology occurring in captured or overexerted wildlife, heavily exacerbated by deficiencies in selenium and vitamin E.

Fat-Soluble Vitamins

Vitamins A, D, E, and K; organic compounds comprised exclusively of carbon, hydrogen, and oxygen that are absorbed with lipids, stored in organs such as the liver, and can produce hypervitaminosis toxicities.

Water-Soluble Vitamins

Vitamins B-complex and C; organic micronutrients that are readily excreted in urine, cannot be stored long-term in body tissues, and require continual dietary replenishment.

Proventriculus

The anterior, glandular stomach chamber of birds that secretes gastric acids, hydrochloric acid, and pepsin prior to the mechanical breakdown of food.

Ventriculus (Gizzard)

The thick, muscular portion of the avian stomach that grinds ingested coarse food particles into small fragments, functioning mechanically like teeth.

Ceca

Paired blind sacs positioned at the junction of the small and large intestines housing symbiotic anaerobic microbes that facilitate fermentation, electrolyte balance, and vitamin synthesis.

Ruminant Stomach

A specialized four-chambered mammalian digestive system comprising the rumen (papillated fermentation vat), reticulum (honeycomb chamber), omasum (particulate filter leaves), and abomasum (acidic true stomach).

Wildlife Guzzler

A self-filling, low-maintenance artificial catchment and cistern designed to trap and store precipitation for wildlife in arid and water-limited environments.

Browse Line

A distinct horizontal demarcation on trees and shrubs up to the maximum feeding height of ungulates, below which all palatable woody twigs and leaves have been removed.

Harvestable Surplus

The seasonal biological surplus produced by a wildlife population above the carrying capacity ($K$) that exceeds the breeding stock required to sustain population levels.

Sustained Yield

The harvest rate of an animal population that can be extracted annually without causing long-term population decline, mathematically maximized at approximately half of carrying capacity ($\text{MSY}$).

Utilitarian Attitude

A public value orientation toward wildlife that focuses primarily on practical exploitation, usefulness, and direct material benefits to humans, such as meat, hides, and tools.

Humanistic Attitude

A perspective toward wildlife characterized by strong emotional attachment, anthropomorphic affection, love for animals, and treating them like companions or family.

Moralistic Attitude

An ethical orientation centered on opposition to animal exploitation, cruelty, or hunting, prioritizing animal welfare and ethical parity between animals and humans.

Naturalistic Attitude

A perspective that prioritizes direct exposure to wildlife, wilderness immersion, non-consumptive outdoor recreation, and nature photography.

Ecologistic/Scientistic Attitude

An orientation characterized by biological inquiry, systematic study of ecological systems, species interdependence, and endangered species protection.

Dominionistic Attitude

A perspective emphasizing mastery, control, and physical conquest of wildlife, commonly expressed through trophy hunting, predator eradication, and rodeos.

Negativistic Attitude

An attitude toward wildlife governed by avoidance, active fear, dislike, or indifference, often tied to disease risks, damage, or dangerous pests.

Leopold's Land Ethic

The conservation philosophy established by Aldo Leopold stating: 'A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.'

Fair Chase Principle

An ethical hunting standard formulated in the late 1800s by the Boone and Crockett Club prohibiting unfair advantages over animals, including vehicle pursuit, electronic calls, or high-fence shooting.

Spatial Control

A harvest management approach that regulates where wildlife can be taken across designated hunt units rather than regulating the exact numerical quotas or equipment.

Cooperative Parts Collection Survey (Wing Bee)

An annual state and federal monitoring workshop where waterfowl wings and tail feathers mailed in by hunters are examined by biologists to identify species, age, and sex composition.

Traditional Deer Management

A management framework where any antlered buck is eligible for harvest regardless of antler quality or age, while the harvest of female antlerless deer is severely restricted.

Trophy Deer Management

An intensive management framework where buck harvest is restricted exclusively to mature animals ($5\frac{1}{2}\text{ to }7\frac{1}{2}$ years old) with exceptional antlers, accompanied by aggressive doe harvest.

Quality Deer Management (QDM)

A deer management approach uniting four core components—herd management, habitat management, herd monitoring, and hunter management—by protecting young bucks and harvesting adequate does to balance the herd with habitat.

Lingual Crests

The sharp ridges of enamel and dentine points running along the inner, tongue-side edges of the cheek teeth in a deer's lower jaw, used to estimate age by evaluating wear.

Tricuspid Third Premolar

A deciduous (milk) cheek tooth featuring three distinct cusps present in the lower jaw of white-tailed deer fawns and yearlings, which is replaced by a two-cusped permanent premolar at approximately $1\frac{1}{2}$ years of age.

Boone and Crockett Scoring System

An official big-game antler measurement method based on symmetry that scores inside spread, point lengths (minimum $1\,\text{inch}$), main beam lengths, and 4 circumference measurements per beam after a mandatory 60-day drying period.

Aesthetic/Symbolic Attitude

A public value orientation toward wildlife that focuses primarily on appreciating the physical beauty, artistic representation, and cultural or mythological meaning of animals and landscapes.

Rumen Acidosis

A fatal digestive disorder in ungulates caused by an abrupt shift from a woody browse diet to readily fermentable carbohydrates, triggering an overproduction of lactic acid.

Forage Preference

A behavioral feeding dynamic demonstrated when an animal's proportional consumption of a specific plant species significantly exceeds the relative abundance of that plant in the environment.

Avian Crop

An expanded, thin-walled pouch of the bird esophagus that serves as a temporary food storage organ, enabling rapid feeding and subsequent transfer of nutrition to offspring.

Placental Scars

Pigmented bands along the uterine endometrium of female mammals that mark past embryo attachment sites, evaluated during post-mortem examination to establish reproductive history.

Crown-Rump Length

The anatomical distance measured from the apex of the skull to the base of the tail in fetuses, used alongside developmental scales to calculate conception dates and fetal age.

Maximum Sustained Yield (MSY)

The largest annual harvest extraction rate that can be maintained indefinitely without causing population decline, achieved theoretically when population size is held at roughly half of carrying capacity ($\frac{K}{2}$).

Antler Spread Restriction

A selective buck harvest regulation requiring a minimum inside width between antler beams (typically $13\,\text{inches}$), designed to protect young, genetically capable animals while allowing mature bucks to be taken.

Early Antlerless Harvest

The strategy of taking female deer during the initial weeks of the hunting season to protect winter forage supplies, balance sex ratios prior to the rut, and prevent accidental shooting of male fawns.

Waterfowl Flyways

Four primary continental migratory routes in North America—Atlantic, Mississippi, Central, and Pacific—delineated through bird banding recoveries to establish regional harvest frameworks.

Essential Fatty Acids

Lipids containing specific chemical double bonds that mammals cannot synthesize endogenously, required in the diet to support cell membranes, epidermal integrity, and hormone synthesis.

May Pond Counts

An annual aerial survey that quantifies wetland breeding habitats across Prairie Canada and the north-central United States to predict continental duck production and fall flight sizes.

Kjeldahl Method

A standard laboratory procedure that quantifies total organic nitrogen content in plant tissue or animal feed, used to calculate crude protein by multiplying measured nitrogen ($\text{N}$) by $6.25$.

Calcium-to-Phosphorus Ratio ($\text{Ca:P}$)

The physiological proportion of macro-minerals recommended near $2:1$; elevated dietary phosphorus relative to calcium impairs calcium absorption and induces chronic bone disorders like rickets or osteomalacia.

Herbivore Sodium Drive

An intense behavioral instinct compelling herbivores to seek natural mineral licks or salt sources, driven by the fact that terrestrial plants do not require sodium and are frequently sodium-deficient.

Nutritional Muscular Dystrophy

A degenerative muscle pathology occurring in wild animals, characterized by muscle stiffness and white striations in skeletal tissue, brought on by severe dietary deficiencies in vitamin E and selenium.

Omasum

The third chamber of the ruminant stomach, composed of multiple muscular sheets reminiscent of book pages, that acts as a sieve to regulate particulate flow while reabsorbing water and volatile fatty acids.

Primary Feather Molt Sequence

The chronological replacement of avian flight feathers running sequentially from inner primary #$1$ outward to primary #$8$, while juveniles retain unmolted outer primaries #$9$ and #$10$ until their second autumn.

Body Condition Scoring (BCS)

A standardized visual and physical assessment scale ranging from $1$ (emaciated) to $5$ (obese) that estimates energy reserves in ungulates by palpating tissue over the pelvis wings, sacrum, and rump.

Antler Point Restriction (APR)

A harvest rule establishing a minimum tine count on buck antlers; it often proves ineffective in high-quality habitats because fast-growing yearling bucks can reach the tine threshold and face premature harvest.

Mail Questionnaire Survey

A federal monitoring program operated annually since 1952 surveying roughly $70{,}000$ hunters to quantify hunting effort, total retrieved harvest, and unretrieved crippling loss across regions.

Exclosure Studies

A field evaluation method that compares fenced, ungulate-proof vegetation plots against open browsed plots to measure forage production, browse pressure, and total habitat utilization.

Criteria of Ideal Nutritional Indices

Five methodological standards required for an effective wildlife nutritional index:

• Sensitivity: Accurately detects slight shifts in nutritional status.

• Specificity: Isolates clear physiological deficiencies without ambiguity.

• Practicality: Utilizes tissues easily collected by relatively unskilled personnel.

• Independence from Stress: Remains reliable across seasons, sexes, and age classes without capture-stress interference.

• Reproducibility: Yields objective and repeatable measurements.

Nutritional Sex Ratio Allocation

A maternal investment response in white-tailed deer (Odocoileus virginianus) demonstrated by research showing that does receiving high-plane nutrition produce fawn cohorts skewed toward females ($35.6\%$ male), whereas nutritionally stressed does produce offspring heavily skewed toward males ($68.4\%$ male).

Plant Protein Nitrogen Conversion Factor

The empirical laboratory multiplier used in place of the standard $6.25$ factor when analyzing wild vegetation. Because nitrogen content fluctuates substantially across wild forage plants ($3.28\%$ to $5.16\%$), nutritional ecologists recommend using an adjusted mean factor of $4.43$.

Mechanisms of Vitamin D Homeostasis

Three primary physiological mechanisms triggered by active vitamin D metabolites in response to declining blood calcium:

• Enhancing active calcium absorption across the small intestine.

• Stimulating osteoclastic resorption of calcium and phosphorus from bone mineral reserves.

• Increasing renal calcium reabsorption within the kidney tubules.

Avian Tongue Adaptations

Morphological adaptations fulfilling three primary functions in avian nutrition:

• Food Gathering: Specializations such as the barbed, sticky tongue of woodpeckers or the tubular nectar-sipping tongue of hummingbirds.

• Intra-oral Manipulation: Positioning seeds, nuts, or prey for mechanical preparation.

• Swallowing Facilitation: Caudally directed horny papillae that channel food toward the esophagus.

Reticulum

The second compartment of the ruminant stomach, distinguished by internal honeycomb-shaped ridges. It acts continuously with the rumen to sort coarse particulate matter, forms regurgitation boluses (cud), and traps ingested dense debris.

Abomasum

The fourth compartment and true glandular stomach of ruminants, functioning analogously to the monogastric stomach by secreting hydrochloric acid, pepsin, and gastric enzymes to break down incoming digesta and symbiotic microbial protein.

Animal Rights vs. Wildlife Conservation Philosophy

A fundamental contrast in wildlife management philosophies:

• Animal Rights: Focuses on individual animal sentience, opposes human-caused pain or death, grants equal moral standing to non-humans, and considers ecosystem health secondary to individual welfare.

• Wildlife Conservation: Focuses on the health, balance, and viability of populations and ecosystems, endorsing regulated harvest of surplus animals in alignment with Leopold's Land Ethic.

Live Buck Aging Characteristics ($1\frac{1}{2}\text{ vs. }3\frac{1}{2}$ Years)

Comparative field-aging traits of white-tailed bucks observed on the hoof:

• $1\frac{1}{2}$ Years Old: Resembles a doe with antlers; features an unmuscled neck, thin shoulders, an upward abdominal tuck near the hams, and legs appearing disproportionately long.

• $3\frac{1}{2}$ Years Old: Exhibits a muscular, athletic 'racehorse' profile; displays a thickened neck blending into a defined brisket, along with straight, parallel belly and back lines.

Live Buck Aging Characteristics ($4\frac{1}{2}\text{ vs. }5\frac{1}{2}+$ Years)

Comparative field-aging traits of mature white-tailed bucks observed on the hoof:

• $4\frac{1}{2}$ Years Old: Possesses a heavily muscled neck, deep chest, heavily stained black tarsal glands, and legs that appear fully proportional or short.

• $5\frac{1}{2}+$ Years Old: Characterized by loose facial skin, squinted eyes, a thick neck merging seamlessly into a protruding brisket, a sagging swayback, and a rounded pot-belly hanging flush with or below the chest line.

Severinghaus Jawbone Aging ($2\frac{1}{2}\text{ vs. }3\frac{1}{2}$ Years)

Key dental eruption and wear indicators on the lower jawbone of white-tailed deer:

• $2\frac{1}{2}$ Years Old: Permanent dentition is complete with a two-cusped third premolar; lingual crests are sharp with narrow dentine lines on the molars.

• $3\frac{1}{2}$ Years Old: Noticeable wear appears on lingual crests; the dark dentine line on the first molar (#$4$ cheek tooth) is wider than the surrounding enamel borders, and the posterior cusp of the third molar is worn flat.

Severinghaus Jawbone Aging ($4\frac{1}{2}\text{ vs. }5\frac{1}{2}$ Years)

Advanced dental wear indicators on the lower jawbone of white-tailed deer:

• $4\frac{1}{2}$ Years Old: Lingual crests on the first molar (#$4$ cheek tooth) are worn completely smooth, and crests on the fifth and sixth cheek teeth are blunt.

• $5\frac{1}{2}$ Years Old: The fourth cheek tooth is dished out ('cupped'), lingual crest wear is extreme across all molars, and all three premolars exhibit heavy abrasive wear.

Antler Nutrient Allocation Priority

An ungulate physiological hierarchy in which ingested nutrients and systemic mineral stores are channeled to antler growth only after satisfying the higher-priority demands of skeletal frame expansion, vital organ maintenance, and basal fat accumulation.

Four Core Pillars of Quality Deer Management (QDM)

The foundational components uniting a comprehensive deer program:

• Herd Management: Balancing deer density with habitat carrying capacity and protecting young bucks.

• Habitat Management: Improving native browse through timber management, prescribed burns, and food plots.

• Herd Monitoring: Collecting harvest weights, jawbone ages, lactation checks, and camera census data.

• Hunter Management: Training hunters in field aging, selective doe harvest, and sportsmanship.

Fecal and Pellet Food Habit Analysis

Laboratory evaluation techniques analyzing excreted wildlife matter:

• Fecal Analysis: Examines microscopic plant and animal fragments in scat, but often underestimates highly digestible, succulent foods.

• Pellet Analysis: Evaluates regurgitated casting pellets from raptors and wading birds, though results are biased by prey whose skeletons are completely digested.

Physiological Adaptations to Water Scarcity

Mechanisms utilized by wildlife to survive acute or seasonal water deficits:

• Behavioral Shifts: Adopting fossorial (burrowing) or nocturnal activity to minimize evaporative water loss.

• Excretory Conservation: Producing hyper-concentrated urine and dry feces to retain systemic moisture.

• Oxidative Hydration: Utilizing endogenous metabolic water generated from cellular respiration of carbohydrates and lipids.

• Reproductive Synchronization: Aligning breeding and lactation periods with seasonal rainfall pulses.

Selenium Deficiency vs. Toxicity Dynamics

Nutritional dynamics of selenium ($\text{Se}$) in wild ungulates:

• Deficiency: Prevalent in the Pacific Northwest, Lake States, and Atlantic coast; induces nutritional muscular dystrophy (white muscle disease) and intensifies capture myopathy.

• Toxicity: Occurs in seleniferous soils of the western United States, where excess selenium substitutes biochemically for sulfur in amino acids, disrupting protein structure.

Supplemental Winter Feeding Ecological Risks

Three major ecological and management hazards associated with ungulate feedlines:

• Artificially elevates population density beyond natural habitat carrying capacity ($K$).

• Gathers high concentrations of animals in localized areas, greatly elevating the transmission rates of contagious diseases (such as chronic wasting disease and brucellosis).

• Creates high recurring economic costs and usually requires supplemental lethal culling to maintain herd health.

Boone and Crockett Antler Scoring Standards

Official measurement standards established in 1950 to quantify big-game antler development:

• Evaluates inside spread at the widest point between main beams.

• Measures length of all points reaching a minimum of $1\,\text{inch}$.

• Measures total midline length of main beams and four circumference (mass) measurements per antler.

• Enforces a mandatory 60-day drying period and applies deductions for bilateral asymmetry ($170$ minimum for typical white-tailed deer; $195$ for non-typical).

Five Biological Justifications for Early Antlerless Harvest

Key management reasons for harvesting female deer during the initial weeks of the hunting season:

• Reduces Buck Fawn Harvest: Male fawns are easiest to distinguish from adult does early in the fall.

• Conserves Forage: Preserves critical winter food resources, as each adult deer consumes nearly one ton of forage annually.

• Balances Sex Ratios: Adjusts the buck-to-doe ratio immediately prior to the breeding rut.

• Intensifies Breeding Competition: Increases competitive selection among mature bucks for receptive does.

• Ensures Quota Completion: Guarantees antlerless harvest objectives are reached before late-season weather discourages hunter effort.

Live Buck Aging Characteristics ($6\frac{1}{2}+\text{ Years}$)

Distinctive phenotypic traits identifying post-mature, geriatric white-tailed bucks on the hoof:

• Front knees bend while walking to support the excessive combined mass of the neck and antler rack.

• Deeply sagging swayback and a heavily rounded belly hanging well below the chest line.

• Drooping ears during periods of relaxation and permanently squinted eyes.

• Noticeable loss of body mass, deteriorated muscle tone, and faded or lighter coat color.

Severinghaus Jawbone Aging ($6\text{ Months vs. }1\frac{1}{2}\text{ Years}$)

Key dental eruption milestones in young harvested white-tailed deer:

• $6\text{ Months Old}$: Only four cheek teeth are erupted (three premolars and one molar); the third premolar features three distinct cusps (tricuspid).

• $1\frac{1}{2}\text{ Years Old}$: The third molar is actively erupting or newly erupted; the deciduous third premolar is heavily worn and tricuspid, or is in the process of being replaced by a permanent two-cusped (bicuspid) premolar.

Key Determinants of Antlerless Harvest Quotas

Core biological and operational variables required to establish annual doe harvest prescriptions:

• Herd Demographics: Absolute deer density, buck-to-doe sex ratio, fawn recruitment rate, and female age distribution.

• Ecological Variables: Native browse quality, overall habitat carrying capacity, and seasonal weather patterns.

• Management Framework: Property acreage, neighboring hunting practices, and overarching landowner objectives.

Pope and Young Club vs. Longhunters Society

Weapon-specific record-keeping organizations for North American big game:

• Pope and Young Club: Founded in 1961 to verify and log trophy animals taken exclusively with archery equipment.

• Longhunters Society: Specialized record organization dedicated exclusively to logging trophy big game taken with traditional muzzleloading firearms.