Species who distributions don’t overlap. They will not interact.
Species who distributions do overlap. They will interact.
Occur in the same area, but do not affect each others success in any way. Ex: bat(0) and mouse(0)
Live together and don’t harm each other but one species gains something. Ex: Oxpecker(+) and Rhino (0)
One species gains at the detriment to the other species (death). Ex: Lion(+) and wildebeest(-).
One species gains at the detriment to the other species (not always death). Ex: Lamprey (+) and trout (-).
Both species help each other. Both adapted to need each other. Ex: Ants (+) and acacia (+).
Two species help each other, but don’t need each other to survive. Ex: Badgers(+) and Coyotes(+).
Both species have less resources available. Equally detrimental to both. Ex: Hyena(-) and Lion(-).
Competitive Exclusion Principle
The probability that two or more species may coexist is inversely proportional to their amount of niche overlap. More competition = less likely to coexist.
Responses to Competition
Numerical Consequences: Decrease in reproduction and survival density distribution. Functional Changes: Either morphological or behavioral changes.
Evolution of physical differences to allow exploitation of different resources. Ex: Different finches living on one island.
Direct displacement of competitors through aggression. Greater ferocity, numbers, or size.
One species makes more efficient use of a common resource. Ex: selecting different foods in one habitat, occupation of different areas in same season, access to different foods vertically.
Jackal Vs Foxes Case Study
Competing Jackals: Many food sources, so behavioral changes between species more possible to develope. Couldn’t evolve to different sizes because too much competition. Competing Foxes: Few food sources, can change morphological to have different requirements cause not a lot of competition.
Killing and eating potential competitors.
Coyote/GrayFox/Bobcat Study Methods
Food habits: Scat frequency and size.. Distribution: Foot holds, camera traps, cage traps, telemetry. Activity Patterns: Camera Traps, Telemetry. Mortality: Telemetry, crime scene investigation, dissection, location.
Food: Fox diverse, coyote diverse, bobcat mostly meat. Covertype: Fox brushy prefered, coyote open prefered, bobcat mostly open some brush. Activity: Fox active at night most, coyote/bobcat more active at day.
Gray fox behavior somewhat different to avoid competition. Intraguild predation high thus regulated by interference competition.
Reasons for Population Estimates
Too few? Need to start restrictions. Too many? Cultural carrying capacity. Enough? Maintaining sustainable harvest. Health of Pop? Trends appearing call for action.
Population Count Biases
Conditions: Weather, accessibility, density, vegetation/topography Observer Effect: Variability in observer experience and errors in sample size. Timing: Season, hour of day. Animal Behavior: Differential observability between genders, variations in distribution, different “catchability” or shyness/camouflage.
Ideal Population Estimation
Systematic (controlled/consistent), statistically reliable (accounts for biases), and repeatable.
Types of Pop Estimates
Census: Most precise, exact complete count. Estimate: Educated guess with idea of how right or wrong. Index: Least precise, quick scan for general abundance.
N=Total # of individuals in population at sampling. M=# of individuals marked in 1st sample. C=Total # of individuals captured in 2nd sample. R=# of marked individuals in 2nd sample. (Recaptures) Formula: N/M=C/R or N=(C?M)/R
Equal catchability among animals, no marks lost, no immigration or emigration, and and marking does not affect catchability.
Tropical: Consistent temp. Very seasonal large rainfall amounts and very dry seasons. Ex: Savannah. Temperate: Seasonal temps, variable rainfall but fairly consistently available. Tundra: Seasonal temps, but generally colder. Mostly dry, small rainy season.
More variability than immediately apparent. Variability of water drives migration patterns.
Prevents shrub/tree growth, minimal actual damage to grass plants(most roots underground, fast regrowth). Forces availability of more nutritious new growth for grazers. Does cause direct and indirect animal death.
Grassland Species Interactions
Sparse landscape means interactions have less flexibility and are specific to be successful. Ex: Bison flatten grass, prairie dogs see predators better, ferrets more likely to survive.
Domestic Livestock Grazing
Grazing is a natural process, but livestock create prolonged heavy pressure. Some exotics planted to prevent erosion, but now replacing natives.
Over Grazing Effects
Non-edible shrubs/brush dominate as edibles over grazed changing species composition. Thus changing ground cover conditions increasing soil erosion. Thus less water retained and desertification occurs.
Livestock Vs Wildlife Grazing Competition
Both graze the same foods creating unnatural competition conditions. Domestics have our help to survive so more successful.
Grassland Management Types
Change Fencing: Smart fences allow movement of wildlife, still restrict livestock. Strategic placement and timed movement to match migration patterns. Maximum Yield: Determine sustainable grazing amounts (duration, amount, area). Alternative Species: Harvest/domesticated native species.
Untouched before industrial revolution. Not really around anymore.
US Forest History
1600-1890: Thought an inexhaustible resource. Concern begins when pacific reached. 1891: Congress designates 1st Federal Forest Reserve. 1900s: Dept. of Agriculture (Teddy/Pinchot) sets up 1st national forests increasing protected land 8x. First forestry college stuff. 1950: Post WWII boom pushed for “multiple use management” conservation, not preservation. More science! 1976: National Forest Management Act.
Forest Ownership in US
Southeast: 73% Private owned but mostly corps. West: Only 21% privately owned. More managed. Massachusetts: 85% private owned but mostly private people, not corps.
Ecological replacement of one plant community with another. Natural change overtime. Cleared>grass>shrubs>low trees>high trees.
Regeneration, tending, and harvesting of the forest. Tree based agriculture.
Sustained Yield Management
Maintaining a constant supply over time. Based on growth/seeding patterns of ecosystem.
Number of years between the time a tree or stand is cut and the time it is replaced. (Can be cut again).
Selective cutting to maintain range if tree ages. Difficult and slow.
Clear cutting. Can mimic natural clearing events (fire, storm) but high intensity can cause fragmentation of habitat.
Snags and Deadwoods
Snags are dead standing trees and Deadwoods are downed woody debris. Both important to wildlife for hiding, young, and food.
Complete VS Wildlife Clear Cutting
Complete leaves nothing and does not consider wildlife. Wildlife leaves young trees, snags, and deadwood that benefits animals and is unusable anyway.
A natural part of forest ecosystems. Longleaf pine needs it to knock out competition. Endangered warble species need jack pine, jack pine needs fire to spread seeds.
Tree Size Classes
Seedlings: <1" Diameter at Breast Height (dbh) Sapling: 1-5″ dbh Pole (firewood): 5-9″ dbh Sawtimber (boards): >9″ dbh
Habitat loss of forests, wetlands, other cover for farming. Pesticide and fertilizer use changing species/nutrient composition. Fall plowing clears winter cover/food and increase susceptibility to wind erosion and siltation of wetlands.
Field Borders of vegetation. Conservation tillage where only roots cut and dead tops prevent wind erosion. Preserve wetlands. Use native grass species and revised grazing regimes/mowing schedules.
Conservation Reserve Program
Government paid farmers for every 10 acres they didn’t farm and left untouched for 10 years. An investment for farmers but good if farming too expensive anyway. Success led to Farm Security and Rural Investment Act.
Types of Biodiversity
Ecosystem, community, species, and genetic.
Provides an understanding of evolutionary processes and identifies levels of genetic diversity.
Sample Collection: Organs, blood, hair scat. Sample Analysis: Enzymes, mitochondrial DNA, Nuclear DNA & RNA, and PCR.
Genetics Among Species
Answers questions about multiple species. Ex: How are Raccoon, black bear, panda and red panda related?
Genetics Within a Species
Determining why populations of the same species differ. Usually due to geographical history Ex: Bananaquit pops on different islands.
Genetics Among Individuals
Determines how diverse gene pool is among individuals, how close individuals related. Ex: Gray wolf offspring dispersal amount determination.
Animal Home Range
Area an individual animal uses for obtaining resources. Food, mates, young raising. Bigger size and tropic level determines bigger size of home range.
Range Residency: Permanente occupations cause resources year round and distributed regularly. Migration: Annual movement, relatively long distances, resulting from seasonal change in resource abundance/distribution. Nomads: Unpredictable resources over time/distribution results in large scale movements.
Defense of a geographic area either direct (fighting) or indirect (displays, marks). Resource based or mating and so seasonal and varies greatly between species.
Monogamy: 1 male and 1 female for extended period. Ex: Canada goose. Polygyny: 1 male and many females. Ex: Elk Polyandry: 1 female and many males. Ex: Spotted Sandpiper Promiscuity: Mate with whoever is around. Ex: Humpback whale.
Solitary: Alone except for mating or female with young. Ex: Leopard. Pairs: Monogamous or shared homerange. Ex: Red Fox. Groups: Any amount more than 2 individuals. Use despotism or hierarchy.
Evaporative Heat Loss
When heat is transfered from the animal to the environment via evaporation of water from body surface. In birds use panting over mucus membranes in head to cool.
Allowing body temp to rise during the day and then release heat at night during rest when temp lowers. Or by returning to a burrow/cool area.
Behavioral Heat Reduction
Timing of Activity, Use of Microclimates, Body Orientation.
Pelage, Plumage, & Horn Heat Transfer
Pelage can insulate against temp change, but prevent evaporation. Color also can reflect heat if light, absorb if dark. Highly vascular horns can facilitate heat disipation.
Wildlife Water Development “Guzzler”
Most common precipitation catchment used to supply water for wildlife. Collect water and store it for access to wildlife in drought times.
Most common, capture a wide variety of prey and take based on availability not relative abundance. Ex: Coyote
Can capture other prey, but persist only certain prey. Ex: Canada lynx pop directly dependent on snowshoe hare pop.
Prey Vulnerability Factors
Age (elderly and fawns), physical condition (injured or sick), environmental conditions (harsh winter), activity (susceptible while foraging), and group size (more = safer).
Predator Control Problems
Increasing undesirable populations, secondary affects not predicted, and cascade affects.
Bottom-Up Predator Regulation
Regulating the food source so that the eater is forced to be less abundant.
Top-Down Predator Regulation
The reduction of top predators to increase their prey neighbors.
The sexes use different habitats or select similar habitats in different places. Ex: Male speed whales migrate to higher latitudes while females stay in tropical areas with young.
Natal dispersal is the movement of an animal from the home range to the home range it first reproduces in. Breeding dispersal is movement to new home range between breeding events. A permanent or long term movement from one home range to another.
A critical, repeated phase in a life cycle that has major impacts on the physiology and behavior of individuals.
Emigration (leaving current home range), transfer (moving through unfamiliar territory), and immigration (settlement into a new home range).
Vigilance, use of refuges, grouping.
Benefits to Group Living
Protection, pooled resources, better environment (huddling), mating.
Habitat as Species Specific
Each species has a unique set of physiological, morphological, and behavioral adaptations that are suited to a particular suite of conditions and resources.
An area with cues to an animal that it provides habitat resources, but where animals have relatively low rates of survival, reproduction, or both.
Habitat Conservation Areas (HCAs)
Patches of forest designated to be maintained for northern spotted owl survival based on home ranges of 20 pairs.
Agencies/Organizations for Conservation Planning
US Forest Service, US Fish & Wildlife Service, Natural Resource Conservation Service, US Army corps of Engineers, Bureau of Land Mgmt, Department of Defense, and National Parks Service.
Safe Harbor Agreements
Voluntary arrangements between the USFWS or NMFS and cooperating non federal landowners to promote management for threatened and endangered species.
Conservation Planning Process
State Goals and Objective Identify and Assign Task Conduct Tasks Evaluate Results Modify Plan Restart cyle.
Monitoring in Conservation
Provides the details needed to successfully evaluate the management plan whether desired goals and objectives are achieved.