predator maangement

predator-prey interactions

some of the most dramatic events in wildlife ecology

hunters and preservationist groups

public perceptions of predators are between…

public perceptions of predators

frequently drive by emotion rather than ecological science

hunters

historically viewed predators as direct competitors for valued game

preservationist groups

maintain predators should never be managed

predator control

shifted from routine practice to a highly controversial management action

predator removal

historically, ______ was used to increase game populations

secretive behavior and low densities

predators are hard to study because of…

indirect methods

must rely on _____ to assess predator diets and prey use

predation

one organism kills and consumes another for food

carnivory

directly influences game populations and management decisions

canidae, felidae, mustelidae, ursidae, marine mammals, and marsupial carnivores

mammalian predators in predator taxonomy

wolves, jackals, and coyotes

mammals in canidae family

cougars, jackals, and tigers

mammals in felidae family

martens, otters, and weasals

mammals in mustelidae family

bears

mammal in ursidae family

pinnipeds and odontocetes (toothed whales)

types of marine mammals

quolls and Tasmanian devils

types of marsupial carnivores

hawks, eagles, owls, and falcons

examples of raptors

herons, shrikes, corvids, skuas, and piscivorous seabirds

other types of avian predators

prey abundance

predator population often have a numerical response to ______

wolves, cougars, and owls

examples of territorial species

wolves

cooperative packs with fixed territories

cougars

solitary

male ranges overlap multiple females

owls

strongly territorial during breeding season

eye sight, hearing, olfaction, and specialized senses

types of predator senses

avian predators

many _____ possess exceptional visual acuity

raptors

have eyes that occupy about 2/3 of skull volume and resolution 5-10x that of humans

owls

exhibit specialized auditory anatomy

prey localization

asymmetrical ears and enlarged cochlea enable precise…

olfaction (scent)

a critical hunting cue for many mammals

canid and mustelids

rely heavily on olfactory information

pit vipers, bats, and dolphins

species with specialized senses

pit vipers

detect infrared radiation to locate endothermic prey

bats and dolphins

use echolocation to detect prey

ambush and stalking, pursuit, systematic foragers, group hunters, and foraging aggregations

types of hunting tactics

ambush and stalking

rely on stealth and suprise

cougars, Cooper’s hawks, and rattlesnakes

species that use ambush and stalking

pursuit

capitalize on speed and endurance

wolves, cheetahs, and gyrfalcons

species that use pursuit

systematic foragers

search habitats using multiple senses

rat snakes and raccoons

types of systematic foragers

group hunters

coordinate behavior to increase success

wolves, lions, and Harris’s hawks

types of group hunters

foraging aggregations

form around ephemeral prey pulses

brown boobies and northern ganets

species that use foraging aggregations

generalist predators

exhibit dietary flexibility

population stability

arises from the ability to exploit diverse resources

coyotes and red-tailed hawks

examples of generalist predators

specialist predators

depend on one or few prey types

black-footed ferrets, canada lnyx cycles, and gyrfalcons

examples of specialist predators

black-footed ferrets

rely on prairie dogs

canada lynx cycles

track snowshoe hare abundance

gyrfalcons

specialize on ptarmigan in Artic systems

specialists, generalists

_______ are more vulnerable to prey declines than ____

biological condition, environment, and behavior

prey vulnerability is shaped by…

young or delibitated

_______ individuals are taken disproportionately

environmental stressors

weaken prey and elevate risk

deep snow or drought

types of environmental stressors

feeding distration

can increase capture probability

behavorial

vulnerable portion

predators tend to explot the most _____ of prey populations

surplus killing

occurs when predators kill more prey than they can immediately consume

predator success

seasonal changes in prey condition alter…

predation risk

translocations and reintroductions can elevate…

release time

critical for survival

poorly timed releases perform poorly

fear and behavior

Quammen (2003) stated that primal “awareness of being meat” shaping human ________

domestication

intensified conflict between humans and predators

game abundance

in the early 1900s, wildlife management prioritized maximizing…

predator control

in the early 1900s, ____ was the default management tool

Aldo Leopold

reframed the role of predators within ecosystem

population regulation

involves both density dependent and independent processes

coyotes in Yellowstone

winter range limits prey more than predation

wolves of Mount McKinley

1^st detailed wolf ecology, emphasizing ecosystem context

coyotes in yellowstone and wolves of Mount McKinley

Adolph Murie studies that challenged assumptions about predator limits on big game

doomed surplus context

predators often remove inidviduals unlikely to survive for other reasons

Paul Errington

introduced the doomed surplus context

Craighead & Craighead

advanced raptor ecology

raptor ecology

raptors tend to take prey in proportion to prey density and can sometimes regulate prey below habitat capacity

Lotka and Volterra

provided the math foundation for pred-prey theory

predator-prey theory

cornerstone for conceptualizing interactions despite simplifications

prey grows exponentially unless checked by predators and predator mortality and reproduction depend on prey capture

basic assumptions for Lotka-Volterra model

numerical response of predators

predator numbers change with prey abundance

reproduction and suvival

aggregate response

immigration concentrates predators where prey are abundant

functional response

changes in prey killed per predators as prey density changes

type I

linear increase until satiation

filter feeders

example of type I functional response

type II 

decelerating due to handling time

wolves and kestrels

example of type II functional response

type III

sigmoid with prey switching or search-image formation

potentially stabilizing 

type III functional response

may protect rare prey by shifting pressure to common species

the ecology of fear

nonlethal predator effects influence prey decision

yellowstone

an example of fear-driven habitat shifts

yellowstone

elk distributions changed under wolf pressure, with riparian vegetation repsonses

fear effects

can alter effective carrying capacity and must be considered in planning

predator community interactions

predators interact with one another

competition, kleptoparasitism, and intraguild predation

types of predator community interactions

competition

herring gull foraging success declines in presence of northern genets

kleptoparasitism

eagles steal prey from falcons and raptors

intraguild predation

canids and felids sometimes kill other predators

mesopredators

apex predator loss can lead to increases in…