Movement Patterns and Spatial Relationships

Home Range

  • Definition:
    • The general area in which an animal lives, characterized by repeated use.
    • Burt (1943): The area traversed by an individual in normal activities such as food gathering, mating, and caring for young.
    • Occasional exploratory sallies outside the area are not considered part of the home range.

Why Have a Home Range?

  • Knowledge of:
    • Forage patches or good hunting grounds.
    • Safe places to rest.
    • Nesting or denning sites.
    • Other conspecifics (competitors or mates).
    • Places with high predator densities or predation risk.
  • Information is power.

Site Fidelity

  • Definition: Repeated use of a small area, generally to perform a specific behavior.
  • Examples:
    • Travel corridors.
    • Den sites.
    • Hunting or foraging areas.
    • Social interactions.
  • Can an animal have a home range without high site fidelity?
    • Yes, especially at small scales.
    • Within a familiar range, animals can use similar habitat types for efficient foraging, effective refuge use, and knowledge of predators/competitors.
  • Animals need not have strong site fidelity to exhibit home range behavior.

Home Range Dynamics

  • Home ranges are not always static; they can have annual shifts.
  • Example: Coyote (Canis latrans) home ranges.

Determinants of Home Range Size

  • Factors influencing home range size:
    • Body mass.
    • Environment.
    • Diet.
  • Body mass vs. Home range size:
    • Carnivores tend to have larger home ranges compared to herbivores and omnivores.
    • Marine animals tend to have larger home ranges compared to terrestrial animals.
  • Referencing Tucker et al. 2014, shows graphs illustrating the relationship between body mass and home range size for carnivore, herbivore, omnivore, marine and terrestrial animals

Sensitivity of Africa’s Larger Mammals to Humans

  • Factors:
    • Body mass
    • Home range size
  • Referencing Riggio et al. 2018

Home Range vs. Territory

  • Home Range: General area in which an animal lives, characterized by repeated use; used for daily activities and contains resources required for survival and reproduction.
  • Territory: Area of an animal’s home range that it defends from conspecifics.

Territory

  • The area of an animal's home range that it defends from conspecifics.
  • Actively defended.
  • Contains resources an animal wants to control and restrict access to by others.

Territory Defense

  • Methods of defense:
    • Direct conflict.
    • Communication (visual presence and displays, scent marking, vocalization).
  • Defense by communication is often favored due to safety (evolutionary advantage)
  • Who defends:
    • Individual
    • Mating pair
    • Family or communal group

Territory Defense Examples

  • Mountain Lion (Puma concolor)
    • Who: Individual males defend against other males.
    • How: Scent marking and direct conflict.
    • Limiting resource: Breeding opportunities.
  • N. American Beaver (Castor canadensis)
    • Who: Mating pair.
    • How: Scent marking and direct conflict.
    • Limiting resource: Food & lodge sites.
  • Chimpanzee (Pan troglodytes)
    • Who: Group defends against other groups.
    • How: Boundary patrols.
    • Limiting resource: Food, breeding opportunities.

Territories and Habitat

  • Territorial behavior should only arise if a resource can reasonably (and economically) be defended.
  • Mountain Lion (Puma concolor)
    • Female home ranges are relatively stable and related to food availability, denning habitat.
  • N. American Beaver (Castor canadensis)
    • Lodge site availability is related to stream/pond and meadow characteristics (e.g., surrounding willows for food and construction materials).
  • Chimpanzee (Pan troglodytes)
    • Fruiting trees and other food resources are related to habitat type.

Understanding Wildlife Ecology Through Home Ranges

  • Selection for resources:
    • Where are animal home ranges relative to the landscape?
    • How do animals preferentially use habitats within their home ranges?
  • Area requirements:
    • How much space do animals need?
    • Do their home ranges overlap or not (territoriality)?
  • Energetics and behavior:
    • How much do animals move? Why? What is the cost of that movement?
  • How resilient are animals to environmental change?
    • Are they anchored to specific locations? Do they have access to a diversity of habitat types?

Dispersal

  • Benefits: Avoidance of inbreeding and local competition.
  • Two major types:
    • Natal dispersal: Movement from range where born to range where first reproduction occurs.
    • Breeding dispersal: Movement to new range between reproductive events.
  • Difficult to study because it involves individuals.
  • Usually biased by sex (mammals usually males).
  • In some species, both sexes disperse, with usually one sex dispersing further.
  • Three stages:
    • Emigration – leave current range
      • Dispersal can be genetically hardwired or condition dependent
      • Sex ratio, habitat condition, body condition
    • Transfer – movement through unfamiliar territory
      • Difficult to measure because it is hard to differentiate between failed attempts to disperse and test-drives
    • Immigration – settlement into new range
      • Involves habitat selection and social integration
      • Dispersers may accept lower quality habitat to fit in

Migration

  • An extreme strategy to manage variability in resource availability.
  • Repeated movements between distinct, non-overlapping ranges.
  • A widespread phenomenon across taxa to deal with seasonal (and otherwise varying) environments.
  • Typically, the animals that exhibit migration behavior are highly mobile.
  • Aerial and marine migrants generally move farther than terrestrial migrants.

Importance of Migration

  • Allows migrants to reach higher densities or persist at all.
  • Increases growth, reproductive success, or survival.
  • Provides access to differential resources required during different times of year.

Types of Migration: Descriptive

  • Range residency
  • Dispersal
  • Nomadism
  • Migration
  • Partial migration: not all individuals from a population migrate; often related to competition within the population.
  • Facultative migration: animals only migrate some years, dependent on internal state or environmental conditions.
  • Mixed migration: animals may have different summer or winter ranges year to year, therefore they migrate different distances.
  • Referencing Kauffman et al. 2021

Types of Migration: Space

  • Latitudinal migration: Whales, wildebeest, saiga antelope.
  • Altitudinal migration: Guanacos, bighorn sheep, elk.
  • Migration not related to latitude or elevation: Elephant seals.

Types of Migration: Scales

  • Temporal:
    • Seasonal.
    • Diel.
  • Spatial:
    • Regional.
    • Local.
  • Referencing Courbin et al. 2019

Types of Migration: Drivers

  • Alimental movement / feeding / tracking: To increase access to food and water.
  • Climatic movement / wintering / refuge: To avoid unfavorable conditions and predation, parasitism, or disease.
  • Gametic movement / spawning / breeding: To access mates or increase offspring recruitment.
  • Some animals may use all three!

Who Migrates? (Ungulate edition)

  • Ruminants (artiodactyls) vs. hindgut fermenters (perissodactyls).
    • Ruminants are less tolerant of low-quality forage – migrate for food.
    • Hindgut fermenters limited by water – migrate for surface water.
  • Large vs. small body size.
    • Smallest ungulates to migrate are gazelle, ~50 lb.
    • If too small, it’s just not efficient to travel far to look for food!
    • Small-bodied ruminants track high-quality forage more closely – larger animals can tolerate lower quality food.
    • Medium-sized ungulates often travel farthest distances.
  • High- vs. low-productivity environments.
    • Migration less necessary in high productivity (e.g., tropical) environments.
    • Also, ungulates are often smaller in high-productivity environments.
  • Referencing Kauffman et al. 2021

Types of Migration: Stages

  • Four stages of migration
    • Preparation
      • Fuel loading via increased foraging and metabolic changes
    • Movement
      • Occurs over land or water, birds and marine mammals travel farther than terrestrial mammals
    • Stopovers
      • Settle in habitat to rest and feed, few or many stopovers
    • Arrival
      • Territories are reestablished, mates chosen, energy built up for reproduction