USE OF SPACE:
TERRITORY AND HABITAT SELECTION
Some basics of Natural Selection
Evolution – pattern of change
Natural Selection – process by which evolution occurs
-change in gene frequency in a population
Sexual Selection – subset of natural selection dealing with
different reproductive interests of the sexes
Some basics of Natural Selection
Individuals do not evolve
Evolutionary change happens through the differential
reproduction of organisms with different suites of characteristics
Behavioural Ecology
- Look at costs and benefits
Cost –any factor that reduces reproductive
success (directly or indirectly)
Benefit –any factor that increases reproductive
success (directly or indirectly)
Strategy – a set of behavioural courses of action with a
given survival value under a particular set of conditions
In a successful strategy
C < B or
C
<1
B
Territory vs. Home Range
Territory vs. Home Range
Territory
- an area occupied by an animal or group of animals from which
others are excluded by aggression or threat
Functional Classification of Territories
Mating Territory
Functional Classification of Territories
Breeding Territory
Functional Classification of Territories
Feeding Territory
Greater Shearwater (Puffinis gravis)
Functional Classification of Territories
Multipurpose Territory
Territory - Participation Level
Individual
Territory - Participation Level
Pair
Territory - Participation Level
Group
Territory - Structure
Size affected by:
1) Species
2) Function
Mating
Breeding Feeding
Multipurpose
Territory - Structure
Size affected by:
1) Species
2) Function
3) Body Size
Log body size
Log territory size
Territory - Structure
Size affected by:
1) Species
2) Function
3) Body Size
4) Food habits
Predator
Non predator
Territory - Structure
Size affected by:
1) Species
2) Function
3) Body Size
4) Food habits
5) Age
Territory - Structure
Size affected by:
1) Species
2) Function
3) Body Size
4) Food habits
5) Age
6) Population density
7) Predator pressure
8) Food abundance
Size
Population density or Predator pressure or Food abundance
Territory - Structure
Defining the Boundaries
High
Tendency
Fight
Low
Flee
Tendency to flee
Tendency to fight
Tendency
Boundary
Distance from centre of territory
Territory - Advertising
Modalities
Visual
Territory - Advertising
Modalities
Acoustic
Territory - Advertising
Modalities
Chemical
Territory - Economics and Costs vs Benefits
Resource quality and distribution
High
Quality
Defendability
Low
Sparse
Clumped
Distribution
Territory - Economics and Costs vs Benefits
Resource quality and distribution (Holldobler & Lumsden, 1980)
Weaver Ant
Oecophylla longinoda
Insects in vegetation
Uniform distribution in
space and stable over time
Harvester Ant
Pogonomymex barbatus
Patches of seeds
on the ground
Patchy distribution in
space and stable over time
Honey Ant
Myrmecocystus mimicus
Termites under
dung
Patchy distribution in
space and unstable over
time
What kind of territory is most effective for each??
Territory - Economics and Costs vs Benefits
Resource quality and distribution (Holldobler & Lumsden, 1980)
Weaver Ant - Oecophylla longinoda
Insects in vegetation
3 dimensional territory
multiple nests
Harvester Ant - Pogonomymex barbatus
Patches of seeds on the ground
Central nest
temporary foraging trails
Honey Ant - Myrmecocystus mimicus
Termites under dung
Temporary territory
around resource
Territory - Economics and Costs vs Benefits
Resource quality and distribution
benefits
Costs or
benefits
costs
x
Z
Territory Size
x = smallest economically defendable territory
y = largest economically defendable territory
Z = territory with the greatest net benefit
y
Territory - Economics and Costs vs Benefits
Resource quality and distribution
benefits
Costs or
benefits
costs
x
Z’ Z
y’ y
Territory Size
= increased costs
decrease territory size
Territory - Economics and Costs vs Benefits
Resource quality and distribution
benefits
Costs or
benefits
costs
x’ x
Z’ Z
y
Territory Size
= increased benefits
decrease territory size
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Currency - what is being optimized
- maximum net calorie intake ?
- maximum net nutrient intake ?
- minimize daily variation in food intake ?
- decrease exposure to predators?
- maximize the number of mates attracted?
An currency is optimized within the context of the overall energy budget
Growth
Reproduction
Respiration
Feeding
Mate Seeking
Defense
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Case study #1 - Rufous hummingbird (Selasphorus rufusi)
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Case study #1 - Rufous hummingbird (Selasphorus rufusi)
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Case study #1 - Rufous hummingbird (Selasphorus rufusi)
4000
20
3000
15
Territories
Flowers
2000
10
1000
5
0
0
Day 1
Day 7
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Case study #1 - Rufous hummingbird (Selasphorus rufusi)
Predicted
Observed
Log
Territory
Size
Log Flower Density
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Predicted
Observed
Log
Territory
Size
Log Floral Unit Density
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Motacilla alba Pied wagtail
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Motacilla alba
Renewal time = 40 mins
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Motacilla alba
Renewal time = 20 mins
Territory - Economics and Costs vs Benefits
Resource quality and distribution
Food supply
Very low
Motacilla alba
Behaviour
- feed elsewhere
- return to evict
intruders
Moderate
- stay & feed on territory
- evict intruders
High
- share territory with
satellite
Very high
- feed on territory
- no attempts to defend
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Mnais pruinosa
Lifespan (days)
Territory
holder
Satellite
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Yarrow’s spiny lizard
Experimentals
Capture in non-territorial season
Implant with testosterone capsule
Release
Controls
Capture in non-territorial season
Implant with empty capsule
Release
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Yarrow’s spiny lizard
% active
Implants
Controls
0600
1200
Time of Day
1800
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Yarrow’s spiny lizard
% alive
Controls + supplement
Controls
Implants
0
10
20
30
40
Days
50
60
70
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Side blotched lizard
Territory - Economics and Costs vs Benefits
Costs of holding a territory
Testosterone level
Side blotched lizard
Survivorship
Orange
Large territories,
multiple females
Yellow
Blue
Orange
Blue
Small territories,
one female
Yellow
No territory,
‘sneaker’
Territory - Economics and Costs vs Benefits
Benefits of holding a territory
American redstart
Setophaga ruticilla
Winter territories
Territory - Economics and Costs vs Benefits
Benefits of holding a territory
American redstart
Setophaga ruticilla
Winter territories
Mangrove residents
%
Departing
Forest residents
12
30
April
1
15
May