Space use, dispersal behaviour and habitat choice

Jean-François Le Galliard CNRS, University Pierre & Marie Curie, France

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Basic notions Dispersal is the movement of an individuals from its breeding or natal territory / range to another breeding territory / range [sometimes equivalent to transfer, migration or movement] Many types of dispersal are possible natal / breeding dispersal habitat / population dispersal efficient dispersal = migration Dispersal involves three key steps departure / emigration transfer / exploration settlement / immigration = one form of habitat choice

Measuring dispersal behaviour Direct measurements observation and/or captures of marked animals within and between their territories and ranges tracking techniques [radio-transmitters, passive integrated transponders, harmonic radars, satellite based tracking]

Indirect measurements genetic tools [F statistics, assignment of migrants] demographic tools [mark-recapture analysis of recruitment; observation and/or captures of marked animals within their territories and ranges]

Measuring dispersal behaviour: example 1

Measuring dispersal behaviour: example 2

Cant Proceedings London 2004

Measuring dispersal behaviour: example 3 ICARUS – Martin Wikelski, Max Planck Institute Germany International Cooperation for Animal Research Using Space

http://icarusinitiative.com/ Wikelski, M., R. W. Kays, N. J. Kasdin, K. Thorup, J. A. Smith, and G. W. Swenson. 2007. Going wild: what a global smallanimal tracking system could do for experimental biologists. Journal of Experimental Biology 210:181-186.

Example of dispersal kernels Natal dispersal distance in great tits in a deciduous forest (UK) After Tully, unpub. data

Sex biased dispersion 25

Females Males

proportion of individuals

20 15 10 5 0 0

500

1000

1500

2000

2500

3000

3500

Natal dispersal distance (linear distance m between nest boxes)

4000

Another example of dispersal kernel

Another example of dispersal kernels Annual dispersal probabilities and distances per age and sex classes in the common lizard After Massot et al. 1992

Dispersal kernel in plants : seed dispersal Modelled dispersal distance of seeds in Cecropia latiloba (tropical tree) by a frugivorous fish

Anderson, J. T., Nuttle, T., Saldaña Rojas, J. S., Pendergast, T. H. & Flecker, A. S. 2011. Extremely long-distance seed dispersal by an overfished Amazonian frugivore. Proceedings of the Royal Society B: Biological Sciences.

Dispersal distance variation across species Allometry of dispersal distance (mean and maximum) across 740 species of animals from 15 Orders (mammals, amphibians, birds, butterflies, spiders, odonates, beetles)

Stevens, V. M., Whitmee, S., Le Galliard, J.-F., Clobert, J., Böhning-Gaese, K., Bonte, D., Brändle, M., Matthias Dehling, D., Hof, C., Trochet, A. & Baguette, M. 2014. A comparative analysis of dispersal syndromes in terrestrial and semi-terrestrial animals. Ecology Letters 17: 1039-1052.

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Space use and habitat choice Home range area / volume of residency of an individual [movements within the range are not dispersal]; often defined by its size and its overlap with neighbouring ranges

Types of home ranges overlapping / non overlapping home ranges territories (exclusiveness + active defence) versus colonies / families breeding and foraging ranges

Habitat choice within a range (space use) between ranges (dispersal and immigration)

Measuring space use Direct measurements tracking techniques give repeated measurements of spatial location that can be used to “draw” the range / territory of each individual in the population [convex polygon techniques, kernel estimation …]

Male territories in scotish red grouses Female home ranges in root voles (Microtus oeconomus)

Andreassen & Ims JAE 1998

Watson & Miller JAE 1971

Space use and territoriality

Space use, territoriality and the resource holding potential (RHP)

Core

What type of social structure ? What determines home range size and overlap ? What determines movements and home range structure ? How do animals behave at boundaries and towards neighbours ? How does an animal fighting ability (RHP) influences space use ?

Seasonal variation in social structures

Summer increase

Andreassen & Ims. Ecology 2001.

Winter crash

Aars & Ims. Ecology 2002

Seasonal variation in social structures Characterisation of female social structures from summer 2004 to spring 2005 home range size home range overlap Comparison across age classes (founder versus field-born) reproductive stages density season

Passive radio-tracking of each animal

Seasonal variation in social structures Demographic data

More variation in density between plots than within plots across seasons Clear seasonal fluctuation in reproductive status Natal dispersal stops during the winter

Founder females : 49 m2 ± 2.8 s.e. Field-born females : 35.6 m2 ± 3.9 s.e. Home range size n.s. effects of season, density and reproductive status

Seasonal decline in prop. exclusive home range Home range overlap

Hoset, Le Galliard et al.. Behav Ecol. 2008

Age class by density interaction on prop. exclusive home range

Seasonal variation in social structures

Hoset, Le Galliard et al. Behav Ecol. 2008

Seasonal variation in social structures A significant social hierarchy between founder and field-born females Exclusive territories in founder females are more likely at low population densities No clear effect of breeding state per se Seasonal changes may be explained by energetic and climatic constraints home range size constrained by both food quality and thermoregulatory costs of locomotion home range overlap indicative of ”huddling behaviors”

Additional winter studies needed to link demographic processes with these space use changes

Social structures during the breeding season Females

Males

Andreassen & Ims Ecology 1998

Aars & Ims Ecology 1999

Highly dispersive males with pronounced territoriality Philopatric females with plastic overlapping ”territories”

Investment in territorial behaviors

Videotapes of 5mins contest in field arenas Familiar

Strangers

Recordings of behavior aggressiveness subdominance investigative avoidance approach (not analyzed here) Calculation of total duration

Resident

Intruder

Comparison of dyads across treatment and sex groups Analysis of behavioral dominance between resident and intruders as a function of status and resource holding potential (body mass)

Investment in territorial behaviors

300

14

Neighbours Strangers

††

12 10 8 6 4

†† Avoidance behaviours (s.)

Subdominant behaviours (s.)

16

††

280

*

260 240 220 200 180

2 160 0

Investigative behaviours (s.)

Females 30

††

†

Females

Males

Males

20

10

0

Rossell, Gundersen & Le Galliard BES 2008

Investment in territorial behaviors Dominance index = aggressiveness resident – aggressiveness intruder

Sex × Treatment effect : F1,36 = 10.26 P = 0.003 RHP effect : F1,35 = 0.03 P = 0.86

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Multiple factors affecting the evolution of dispersal Dispersal has several direct fitness costs predation risks energetic investment delayed reproduction …

Dispersal can bring several potential fitness benefits colonisation of empty patches avoidance of competition or parasitism in source patches exploitation of spatially and temporally varying resources ….

Factors affecting the evolution of dispersal Social factors local interactions (kinship) conspecifics interactions (density-dependence) Habitat quality and local adaptation Mate choice inbreeding avoidance sexual selection Interspecific interactions competitors and predators parasites Dispersal costs

Kinship dependent dispersal Mother-offspring competition Parents can sometimes enforce natal dispersal, but that seems to be a rare situation.

Mother (father) - offspring competition offspring disperse in response to strong expectations of motheroffspring competition, irrespective of their sex or more often in females than in males mothers disperse to bequeath their range to their offspring, most likely their daughters

“Overall, the available evidence in favour of [parent-offspring] competition influencing dispersal is little more than anecdotal” (Lambin et al. 2001)

Kinship dependent dispersal Mother-offspring competition in a lizard Manipulation of mother presence in experimental patches of natural habitat Common lizard : assessment of natal dispersal during two successive years

Le Galliard et al. Proc. Roy. Soc. 2003

Kinship dependent dispersal Do mothers bequeath their breeding territory ? Observation of breeding movements in mammalian species breeding movements by females are often rare (and often associated with breeding failures) yet, some females move despite successful breeding breeding movements could save space for daughters if daughters inherit the breeding range of their mother and benefit from territory inheritance

Critical assessment of territory bequeathal (Lambin BES 1997) most evidence in small mammals are anecdotical best evidence so far from species like squirrels, kangaroo rats and a fossorial marsupial

Kinship dependent dispersal Territory bequeathal in a rodent Test of four hypothesis (1) breeding movements more likely if many daughters compete for the mother range (2) breeding movements more likely in early spring when daughters are likely to reproduce (3) daughters benefit from mothers abandoning their range (4) daughters actually inherit the range of their mother Analysis of breeding movements and daughters’ reproduction within one field season in Townsend’s voles in one study area [ability to track juvenile voles is a “plus” of that study]

A test of territory bequeathal with a rodent

Correlation between mother movement and natal dispersal r2 = 0.12, n = 55, P > 0.3

Lambin BES 1997

Breeding dispersal by female red squirrels Long-term study of breeding movements and natal dispersal in North American red squirrels (Tamiasciurus hudsonicus) 9 years, 485 litters and ca. 600 juveniles Strong dependence on middens to overwinter and successfully reproduce

Stay and keep the breeding territory mean = 44 %

Stay and share the breeding territory mean = 42 %

Leave and “bequeath” the breeding territory mean = 15 %

Kinship dependent dispersal Maternal dispersal : causes and consequences

Test of three main questions (1) factors affecting breeding movements (stay, share or bequeath) (2) consequences of breeding movements for breeding females (3) consequences of breeding movements for offspring Hypothesis: bequeathal enables offspring to inherit the breeding territory of their mother, and enhance settlement success in offspring

Berteaux & Boutin Ecology 2000

Kinship dependent dispersal Maternal dispersal : statistical model

Berteaux & Boutin Ecology 2000

Kinship dependent dispersal Maternal dispersal : causes and consequences

Older females more likely to bequeath

Females more likely to keep after food shortage

Females more likely to bequeath if they have more weaned offspring Berteaux & Boutin Ecology 2000

Kinship dependent dispersal Maternal dispersal : causes and consequences Female survival and reproduction Independent of post-breeding decisions (keep, share or bequeath)

Offspring settlement, survival and reproduction Share and bequeath females = 50% of resident daughters versus 36% of resident sons (sex-bias is significant)

Possibility to score future survival and reproduction depending on behavioral decisions (based on long-term monitoring with mark-recapture and telemetry techniques)

Berteaux & Boutin Ecology 2000

Kinship dependent dispersal Maternal dispersal is a form of parental care Low

High

Berteaux & Boutin Ecology 2000

Dispersal and kin competition direct effect (costs) indirect effect (benefits)

Local competition Dispersal behaves like an altruistic trait !

Dispersal and kin cooperation direct effect (costs) indirect effect (costs)

Local cooperation kin facilitation : tolerance among kin kin cooperation : active cooperation among kin Generates strong selection against dispersal

Social structures and natal dispersal There is a whole range of social systems, especially in mammals, ranging from extremely competitive systems to extremely cooperative systems.

Mother (father) - offspring cooperation offspring are retained by parents to increase “group” productivity offspring do not disperse to benefit from the active cooperation of their siblings and/or parents

“Kin cooperation constitutes an important selective pressure for philopatry” (Perrin et al. 2001)

“Loose” kin cooperation Manipulation of mother presence in experimental patches of natural habitat Root voles: assessment of natal dispersal during 20 days

A)

0.8

0.6

1.0

0.4 Females in control plots Females in treatment plots Males in control plots Males in treatment plots

0.2

0.0 0

5

10

15

20

Overlap with the adult female

Natal dispersal probability

1.0

B) 0.8

0.6

0.4

0.2

0.0 0

5

10

15

20

Le Galliard et al. Behav. Ecol. 2007

Cooperation and other details that matter Group size Kinship with same-sex parents Kinship with opposite-sex parents

Resident / Disperser

Local competition / cooperation Kin competition / cooperation Inbreeding risks

Costs of dispersal Opportunities for independent breeding

Modulated by resource holding potential

Dispersal and breeding in cooperative families Not kin Low rank Not kin

Not kin Younger Not kin

Le Galliard & Ferrière. Book: Behavioral Ecology 2008

Do animals disperse to avoid inbreeding ?

Inter-specific patterns of sex-biased dispersal

Pusey. TREE. 1985

Inter-specific patterns

Clutton-Brock. Nature. 1989

Inter-specific patterns

Clutton-Brock. Nature. 1989

Inter-specific patterns: conclusions Sex-biased dispersal is common but which sex disperses depends on taxonomy and the mating system predominant male dispersal in mate defence mating systems predominant female dispersal in resource defence mating systems strong sex bias in cooperatively breeding species

Temporal patterns of male/female residency and male/female age at sexual maturation suggest tight associations between sexual maturation, residency and inbreeding avoidance in (social) mammals with male-biased dispersal

Inbreeding avoidance is an important factor of sex-biased dispersal; yet, other factors are needed to explain the observed variation

Models for the evolution of sex-biased dispersal Greenwood scenario (1980, 1983): important of asymmetrical competition between the sexes Mate defence mating systems (“polygyny”) strong competition between males for mates female invest in resources and compete for food

male-biased dispersal

Resource defence mating system (“monogamy”) weaker competition between males for access to breeding territories/mates symmetrical sex roles in parental cares and breeding effort benefits for males of acquaintance with the breeding territory (familiarity)

female-biased dispersal

These inherent bias will be further reinforced by inbreeding avoidance

ESS sex-specific dispersal rates Symmetrical competition

Genetic load

Patch size

Perrin & Mazalov Am Nat 2000

ESS sex-specific dispersal rates Male mate competition only

Genetic load

Patch size

Perrin & Mazalov Am Nat 2000

Intra-specific patterns: Antechinus

Antechinus swainsonii

Antechinus stuartii

1 week 5-7 weeks

8-10 weeks

Promiscuous mating

several months

Promiscuous mating

Fathers death

Abrupt dispersal of (almost) all males

Pough youngs Nest youngs Cockburn et al. Anim Behav 1985

Intra-specific patterns: Antechinus spp. Cockburn et al. Anim Behav 1985

No association between (rare) male philopatry and litter size

Strong effect of mother removal on sex-biased dispersal

Strong effect of mother removal on male immigration

Inbreeding avoidance in white-footed mice Higher population density than 1989 Removal of ca 50% of parents (same density due to immigration)

Wolff. Nature. 1992

Inbreeding depression

Mating with females in the laboratory

But significant inbreeding depression with fullsiblings and half-siblings in the lab. relative to outbred animals !

Keane Anim Behav 1990

Complications with inbreeding depression Sex-biased dispersal and inbreeding depression, complications : Inbreeding load: genetic purging Asymmetric costs of inbreeding depression between the sexes Dispersal does not mean reproduction : delayed sexual maturation in social mammals and birds Dispersal and mate choice : selective preferences for outbred mating partners

“Simple” patterns of sex-biased dispersal and inbreeding in natural populations cannot reveal whether dispersal is the cause or the consequence of inbreeding avoidance = need for more manipulative studies or detailed studies of mate choice

Density-dependent dispersal: ESS models Death Immigration from the dispersers’ pool (s=DD immigration)

Transition history of a single patch

Catastrophes

Local recruitment (birth and philopatry)

ESS dispersal : “bang-bang” strategy Below x*, d = 0 and s = 1 Above x*, d =1 and s = 0 At x*, no single ESS (one-dimensional continuum of ESS) Metz & Gyllenberg. Proc Lond 2001

Density-dependent dispersal: an example

Male dispersal (generation F0)

Female dispersal (generation F0)

Aars & Ims Am Nat 2000

Density-dependent dispersal: overview

Matthysen. Ecography. 2005

Density-dependent dispersal: explanations Positive density-dependence predicted in density-dependent regulated species, with large dispersal capacities, small costs of dispersal, a poor spatial autocorrelation in local densities and with no variation in habitat quality density-dependent fitness: strong costs of residency at high density dispersal is efficient at avoiding local competition exploration is not constrained by high population density -----------------------------------------------------------------------------------------Poor/positive density-dependence ® conspecifics attraction (see next section) or density-independent dispersal Large costs of dispersal ® constrained philopatry Strong spatial autocorrelation ® high local population density indicates habitat saturation High population density can be indicative of local habitat quality

Inter-individual variation in density-dependence

Potential individual factors that can affect density-dependence Resource holding potential (e.g. age, sex or body size) Individual behaviour Chitty’s hypothesis = differences in individual aggressiveness and population cycles in small mammals Individual sociality

Several studies have shown that an individual state can influence the sensitivity of dispersal to population density

Inter-individual variation in density-dependence

Low density

Low density

High density

High density

Emigration

Settlement

Relationship with individual “social personality” Cote & Clobert Proc London 2007

Inter-individual variation in density-dependence

Cote & Clobert Proc London 2007

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Habitat choice behaviour

Habitat choice and the ideal free distribution

Ideal free distribution stable variation in habitat quality between patches scramble competition for resources full knowledge of habitat quality (“ideal”) cost-free dispersal and exploration (“free”) IDF = distribution (density) reflect variation in habitat quality and equalize fitness among patches Fretwell & Lucas, 1970; Morris Nature 2006

Large scale distribution reflects IDF in pikes

Habitat 1

Large pikes (> 55 cm)

Small pikes (< 55 cm)

Habitat 2

Perch (prey)

Mark-recapture data for pikes

Density-dependence for survival and fecundity

Expected intrinsic fitness in each basin Expected fitness gradient and dispersal probabilities Expected realized fitness in each basin (Ψ = observed dispersal)

Expected isodars (equal realized fitness between basins) Haugen et al. Ecol Monog 2007, Proc London 2006

Intrinsic fitness and dispersal fluxes Expected intrinsic fitness in each basin Intrinsic fitness higher in the south

Intrinsic fitness higher in the north Haugen et al. Proc London 2006

Realised fitness and density distribution Expected realized fitness in each basin

Expected isodar (line of equal fitness)

Observed isodar

Very good match !

Haugen et al. Proc London 2006

Ideal free distribution in pikes ? Assumptions density-dependent fitness = supported for survival and fecundity (as well as body growth), competition is asymmetric between age classes and lies in between scramble and contest competition stable variation in habitat quality = habitat quality not well defined and strong variations in population densities full knowledge of habitat quality = pikes are extremely mobile cost-free dispersal = no data Distribution observed dispersal fluxes match temporal variation in intrinsic fitness density distribution (isodar) results in equalised (expected) realised fitness between the two basins The IDF holds at a large scale despite temporal variation in population densities !

Alternative forms of competition Contest competition IDD = ideal despotic distribution [monopolisation of high quality patches by individuals with a high RHP] = maintenance of fitness variation between patches

Allee effects (mating / cooperative interactions) IFD = fitness equalisation among patches, but habitat choice at low population densities is based on conspecifics attraction

Studies of distribution at the individual / population level have revealed consistent deviations from the IDF

Conspecifics attraction in Anolis lizards Anolis aeneus terrestrial lizards inhabiting two types of habitats juveniles are born in forest and migrate to clearances juveniles compete for territories in clearances until they reach a critical size large juveniles then return to the forest for breeding

Juveniles are strongly gregarious Conspecifics attraction has been observed in the laboratory Field studies were conducted to confirm this pattern

Preference for previously occupied areas

Stamps Am Nat 1987

Preference for currently occupied areas Stamps Am Nat 1988

Trials 1, 2 and 6

Trials 3, 4, and 5

Alternative explanations for conspecifics attraction Potential value of conspecifics attraction Simple, cost free decisions based on the presence of conspecifics Use information derived from conspecifics to choose an (optimal) habitat = public information

Population and fitness consequences of conspecifics attraction Non-independence in habitat choice decisions [like for mate copying] Traditional aggregations / strong sensitivity to colonizers behaviour Aggregates above the “carrying capacity” of patch Mismatches with habitat quality in a variable environment

Tactics that mitigate the costs of habitat choice The “free” assumption is not true Prospecting is energetically and time consuming Exploration entails a variety of ecological costs (e.g., predation)

Alternatives ways to sample the habitat and gather information

Direct sampling : sampling based directly on habitat quality Conspecifics attraction : sampling based on conspecifics presence Public information (sensu stricto) : sampling based on the (observed) reproductive success (or performance) of conspecifics

Danchin et al. in Dispersal book 2001

When public information comes into play ! Habitat choice based on conspecifics performances reproductive / breeding performances potential quality of conspecifics (including quality as future mates) …

When does public information come into play ? intermediate and high levels of temporal auto-correlation tend to favor the “public information” strategy “conspecifics attraction” strategy maintain by parasitizing other strategies

See our practical “Habitat choice based on public information” for some examples Doligez et al. Anim Behav. 2004

Manipulative experiment in a non-colonial bird

Doligez, B., Danchin, E. & Clobert, J. 2002. Science 297: 1168-1170.

Habitat choice based on immigration

?

Habitat choice based on immigrants: an experiment

Low density

Low density

High density

High density

Observation phase

Immigrant lizards Resident lizards

Manipulative phase Cote and Clobert Ecol. Letters. 2007

Habitat choice based on immigration: an experiment Immigrants from high density

Immigrants from low density

Resident lizards at low population density

Resident lizards at high population density Cote and Clobert Ecol. Letters. 2007

Course program

1) Basic concepts 2) Space use and territoriality 3) Dispersal behaviour 4) Habitat choice behaviour 5) Complexities in dispersal patterns

Complexity in dispersal patterns

Three key issues

(1) behavioural flexibility in dispersal tactics enables organisms to cope with social selection resulting from spatial and temporal heterogeneity at several spatial scales (2) dispersal status covaries with a suite of behavioural, morphological and life history attributes that could facilitate transfer and settlement (3) condition-dependent dispersal is ubiquitous and can result in complex relationships between environmental variability, individual quality and habitat fragmentation.

Spatial scale of dispersal and dispersal evolution Benefits of dispersal

Costs of dispersal

Local crowding Kin interactions and inbreeding avoidance Parent-offspring interactions

Dispersal distance After Ronce et al. in Dispersal (Oxford University Press) 2001

Behavioural flexibility in dispersal tactics enables organisms to cope with social selection resulting from spatial and temporal heterogeneity at several spatial scales

Phenotype-dependent dispersal Physiological components that determine dispersal propensity (e.g. flight muscles in insects, activity metabolism in mammals)

Suites of correlated traits that covary with dispersal behaviour due to the combined effects of correlational selection processes and constraints from physiological trade-offs “behavioural syndromes”

“life-history syndromes” “life-history trade-offs”

Discrete dispersal polymorphism: insects

Threshold polymorphism

Specialized life stages

Crickets

Termites, Ants

Aphids

Discrete dispersal polymorphism: mammals

Dispersing (left) and non-dispersing siblings (right)

Dispersing naked-mole rats are fatter than their non-dispersing siblings

Dispersing naked-mole rats exhibit mate preferences for non-colony members (neophilic) and other strong behavioural differences (more activity, less cooperation)

Evidences for strong constraints on dispersal propensity in this species

After O’Riain et al. Nature 1996

Behavioural attributes of dispersers Dispersal propensity has been linked with several behavioural components Sociability

Dispersers less sociable than residents in Clethrionomys rufocanus (Ims 1990), but can be less or more sociable in the common lizard (Cote & Clobert 2007)

Activity and exploration

Activity levels higher in dispersers of Microtus agrestis (Ebenhard 1987) but not in two other Microtus species (M. pennsylvanicus & M. ochrogaster; Myers and Krebs 1971) Dispersers display faster exploration abilities in a novel environment in great tits (Dingemanse et al. 2003)

Aggressiveness Dispersing male voles and lemmings can be more or less aggressive than residents depending on species and the phase of the population cycle (Myers and Krebs 1971, Krebs 1978)

Behavioural attributes of dispersers Pre-weaning

Weaning

Rearing

Maturation

Dispersal

Hoset, Le Galliard et al. Behav Ecol 2011

Morphological attributes of dispersers Dispersal propensity has also been linked with several morphological traits

Contrasted effects of body size/mass (for voles) Non-significant associations between body mass and dispersal in 9 species, including 4 experimental manipulations of food intake Bigger individuals tended to disperse less in 4 vole species, but bigger males tended to disperse more in 3 others

Body condition Dispersing common lizards have larger body condition than residents (Massot et al. 2000), as for great flamingos (Barbraud et al. 2003), ground squirrels (Nunes and Holekamp 1996) and imperial eagles (Ferrer 1993) among other vertebrate species

Overview Swingland, I. R. (1983) Intraspecific differences in movement. The ecology of animal movement (eds I. R. Swingland & P. J. Greenwood), pp. 102-115. Clarendon Press, Oxford.

After Clobert, Le Galliard et al. Ecology Letters. 2009

Life-history attributes of dispersers

Life history (genetic) correlations for a threshold migratory traits

Juv. Horm. esterase

Flight propensity

Developmental time

Wing morph

Muscle weight

Fecundity

Life history (phenotypic) correlations for a dispersal behaviour

Larger body growth and adult body size

Dispersal propensity

Larger size-independent reproductive effort After Roff et al. JEB 1997, and Ebenhard Ecology 1990

Stereotyped dispersal “syndromes” Blue “mate-guarding” males mate guarding

After Sinervo and Clobert Science 2003, Zamudio and Sinervo PNAS 2000

“genic” based aggregation

“cooperative” head bobbing and extensive communication territorial and aggressive patrollers “genic” based seggregation random genic dispersal

Orange “ultradominant” males

Yellow “sneaker” males

high circulating T-levels and activity lower survival

strong sperm competition

female-like behaviour

Condition-dependent dispersal

External state (environment) Past (maternal)

Past (natal)

Present

Stay in natal area ?

Dispersal decision

Go from natal area ? Internal state (phenotype)

Patterns of condition-dependent dispersal

DIRECT ADDITIVE EFFECTS Environment

Dispersal

DIRECT INTERACTIVE EFFECTS Environment Dispersal

Phenotype

INDIRECT “ADDITIVE” EFFECTS Environment

Dispersal

Phenotype

INDIRECT “INTERACTIVE” EFFECTS

Environment Dispersal

Phenotype

Phenotype

After Ims and Hjermann in Dispersal (Oxford University Press) 2001

Examples of condition-dependence DIRECT ADDITIVE EFFECTS Density

Dispersal

DIRECT INTERACTIVE EFFECTS Population growth Dispersal

Kozakiewicz 1976

Body size

INDIRECT “ADDITIVE” EFFECTS Density

Dispersal

Aggressiveness

Myers & Krebs 1971

INDIRECT “INTERACTIVE” EFFECTS ?

Phase of cycle Dispersal

Andreassen & Ims 2001

Maturation / size

Interfamilial variation

Hilborn 1975

Example of maternal effects in Microtine rodents

Delayed effects of malnutrition during lactation

Female dispersal Low food quality during lactation Male dispersal Aggressiveness during social encounters Hyperactivity patterns in the laboratory Short-term effects on body size Clethrionomys rufaconus Andreassen & Ims 1990 Microtus pennsylvanicus Wong & Bondrup-Nielsen 1992 Bondrup-Nielsen 1993

Interactive effects of individual and habitat quality Habitat quality manipulation

Past (maternal)

Stay in natal area ?

Present

Dispersal decision

Go from natal area ? Individual quality

Litter size manipulation Microtus oeconomus (root vole) After Rémy, Le Galliard et al. Submitted

Interactive effects of individual and habitat quality

Interactive effects of individual and habitat quality Habitat quality manipulation Low habitat quality depresses several components of a female fecundity Low habitat quality enhances female dispersal Individuals prospect more before settling in low quality patches

Litter size manipulation Litter size enlargement has (i) long-lasting effects on structural size (ii) short-term effects on mortality Natal dispersal and settlement behaviour unaffected by this manipulation Larger individuals settled in higher quality patches irrespective of the manipulation Microtus oeconomus (root vole) After Rémy, Le Galliard et al. Submitted

Example of maternal effects in Microtine rodents

Delayed effects of malnutrition during lactation

Female dispersal Low food quality during lactation Male dispersal Aggressiveness during social encounters Hyperactivity patterns in the laboratory Short-term effects on body size Clethrionomys rufaconus Andreassen & Ims 1990 Microtus pennsylvanicus Wong & Bondrup-Nielsen 1992 Bondrup-Nielsen 1993

Consequences of dispersal strategies Environment Dispersal Phenotype

(1) the relative importance of flexibility vs. rigid syndromes should be crucial to invasion success (2) interactive effects between environmental variation and phenotypic traits mean that dispersal involves qualitative changes in spatial population dynamics, not just numerical changes (3) phenotype dependent dispersal can affect the distribution and maintenance of genetic variation for key phenotypic traits and therefore local adaptation

Consequences of dispersal strategies Proportion of colonizers from 0.5 to 0.99

After Clobert, Le Galliard et al. Ecology Letters. 2009

Consequences of dispersal strategies Temporal change in breeding value of body mass = strong spatial structure

Similar selective pressures across space Greater heritability of the trait in the north than in the east Significant influx of larger immigrants in the north

Effects potentially driven by variation in habitat quality and some “quality*body mass” dependent dispersal

After Garant et al. Nature 2005

Dispersal syndromes and invasion success

After Duckworth & Badyaev PNAS 2007

Dispersal syndromes and invasion success

(1) dispersal and aggression are correlated (2) aggression helps dispersing males acquire breeding territories in the first place (3) aggression is selected against by sexual selection in established populations After Duckworth & Badyaev PNAS 2007