ANB 218A Fall 2013 Movement and Migration Part 2

ANB 218AFall 2013

Movement and Migration Part 2

Outline1. Introduction –

kinds of movementevolutionary theory and migration

2. Concept of annual routines (life cycles) and phenotypic flexibility

3. Life history stages and how environmental conditions influence their progression

4. Classification of environmental cues: predictable, unpredictable

5. Genetic basis for migratory traits

6. Conclusions







6. Conclusions

Environmental information can be divided into two categories

Predictable cues (reliable, temporally relevant):Initial predictive – daylength, circannual rhythms, seasonality

Local predictive –Current environmental conditions, temperature, food, other resources, wet / dry seasons, geomagnetic information, planetary cues, etc

Unpredictable cues (labile, unexpected): - - Huge swings in climatic conditions, food supply,

social dominance, disease, predators

- Exposure leads to a modification of the current LH stage

Classification of environmental cues

Storm fronts/prevailing windsSeasonal TemperatureOcean currentsLandscapesCelestial cuesSetting sunPolarized lightGeomagnetic forcesPredatorsSeasonal fluxes of foodSolar time cycle

StormsPollutionDiseaseLoss of habitatChange in foodGlobal changesSocial conditions

Predictable Cues Unpredictable Cues

Early phase

Late phase

Effect of the magnetic field on orientation ofEuropean robins, Erithacus rebecula

Autumn recoveries of Thrush Nightingale from SE Scandinavia to E Mediterranean.

(Kullberg et al. 2003)

Early Migration Later Migration

Experimentals

Controls

Long distance migrations of marine turtles raise questions of the source of cues

Ascension Islands

Magnetic lineations along the seafloor created by fracture zones along spreading ridges





Facultative responses to an unpredictable cue – Emergency life history stage

(Wingfield et al 1998)

Emergency life history stage represents interrelationships of substages

(Wingfield and Ramenofsky, 2011)

Modeling responses to unpredictable events or labile perturbation factors:Allostatic Load.

2

Energymetabolism

Immunefunction

Behaviorb-ENDORPHIN

Analgesia,behavioral effects

(Landys, Ramenofsky, Wingfield, 2006)

Associations of homeostasis, allostasis and physiological state

Meta Landys working withBar-tailed godwits in the Netherlands

Taking an Allostatic Load Approach to the studies of migration

Departure biology of long Bar-tailed Godwits from Spring stop-over site

(Landys et al. 2002)

Corticosterone Baseline in Migrating Godwits

Cor

ticos

tero

ne B

asel

ine

(ng

/mL)

0

5

10

15

20

25

LATE-FLIGHT REFUELING

EARLY MIDDLE LATE

56 82 113 43

ANOVA(on log10 corticosterone)Period: P < 0.001

error bars = standard error of the mean

Corti

cos t

eron

e ng

/ml

Do these peaks of corticosterone represent allostatic overload?

One might ask:

NO!

Model of the relationships across available energy (resources), demand and glucocortiocoid levels

(Landys et al 2006)





Jenni et al, 2000

Corticosterone levels of a variety of transequatorial migrants following migration across the Mediterranean Sea during spring migration.

Behavioral responses to the unpredictable - Facultative movements - Partial migrants

Within a wintering flock some members will remain on or nearby the breeding grounds while others will migrate away depending upon local environmental conditions. This is also considered an evolutionary stable strategy (ESS).

Schwabl et al 1985

Map of Europe

Breeding range ofEuropean Blackbird

Wintering range

Adults remainOn breeding range

SEVERE MILD0

5

10

15

AdultFirst year

Male European Blackbird

Weather conditions

Cort

icoste

ron

e,

ng

/ml

SEVERE MILD0

5

10

15

AdultFirst year

Female European Blackbird

Weather conditions

Cort

icoste

ron

e,

ng

/ml

(Schwabl et al., 1985)

Geographical range of European Blackbird, Turdus merula

Residents

Partial migrants

(Partecke et al., 2007)

Red crossbill: a facultative migrant

Irregular movements of flocks that coincide with availability of cone crops

Red Crossbill (Loxia curviostra) Douglas fir conePseudotsuga Menziesii

(Hahn et al., 2008)

Annual reproductive schedules of red crossbills

Suggestions of how Red crossbills react to food shortages

(Cornelius et al., Proc. R. Soc., 2010)

Public information and movement in red crossbills

(Cornelius et al., Proc. R. Soc., 2010)

Key Points

1. Migrants respond to both predictable and unpredictable environmental cues but the physiological mechanisms differ

2. Predictable cues influence the speed of progression through the life history stagewhereas, unpredictable cues induce an alternative - Emergency life history stageThe physiological mechanisms of this have been aligned with the Allostatic load models







6. Conclusions

Be(Berthold and Pulido, 1994)

Morphological changes in phenotype with range expansion of a long-distance migrant:Assortative mating promotes microevolution of a migratory population

(Gunnarsson et al 2012)

Documents

ANB 218A Fall 2013 Movement and Migration Part 2