The Migration Ecology of Birds

Front Cover
The Migration Ecology of Birds
Copyright Page
Contents
Preface to the first edition
Preface to the second edition
1 Introduction
	Types of bird movements
		Constraints of breeding
	Adaptations for migration
	The diversity of migration
		Difficult journeys
	Sedentary populations
	Hibernation
	Summary
	References
2 Methodology for migration studies
	Observations of birds on migration
	Radar studies
	Distribution studies
	Ringing
	Tracking devices
		Very High-Frequency radio-transmitters
		Satellite transmitters
		The mobile phone network
		Geolocation (Global Location Sensing or GLS logging)
		Passive Integrated Transponders tags
		Other sensors
		Effects of tags
		Storage of data
		Future developments
	Isotopes and other internal markers
	Research on captive birds
		Wind tunnels
		Breeding programmes
	Mathematical models
	Concluding remarks
	Summary
	References
1 The migratory process
	3 Migratory flight
		Body weight, speed and flight mode
			Wing shape
			Power requirements in relation to body weight
			Effects of migratory fattening
			Ascending
			Descending
			Effects of wind conditions
			Cutting the costs of flight
		Consequences of flapping and soaring flight
			The high performance of some migrating waders
		The role of body size in bird migration
		Migration by walking or swimming
		Social factors
		Rest and sleep
		Concluding remarks
		Summary
		References
	4 Weather and migration
		Importance of wind
			Correction for drift
			Detection of drift
		Recent developments
		Low level flight
		Soaring species
		Global wind patterns and migration routes
		Altitude of migration
			Changes in conditions with altitude
			Consequences of high-altitude flight
		Diurnal and nocturnal flight
		Reverse migration
		Detours
		Summary
		References
	5 Fuelling migration
		Energy needs and body composition
			Costs and benefits of body reserves
			Water balance and thermoregulation
		Migration strategies
			Alternative strategies
		Mechanisms of fuel deposition
			Increased feeding rates and feeding times
			Change of diet
			Changes in gut structure and digestive capacity
			Digestive limitations
			Reducing expenditure
			Relative contributions
		Daily rates of weight gain
		Changes in body composition
			Body reserves for survival and breeding
		Concluding remarks
		Summary
		Appendix 5.1 Calculation of flight ranges
		References
	6 Amazing journeys
		Ocean-crossings by landbirds
		Desert crossings
			Trans-Saharan flights
			Physiological constraints
			Asian deserts and mountains
			North American deserts
		High mountains
		Ice fields
		Other remarkable migrations
		Concluding remarks
		Summary
		References
	7 Raptors and other soaring birds
		Major routes
			The trans-American flyway
			The Western European–West African flyway
			The Eurasian–East African flyway
			The East Asian Continental flyway
			The East Asian–Oceanic flyway
			Some general points
			Loop migrations
		Use of thermals and other updrafts
			Water crossings
			Extension of migration as a consequence of soaring
			Timing and food supplies
			Multiple wintering areas
			Social factors
			Numbers entering Africa
			Numbers entering Central and South America
			Feeding and energy reserves
		Summary
		References
	8 Seabird movements
		The marine environment
		Winds and seabird movements
		Migration patterns
			Direct migrations from breeding areas to lower latitudes
			Direct trans-equatorial migrations
			Figure-8 trans-equatorial migrations
			Dispersive migrations
			Migrations to higher latitudes in winter
			Migrations to east or west
			Circumpolar migrations
		Migratory stopovers
		Long-distance foraging trips
			The pre-laying exodus
			Foraging flights during incubation and chick care
		Fattening of chicks
		Pre-breeding years
		Navigational achievements
		Conclusions
		Summary
		References
	9 Speed and duration of migratory journeys
		Theoretical basis
			Getting around the problems
		Measures of migration speed
			Migration speeds from individual ring recoveries
			Average migration speeds from population-based ring recoveries
			Migration speeds from tracked birds
			Seabird migrations
		Proportion of migration spent in flight
		Penguins
		Migration and geographical range
		Concluding remarks
		Summary
		References
	10 Finding the way: senses, displacements and social influences
		Sensory systems
		Orientation and navigation
		Displacement experiments
			Other evidence for inherited directional preferences
			Return of displaced adults to breeding sites
			Return of displaced birds to wintering sites
			Further comments on displacement experiments
		Uncertainties over juveniles
		Convergence of migration routes
		Social influences
			Re-establishment of migration routes
		Summary
		References
	11 Finding the way: orientation and navigation
		Visual landmarks
		The sun and polarized light
			Evidence that birds use the sun as a compass
			The sun and navigation
			Evidence that birds use polarized light as a compass
		The stars
			The stars and navigation
			Integrated use of celestial cues
		The magnetic field
			Evidence for use of the magnetic field
			Magnetic navigation
			Pelagic seabirds
			Response to specific areas (location cues)
			Magnetic cues and vagrancy
		Odours
		Infrasound and pressure changes
		Cue conflicts
			Conclusions on cue-conflicts and recalibration
			Problems at high latitudes
			Problems at low latitudes
		Rhumblines and great circles
		Dispersive migration
		Concluding remarks
			Genetically encoded spatial information
		Summary
		References
2 The timing and control of migration
	12 Annual cycles
		Variations in annual cycles
			Split migrations
			Other movements
			Geographical and other variations within species
			Relationship between moult and migration
			Breeding seasons split by migration
			Sex and age differences
			Exceptions to general patterns
			Concluding comments on annual cycles
		Non-annual cycles
		Domino effects, catch-ups and delays
		Internal time keeping
			Importance of daylength
			Endogenous rhythms in migrants
			Geographical variation in photoperiodic responses
			Equatorial birds
		Flexible cycles
		Summary
		References
	13 Migratory control mechanisms
		Obligate and facultative migration
			Role of dominance in facultative migrants
		Migration timing, distances and directions
			Time-distance programmes
			Directional preferences
			Integration of time–distance and direction programmes
			Role of experience
			Migratory fattening and restlessness
			Diurnal patterns
		Autumn migration
			Split migrations
			Relationship between breeding, moult and autumn migration
		Spring migration
			Spread and consistency in spring departure dates within populations
			Different populations of a species wintering in the same area
			Return migration from variable wintering areas
			Relationship between the internal rhythm and prevailing daylength
		Relationship between spring arrival, breeding and autumn departure
		Deferred return to breeding areas
		Concluding remarks
		Summary
		References
	14 Stopover ecology
		Breaking the journey
		Important re-fuelling areas
		Resuming the journey
			Change in the diurnal cycle
			Weather and other factors influencing departure
			Other findings
			Age and sex effects
		Conclusions
		Summary
		References
3 Large-scale movement patterns
	15 Seasonal reoccupation of breeding and wintering areas
		Latitudinal trend in the timing of spring
			Species differences in spring migration dates
		Recolonisation patterns
			Patterns within species
			Duration of residence
			Annual variations in spring migration dates
			Evidence on migration timing from the field
		Reoccupation of local breeding areas
			Settlement on territories
			Components of early migration
		Withdrawal from breeding areas
			Competition for winter habitat
			Winter movements
		Concluding remarks
		Summary
		References
	16 Geographical patterns in migration
		Latitudinal trends
		Migration and diet
			Causes of latitudinal trend
		Distributional shifts
			Trends within species
		Altitudinal shifts
		Ecological niches
		Comparisons between hemispheres
			Populations in both hemispheres
		Relationship between breeding and wintering areas
			Patterns in distribution
			Comparison of sizes of breeding and wintering areas
		Migration within the southern continents
			Africa
			South America
			Australasia
		Concluding remarks
		Summary
		References
	17 Variations on a migratory theme
		Moult migrations
			Moult migration as originally defined
			Altitudinal moult migrations
			Moult at staging sites on autumn migration
		Movements within the breeding season
		Movements within the non-breeding season
			Facultative movements in relation to food supply
			Facultative movements in relation to weather
			Overview
		Opposite-direction migrations
		Nomadism
			Desert wetlands
			Irruptive movements away from deserts
		Concluding remarks
		Summary
		References
	18 Sex and age differences in migration
		Arrival in breeding areas
			How does one sex achieve an earlier arrival than the other?
			Age differences in arrival dates
		Departure from breeding areas
			Age differences in departure from breeding areas
		Migratory distance, body size and dominance
			Age-related differences in migration distances
			Competition and migration distances
		Migration and deferred breeding
		Over-summering in ‘wintering’ areas
		Other differences between age groups
		Concluding remarks
		Summary
		References
	19 Dispersal and site fidelity
		Benefits and costs of site fidelity
		Natal dispersal
			Seabirds and other colonial species
			Sex differences in natal dispersal
			Competition and natal dispersal
		Breeding dispersal
			Dispersal within a breeding season
		Long-distance natal and breeding dispersal
		Nonbreeding dispersal
			Multiple wintering sites
			Pelagic seabirds
			Sex-related differences
			Age-related differences
		Comparison of breeding and non-breeding site fidelity
		Fidelity to stopover sites
		Fidelity to migration routes
		Post-fledging dispersal
		Dispersive migration
		Site attachment
			Attachment of young birds to natal sites
			Attachment of young birds to wintering sites
		Summary
		References
	20 Irruptive migrants: boreal seed-eaters
		Seed crops
		Irruptive seed-eaters and fruit-eaters
		Twice-yearly migrants
			Breeding densities
			Breeding dispersal
			Autumn emigration
			Migration timing
			Migration directions
			Winter densities
			Changes in wintering areas: evidence from ringing
			Breeding in migration and wintering areas
		Once-yearly migrants
			Crossbills
			Annual cycle
			Irruptions
			Change of breeding localities
			Other Eurasian crossbills
			North American crossbills
			Nutcrackers
		Overview of seed-eaters
			Coping with boom-and-bust
			Regularity in irruptions
			Directional preferences
			Other seed-eaters
		Concluding remarks
		Summary
		References
	21 Irruptive migrants: owls, hawks and ducks
		Rodents and rodent-eaters
			Breeding dispersal
			Locating areas with abundant food
			Geographical variation in movement patterns within species
			Irruptive migrations
			Changes in wintering areas
			Nesting outside the regular range
			Rodents and reproduction
		Hares and hare-eaters
		Ducks and ephemeral wetlands
			Breeding distributions
			Winter distributions
			Eurasian ducks
		Concluding remarks
		Summary
		References
4 Evolution of movement patterns
	22 Evolution and inheritance of migratory behaviour
		Adaptations for migration
		Adaptive timing
		Partial migration
		The genetic control of migration: experimental evidence
			Migratory inclination
			Timing and distance
			Migratory directions
			Morphological features
			Natural variability
			A natural change in the migration of Eurasian Blackcaps
			Heritability and other studies
		The genes involved
		Concluding remarks
		Summary
		References
	23 Recent changes in bird migrations
		Migratory to sedentary
		Sedentary to migratory
		Shortening of migrations
		Lengthening of migrations
		Changes in migratory directions
		Changes in migration timing
			Spring dates
			Autumn dates
		Times spent in breeding and wintering areas
		Ecological mismatches
		Other climate-driven changes
		Other rapid changes in behaviour
		Genetic and facultative responses
			Genetic responses
			Facultative responses
		Summary
		References
	24 Glacial legacies in bird migrations
		Indirect routes to distant wintering areas
			Further comments on the legacy of glacial changes
			Abrupt changes in migration routes
		Migratory divides
		Evolution of barrier crossing
			Topographic influences
		Loop migrations
		Migration development towards higher or lower latitudes
			Evidence from DNA studies
			Colonization of wintering from breeding areas
		Development of migration patterns
		Concluding remarks
		Summary
		References
	25 Distribution patterns and connectivity
		Longitudinal patterns
			Parallel or fan patterns
		Latitudinal patterns
		Evolution of alloheimy
		Nonbreeding distributions among seabirds
		Connectivity
			Relationship to population limitation
			Relationship to genetic divergence
		Time and energy considerations
		Summary
		References
5 Migration systems and population limitation
	26 The Palearctic-Afrotropical migration system
		The birds involved
			Social systems
		The African Wintering areas
			Seasonal changes
			Wetlands
		Bird movements within Africa
			Recent tracking studies
		Relationships between Eurasian migrants and native African species
			Habitats
			Mobility
			Sahel food supplies
		Fluctuations and declines in migrant numbers
			Population fluctuations
			Population declines
			Climate and habitat changes in Africa
			Hunting and predation
			Natural predation
			Events in breeding areas
		Summary
		References
	27 The Nearctic–Neotropical migration system
		The birds and their wintering areas
		The neotropical wintering areas
			Migrant social systems
		Bird movements within the Neotropics
		Population declines in migrants
		Causes of declines operating in breeding areas
			Forest loss and fragmentation
			Predation
			Parasitism by cowbirds
			Food supplies
		Causes of declines operating in non-breeding areas
			Factors operating on migration routes
		Concluding remarks
		Summary
		References
	28 The East Asian–Australasian and other migration systems
		The EAA migration system
		The birds
		Population declines
			Shorebirds in Australasia
		Declines in Shorebirds – the Yellow Sea problem
		Other migration systems
			The Central Asian (Trans-Himalayan) system
			The Central Pacific migration system
		Concluding remarks
		Summary
		References
	29 Population limitation – breeding and wintering areas
		Some general principles
			Effects of habitat gain or loss on migrants
			The buffer effect and density dependence
		Examples of species affected by events in breeding or wintering areas
			Climatic factors acting in both breeding and wintering areas
			From winter-limited to summer-limited
			Convergent and divergent patterns
		Carry-over effects
		Other aspects of population limitation in migrants
			Range size and population limitation
			Connectivity and population limitation
			Range segregation and sex ratios
			Climate change and phenological mismatch
			Human hunting
			Pathogens and diseases
		Concluding remarks
		Summary
		References
	30 Population limitation – migration routes
		Conceptual models
		Food limitation at stopover sites
			Migrant numbers in relation to food supplies
			Depletion of food supplies
			Food supplies and fattening rates
			Social interactions, feeding and fuelling rates
			Poor condition and mortality at stopover sites
		Influence of weather
		Influence of predation, disturbance and parasitism
		Body condition and subsequent performance
		Effects of stopover events on populations
			Change of stopover sites
		Concluding remarks
			Residual body reserves
			Winter or spring limitation?
			Interactions between populations
			Conservation issues
		Summary
		References
	31 Mortality on migration
		Mortality on route
			Age differences
			Mortality and migration distance
		Mass mortality events
			Weather and in-flight mortality
			Unseasonable cold before departure from breeding areas
			Unseasonable cold soon after arrival in breeding areas
			Conclusions on weather-induced mortality events
		Human-induced losses
			Human hunting
			Illuminated structures
			Wind turbines
			Power lines
			Oil and gas platforms
			Artificial light
			General comments
		Concluding remarks
		Summary
		References
Glossary
Index
Back Cover