Avian 2-10

Avian 2-10 - Evolution of migration-Migratory and migratory...

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Avian 2/10 Migration - Not necessarily back and forth on same route- environment is different - Go north to next, go south to survive - There’s a race to get to breeding grounds, less for overwintering grounds - Paleotropic paleoarctic (?) - New world to pacific o North south - Old world o Lots of east west migration o Because mountains and deserts - Things move to areas for breeding success - Migration also prevents mass predation - Saves calories that would have been used in staying warm in winter - Costs and benefits of o Migrating during day Benefit Use thermals/ air currents from waves Visibility coordination Feeding Cost Predation Thermoregulation, difficult to lose heat o Migrating during night Benefit Better heat loss Avoid predation Calmer winds, less energy Less water loss Cost No thermals No feeding o Songbirds- night o Swifts/swallow-day Feed on insects during day o Shorebirds- both Big enough to store food o Soaring birds- day Using currents and hunt during day
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Unformatted text preview: Evolution of migration-Migratory and migratory species-Radiation causes things to exist in separate areas, and reproductive isolation can evolve from one species-Is it really genetically controlled, or is it just response to local conditions? o Phenotype= genotype x environment o Can determine by eliminating environmental conditions o Experiment in Germany, 1950 Birds get restless around migration time Zugunruhe-Common garden o Take three groups, see how things respond-Direction and distance o Measured by the wire mesh and cone setup, with ink on feet-When to go? o From input from environment o Experiment- measured body mass with change in time o Body mass spikes before migration Assimilation varies, actual organs become bigger or smaller Relative intake is different as things different Efficiency goes down during spring, because don’t need to maintain. Lots of food around....
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This note was uploaded on 02/13/2012 for the course BIO 470 taught by Professor Dr.lukebutler during the Spring '12 term at TCNJ.

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Avian 2-10 - Evolution of migration-Migratory and migratory...

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