Social Behavior

-- includes nonbreeding and breeding activities

-- how birds interact with each other, space themselves,and maintain high fitness and survival

-- feeding flocks common, especially in winter

-- allow greater protection from predators, facilitates foodgathering, saves energy from trying to keepindividual territories

-- some examples previously given: Harris’ Hawk, WesternGull and gull ‘gangs’, Double-crested cormorantsswimming in formation to herd schools of fish

Blackbirds, including starlings, red-winged blackbird, and gracklesare well known for their huge winter flocks that can number in thehundreds of thousands

Short-tailed Shearwater, Alaskaalaska.usgs.gov

Mixed species feeding flocks also common in winter

-- provides greater protection to all individuals

-- each species knows each others’ alarm calls

-- can form for just an hour or the day

-- may learn new foraging strategies by watching others

-- no interspecific competition for food as each species hasits own niche (e.g., warblers, chickadees, titmice,and woodpeckers feeding and moving together)

-- seabird feeding flocks with diving, dipping behaviors among different species

Feeding Guild

A group of species feeding on the same resource in different ways

flickr.com

Vultures along can strip a zebra carcass of all flesh in 30 minutes

Roosting flocks also possible

-- birds forage individually in day, flock together at onesite for night

-- crows and ravens, vultures, ibis, herons, blackbirds, gullsand some shorebirds especially known for this

-- many advantages:

1. Predator avoidance/protection2. Thermoregulation3. Information exchange4. Develop pair bonds

Pygmy NuthatchFamily Sittidae

Nuthatches drill their own cavities, use for winter roostingas well as breeding

naturalmoment.com

Roost cavities become important for thermoregulation at night in winter

Record roost for pygmy nuthatch in Flagstaff, AZ, winter 1981-82

10 winter social groups converged on one cavity from as far awayas 1.7 km, total in cavity was 167, most ever recorded

Gull ‘clubs’

Breeding and non-breeding season, gather at dusk or hang outall day

Non-breeders may establish pair bonds here, mate for life, practicebuilding nests, and build social skills

Behavioral Ecology in Birds

Field pioneered by Konrad Lorenz and Niko Tinbergen,1950s and 60s

Set foundation for modern behavioral studies

Lorenz (1903-1989) was an Austrian ornithologist

Famous for work on imprinting behavior in Greylag Geese

Lorenz is considered the ‘father of ethology’, or study of animal behavior

Besides research on imprinting behavior, also studied innate behavior and ‘fixed action patterns’

e.g., gull chicks always respond to red dot on adult bill by begging for food, pecking on spot to stimulate regurgitation of food by adult

Used models to illustrate how the behavior is innate

Greylag goose and FAP

Niko Tinbergen (Dutch ornithologist, 1907-1988)

Studied behavior of Herring Gulls

Proposed that any behavior should be examined in terms of causation, ontogeny, adaptation, and phylogeny

Shared 1973 Nobel Prize with Konrad Lorenz and Karl von Frisch

Causation

• Internal factors– Hormonal– Physiological

• External factors– Changes in season,

photoperiod impacting hormones and behavior

Ontogeny• Studying how individual behaviors develop

– Innate vs. learned

• “Double-scratch” of New World sparrows– Rapid backwards kick performed with both feet to

clear superficial layer of the surface (feeding)– Innate--appears in isolated and hand-raised birds

• Environmental influence on learned behaviors

http://eema-le.blogspot.com/2009_04_01_archive.html

Adaptation• How behavior functions for:

– Survival– Improving fitness– Reproductive success

e.g., winter attendance in

murres and gulls

Habituation to save energy

Phylogeny• Behaviors can be inherited or innate (passed on

from generation to generation)• Become characters for determining phylogenetic

relationships– Courtship displays (Stereotyped movements &

vocalizations)– Urohydrosis (Ciconiiformes)

http://www.calacademy.org/blogs/rainforest/?p=620

Innate behavior• Behaviors that require no learning, are

genetically controlled• Simple reflex behavior and fixed action patterns• Feeding and begging behaviors

– Gulls chicks peck at red spot on adult bill– Making begging calls when adult returns to nest

• Desire to incubate eggs– Common murre, penguins

Learned behavior• Opposite of innate• Young or adult birds watching other

adults and mimicking• Learn new skills for foraging,

defense, etc.• Classic example: Titmice in England

and milk bottles– at least 11 species of birds learned this

behavior within 10 years

http://www.corbisimages.com/stock-photo/rights-managed/FL003273/blue-tit-drinking-from-milk-bottle

Studying animal behavior

• Blind observations– See large part of colony– Sit comfortably without disturbing birds

• Establish methods for systematic observations• Quantify results from counting and coding

observations

Penguin predation study• Research questions:

– Are birds on the edge more susceptible to predation?

– Do predators vary their activities with time of day and season?

• 2 hr observations beginning at 6-8am, extending throughout the day

• Score behaviors by predators:– Searching– Attempts– Successful predation

• Record codes while observing, add codes to computer later

• Allows statistical analysis of behavioral observations

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