lecture7 - Social Systems 1 July Sociality when individuals...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Social Systems 1 July 1 Sociality – when individuals live together in groups due to their mutual attraction for one another and interact cooperatively Does not include aggregations due to attraction to other factors in the environment Cooperation – interactions among individuals in which all benefit Why are some species social and others live solitarily? Why are some species social and others live solitarily? Species should be social when benefits > costs Possible costs Possible benefits Factor
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Social Systems 1 July 2 Experimental Analysis of the Relation Between Experimental Analysis of the Relation Between Flocking and Predation in Starlings by Powell Flocking and Predation in Starlings by Powell % time feeding % time surveillance Reaction time (sec) Flock (10 starlings) Solitary starlings Predation by Merlins on Sandpipers by Page and Whitacre Predation by Merlins on Sandpipers by Page and Whitacre 50-500 11-49 2-10 1 Merlin capture success (%) Sandpiper group size Group Sizes of Foraging Lions by Caraco and Wolf Group Sizes of Foraging Lions by Caraco and Wolf 4-7 Wildebeest and zebra Wet 1-2 Thompson’s gazelle Dry Group size Prey Season Conclusions Conclusions ± Lions could obtain enough food to meet their physiological requirement over a broader range of group sizes when capturing ± Observed group sizes tended to be larger than optimal for foraging. Why?
Background image of page 2
Social Systems 1 July 3 Colonial Orb Colonial Orb -weaving Spiders in Mexico weaving Spiders in Mexico By George Uetz and Margaret Hodge By George Uetz and Margaret Hodge usually large high wet Metepeira incrassata usually solitary low dry Metepeira atascadero Group size Food supply Habitat Species The The “ricochet effect ricochet effect ” occurs when prey bounce off one web
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/06/2010 for the course EVE 101 taught by Professor Strong,d during the Spring '08 term at UC Davis.

Page1 / 6

lecture7 - Social Systems 1 July Sociality when individuals...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online