Announcements Final Exam May 11, 8-11 am.

1. Announcements Final Exam May 11, 8-11 am.

2. Packer Caraco and Wolf

3. Why do humans use spices? H1: They provide extra calories But very little amounts are used H2: They provide rare nutrients Nutritional analyses say no

4. H3: They help to preserve food longer Prediction 1: spices show antimicrobial properties See also: Srinivasan K. Food Research International 38 (1): 77-86. 2005

5. H3: They help to preserve food longer Prediction 2: spice use should be proportional not to availability, but to risk of food spoilage Spices are more commonly used in hot climates where spoilage is more common. Sherman PW , Billing J Source:  BioScience 49: 453-463 1999

6. Habitat selection, dispersal and territoriality

7. Spatial distribution of resources: random, clumped, dispersed Ideal Free Distribution: Individuals should distribute themselves among habitats so that every individual maximizes its net rate of return

8. Homerange: area which an individual, pair, or group occupies or regularly returns to Core Area: area of heaviest use, may center on a resource, i.e. nest, water source, food source Territory: any defended area; area of more or less fixed boundaries from which rival conspecifics are excluded through Aggression (self-preservation, protection of the young, or resource competition) Lek: a communal mating area in which individuals hold small territories solely for courtship and copulation

9. Different estimators of home range Kernel (95 and 50%) 95% Minimum Convex Polygon

10. Horned lizard home ranges overlap with their food - ant colonies

11. Dispersal:Ecological processaffecting distribution. leaving an area of birth or activity; largely a short range effort but can also be long range Genetic perspective - can affect geographic differentiation and variation Choice: Stay in the safety of home (the tendency for offspring to breed in their natal home range is referred to as philopatry). or Disperseand take chances: high mortality but high payoffs.

12. Juvenile dispersal: Hatching juveniles or fledglings leave their natal area. Mostly short range but can be long distance (migratory spp.) birds - bird banding records have found juveniles settling 1000's of kilometers away from their natal area. lizards - 1.5 km. Given the length of a hatchling (2.5 cm), this amounts to approximately 60,000 body lengths the human equivalent of 120 km traveled in the first week or two of life.

13. Long range dispersal: Can occur naturally : e.g. Cattle egrets, rafting, storms Cattle Egrets - original range in Africa 1880 - West Suriname 1930 - South America, North America

14. Long range dispersal: Unintentional or intentional dispersal by humans. The Argentine ant

15. The Argentine ant

16. Definitions: Introduced (non-native, exotic) - species introduced deliberately or accidentally from somewhere else Domestic/Feral (released pets, livestock and game animals) - can spread disease, compete with native species Human commensal or subsidized (out of control natives) - native species that benefit from our land use (disturbance) Invasive species - species that spread subsequent to establishment usually at some cost.

17. Invasive Species • Some introduced deliberately: • naturalization societies • Shakespeare fans • game animals • domestic animals • Some accidental: • ballasts of ships • unprocessed wood • fruit shipments • by-pass natural barriers

18. Dispersal: Can have incredible energetic costs. A moving animal may be at great risk of predation. How do you find right habitat? abiotic cues conspecific attraction Outbreeding depression Why do juveniles of most species tend to disperse despite these costs? Inbreeding avoidance Reduce competition with relatives Colonization of new habitat (ideal free distribution)

19. Sex-biased dispersal - kin avoidance mechanism Because dispersal entails costs, both sexes of progeny need not disperse to dramatically lower the probability of inbreeding. Belding’s ground squirrels

21. One way to reduce costs of dispersal: hitch a ride!

22. Dispersal: typically associated with a once in a lifetime event -- movement to a new habitat Orientation: the use of external cues to move about the environment (visual - landmarks) Navigation: moreinvolved - need to where you are in addition to a “compass sense” (a sense of the appropriate direction in which to move) Migration: distinct from dispersal - migratory animals typically move from one geographic region to another,without using the intervening habitat. movements often associated with a particular season, and tied to the reproductive cycle.

23. Who migrates? birds insects (e.g., Monarch butterflies) mammals (caribou, wildebeests, whales) amphibians (e.g., newts to their natal pond) reptiles (e.g., sea turtles) fish (salmon, eels)

24. Arctic terns

26. Monarchs take two generations to complete migration!

29. Cues used for migration: Celestial compass (sun and polarized light) Stars Geomagnetic field Visual (landmarks, shore lines) Smell?

31. Cochran et al. 2004 Science

32. Territoriality: Defending an area from conspecifics. (territory - an area occupied and defended from competitors) Costs: time, energy, potentially harm Benefits: resources (shelter, nest sites, food), access to mates Alternate strategies: sneakers, satellites.

33. Yarrow’s spiny lizard

34. Surgeon fish

35. Why do territorial holders usually win contests when their territory is challenged?

36. The “dear enemy effect” Neighbors may learn to recognize each other and reduce aggression as a response. - lower costs associated with maintaining territory - gang up on foreign intruders. Evidence in some birds and ants.