1. Behavioral Ecology: Movement & Orientation I.Why move? A.Types of movement B.Metapopulations II.Local Distribution A.Home Range B.Territoriality III.Migration - Mass movements A.Breeding B.Over-wintering IV.Movements of juveniles - Dispersal V.Homing/Orientation

2. I. Why move? Reasons to move: Mortality can be high when individuals move from one habitat to another

3. A. General types of movement Herps are not distributed randomly! Some places are better than others… 1)Station keeping: movements directly related to the acquisition of resources within a home range 2)Ranging behavior: exploring new habitats or resource patches 3)Dispersal: juveniles leaving their parent’s home range to find their own

4. B. Metapopulations – populations of populations Spatially subdivided populations

5. II. Local distribution of individuals A.Home ranges = area which individuals move within & do not defend from conspecifics  Association between body size & home range –Resources Food, shelter, thermoregulation sites, escape routes –Social activities Finding mates  Calculating home range – minimum polygon method

6. Minimum polygon method of calculating home ranges –  Measure the area that encompasses all of the outer points within which an individual occurs.  Most widely used method  Good for species living in 2D habitats  Does not take into consideration amount of time or relative frequency with which an individual might use different parts of the home range

7. Anolis transversalis -

8. Home range can vary through time/space Terrestrial amphibians, during non-breeding season have small home ranges away from water –Pond breeding species, home range breaks down during breeding events Microhabitat specificity a factor Vary w/sex & reproductive state

9. Resource dispersion & home range Habitat = resource patches Depleted / not depleted How rapidly will resources be replenished? –Abundant resources = limited home range –Resources renewed slowly = wider home range

10. Masticophis (whiptail) – has to go where the food is… Herbivores – wider food sources, but abundant…

11. Dermochelys coriacea Hoplocephalus bungaroides Iguana iguana

12. B. Territoriality Territory = area within the home range which is defended against conspecifics & other species Usually has some sort of defendable resource –Defense results in exclusivity Most often males defend territory –Direct combat –Threats –Avoidance Selection favors those that control & use resources in a way that positively influences their reproductive success

13. Plethodon cinereus Dendrobates pumilio Amphibians exhibiting territoriality:

14. III. Migration - Mass movements A. Breeding migrations Amphibians - Triggered by rainfall & temp, usually starting at night – but continuing through day Mass movements – explosive breeders, i.e. Ambystoma & Bufo move en masse to and from breeding ponds Reptiles – Vipera, Kinosternon, Chelydra, Crocodylus, Iguana, Sea turtles

15. Loggerhead turtle –movement monitored via satellite

17. B. Over-wintering movement Seeking more hospitable climate Flowing water of streams vs. frozen water of lakes/ponds

18. IV. Dispersal usually refers to juveniles leaving home ranges of parents to find a home of their own, reasons to disperse: Costs =

20. V. Homing Behavior Ability of displaced individuals to return to their original location – animals must be able to sense the direction they are moving

21. ORIENTATION Pilotage - orientation with respect to fixed landmarks home

22. Mechanisms of orientation Local environmental cues (landmarks) –Smells, visual cues Compass orientation –X-Y axis orientation Depends on sunny conditions Must have built in sense of daily changes in the sun’s position (internal clock) Celestial orientation Magnetic orientation

25. Navigation - orientation without fixed landmarks