Island Syndromes: Insects & Birds

1. Island Syndromes:Insects & Birds

2. Questions • What are the two main reasons for the development of wings? • What are some of the reasons that loss of flight/wings has evolved? • What part does inbreeding play in flightless/wingless organisms? • In terms of the progression, what are the differences between the initial and final stages?

3. Introduction • The first insects could not fly • Evolved wings • Escape predators • Obtain food • Fold wings over body • Mobility • Hiding • Food

4. Birds Pennula sandwichensis Hawaiian Is. rail Porzanula palmeri Laysan Is. rail Insects Orthoptera Hemiptera Neuroptera Lepidptera Coleoptera Hymenoptera Diptera Types of Organisms

5. Reasoning • Feeding on or near the ground • Crawling, walking, or hopping • Escaping predators • Hawaii has less predators • A lot of energy • Large wing muscle

6. Reasoning • Limits movement • Optimal for reproduction • Shifting diet • Missing mammals & large invertebrates • Outgrown wings • Wind conditions • Issue of blown away

7. Islands • Islands have three unique situations • cut off • small number of individuals • small area

8. Islands Inbreeding • New genetic material • Mutations • “healthy” genetically • “Only a slight deterioration of wings is needed to stop flight” (Island Biology, 1965)

9. Progression • Front & rear wings • Flat, few hairs, thin, narrow veins • Irregular, indented wing shapes • Greatly reduced rear wings

10. Progression • Smaller front wings • Develop a heavier texture • Veins thicken • Rear wings vanish • Odd shaped front wings • Could be covered with spines

11. Summary • What are the two main reasons for the development of wings? obtain food & escape predators

12. Summary • What are some of the reasons that loss of flight/wings has evolved? feed on or near the ground Hawaii has less predators conserve energy shifting diet out grow them

13. Summary • What part does inbreeding play in flightless/wingless organisms? Island species have a limited number of possible mates so inbreeding occurs. Mutations can occur that create the slightest change and causes loss of flight.

14. Summary • In terms of the progression, what are the differences between the initial and final stages? • Front & rear wings • Flat, few hairs, thin, transparent, narrow veins • Rear wings vanish • Thick veins and heavier wings • Odd shaped front wings • Could be covered with spines

15. Sources Brown, James H. & Lomolino, Mark V. (1998). Biogeography second edition. Sunderland, MA: Sinauer Associates, Inc. Publishers. Carlquist, Sherwin. (1980). Hawaii A Natural History. Honolulu: SB Printers, Inc. Carlquist, Sherwin. (1965). Island Life. New York: The Natural History Press. Howarth, F.G. & Mull, W.P. (1992). Hawaiian Insects and Their Kin. Honolulu: University of Hawaii Press. Pratt, Bruner, & Berrett. (1987). A Field Guide to The Birds of Hawaii and the Tropical Pacific. New Jersey: Princeton University Press. Wagner, Warren L. & Funk, V.A. (1995). Hawaiian Biogeography: Evolution on a Hot Spot Archipelago. Washington, D.C.: Smithsonian Institution Press.