General adaptations?

1. General adaptations?

3. Predator adaptations (cont.) • The variety of predator adaptations is remarkable: • consider grasping and tearing functions: • forelegs for many vertebrates • feet and hooked bills in birds • distensible jaws in snakes • digestive systems also reflect diet: • plant eaters feature elongated digestive tracts with fermentation chambers to digest long, fibrous molecules comprising plant structural elements

5. Osprey feet

7. Prey adaptations. • Prey escape mechanisms: • in animals: • in plants:

8. Bombardier beetle

9. Crypsis and Warning Coloration • Crypsis - blending with background: • are typically palatable or edible • match color, texture of bark, twigs, or leaves • not concealed  mistaken for inedible objects • behaviors corresponds to appearances.

10. Crypsis Peruvian katydid

11. Costa Rican mantid Photo by C. Corbin

13. Lonomia moth in Costa Rica

14. Scorpion fish in Philippines

16. Sage thrasher

17. American Dipper

18. Jack-snipe

20. Warning Coloration • Unpalatable animals • Noxious chemicals • From food • Manufacture • Often warning is involved • predators learn to avoid such animals after unpleasant experiences • certain aposematic colorations occur so widely that predators may have evolved innate aversions Why aren’t all prey unpalatable?

21. Mimics • Henry Bates – palatable species mimic unpalatable (models) • Fritz Müller –unpalatable species that come to resemble one another (all mimics and models)

22. Batesian mimics

25. Müllerian mimics

26. Parasites adaptation = dispersal • Parasites usually smaller than host • Externally (ectoparasite) or internally • internal parasites exist in a benign environment: • food • stable conditions

27. Internal parasite Tapeworm of US soldier in Hawaii. Left: after barium infusion. Right: after vermifuge treatment

28. Ectoparasites Purple finch

29. Cost of being a parasite… • parasites must deal with a number of challenges: • host organisms have mechanisms to detect and destroy parasites • parasites must disperse through hostile environments, • often via complicated life cycles with multiple hosts,

30. Plasmodium life cycle Fusion of gametes Zygote forms cyst in gut wall of mosquito Feeding mosquito ingests gametes Zygote divides into sporozoites Some merozoites form into male and female gametes Salivary glands 48-hr cycle of invasion, lysing, reinvasion Injection of sporozoites into human host’s blood • Merozoites can: • Reinfect liver cells • Infect rbc’s Liver cells

31. One strategy… • Circumventing the host’s immune system: • suppress it (AIDS virus) • coat themselves with proteins mimicing host’s proteins (Schistosoma) • continually coat their surfaces with novel proteins (trypanosomes)

32. Plants vs. herbivory • Usually biochemical warfare. • Plant defenses include: • low nutritional content • toxic compounds • structural defenses • spines and hairs • tough seed coats • sticky gums and resins “Secondary” Compounds constitutive induced

34. Can herbivores overcome plant’s defenses?Can herbivores control plant populations? • prickly pear cactus in Australia • controlled by introduction of a moth, Cactoblastis • Klamath weed in western US • Controlled by Chrysolina beetles

35. Other examples… grazed • Mauna Loa, Hawaii

36. Spruce budworm – Algonquin PP in Ontario, Canada