FEEDING ECOLOGY OF AMPHIBIANS AND REPTILES When you are hungry what do you do? 1.Dig out wallet/open fridge 2.Decide what you want/can eat 3.Capture Food Item 4.Cook Food Item 5.Consume Food Item 6.Digest 7.Repeat

FEEDING ECOLOGY OF AMPHIBIANS AND REPTILES When a herp is hungry what does it do? 1.Dig out wallet/open fridge—Wild Food Has Cost 2.Decide what you want/can eat—Limitations of Cost 3.Capture Food Item—Often the major cost 4.Cook Food Item 5.Consume Food Item—Not as easy as it sounds 6.Digest—another big cost 7.Repeat—When and how much 8.Hope Nobody Eats You—A REALLY BIG COST 9.Hope Dinner Doesn’t Bite You Back—PARASITES

FEEDING ECOLOGY OF AMPHIBIANS AND REPTILES What do amphibians and reptiles eat?

FEEDING ECOLOGY OF AMPHIBIANS AND REPTILES What do amphibians and reptiles eat? Salamanders: Mostly Inverts Frogs: Animals Tadpoles: Filter feed, algae, larger foods Caecilians: Animals Snakes: Mostly vertebrates, some Inverts Lizards: Mostly insects, Some vertebrates Tuatara: Inverts Iguaninae: Herbivores

WHY ARE THERE SO FEW HERBIVOROUS HERPS Challenges of Herbivory: Very low energetic value May not be an option for small animals Gut Flora Rotting in the Gut—Cold Temperatures Successful Herbivores:Iguanas, 2 Other Lizards Tadpoles (Are Algae Plants?)

FINDING SOMETHING TO EAT Active Predators vs Sit and Wait Risks of Both Predation Energy Gained/Lost Your Defense Chemical Responses Coevolved Prey Phylogenetic Effects

Specializations for Feeding Suction Feeding 1.Only Works in Water 2.Primitive: How Most Bony Fish Eat 3.Difficult to Do Without Gill Slits

Specializations for Feeding Suction Feeding: Primitive Form of Larval and Paedomorphic Salamanders Figs 11-1a, 11-2

Specializations for Feeding Suction Feeding: Modification in Tadpoles Fig11-10, 11-6,

Specializations for Feeding Suction Feeding: Challenge of Life Without Gills Water flow is now 2 directional. How is this a problem? Figs 11-1b

Now suction gives the predator a brief advantage, or at least reduces the “bow push.” Snapping turtles only overcome the disadvantage of moving their head forward

TONGUE FLICKING Found in Mutiple Groups Salamanders Frogs Iguanid Lizards Tuatara Chamaelion In this mode of attack a sticky tongue comes out of the mouth “grabs” food item pulls food into mouth

TONGUE FLICKING: How Does it Work Salamanders Hyobranchia contract forcing tongue forward. Similar to a kid with a mouth full of water. YY Fig 11-21, 11-19, 11-18

TONGUE FLICKING: How Does it Work Frogs Muscle in front of moth contracts pulls tongue forward. Similar to a sling shot. Fig 11-22

TONGUE FLICKING: How Does it Work Chamelions Hyobatrachium acts as a lever, pushes rod out, muscle at tip squezes. Similar to a siege engine. Fig

TONGUE FLICKING: How Does it Work Lizards Lever pushes a rod. Chamelions modified this approach I love these crunchy on the outside chewy in the middle

ALL JOKING ASIDE, WHAT DOES THIS PATTERN SUGGEST ABOUT MODIFICATION OF THE TONGUE AS A PREY CAPTURE MECHANISM?

Power Biters Some reptiles are specialized for powerful snapping. Skull is akinetic Turtles No teeth Keratinous beak Large temporal notch Crocodiles Short depressor mandibulae Massive pterygoids, powerful adductor Narrow Jaw Specialists Wide Jaw Generalists Alligators routinely eat large turtles Fig 11-5

Kinetic Skulls Skulls of Snakes and Lizards are highly flexible Allows changed in skull morphology Tight Fits “Disarticulation” of snake jaws Mandibles connected by cartilage Unilateral Feeding Extreme versatility Figs 11-29b

African egg eating snakes Large gapes Vertebral specializations Hinged Teeth Mostly skink eaters Pit Organs Heat sensitive Role in defense Widely placed phylogenetically Evolved to stay cool (ISU Work) Constriction Specialization for killing Prey Secondarily redeveloped in colubrids ODD Snake Specializations Figs Imager 11-43

Envenomation Poison--delivered orally Venom is injected Three families of snakes + 1 of lizards Colubridae (broadly defined) Elapidae (cobras and kin) Viviparidae Prey restrain, digestion, and defense Figs 11-41

Why Aren’t More Animals Cannibals? Benefits Everything you need Eliminate Competition Costs Reproduction does you no good if you eat the results Great way to get parasites Prions (mad cow disease) When should you be a cannibal?

Steve Lima’s Work Being prey is game over Predation does more than kill 1 individual Trade-offs of short vs long term fitness When to hunt, When to watch When to call, When to hide Temperature Performance Safe Habitat Protection Cryptic Behavior/Appearance Be dangerous Look dangerous (Batsman Mimicry) Look and be dangerous (Mullein Mimicry) How Do You Avoid Getting Eaten Figs 15-8, 15-19e

SPEAKING OF EATING HERPS ASSIMILATION EFFICIENCY SUGGESTS WE SHOULD DO SO What besides assimilation efficiency should we consider? Does agriculture pay any attention to assimilation efficiency? Fig 1-7