Shedding & Molting

Jacobson Organs – Smell & Flehming

6th Sense Pit Vipers

Circulatory System Reptile: 3 chambered heart - 2 atria & one ventricle with partial septum - oxygenated blood has limited mixing with deoxygenated Crocodilians have 4 chambers Birds: 4 chambered heart

Excretory System Ammonia 1. Most ammonia in the body forms when protein is broken down by bacteria in the intestines. The liver normally converts ammonia into urea, which is then eliminated in urine. 2. Birds & reptiles both excrete uric acid crystals (white pasty stuff) not urea. 3. What is the advantage of secreting uric acid Vs. urea? Ammonia

Evolution of the Brain

Hearing Reptiles – have only an inner ear bone that picks up low frequencies from ground vibrations Birds – owls hunting / most birds hear best at frequencies they or their predators produce

Behavior Is it bad to touch young birds because of your scent? What makes dark meat dark and white meat white? Altricial Vs Precocial Dusting and Anting Mobbing

Reproductive Systems Most reproduce sexually though some can produce asexually - Parthenogenesis is a form of asexual reproduction in which females produce eggs that develop without fertilization. All reptiles reproduction is either: Viviparous - live birth Oviparous - external egg laying - leathery covering Ovoviviporous - develop eggs that remain internal until they hatch or are about to hatch Rattlesnake Hemipene

Avian Reproduction Only 3% of all avian species possess a phallus The length and degree of elaboration of the penis in waterfowl is positively correlated with the frequency of forced extra-pair copulation Females Co-Evolution Dead end sacs Clockwise vaginal coils as opposed to the some males with counter-clockwise coils

Better Shot Argentine Lake Duck

Eggs Shell - protective covering made of calcium carbonate. The shell is porous. (There are about 7,000 pores in a chicken eggshell.) This allows the transfer of gases through the shell. 2. Two membranes - outer and inner shell membranes protect the contents of the shell and prevent moisture from leaving the egg. 3. Because the body temperature of a hen is approximately 106° F, eggs are very warm at the time they are laid. As cooling takes place, the contents of the egg contract more than does the shell of the egg. As a result, an air cell forms at the large end of the egg. 4. Albumen provides cushion and a liquid medium in which the embryo develops, and it also contains a large amount of the protein necessary for proper development. 5. The chalazae hold the yolk in the center of the egg. 6. The yolk is the source of food for the embryo and contains all the fat in the egg. 7. The small white spot on the yolk is call the germinal disc. The germinal disc is where the female's genetic material is found.