WILD 3580 1st Edition Lecture 17 Outline of Last Lecture I Breathing and Respiration II Chemoreception III Amphibian Orders Outline of Current Lecture I Frog calls II Reproduction III Parental Investment Current Lecture I Frog calls Make anurans expend a large amount of energy for calls o Most energetic amount increases with the rate of production o Lose weight and heart rate increases when producing calls o Reproduction success is relevant to the rate of production payoff Types of Calls o Advertisement call mating for advertise reproductive state sex and location of an individual species specific both sexes are toned in for these calls attracts females and warns other males to establish territorial boundaries many species use the same area breeding site is species specific commonly pool dry seasonally no fish evolve divergent sounds characteristics prevent sounds from getting swamped and acts as a premate isolation mechanism differ in pitch timber pulse frequencies durations and cadence volumes These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III Typical breeding sequence males gather at breeding site and begin a chorus calling group attracting other males first and then females Females may go to a male directly to mate or they can choose a specific male o Courtship calls Becomes softer when female approaches Encourages females and cannot be heard by other males o Release call Non receptive females Males jump on non calling frog mistaking species and sex Similar species make similar release calls interspecific communication o Alarm distress call When a frog is threatened injured or attacked Loud and high pitch to surprise the predator Make the predator hesitate so it can run away Reproduction External to most frogs and toads Mate Selection 1 Call quality health status 2 Size females prefer larger males 3 Quality of territory for the survival of offspring 4 Nest site better nest ensures better survival males clasp females with front legs Amplexus o brings cloaca openings into close proximity o ensures better fertility inguinal amplexus crapsed in the pelvic region amxillaryamplexus pectoral region o continues until females release eggs almost all anurans are oviparous o fertilized eggs are in large masses or streams o some are laid on leaves over the water so when the young hatch they will fall in o some are in the water close to plants 5 to 6 species are viviparous Parental investment Amount of energy a parents spends to make sure their offspring survive to maturity o Natural selection favors reproductive strategies that maximize the survival of offspring but reduce parental investment o Maximize fitness over an individual Strategies vary based on species 1 Large number of eggs hedging their bets a Taking chance that some of the young will reach maturity b Energy is used upfront c Parental energy in producing the eggs o Ex True frogs and toads lay up to 10 000 eggs o Female uses half of her energy to produce eggs energy built over a year period 2 Produces few large eggs a Egg production invests a lot of energy b Parents provide no protection c Larger tadpoles have a higher chance of survival o Lays 10 large egg that keeps them moist o Ex Microdye members 3 Construct a nest a Parental energy is put into eggs and nest preparation b Smaller number of eggs c Young are concealed to have a better chance of survival o Eggs are deposited in the nest foam keeps eggs moist and conceals them from predators 4 Egg attendance a Parents carry or protect eggs young b Parent investment occurs after eggs are laid c Actively protected and therefore have a greater chance of survival o Ex Poison dart frogs o Male or female stays with the eggs and attacks any intruder 5 A combination of all strategies o Several species carry the egg with them o Gastric brooding females guard eggs swallowing the tadpoles carrying them in her stomach until they metamorphose o Darwin s frogs carry eggs in the vocal sacs o Surinam toads carry eggs in specialized pore on the back
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