Herpetology Final Exam 2

1) Advertisement signals

-long-range (advertise territory, females)

2) Courtship signals

-short range (used during close-up sexual interactions)

3) Aggressive signals

-common (used during contests)

4) Contact signals

-less common (used to keep in touch with other individuals in a group)

They are usually candid indicators of a good immune system

They evolved because they stand out well from random, ambient background noise (both audio and visual)

1) Body size (small animals produce higher-pitched noises)

2) Body temperature (relates to the energy available to be expended on signaling)

3) Predation (calling makes the herp conspicuous)

4) Acoustic/visual/ambient noise

1) In addition to being heard in the air, vibrations travel through the ground to be picked up by other frogs. Therefore, it exploits a relatively noiseless medium of communication

2) frog is protected from predators

Chemical communication. They'll deposit chemical signals in feces to mark territory. Also, the male has a gland at the base of the tail that attracts the female.

1) Nasolabial groove: takes up scents (pheromones and regular smells) from environment.

2) main olfactory epithelium: deals with the sense of smell (from the environment).

3) Vomeronasal organ: deals with pheromones.

Pheromone-secreting glands on the chin. The male will boop the snoot of the female with his chin to deposit pheromones as a part of the mating dance.

1) They arch their backs and raise their tails to signal agitation.

2) Some males develop elaborate crests during the breeding season.

1) They force air into the lungs (positive-pressure ventilation)

2) contract thorax muscles to push air out of glottis.

3) Air goes into vocal sacs.

1) Middle ear cavity through the tympanic membrane.

2) Ambient vibrations travel up the lungs, through the mouth and through the Eustachian tube to the middle ear.

1) Amphibian papilla=low frequency

2) Basilar papilla = high frequency noises

TRUE

1) brightly colored throat sacs in males

2) males might turn a vivid color overall

1) prevents predation

2) might also be a part of mate selection: Among the same species, females prefer colors that mimic those of their same population.

In stream-dwelling frogs

1) nuptual pad glands (found in males)

2) femoral glands (found in males)

Male touches and strokes female on the head with his front feet.

1) Epiplastral ramming: male tortoise rams the back of female's shell with the front part of his plastron to signal courtship. (works well because males have a wider plastron that juts forward compared to females')

2) Xiphiplastral ramming: Male bops the female's shell with the middle of his plastron during mating.

Male bobs head up and down and side-to-side

Chemical glands found under the chin of male tortoises. The Male wipes secretions from this gland on his foreleg scales.

Crocadylians

It's both an acoustic and visual display (because of the posture). Gator arches neck and tail and bellows underwater.

-Chinese gators have shorter bellows.

To advertise their aggression/annoyance.

Males and female rub their heads and snouts together.

TRUE

Perhaps to synchronize hatching?

TRUE

1) the olfactory system

2) Taste buds (lost in some lineages)

3) Vomeronasal system (used for pheromonal communication)

1) advertisement of ownership of a territory and to attract females

2) aggressive interactions with other males

FALSE: They use nano-crystals to structurally reflect light. Color produced depends on the interaction of the xanthophores in the skin and the spacing between the crystals, which can be changed.

yellow light from the xanthophore pigment PLUS the blue light reflected off the nano-crystals (underneath the xanthophores) at their "at-rest" spacing causes the green color.

1) blue

2) yellow

3) longer wavelengths are reflected (so blue-->green-->yellow-->orange-->red)

TRUE

Used for chemical communication. Lizard wipes secretion on substrate.

Tongue picks up particles from the environment and brings them into the mouth. The particles from the tongue diffuse via mucous into the openings of the vomeronasal organ.

methyl ketones

In males, they are used for clasping during courtship

Geckos (notably, barking geckos and tokay geckos).

Mechanism: they alter the shape of the opening of the epiglottis and they stress/relax vocal chords to alter vibrations.

A kind of natural selection that comes not from the environment, but from one sex on another sex.

Females can drive sexual selection in 2 ways:

1) directly, by selecting for specific male traits

2) indirectly, by driving male competition.

Females:

1) large "expensive" gametes

2) more investment in reproduction

3) choose the best mate

4) limited by fecundity

Males:

1) small "cheap" gametes

2) less investment in reproduction

3) choose the most mates

4) limited by number of mates

Competition in which all the males are competing for females (the latter of which are all gathered in the same place). Males all scramble to locate females as quickly as possible, they invest little time in mating with each female and they attempt to mate with as many females as possible.

-Mostly found in Amphibians, especially frogs

-Found when the breeding season is short and females are all gathered in one place

It's literally when males have to search for mates.

Found mostly in solitary reptiles, where the breeding season is long and the potential mates are more widely dispersed.

TRUE

amplexus

Males and females pair bond BEFORE the start of the breeding season; the male will mate guard before the start of the breeding season and during the breeding season.

Also, the same males and females will pair bond for multiple years.

1) When females are in groups, males can continue courtship displays and chasing off other males.

2) Resource defense: a male might guard a resource (food, shelter, nesting site, etc. ) to attract females.

1) Chorus: mostly found in frogs; involves groups of males all singing at the same time.

2) Lek: a group of males all visually displaying at the same time to attract females to that area. (ex: found in crested newts, iguanas, crocadylians to some extent)

They are mobile and can sneak around and mate without the dominant males' knowledge.

They both defend areas that provide good coverage.

Females look at male's poop to see what food is available in his territory when making a mate selection.

1) offspring develop faster

2) less egg predation occurs