herpetology final

Communication by Tuatara

• Nocturnal, but have some visual dsplays [head bobbing and shaking, color change, open mouth, raise dorsal crest, inflate body and throat]

• prob use chemical signals

Communication by iguanian lizard [anoles, fence lizard, chameleon]

• Territorial, sit on perches; spontaneous [not necessarily toward a receiver]

• Visual display: head bobs to four-legged push ups [advertisement and assertion displays]

• Aggressive displays; similar to territorial displays and include dewlap extension, raising crest, moving tail and limbs, body inflation and/or compression, head/throat inflation, and change color

• Color and display behavior

-Brightness of color dependent on healthy of individual [ more important in male-male interaction, female does not choose mate by color]

-Brightness of female color indicates loss of mating potential and is associated with aggressive behavior toward males

• Chemical communication; many species have femoral glands on hind legs; rub on surface of territory; variation within species [sex, individual identity, and kinship

Communication by Scleroglassen lizards [skinks, monitors, racerunners, geckos]

• Visual communication, intensity of color associated with male-male interaction

• Chemical communication; Chemical signals detected by vomeronasal system [tongue flicking and touching] and taste buds

• Acoustic communication; Used by nocturnal geckos [only lizards to have vocal cords]; Male call to advertise territory and attract mate [can have aggressive call too]

Communications by snakes

• Chemosensory information extremely important to snakes; tongue and vomeronasal [jacobson] organ work together; some tactile signals; very few visual signals; no auditory signals

• Male detects and pursues female via pheromones [long-lived] produced in skin; Forked tongue provides a means of direction

• When female is located, male tongue flicks female and then proceeds with tactile signals [varies with species]

• Intraspecific males recognize one another and often battle [try to pin each other down] when female is present

Communications with turtles

• Primarily tactile, known best for courtship [males with long forelimb nails display and stroke] and aggressive interaction; most likely signaled by chemical cues

• Painted turtles [chrysemys] and sliders [ Trachemys] approach females from the front; red-bellied cooter [pseudemys] approach female from above

• Tortoises use visual, tactile, chemical, and acoustic signals; males most likely attracted to females via chemicals, sometimes movement

• Male tortoises communicated with head movements [appear to be species specific] and subdentary glands [attract females and indicated dominance]

-flip each other and bute to assert dominance

-males of some speices use visual, chemical, and/or tactile signals to mimic females [fool the competition]

Communication by crocodiles

• Wide variety of vocal communications; displays combine acoustic, visual and tactile signals

• Advertisement displays by males and females [ownership of territory or attract mate; male bellowing and head slapping]

• Aggressive displays [male-male encounters; visual [raising head and tail, clapping jaws], chasing, lunging, and biting]

• Courtship displays [male-female interactions; female places chin on males head or snout] or stroke back

• Signals between eggs prior to birth [ synchronous hatchlings] females attracted to call, will dig out juveniles from nest, distress call evoke protective response

Communication can meet environmental interference [noise]

• Auditory [wind,rain, waterfalls, sounds of other animals]; can be beat with call repetition

• Visual [ stand out against background’ move body part (jerky); jump; change postiion]

Communication by salamanders

• Chemical, visual and tactile signals used; most occur at close range [near-sighted]; not well known

• Plethodontids: some signal aggression by elevating or submission by flattening their bodies; most use chemical communication

• Tapping snouts to ground enhance nasolabial groove ability to detect chemical signals; liquids transferred to vomeronasal organ

• Chemical senses detect food, territory, and potential mates; pheromones produced from glands of head and cloacal region

• Females uses chemical cues of male fecal pellets to assess quality of food sources; Chemical signals used for species and sex recognition

• Chemical cues complemented by visual and tactile signals [primarily courtship]

• Male pheromones increase female receptively [some males bite and “inject” pheromones into female; reduced courtship time and vilnerability

Communication by anura

• Larvae have well-developed chemical signals that allow them to determine kin and predators

• Some adults communicate chemically [pheromones]; new zealand species [leiopelma]use fecal pellets; much to be learned

• Visual: change color, posture, inflate, throat, and move fore and hind limbs; may be used interspecifically and intraspecifically

• Acoustic: Very important to most frogs; vocal muscles contain energy stores [high energetic cost to call]; increased size of vocal sac leads to louder calls

-Variety of call dependent on behavior; advertisement [attract mate and demonstrate ownership] is species specific [frequency, repetition, and loudness detected]

-Calls most often received via tympanium

-Defense and aggression [differe from advertisment calls by duration and pulse reptition rate]

-Courtship calls [close-range interactions]; release calls [given by males and females]; defensive calls [toward a potential predator]

-Some females have response call toward males [and males usually change their advertisement call for females]

Tactile signal

• Involve touching or surface waves and vibrations; short-range yet can be complex [timing and intensity]

-Constraints: small animal size limits distance signal can travel; high frequency sounds absorbed by environment; temp effects signal production; energy costs; signaling may attract predators

Classification of signals

1. Advertising [males advertise ownership of territory and/or to attract mate]

2. Courtship [ close range male/female interactions

3. Aggression [typically between individuals of the same sex]

Acoustic signals

• Travel far, direction of signal is generally easy to locate, can be detected at night, and cab be changed [ intensity, frequency, or timing]

What are the modes of communication

• acoustic, visual, chemical and tactile

• dependent on sensory capability of the species and its environment

Visual Signals

• Most effective at short distances, can be obstructed by environments barriers, and are dependent on light; complex messages involving color, movement and posture

Chemical signals [pheromones]

• Effective day or night, efficiency dependency on environment; cannot be modified; offer simple messages

-Males often have femoral pores on hind-limbs [leave trails]

• Can last a long time

Meanings of a signal

• Approach, retreat, attack, or defend, courtship

What can a signaler advertise

• identity [species], sex, physical location, size, reproductive state, territorial status, and individual identity

What is biogeography

• Science that attempts to document and understand spatial patterns of biological diversity; direct communication with earths history

Biogeographical data

1. Organisms-distibution, species, ecology, demographic propertied [population structure, dispersal abilities]

2. Earth history- Past continental movements and additional geological events [origiin if mountain ranges or islands, climate change dispersal opportunites, rounge fragmentation

Ecological Biogeography

• Ecological factors influencing the distrubution of species

Historical Biogeography

• Relationship of diversity and distribution of species, and the physical history of Earth

Island Biogeography

• Extinction, dispersal, and geography assoc. with patterns of biodiversity of islands

What is the goal of biogeography

• To understand causative agents affecting distributions of species [historical/recent, local/continental]

Importance of biogeography

• Identifies areas of potentially high biodiversity and understanding of environmental alterations; Range fragmentation; extinction; global climate change [prediction and conservation tool]

• Helps explain endemism [distribution restriction] and disjunct distribution

Disjunct distribution mechanisms

1. Dispersal- organisms have migrated across pre-existing barriers to create their present distribution

2. Vicariance- Formation of barriers to fragment ancestral ranges that were once continually distributed organisms

What do phylogenetic relationships tell us

• Branching pattern and relative timing of speciation events in a lineage [associate with earths history: Area cladogram][