Herp exam 2 Flashcards
1
Q
Osmoregulatory challenges
A
organism must maintain control of water an salt balance since few environments are isotonic with the fluids of an organism
2
Q
Homeostasis
A
maintaining stable internal conditions in a challenging environment
3
Q
Osmoregulation
A
the control of water and salt balance
4
Q
Structures involved in osmoregulation
A
skin, gills, digestive tract, cloaca, kidneys, bladder
5
Q
isotonic
A
no net gain or loss of water
6
Q
Marine osmoregulation
A
an organism is hyposmotic with the environment, meaning there is a higher ion concentration externally and lower concentration internally
7
Q
Hyposmotic characteristics
A
prone to dehydration, prone to ion gain
8
Q
How hyposmotic creatures regulate, avoid dehydrarion
A
decreasing skin permeability, decreasing urine output, expelling salt through glands
9
Q
Freshwater osmoregulation
A
an organism is hyperosmotic relative to the environment, meaning ion concentration is higher internally than externally
10
Q
hyperosmotic characteristics
A
prone to water gain, ion loss
11
Q
How hyperosmotic creatures regulate
A
decrease skin permeability, increase urine output
12
Q
Terrestrial osmoregulation
A
evaporative water loss
13
Q
evaporative water loss
A
water loss by evaporation, increased ion concentration
14
Q
amphibians and reptiles consist of
A
70-80% water
15
Q
Amphibian osmoregulation (water gain and loss)
A
skin is highly water permeable
cutaneous respiration, skin must be moist
evaporative water loss is major concern
Gain water through: food, integument, metabolism
Lose water through: excretion, feces, urine, integument, respiration
16
Q
Amphibian morphological osmoregulatory features
A
smooth and granular skin, granular skin enhances water absorption through increased capillary action
pelvic patch- highly vascular patch of skin that absorbs water near cloaca (toads rely)
secretions from lipid glands waterproof frogs
17
Q
Amphibian behavioral osmoregulatory features
A
daily and seasonal activity adjustments minimize water loss temporal adjustments different postures that keep/lose water burrowing/microhabitats impermeable cocoon to keep water in
18
Q
Reptile osmoregulation (water gain and loss)
A
skin is largely impermeable to water
drinking is important
gain water through: drinking, food, metabolism
lose water through: excretion, feces, urine, salt glands, respiration
19
Q
Reptile morphological osmoregulatory features
A
bodies collect + hold water (bladder, lymph sacs, stomach)
capillary action
condensation
20
Q
Reptile behavioral osmoregulatory features
A
seasonal/ daily activity adjustments temporal adjustments aestivation nocturnal aggregation
21
Q
Nitrogen Excretion
A
prolonged dehydration leads to accumulation of nitrogenous waste, can be lethal
22
Q
Nitrogenous waste
A
urea, ammonia, uric acid
23
Q
ammonotelic
A
excrete ammonium
ammonia highly toxic
diffuses across skin/gills
24
Q
ureotelic
A
excrete urea
less toxic
25
uricotelic
excrete uric acid
less toxic
requires little water to excrete
26
Thermoregulation
heat gain and loss, keep body temp within boundaries to increase performance in a challenging environment
requires balance of heat budget over time so that rate of heat gain + rate of heat loss
27
ectotherm
absorbs heat from outside environment (amphibians and reptiles)
28
endotherm
internally heats
29
Global temp
temp determine where herps distribute
30
local temp
temp determines spatial and temporal patterns of herp activity
31
Performance
biochemical and physical properties are sensitive to temp changes
so, changes in body temp affect an individuals behavior and performance
32
sun
ultimate source of heat for amphibians and reptiles
33
4 forces of termoregulation
radiation: transfer of heat between objects NOT in direct contact
Conduction: transfer of heat between objects that ARE in direct contact
Convection: transfer of heat by moving air or water over an object
Evaporation: loss of heat occurs when a liquid turns to gas
All of these vary depending on the individual and depending on the situation
34
Activity temp range
the normal range of temp in which activity occurs voluntarily
35
voluntary min and max
extremes of how much water gain/ loss an individual can take without being out of balance
36
mean body temp
average body temp over the course of daily activity
| varies with species/ family
37
critical thermal min
the low temperature that produces cold narcosis, thus
| preventing locomotion and escape
38
critical thermal max
the high temperature at which locomotion becomes
| uncoordinated, thus preventing escape
39
hypothalamus
a region of the brain that controls temperature regulation
40
behaviors that influence thermoregulation
```
microhabitat selection
temporal adjustments
posture adjustment
burrowing
aggregation
```
41
morphgologies that influence thermoregulation
integument: skin color mods
albedo: proportion of light that is reflected
dark colors: absorb light
light colors: reflect light
42
Physiological shit that influences thermoreg
```
evaporative cooling:
water loss from skin
panting
respiratory water loss
salivation
urination
```
Heat production:
shivering, increased metabolism
43
Dormancy
inactivity when conditions are severe, driven by climate changes
44
Hibernation
avoidance of freezing conditions
45
aestivation
avoidance of extreme heat/ dryness
46
Hibernacula
refuge for hibernating individuals
temp higher inside than outside
ex: fish hibernate on the bottom of waterbody, 4 degrees: increases risk of predation
extrapulmonary respiration
ex: terrestrial organisms hibernate below frost line
47
freezing tolerance
antifreeze in blood keeps organs from freezing
| frogs, turtles, squamates
48
Aestivation
amphibians in arid climates
vulnerable to evaporation
burrowing
water-impermeable cocoon
49
local distributions
clumped pops because of environmental heterogeneity (variable environments)
Physiological requirements of individuals and physical characteristics of their habitat
shape the distribution of individuals across the landscape
50
biotic factors that affect local distributions
predator density
prey density
mate choice
competitiors
51
abiotic factors that affect local distributions
resource availability
refuge/nesting
environment quality
microclimatic conditions
52
home range
the broader area within which
an individual in a population moves
foraging/social behaviors
determined by: food, shelter, mates, thermoregulation sites, escape routes
size changes within and between species, and with sex, body size, density of conspecifics, seasons, microhabitats
measured w polygons for area, density, and overlap
53
territory
the portion of a home range
that is actively defended against conspecifics
```
benefits to territoriality:
access to resources
access to shelter
access to mates
favorable environment
```
```
Costs to territoriality:
expenditure of energy
expenditure of time
risk of injury
risk of predation
```
54
fitness is measured by
reproductive sucess
55
movement of herps within home range
```
most move relatively little
move for survival/ reproduction
acquiring food/ mates
avoiding predators
avoiding env extremes
```
56
movement of herps ourside homerange
breeding
chance of finding more food/water
overwintering
57
environmental factors that influence movement
```
daily temp
seasonal temp
humidity
habitat type/quality
catastrophic events
```
58
population factors that influence movement
```
density
sex ratio
size structure
age structure
disease
```
59
individual factors that influence movement
```
sex
body size
age
physical condition
reproductive state
```
60
types of movement
migration and dispersal
61
migrations
```
for breeding, overwintering, or habitat changes
directional
take individuals out of home range
beginning and endpoints
energy allocated for this
```
62
dispersal
unidirectional movement to places unknown to the individual
habitat instability
inbreeding
intraspecific competition
benefits: chance of finding better resources, increased likelihood of outbreeding, reduced local competition
costs: increased predation risk, difficulty finding food/ shelter, increased aggression from
unfamiliar conspecifics
63
homing
the ability of displaced individuals to return to their original location (orientation required)
• Breeding sites
• Overwintering sites
64
ways of orientation
* Landmarks
* x-y orientation
* Polarized light
* Chemical cues
* Magnetic orientation
65
communication
– the cooperative transfer of information from a signaler
to a receiver. This transfer is often very species-specific. involves cues
Visual, auditory, tactile, chemical
most effective during breeding season
66
social interaction
interactions between one or more conspecifics
| These interactions ultimately influence an individual’s fitness
67
visual comms
```
Often involves body movement
• Limb movements
• Head bobs
• Rapid shuttling movements
• Open-mouth threats
flashing bodyparts
sexually dimorphic species
lizards
```
68
acoustic comms
rubbing boduparts
slapping body on surface
vocalization
anurans
69
chemical comms
```
odors from glandular secretions
volatile odors (nasal)
surface adherent odors (vomeronasal)
salamanders, skinks, snakes
```
70
tactile comms
Involves one individual rubbing, pressing, or hitting a body part
against another individual
Tactile communication often occurs after visual, acoustic, or
chemical contact has been established
turtles, snakes
71
Caecillians communication
* Communication is chemical
* specialized chemosensory organ (the tentacle)
* Tentacle connects with Jacobson’s organ (a vomeronasal receptor)
* suits their fossorial lifestyle
* Tactile occurs during courtship
72
Salamander comms
Chemical signals are the primary
• Many have elaborate courtship behaviors
• Courtship glands produce pheromones (mental gland, genial gland, caudal gland)
• Pheromones identify sex and reproductive status of conspecifics
• Pheromones also stimulate courtship behavior in receptive females
• During courtship, visual and tactile cues are also important
73
frog comms
acoustic
vocal sacs, size and shape vary
increase frog call rate
only male frog have vocal sac
Courtship call: used to attract a gravid, conspecific female
Territorial call: used to defend a territory in response to the
vocalization of another nearby male
Encounter call: used to defend a territory in response to the
approach of another male
acoustic space competition: call synchronization and alternation
vocal plasticity
74
frog comms cont
communicate through a combination of visual and vocal cues
hand waving, foot raising and lowering, and leg stretching
can be raised and lowered (push ups) or inflated
color change
species that rely on visual signals are diurnal or live near noisy streams
Tactile and chemical signaling not widely used
75
turtle comms
Turtles use combinations of visual, tactile, and chemical signals to communicate
head bobs or displays of colorful patches on forelimbs or neck
head butting and bumping or scratching shells during courtship
Rathke’s glands on the bridge of the shell produce aromatic chemicals (vomeronasal receptor)
Other turtles have mental glands or rely on cloacal secretions (pheromones)
76
croc comms
Crocodylians use combinations of visual and auditory signals to communicate
bellowing and slapping sounds
77
tuatara comms
Visual cues are the primary means of communication among tuataras
Females signal with head nods when approached by a male
the male continues to approach with a slow, ostentatious walk
have a vomeronasal organ
78
lizard comms
Lizards use combinations of visual, auditory, chemical, and tactile
variation among clades
• Gekkota → nocturnal: auditory and visual signals; diurnal: visual signals
• Iguania → visual signals
• Anguimorpha → chemical signals
• Scincimorpha → chemical signals
79
lizard comms cont
visual: Coloration of dewlaps, heads, and patches, Variation in size, color, and pattern is species-specific, Body movement.
80
snakes comms
chemical signals (vomeronasal receptors)
• Pheromones are produced in glands on the dorsal surface
• Tactile cues are important during courtship –
three distinct phases:
• Tactile chase
• Tactile alignment
• Intromission and coitus
81
OSR
operational sex ratio: ratio of males to fertilizable females
if one sex is limited, the other competes
determines intensity of sexual selection
sexual dimorphism
82
monogamy
having only one mate at a time
83
poilygamy
having many mates at a time
84
polygyny
make has many female mates
85
polyandry
female has many male mates
86
mating success and fecundity affect
a pops mating system
ex: monogamy expected when male nor female gains anything from having multiple partners
amphibians: most polygamous
reptiles: most polygynous
