Exam Flashcards
What is ethology?
the scientific and objective study of animal behaviour
What is ethology interested in?
The behavioural process, not animal groups
What are fixed action patterns?
Instinctive responses that would occur reliably in the presence of identifiable stimuli
What is an ethogram?
Precise descriptions of different behaviours
What are ethograms used for?
Creating time budgets, interpreting behaviour
What are Occam’s Razor and Morgan’s Canon?
If there are competing reasons as to why something occurs, we take the explanation that makes the least assumptions
Interpret behaviour using simplest mechanisms
What are the disadvantages to observing animal behaviour?
Observer effect
Observer bias
Anthropomorphic error
What are behavioural bouts?
Continuous balance of energy usage and movement
What is an accelerometer?
It records the movement of animals throughout the day using forces.
What is GPS technology used for?
Records animal’s location over time.
It can examine areas used, distances travelled, habitat choices, movement patterns, patch residency times
What is a home range?
An area utilized by an animal in its natural activities
What are 4 techniques used to estimate home range?
Minimum convex polygon
Kernel density
Local Convex Hull
Brownian Bridge
What is a core area?
A heavily used portion of a home range
What 5 qualities influence home range size?
Trophic status Mode of locomotion Suitable habitat Body size Density
Why do larger mammals have larger home ranges than predicted based on their metabolic needs?
They don’t traverse the whole home range frequently
They share home range with others
They need more area to make up for their metabolic needs
What is a society?
A group of conspecifics organized in a cooperative manner (beyond sexual and parental behaviour)
What are the costs to being social?
Intensified competition
Increased disease/parasite transmission
Increased conspicuousness to predators
Increased chance of misdirected parental care and killing of young by non-parents
What are the 3 forms of communication
Visual
Olfaction
Vocalization
What is a territory?
An area defended by overt aggression or advertisement
What are the costs of having a territory?
Time and energy spent to maintain it
Decreased survival
What are the benefits to having a territory?
Economic dependability
Constant access to resources
What 3 factors affect territory size?
Cost-benefit
Distribution or quality of resources
Number of competitors
What is dominance?
Control of behaviour of subordinate
What are the advantages of being in a group?
Vigilance
Dilution of risk
Kin selection
Hunting success
What is inclusive fitness?
Reproductive success includes own offspring plus offspring of relatives
Why should aggression be constrained?
Because if the loser were to be killed, fighting would have grave consequences for the species
What is Evolutionary Game Theory?
The application of game theory to evolving populations in biology.
Outcomes depend on the value of the resources and the cost due to injury
What is the Evolutionary Stable Strategy?
A strategy where, once adopted by most members of a population, no mutant alternative strategy can do better
What is anisogamy?
The difference in gamete size.
Males have many small, cheap sperm
Females have few large, expensive eggs
What is parental investment
Behaviour that increases offspring’s chances of survival at expense of parent’s ability to rear offspring in the future
What are 3 factors that affect the confidence of parentage?
Internal fertilization
Reproductive success of females based on quality of offspring
Reproductive success of males based on number of offspring
What is Bateman gradient?
The correlation between mating success and reproductive success
What is reproductive skew?
Breeding is monopolized by a subset on individuals
What is an operational sex ratio?
Ratio among reproductively active members of the population
*important for management
What mechanisms adjust sex ratio?
Timing of insemination - more of one sex is conceived earlier and the other later in the estrous cycle
Level of sex hormones at conception
Intrauterine mortality rates - males have a higher IU mortality rate
What is sexual selection?
A process that produces anatomical or behavioural traits that affect an individual’s ability to acquire mates
What are the two types of sexual selection?
Intersexual selection
Intrasexual selection
What are the 3 types of intersexual selection?
Runaway selection - selection of arbitrary traits has cost to survival
Indicator models - traits sexually selected for represent male fitness
Fluctuation asymmetry - random deviations from bilateral symmetry in paired traits
What are the 2 types of indicator models?
Handicap hypothesis - males are able to bear the cost of producing the traits due to good condition
Truth in advertising - trait must be linked to overall fitness
What causes fluctuating asymmetry?
Low food quality and quantity Habitat disturbance Pollution Disease Genetic factors
Besides fighting, what are 2 examples of intrasexual selection?
Sperm competition
Post-conception competition
What are the 2 types of sperm competition?
First-male advantage - mate guarding, copulatory plugs
Second-male advantage - dilution of first male’s sperm
What are the 2 types of post-conception competition?
Bruce effect - in the presence of a new male, female aborts and becomes receptive
Infanticide
How do harem sizes relate to degree of sexual dimorphism?
Sexual selection is more intense when the degree of sexual dimorphism is larger
What are the differences between males and females when it comes to parental investment?
Eggs require more investment, so maternal costs rise quicker than paternal
Optimum offspring number is lower for females, so choice of male is important
What degree of parental care is found in stable environments vs unstable environments?
K-selected-type species, iteroparity, stable home ranges leads to high parental care
r-selected-type species, semelparity leads to either lots of care or little care
What are the 5 mating systems?
Monogamy (9%) Polygamy Polyandry Polygyny Promiscuity
What 3 factors determine mating system?
Group size
Resource distribution
Predation pressure
What are the 2 benefits to being monogamous?
Shared offspring care with mate
Reduced time needed to find mates each season
What are the two types of monogamy?
Faculative - when there’s no other females available
Obligate - when female needs a partner to care for young
What are the 4 types of polygyny?
Resource defence polygyny - females choose territory rather than the male. Male owns the territory
Female defence polygyny - females are in social groups for reasons other than reproduction. Males defend the harems.
Male dominance polygyny - males defend small territories for display purposes (leks).
Scramble polygyny - females are widely spaced and males are highly mobile
When does polyandry occur?
When food availability is low at breeding
When there’s high predation and low offspring survival
What is a domesticated species?
A species that is “bred in captivity for purposes of economic profit to a human community that maintains total control over its breeding, organization of territory and food supply”
Why do we domesticate animals?
Companionship - hunting, predator defense, transportation, war
Predictable and mobile food sources
What are the 5 stages of domestication?
Loose contacts between humans and wild species, no control over reproduction
Individual free-ranging animals confined in and around human settlements, breeding occurring in captivity
Breeding of confined individuals becomes selective with occasional cross-breeding with wild individuals to obtain desired traits
Economic considerations leads to selectivity of various desirable properties, resulting in specific breeds
Wild ancestors of domesticated species are persecuted or exterminated to reduce competition for shared resources. Most ancestral species are now extinct.
What are the 5 characteristics of domesticatees?
Adaptable Highly social Dual resource of products and food Easily bred in captivity Closely herded and not prone to leaving
How long ago were dogs domesticated?
15,000-32,000 years ago
What was the first domesticated livestock, and how long ago were they domesticated?
Sheep and goat
10,000- 15,000 years ago.
What livestock is the most numerous and most economically important and how long ago was it domesticated?
Cattle,
10,000 years ago
What are the 5 morphological and behavioural traits of domestication?
Reduction in size
Skulls are shorter and dentition is reduced
Reduction in cranial capacity
Greater variation in genetic-based coat colours and patterns
Earlier puberty and larger litter sizes
What are the two steps to exploiting humans?
Self-domestication - less aggressive individuals exploit resources from humans
Human-mediated domestication - occurs when humans associate with less aggressive animals
What is a hypothesis, prediction and experiment?
Proposed explanation of an observed phenomenon.
Statement that is expected to be true if the hypothesis is supported and can be tested.
An attempt to show how the hypothesis is false by testing predictions.
What are the 3 types of experiments?
Natural observations (mensurative) - high generality, high realism, little control
Field experiment - manipulate one or more variables, natural observations as a control
Lab experiments - high control, accurate measurement, easy to manipulate variables
What percent of living creatures are mammals?
4%
Are smaller mammals more at risk or are larger mammals more at risk?
Larger mammals
Why are mammals important to us?
Economically significant
Predictors of disease
Predictors of global change
Basis of biological understanding and evolutionary understanding
What are the 3 scenarios of bat evolution?
Echolocation first
Flight first
Tandem evolution
What species have been growing the most in recent years?
Primates, especially neotropical species
What are 3 of the newest species?
Lesula
Saola
Beaked whale species
What is invasiness?
The degree of discomfort, stress or pain experience by the study animal
What are the 5 categories of invasiness?
Experiments on most invertebrates or on live isolates
Experiments which cause little or no discomfort or stress
Experiments which cause minor stress or pain of short duration
Experiments which cause moderate to severe distress or discomfort
Procedures which cause severe pain near, at, or above the pain tolerance threshold of unanesthetized conscious animals
What are the 3Rs in animal care?
Replacement
Reduction
Refinement
What are the 5 methods of monitoring?
Record of occurrence Tracking Fecal sampling Hair sampling Camera traps
How do you estimate abundance?
Use animal occurrences
What are the assumptions and limitations to estimating abundance?
Births and deaths must be accounted for or ignored, and all members of a population have an equal chance of being caught
Abundance is always relative, not absolute counts, high precision but low potential accuracy
How do you estimate population size?
Direct observation and counting of individuals
What are the 4 types of surveys?
Stratification - area is divided into homogeneous blocks (requires previous knowledge of distribution)
Strip - area adjacent to a transcet within which all individuals are counted
Spacing - distance between sampling trajectories
Lines - transects from which the number of individuals and their distance from the line are recorded
What are features of observational methods?
Observability
Variability
Behavioural states
Events
What are the 5 types of observational sampling?
Focal sampling - continuous
Scan sampling - predetermined time intervals
Instantaneous sampling - sequentially recording behaviour at the end of each observation interval
All occurrences sampling - all occurrences of a particular event
Ad libitum sampling - all states or events of all organisms in a group
What are the 3 ways to lay down traps?
Transcets
Grids
Opportunistic
What are the 3 types of drugs?
Analgesics
Anesthetics
Immoblizers
What are the 4 stages of chemical immobilization?
Injection
Induction
Immobilization/anesthesia
Recovery
What are risks of capturing animals?
Physical injury Hyperthermia/hypothermia Respiratory and cardiac stress Convulsions or seizures Capture myopathy
What are 2 reasons for doing lethal captures?
Samples that cannot be taken from live animals
Removals
What are 9 types of field methods?
Nutritional condition Reproductive status Body measurements Monitoring Marking Capture Observations Surveys Abundance estimations
What are the 6 types of lab methods?
Body measurements Reproductive status Nutritional condition Metabolism Stable isotope analysis Genetic and molecular analysis
What are the 2 subclasses of mammalia?
Prototheria
Theria
What is the order of prototheria, metetheria and eutheria?
Monotremes
Marsupials
Placentals
What are the infraclasses of theria?
Metatheria
Eutheria
What are the 11 non-skeletal characteristics of mammals?
Hair/fur Sebaceous and sweat glands Mammary glands Muscular diaphragm Endothermy, high metabolic rate Complete double circulation of blood 4 Chambered heart with left aortic arch Anucleate erythrocytes Loss of renal-portal system Urea as nitrogenous waste Specialized facial musculature
What are the 10 skeletal characteristics of mammals?
Dentary-squamosal jaw joint Articular-quadrate joint is not jaw hinge 3 Middle ear ossicles Mandible of one bone only (dentary) Secondary palate Double occipital condyle Mammalian-type atlas/axis complex Cusps on cheek teeth No lumbar ribs Mammalian-type ethmo-turbinate bones
What is a phylogeny?
The history of some group of species
What are the 2 major evolutionary trends of mammals?
Increased activity and endurance
Reduced number of parts while maintaining performance
What is the order of evolutionary periods when mammals were around and what were the major events?
Pennsylvanian - appearance of synapsids
Permian - therapsids, cynodonts
Triassic - appearance of mammals
Jurassic - archaic mammals
Cretaceous - appearance of metatherians and eutherians
Paleogene - adaptive radiation of metatherians and eutherians
What are the 12 parts of the synapsid skull?
Premaxilia Maxilia Nasal Lacrimal Prefrontal Postfrontal Frontal Orbit Postorbial Parietal Temporal opening Squamosal Jugal
What are the 3 types of amniotes?
Synapsida
Anapsida
Diapsida
What are the 2 types of synapsids and what was their main difference?
Pelycosauria - most primitive
Therapsida - most advanced, top carnivore
Therapsida has:
Larger temporal opening
Larger dentary and smaller angular
Heterodont cheekteeth
What are the 3 suborders of pelycosauria?
Ophiacodontia - most primitive
Edaphosauria - herbivores
Sphenacodontia - carnivores
What are the 2 suborders of therapsida?
Anomodontia - herbivores
Theriodontia - carnivores
What traits did cyondonts evolve after therapsids?
Secondary palate - allows breathing during eating, and suckling as a neonate
Double occipital condyles - finer control of head, reduced tension on spinal cord
What’s the biggest difference between mammals and early synapsids, what was the problem, and what as the trait of the intermediate?
Middle ear ossicles and jaw bones.
There’s no transitional form that has 2-3 jaw bones or 2 ear bones.
A cyondont intermediate had 2 functional jaw articulations (entary-squamosal and quadrate-articular). It allowed the post-dentary bones to assume a new function.
What are the advantages to having larger dentary bones?
Higher food processing for higher metabolic rate
Stronger jaw muscles
What are the names of the modern mammal angular and quadrate bones?
Malleus and incus (stapes was always there)
Is there one common ancestor for mammals?
Yes, mammals are monophylectic. Prototheria and theria split from therapsida after they evolved the dentary-squamosal articulation.
What is a cusp and what were the patterns on therapsids, primitive mammals and derived mammals?
Projection or elevation on the occlusal surface of the tooth.
Therapsids had no cusps
Primitive mammals had 3 cusps in a row (triconodonta)
Derived mammals had cusps in a triangular pattern (symmetrodont)
What are tribosphenic molars and what mammals have them?
Tooth with a pair of triangular patterns.
Lower molar has a trigonid (raised) and a talonid (flat), while upper molar has a trigon.
They’re seen in modern marsupials and insectivores
When were pigs, horses and cats domesticated?
About 6,000 years ago
About 5,500 years ago
Unknown for cats, but they were first domesticated by Egyptians
Why study teeth?
Some fossil lineages are only known from teeth
Know trophic level
Feeding specialization
Secondary function such as grooming, defense
Know individual characteristics such as age or sex
What 2 levels of information do teeth tell you?
Form of teeth tells you about the species
Wear of teeth tells you about the individual
What is a caveat?
Wear only informative for closed-rotted teeth
What is the wear of the teeth dependent on?
Tooth hardness
Food quality
What is enamel?
Hard, heavy outer coating of dentine in the crown. It can’t regenerate
What animals don’t have enamel and why?
Aardvarks and armadillos, because their diet is easy to consume and doesn’t require any chewing.
What is dentine?
The main body of the tooth, it contains the pulp cavity which has blood and nerves, and provides the tooth is nutrients
What is the cementum?
Modified bony material that covers the dentine in the root of the tooth.
It’s reformed annually.
It anchors the tooth to the alveolus with connective tissue
What are the 2 types of tooth growth?
Open-rooted (ever going) - pulp cavity open at base
Closed-rooted (no growing, wearing) - pulp cavity closes
Why are most mammals heterodont, and what groups aren’t?
Improves efficiency with obtaining and processing food.
Homodonts have only one kind of tooth, and Edentate have few or no teeth.
What is dental formulae?
It desctibes the number and position of teeth
What are the 2 types of crown height?
Brachyodont - low-crowned
Hypsodont - high-crowned
What are quadritubercular teeth?
Molars with 4 cusps, like in humans
What are the 9 types of molars?
Tribosphenic Tuberculo-sectorial Sectorial Piscivorous Myrmecophagus Homodont Bunodont Selenodont Lophodont
What are myrmecophagus teeth?
Teeth that play no role in processing food.
Degeneration from tribosphenic molars
Pegs of dentine without enamel
Extrememe edentate
What are tuberculo-sectorial molars?
Talonid basin from tribosphenic molar is retained, but it’s combined with carnassial shearing tooth.
*Carnassials are the upper 4th premolar and the bottom first molar
Molars can also crush bone
What are sectorial molars
Carnassial specialization, without crushing heel, only for shearing
Found in felidae
What are piscivorous molars
Strongly recurved cusps, used for grasping prey (similar to homodont).
Elaborate cusps for straining prey from water when filter feeding
What are bunodont molars?
Low-crowned, squarish teeth with rounded cusps used for crushing and grinding
Found in pigs, primates, some carnivores
What are lophodont molars?
Cusps form continuous, straight cross-ridges that are perpendicular or parallel to the jaw, used for efficient grinding
Only in high-crowned teeth
What are selenodont molars?
Lophs are isolated and crescent-shaped in a longitudinal arrangement
Teeth wear down unevenly to maintain the ridges
What is a diphyodont?
An animal that has two types of teeth in their lifetime
Deciduous milk teeth are replaced by permanent adult teeth
What is the difference between tooth replacement in eutherians and metatherians?
In eutherians, all teeth except molars have deciduous counterparts
In metatherians, only premolars (except last) and molars have deciduous counterparts
What is supernumerary dentition?
Extra teeth in a position
What is agenesis?
Reduced number of teeth in a position
What is the difference between herbivores and carnivores when it comes to jaw articulation?
Articulation of mandibular condyle with the fossa of the cranium, and the primary muscle group closing the jaw
Carnivores’ articulation is level with with dentition, while herbivores’ articulation is above denition
Temporalis the the primary chewing muscle for carnivores while the masseter is the primary chewing muscle for herbivores
What factors affect the mode of feeding?
size energy content availability capturing processing
How do terrestrial insectivores capture individual prey and colonial prey?
Grasping with incisors
Specialized sensory organs allow niche exploitation
Elongated digits to capture prey
Elongated snouts and forelimbs for digging
Long, sticky tongues
Reduced dentition or edentate
How do aerial insectivores capture prey?
Gleaning or open air foraging
Captured using mouth or uropatagium
How is food processed in insectivores?
Simple digestion - goes in stomach, goes though short intestine, comes out of anus
Insects are high energy food, so simple digestion is enough
What is a sanguinivore?
Blood eater
What are 4 traits of aerial carnivores?
Reduced rostrum and blade like incisors and canines
Reduced cheekteeth
Tubular, extended stomach
Thin walled intestine
Two-phase renal function - water is dumped first, then waste
How is food processed in carnivores?
Simple digestive system with small or absent cecum
High energy diet, lots of protein
What are the 2 types of fermentation for herbivores?
Foregut and hindgut fermentaion
What is the process of foregut fermentation?
Complex, multichambered stomach with cellulose-digesting microorganisms.
Food enters rumen and is mixed with microorganisms
Food goes to reticulum and forms a cud
Cud is regurgitated and chewed
Food is swallowed again and enters the omasum where it’s kneaded
Food passes to true stomach where digestive enzymes kill and breakdown microorganisms
Food moves to small intestine
What is the process of hindgut fermentation?
Cellulose-digesting microorganisms in colon/cecum
Chemical breakdown in mouth with salivary enzymes
Digestive enzymes continue to work in simple stomach
Nutrients absorbed in small intestine
Small particles move to cecum and large particles move through the large intestine and pass a feces
Fermentation occurs in colon or cecum
What is coprophgy?
A type of hind gut fermentation where the animal eats feces to process more nutrients that were not processed in the cecum
What is the 4 main benefits to foregut fermentation?
More efficient breakdown of food
Microorganisms are also food
Detoxification of alkaloids
Allows for addition nutrient intake during rest
What are the 4 main benefirs to hindgut fermentation?
Process food quickly
Large volumes of food can be consumed
More effective when food has high amounts of indigestible material
Supports more generalist feeding
What is the evolutionary paradox of hair and what was the solution?
Hair provides insulation, which would be maladaptive for an ectothermic ancestor. However, there’s evidence that endothermy erupted before hair did.
What are the 2 types of hair growth?
Angora - continuous
Definitive - grows to a certain length and falls out
What are the 3 layers of hair shafts?
Medulla - core
Cortex - tightly-packed cells with melanin
Cuticle - thin, transparent scales
What are the 2 components of pelage?
Underfur - short, dense, fine. creates dead space for insulation
Guard hairs - long, coarse. protects underfur
What are the 3 secondary functions of guard hairs?
Camouflage
Disruptive colouring
Defense
What are the 3 patterns of moulting?
Post-juvenile
Annual
Seasonal
What is vibrissae?
Long, stiff hair enervated at the base.
Functions as tactile receptors
What are rhino horns?
Not true horns due to them not having a bony core or keratinized sheath, nor is it attached to the skull
What is a horn?
An extension of of the frontal bone, with an outer keratin sheath. It’s not vascularized, it grows continuously, it’s never shed and has no branches
What’s different about pronghorn horns?
The keratinized sheath sheds, but the bony core doesn’t
What makes giraffe horns different?
They have ossicones. They develop differently and are sutured to the skull, rather than growing from it. They’re also covered in hairy skin
What are antlers?
Bone grows from pedicel on the frontal bone. When they are growing, they are covered in vascularized velvet, which sheds when growth is complete.
They are branched and regrow annually.
What are the 3 hypotheses for female caribou having antlers?
Female defense hypothesis
Andromimicry hypothesis
Resource defense hypothesis
What are the traits of monotreme female reproductive tracts?
Cloaca
Ovaries produce large follicles
Eggs are able to absorb nutrients in oviduct
Separate uteri with separate openings into the urogenital sinus
What are the traits of marsupial female reproductive tracts?
Females have bifurcated (paired) reproductive tract
Lateral vaginae on both sides and medial vaginal canal
Duplex uteri
Youlk-sac placenta, less efficient that eutherian placenta
Short gestation and birth
What are the 4 types of uterine in placentals and what animals have them?
Duplex - two separate uterine horns and two cervix (lagomorphs and rodents)
Bipartite - two separate uterine horns, one cervix (most carnivores and whales)
Bicornuate - distal separation of uterine horns, single cervix (bats, ungulates, primitive primates)
Simplex - no separation between uterine horns, single cervix (higher primates, some bats)
What are the 2 types of placentas and what are their properties?
Chorioviteliine: enlarged yolk sac lack villi weak mechanical connection to uterine lining embryo doesn't implant deeply
Chorioallantoic: embryo embeds deeply into endometrium lining strong connection due to villi uterus becomes highly vascularized allows greater development of embryo
What are the 4 types of chorioallantoic placentas and what animals have them?
Diffuse - even distribution of villi (non-ruminating artiodactyles, perissodactyles, lemurs)
Cotyledonary - villi distributed in patches (ruminating artiodactyls)
Zonary - continuous band (carnivores)
Discoid - 1-2 disk-shaped areas (primates, lagomorphs, bats)
What are the 6 reproductive stages?
Ovulation Copulation Fertilization Implantation Gestation Partuition (birth) Lactation
What are the 5 variations to the reproductive stages?
Induced ovulation Delayed fertilization Delayed implantation Delayed development Embryonic diapause
What is the order of the reproductive stages for induced ovulation and what animals experience this?
Copulation
Then everything else is the same
Seen in rabbits, all cats
What is the order of the reproductive stages for delayed fertilization and what animals experience this?
Copulation
Delay
Then everything is the same
Seen in bats
What is the order of the reproductive stages for delayed implantation and what animals experience this?
Ovulation Copulation Fertilization Delay Then everything is the same
Seen in small, solitary carnivores, seals, bears, rodents
What is the order of the reproductive stages for delayed development and what animals experience this?
Up until implantation, everything is the same
Delay
Then everything is the same
Seen in bats
What is the order of the reproductive stages for embryonic diapause and what animals experience this?
Similar to delayed development, but the presence of other babies causes the embryo to delay its growth. When the baby stops suckling, the embryo would grow
Only seem to be seen in red kangaroos
What are the 3 roles of lactation?
Provides nutrients
Provides immunity
Bonds mother to child
What is Aristotle’s theory of teat number?
The number of teats is correlated with the size of the litter.
Litter size is about half of the amount of mammae available
What are the 4 evolutionary hypotheses on lactation?
Themoregulatory hypothesis - secretions helped warm eggs
Water balance hypothesis - young learned how to lick water from secretions
Behavioural hypothesis - pheromone in secretions helped bond young to mother
Immunological hypothesis - secretions provided anti-bacterial and anti-fungal protection
What is the article by DelGiudice (Surplus killing of white-tailed deer by wolves in northcentral minnesota) about, what were the hypotheses, predictions, methods and what were the major findings?
They wanted to see why wolves killed deer excessively.
If excessive killing of deer is related to winter severity and snow depth, then more kills would occur when snow depths are > 70cm.
They used telemetry to monitor and locate the deer, tracking to see if they were killed by wolves and obtained bone marrow to find fat quantity in deer.
In years were there was > 70cm snow depth for 4-8 weeks, deer were excessively killed. It took more energy to escape, and deer ended up using almost all of their fat stores.
What is the article by Arnemo et al. (Risk of capture-related mortality in large free-ranging mammals: experiences from Scandinavia) about?
It mentions how anesthesia in a controlled setting has very low mortality rates (1-0.05%) but this isn’t the same for wild animals (2%).
They mentioned how direct, indirect and secondary factors lead to mortality, such as hypothermia, drowning during induction, or trauma from traps, leads to higher mortality rates when studying captured wild animals.
Arnemo gives suggestions to lower the mortality rate, due to 2% being unacceptable.
What was the article by Wilson (Adaptive radiation of multiturberculate mammals before the extinction of dinosaurs) about and what were the major findings?
It mentions how multiturberculate mammals radiated before the cretaceous-paleogene extinction, which was what help facilitate the radiation of modern mammals.
From 160-50 million years ago, multiturberculate mammals had changes in the cusps of their cheekteeth. They went from being simple to more complex. They used OPC to calculate this. Relating to modern mammals, a lower OPC signified a carnivorous diet, which a higher OPC signified a herbivorous diet. Multiturberculate species became more herbivorous over time, until the K-Pg extinction, where they went back to being more carnivorous.
As time went on, multiturberculate species richness increased as well as body size, despite the presence of dinosaurs. This could have been due to the increase of plant diversity and the exploitation of new niches where new plants grew. This also explains why they became more herbivorous.
After the K-Pg extinction, there was more room for modern mammals to grow and evolve. This new competition could have caused multiturberculate species decrease in numbers.
What was the article by Clutton-Brock et al. (Fitness costs of gestation and lactation in wild mammals) about, what were the methods and findings?
Life histories of about 300 female red deer in food limited populations were recorded.
Females who didn’t produce young, or had young that died before 3 weeks had high survivorship, while females that produced young that died younger than 12 months or had young that survived past 12 months had decreasing survivorship as rainfall increased and food became more scarce. This same trend was seen for the ability to produce young in following years.
Mothers who lost their calves early or who didn’t produce any were able to produce significantly heavier calves in following years than the mothers who’s calves survived less than or past 12 months.
There was a link between lactation, survivorship and fecundity. Mothers who lactated for a long period of time had lower survivorship and decreased fecundity due to the amount of energy needed to lactate.
What was the hypothesis, prediction and major findings of the article by Milena et al. (Arboreality has allowed for the evolution of increased longevity in mammals)?
Since bats and birds have long lifespans due too having a lower extrinsic mortality rate, they predicted that mammals that are arboral would have longer lifespans than terrestrial counterparts due to them having lower extrinsic mortality rates.
Arboral mammals generally have longer life spans, which semiarboral mammals have lifespans longer than terrestrial counterparts, but lower than arboral counterparts. This trend is not as strong with marsupials. Socialness of of animals, such as higher primates increases lifespan as well.
What are the major findings from the article “the evolution of social monogamy in mammals” by Lukas and Clutton-Brock?
Not many mammals are socially monogamous; most tend to either be solitary or in groups.
It’s assumed that the ancestral condition had solitary females and roaming males.
Social monogamy could have arose from increased female competition, low female tolerance (by other females) and low female densities. This caused males to guard single females due to them being unable to guard multiple at once.
In unpredictable environments, socially monogamous pairs also became sexually monogamous, and formed groups where offspring is raised by family. Biparental care is a consequence of monogamy, not a precursor to monogamy.
