Set 9 - Predation & Foraging

Picas

• Live in the mountain

• Forage close to their habitat because of eagles and for the wwinter

• Forage for plants with varying poison which acts like a preservative

Important Factors of Food

• Energy content

• Nutrational content

• Cost

Humans are adapted to

Maximixe food and minimize energy expenditure

2500% increase in

Sugar consumptions over 200 years

1500% increase in

Vegetable oil consumptions over 110 years

25% increase in

Human energy consumptions over 50 years

How much do US humans move compared to hunter gatherers?

20%

Metabolic Equivalent

Ratio of physical activity metabolic rate over resting rate, 25% decline

More than 60% of canadians are

Overweight or obese

Having a BMI greater than 25

Increases death

Poor diet and exercises causes

63% of premature death

Presenteeism

Decrease productivity at ork

Ultimate Exercise Benefits

• Maintain weight, health

• Decrease risks of disease/metal health

• Increase survival of new neurons

70% decrease in mortality from

2.5H of weekly exercise

Proximate Benefits of Exercise

• Improves blood flow to brain

• No micro strokes

• Anti inflammatory effects

• Decrease neurodenerative disease 

Exercise in rodents

Double new neurons

Exercise in humans

Increase blood vessel formation

What happens hen mice have an enriched and/or exercise

Neurogenesis in DG hippocampus increase

60% of strokes, 40% of dementia and 35% of late life depression decrease if

Factors such as alcohol consumptions, diet, and physical activity are improved

Men and Women have about

10-20% or 15-25% of fat

More then 60% of the brain is

Fat, myelin is 35% fat

White Throated Sparro store more fat`

In the winter

How does interuption to feeding impact Starling fat storage?

• In the morning, there’s less fat storage

• In the afternoon, there”s more storage because they assume they’ll need to make it through the day/night

Even though prey 1 is less common

It should be the only one eaten if above threshold

Positive correlation between

Patch residency and food intake ratio

Great Tit Container Experiment

As time to open container increase, so did time in that patch

Moose Altered Theory

Mooses must spend 18% foraging for Na rich aquatic animals

Adaptations to Avoid Being Hit by a Car

Avoidance in space, time and inspection

Crown Eagles

Prey on monkeys and defend territory to have enough feed to feed offsprings

Tungara Frogs Mating Calls

Attracts flies around 284 bites per hour

Ants prefer

Safer, less rewarding patches as long as it’s not much worse (around 12%), but some are willing to go higher patches with predator

Horse Racing

1.5kg can make a difference in winning

As Starling Weight Increases

Ascent angle decreases, and less weight, ascent angle becomes steeper 

As Zebra Finch Mass Increases

Time to ascend increases

Avenue Nest

Has tall walls running down an open path, surrounded with trinkets males bowerbirds can find

Types of Nests Bowerbirds Make

Avenue or teepee nests

Bowerbirds enhancement

Perform elaborate behaviours and use optical illusions to enriched trinkets

Forced Perspecitve Illusions

Stationary observer see the shells placed by the males on the gesso in a awy that makes the items larger than they are, increasing reproductive success

Intrasexual Selection

Members of sex compete with each other for access to sex

Intersexual Selection

Individual of sex choose which individual of other sex to take as mate

Bateman’s Principles

1. Females should be choosier because eggs expensive and potential success limited

2. Females selection means more variance in reproductive success of males

Females devote more energy before

Birth if internal gestation

African Cichlid FIsh Females select

Males more dominant, aggressive mates

When African Cichild Females saw preferred males win

Increase in reproductive related genes

When African Cichild Females saw preferred males lose

Increase in anxiety/stress related genes

Secondary/Epigametic Characterisitics

Traits that attract a mate

Pulse Song

Singing with interval between pulses which affects females mate choice

Polyandrous

Females mate with numerous males

How Humans Actions influence Female Choice

• Increase hybridization from pollution and poor distinction of different species colours

• Closely related endangered species reared together may sexually imprint on adults of wrong species

• Changes can be interpreted as danger, decreasing reproduction

• Limited males causes females to breed with bad ones and invest less in offsprings

Direct Benefit Model

Selection favors females have genetic disposition to prefer mates that give them tangible resources to increase fertility, females gain something

Nuptial Gift

Prey items consumed during courtship

Scorpionflies Females

Determine mate choice based on size of nuptial gift, and how long to have sex

What’s the relationship bnetween prey size and sex time?

Positive (sex less than 7 mins = no sperm transfer)

Scorpionflies Males

Will discard too small preys, and will steal from each other by micmicking females 

Good Genes Model

Selection favours females to choose better males with best genes best to have superior offspring

Pronghorn Antelope Females

Search to find mates by visiting males with a harem of females and uses current harem defenses as indicator of good genes

Offspring from Attractive Pronghorn Antelope Males

Have a higher survival rate than others

Honest Indicators

Indicators of genetic quality to stop being deceived by males, the more costly the harder to fake

Hamilton-Zuk Hypothesis

Exaggerated ornaments in males evolve as honest indicators of male’s genetic resistance to parasites

Endoparasites

Parasites that live inside host and can’t be seen, females gauge health with a correlated trait

Females choose males based on different

MHC to maintain variability using odour

Stickleback Females Prefer Males with more

MHC alleles = more MHC peptides

Sticklebacks Females exposed to two water columns

• When pair is less than optimal MHC peptide, synthetic one was more attractive

• When pair is optimal, synthetic is less attractive

Females Sticklebacks raid nests after birth

Are repelled by very male MHC odour she was attracted to before mating to prevent her eating her own eggs

Runaway Sexual Selection

Extreme males traits evolve between genetic male trait and females preference

Females Stalk Eyes Flies were Breeded with long or short flies

• Short eye breeding preferred shorter males

• No evidence for long eye stalk between control

Sensory Exploitation Model

Newly emerged trait in males are preferred by females because it elicits a reswponse already in females, not associated with mating preference

Pustulosus and Coloradorum Mate Calls

Both begin with a whine, but putulosus add low frequency chuck to the end which female pustulosus prefer

Coloradorum Females also prefer

Chuck because botrh species prefer low frequency sounds

Exposure to Conditioned Sexual Stimuli

Quicker to have sex, display higher levels of courtship, make more sperm

Sexual Imprinting

Youngs remember behaviour and morphology of aprents and use characteristics to guide subsequency selection of mates

Novel Trait Approach

Offspring raised by parent with same novel trait

When mannikin birds were exposed to parents with red feathers on their head

Males raised with red feather females, preferred them too, and vice versa for females

Dendritic Spines in Neurons associated with 

Learning

Decrease in Dencritic Spines after

Imprinting because learning for preferences not needed since they don’t change

Male Zebra Finch in Isolated for 2 months after a month of being born

Will imprint on the first female’s phenotype it sees after isolation, and decreased spine density after exposure

Japanese Male Quail imprinted on brown females can

Learn to associate breeding chance and changes it preferrence after imprinting

Leks

Black grouse mating arenas in bogs where males gather and defend a small territory and attract females with display

Mate Copying more common in

Younger grouse since older ones mate earlier

Unanimity of Female Sage Grouse Choice increases

As more females mates in a day

Oxytocin

Neurohormone in the pituiary gland, playing a role in social behaviour

Females with no OT gene

Learned normally but didn’t mate copy because they didn’t recognize scent of another female like OT gene females do

When SD songbirds are raised with SD adults or IN adults

Birds paired and mated weith other that have the same rearing which they were raised in, and females prefer songs alike those she was raiseed in

Male Deer Stags

Form harems in mating season and use roaring as an honest indicators of fighting abilityP

Parallel Walks

Males walks alongside each other to assess size and ability

Reed Deer Stag Males that roared more

Had harems, increased when threatened and more like to win a fight

When hearing a large stag road

Males become more attentive and increase rate of roaring

Heavier European Earwig Males

Succeed more in stopping sex between lighter males but lifting them off

Females increase male male competition to have

More chances to mate with the highest ranking male

Majority of Elephant Female Mounts are

Protested andf often interrupted by another male

As harem size increase

Female bodies stay the same

Parental Bluegill Sunfish

Light bodied with dark yellow breasts, build nests, highly territorial, fan eggs to oxygenate them and defends

Sneaker Bluegill Sunfish

Smaller, less aggressive that hide near parental males and swim into territory while breeding to shed sperm 

Satelite Bluegill Sunfish

Imitates females and gets parental male to mate with both of them and the imposter will release his own sperm

Sneaker Bluegill Sunfish invest in

More sperm production with shorter lifespan, higher testes to body size ratio

Parental Bluegill Sunfish invest more in

Higher quality sperm

Spermatophore

Capsule of sperm and proteins which females selects which to put in their ovipore

In presence of males

They’ll make less spermatophores to modify number of sperm and attractiveness

What’s the main message?

egr 1 and c fos gene expression hgiher in associated with reproduction after seeing preferred male win, and highest in areas of brain associated wwith anxiety after watching male lose

What’s the main message?

Natural selection favours large and small gamates