Behavioral

Photo from Wikimedia Commons

Ecology

Ethological Underpinnings of Behavioral Ecology Konrad Lorenz Instinct

,

imprinting

,

etc

.

Photo from http://www.dabase.org/lorenz.htm

Ethological Underpinnings of Behavioral Ecology Niko Tinbergen

Four questions subsumed under

Proximate

questions concerning, respectively,

how

vs.

Ultimate Causes

a behavior is produced ; and

why

it evolved (

i.e.

, evolutionary

Benefit / Cost Ratio

) Photo of Tinbergen from Wikimedia Commons

Ethological Underpinnings of Behavioral Ecology Karl von Frisch Waggle Dance

Of his chosen study organism von Frisch said: “

The honey bee is like a magic well: the more you draw from it, the more there is to draw.

” Photo of von Frisch from Wikimedia Commons

Ethological Underpinnings of Behavioral Ecology Konrad Lorenz Niko Tinbergen Karl von Frisch

Nobel Prize – 1973 Photo from Wikimedia Commons

Genes can influence behavior, so behavior can evolve

E.g.

, artificial selection experiments suggest a genetic basis for “migratory activity” Artificial Selection For higher proportion of migrants For lower proportion of migrants Pulido (2007)

BioScience

, Fig. 2

Foraging Behavior

E.g.

,

ambush predator

and female fly

prey

(also illustrates another

cost of sex

) Photo from Wikimedia Commons

Optimal Foraging Theory

Items with high

profitability

(

P

) are generally preferred

P = E t E

=

net energy value

,

i.e.

, energy gained minus energy invested

t

=

encounter time

&

handling time

invested in obtaining & processing the food Photo from http://www.rspb.org.uk/community/ourwork/b/biodiversity/archive/2013/02/18/ guest-blog-in-the-still-of-the-night.aspx

Optimal Foraging Theory

Conceptual model of OFT Net energy gained = (Total energy obtained) – (Cumulative energy investment) Drops off as animal cannot carry nor ingest more Cain, Bowman & Hacker (2014), Fig. 8.6

Optimal Foraging Theory Marginal Value Theorem

as applied to

profitability

of

foraging patches

Within a

patch

, the

marginal value

for longer time has

diminishing returns

Slopes of straight, solid lines = Energy gained / time Tangent maximizes profitability (slope) & determines

optimal giving up time

Cain, Bowman & Hacker (2014), Fig. 8.8

The Ecology of Fear

Foraging (and other) decisions can be modified by predators

E.g.

, caged grasshoppers foraging in the presence or absence of the

risk of predation

,

i.e.

, with or without a spider (mean  s.e.m. shown) Beckerman

et al

. (1997)

Proceedings of the National Academy of Sciences

, Fig. 1

The Ecology of Fear

Prey sometimes communicate their awareness of predators to those predators

E.g.

,

stotting

/

pronking

Photo from Wikimedia Commons

Social Behavior

Photo of social grooming from Wikimedia Commons

Social Behavior

E.g.

, Optimal Group Size Consider the variable

Benefit / Cost Ratio

Should an individual remain alone or join another to form a group of 2?

Should an individual join a group of 2 or 5?

What is the optimum group size?

What are likely

benefits

and

costs

?

Cain, Bowman & Hacker (2014), Fig. 8.22

Photo from Wikimedia Commons

Reproductive Behavior

The Evolution of Competitive Males & Choosy Females (and sometimes the reverse) Parental Investment

is

“any investment by the parent in an individual offspring that increases the offspring's chance of surviving (and hence reproductive success) at the cost of the parent's ability to invest in other offspring”

(Trivers 1972)

Anisogamy Maternal investment

= nursing

Paternal investment

= brood pouch “pregnancy” Photomicrograph of human egg and sperm cells from Cain, Bowman & Hacker (2014), Fig. 7.7; photo of suckling manatee from http://mammalssuck.blogspot.com/2013/11/mega-mammal-milk-analysis.html; p hoto of “pregnant” seahorses from http://www.scubadiveasia.com/blog/best-dad-award-goes-to-the-seahorse/

Male-Male Competition

E.g.

, male pollen grains compete to fertilize female ovules Photomicrographs from http://prometheuswiki.publish.csiro.au/tiki-index.php?page= Spikelet+sterility+and+in+vivo+pollen+germination+and+tube+growth+under+high-temperature+stress+in+rice

Female Choice – Courtship

E.g.

, courtship in the peacock spider (

Maratus speciosus

) Photo of peacock spider (

Maratus volans

) from Wikimedia Commons

Copulatory Courtship & Cryptic Female Choice

E.g.

, male damselfly

genitalia

(

aedeagi

, plural of

aedeagus

) Photo of Maria Fernanda Cardosa’s sculptures of male damselfly genitalia from http://livingwithinsects.wordpress.com/2012/04/30/insect-reproductive-morphology/

Mating Systems Monogamy Polygyny Polyandry Promiscuity

Photo of horseshoe crabs from Wikimedia Commons

Mating Systems

“Polygyny occurs if environmental or behavioral conditions bring about the clumping of females, and males have the capacity to monopolize them.”

Emlen & Oring (1977) Cain, Bowman & Hacker (2014), Fig. 8.8; schema from Emlen & Oring (1977)

Science

, Fig. 1

Mating Systems Polygyny Threshold Model

Pick a point on the monogamous female curve. The distance to the right to intercept the bigamous female curve is the

polygyny threshold

,

i.e.

, the habitat quality increase required to make it worthwhile for the female to share a mate.

Graphic model from Orians (1969)

American Naturalist

, Fig. 1

Inclusive Fitness & Kin Selection Kin selection

exposes the selfish nature of

altruism

; h elping kin can increase one’s

inclusive fitness

(

direct

plus

indirect fitness

)

Hamilton’s Rule: rB > C Relatedness * (Benefits to recipient) > (Costs to altruist) W. D. Hamilton

Photo of Hamilton from Wikimedia Commons

Relatedness

r

– introduced by Sewell Wright as a measure of

consanguinity

Generation 1 Generation 2 Mother daughter

r

= 1/2

r

Sister = 1/2 Cousin

r

= 1/8 Generation 3 “

I would lay down my life for 2 brothers or 8 cousins

” J. B. S. Haldane

Eusociality in Diploid Organisms

For most individuals in the

colony

the

rB > C benefits

to helping the

queen

outweigh the

costs

of sacrificing their own reproduction Naked Mole Rat Termites Photos from Wikimedia Commons

Eusociality in Haplodiploid Organisms

For most female individuals in the

colony

rear sisters outweigh the

costs

the

benefits

to helping the

queen

of sacrificing their own reproduction

rB > C

Generation 1 Generation 2 Photos of Hymenoptera from Wikimedia Commons Mother daughter

r

= 1/2

r

Sister = 3/4

Behavioral Ecology

Adoption Aggression Anti-Predator Behavior Begging Breeding Brood Parasitism Cannibalism Communication Cooperation Copulation Dispersal Dominance Hierarchies Family Dynamics Flocking Grooming Habitat Selection Herding Homing Infanticide Kin Recognition Mate Guarding Migration Nepotism Nesting Parasite Avoidance Parental Care Playing Predator-Prey Interactions Roosting Scent-Marking Sex Change Schooling Symbiotic Maintenance Territoriality Thermoregulation

Etc

…