Life History Patterns Ch.10 Life history patterns = how they reproduce Maturity = age at first reproduction Parity = # of times an organism reproduces Fecundity = # offspring per reproduction Mortality = death rate Parental care

Inverse relationship between fecundity and parental care fecundity low high Parental care low high ?

Inverse relationship between fecundity and parental care fecundity low high Parental care low high

r vs. k selection r-selected Many small offspring Rapid development Short lived Poor competitors Fast dispersers Little parental care Examples?? Weeds ants k-selected Fewer offspring Slow development Long lived Good competitors Slow dispersers Much parental care Examples?? Trees bears r-selected = opportunistick-selected = equilibrium

altricial vs. precocial Altricial = helpless and featherless 2-10 eggs per clutch Precocial = ready to follow parents 8-20 eggs per clutch (clutch = nest of eggs)

Reproduction Plants: Annuals = lives one year Perennials = live more than one year Semelparity = one reproductive effort per lifetime Also called “big bang reproduction,” “programmed death” i.e. agave (century plant), yucca, salmon Iteroparity = more than one reproductive effort per lifetime Senescence = age, causes decline in fecundity

Mating systems Monogamy = pair bond between one male and one female Polygamy = one individual forms pair bonds with many others Polygyny = male mates with more than one female Polyandry = female mates with more than one male Promiscuity = mate with many, no pair bonds

Monogamy Rare in mammals Common in Birds

Polygyny – one male with many females Common in mammals

Polyandry – one female with many males rare Since females attract mate, they are larger And more colorful than male Wilson’s phalaropes female

Promiscuity – no pair bonds Lek = common mating area Prairie Chicken Male sage grouse

Sexual Selection = choice of one sex by another Sexual Dimorphism = males and females look differently Color- males more brightly colored Ornamentation- antlers Size (if female larger = reverse sexual dimorphism) Hamilton-Zuk Hypothesis More brightly colored males have less parasites (healthier)

Territorial Behavior

Calling

Chasing

Fighting

Sibling Competition