Transcript Slide 1
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 high ?
low low high fecundity
Inverse relationship between fecundity and parental care high low low fecundity high
r-selected Many small offspring Rapid development Short lived Poor competitors Fast dispersers Little parental care Examples??
Weeds ants r-selected = opportunistic r vs. k selection k-selected Fewer offspring Slow development Long lived Good competitors Slow dispersers Much parental care Examples??
Trees bears k-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 female Since females attract mate, they are larger And more colorful than male Wilson’s phalaropes
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