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Happy Wed! 9/8/2010. State which species of turtle nests in the greatest numbers on Jupiter Island. (1 mk ) (b) Compare the distribution of nesting in the three species of turtle along the eastern coastline of Florida. (2 mks ). (a) loggerheads / Caretta caretta 1
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Happy Wed! 9/8/2010 • State which species of turtle nests in the greatest numbers on Jupiter Island. • (1 mk) • (b) Compare the distribution of nesting in the three species of turtle along the eastern coastline of Florida. (2 mks)
(a) loggerheads / Carettacaretta 1 • (b) all three species nest over the same range of latitudeson the same beaches/areas;density of loggerheads is greatest and leatherbacks is lowest;similar relative densities/numbers on the different beaches / latitudes;all three had most nests on Jupiter;more loggerheads at northern end of range /(Do not accept answers givingaround 28 (°N) / on Melbourne;) the range 26–28 or 26–30.) 2 max
Don’t forget... • “Exercises” ?s as you read or after we’ve gone over in class • Make sure you GET IT • “Practice ?s” @ end of chapter— old exam ?s • Studying for quizzes/tests!
5.3.2 Pop growth curves • MODEL • Change in pop size over time • Pop expanding into a habitat offering INITIAL LOW RESISTANCE or LOW LIMITING FACTORS A-Exp = rapid pop growth rate B-slowing but still high C-plateau = pop remains stable w/time; slight oscillations
5.3.3 Phases of pop growth curve…details! EXPONENTIAL PHASE • Low/reduced limiting factors • Pop expands exponentially into hab. @ 2n where n= # of generations • natality + imm. > mortality + emigr. • Note that it does not mean that death/ emigration= 0 !!!
When do you observe exp. phase in nature? Pop of germinating annual plants in new season Bacterial pop @ onset of infection Succession—any species’ pop entering previously uninhabited area
5.3.3 TRANSITION PHASE • Resources reduced, become limiting • Competition…not all survive • NATURAL SELECTION! • lower rate of increase in pop
5.3.3 POPULATION PLATEAU • Pop remains constant over time/generations • Natality + imm = mortality + emig • Pop size determined by CARRYING CAPACITY of habitat @ that time
5.3.4 Factors limiting pop growth • With unltd resources, pop would keep increasing…exponentially! • REALITY CHECK! • Environmental resistance limits it & determines carrying capacity • Shortage of food/prey • Predation, parasitism • Disease • Accumulation of waste • Shortage of space/territory