2.  Deer Population Activity  Each year, some deer have offspring and other deer will die.  You can use this equation to determine the size of population each year:  y= ((p + b)-d)  y= the total population size plus the birth rate and minus the death rate.  p= population size at beginning of the year  b= the birth rate  d= the death rate

3.  The birth rate and death rate will be given for each year.  You will find the population size for each year using the equation and given information.  When graphing the information, x = the year and y= population size to give you the ( x, y ) coordinates.  The population size for the next year will be the y of the previous year.

4. YearPop size 1stOffspringDeathsy= ((p + b) –d)Population size end 1986600200300y= ((600 + 200) – 300)500 198750030050y= ((500 + 300) – 50)750 1998750400150y= ((750 + 400) – 150)1000 19891000400100y= ((1000 + 400) – 100)1300 19901300300100y= ((1300 + 300) – 100)1500 19911500450200y= ((1500 + 450) – 200)1750 19921750600250y= ((1750 + 600) – 250)2100 19932100500300y= ((2100 + 500) – 300)2300 19942300500250y= ((2300 + 500) – 250)2550 19952550400250y= ((2550 + 400) – 250)2700 1996270050450y= ((2700 + 50) – 450)2300 19972300250100y= ((2300 + 250) – 100)2450 19982450300150y= ((2450 + 300 ) – 150)2600 19992600100300y= ((2600 + 100) – 300)2400 20002400300100y= ((2400 + 300) – 100)2600

6.  When forming your graph, the year, or x value goes across the bottom, which is the x-axis.  The deer population size goes up the side of the graph, or the y-axis.  Number the x-axis starting with the earliest year to the latest year.  The example on the previous slide goes from 1985 to 2005 because I was not able to reformat the graph.  The y-axis should be numbered evenly to the highest number needed for the graph.  The example on the previous slide is numbered from 0 to 3000.

7.  The graph shows that the population size steadily rose from 1986 to 1995.  There was a large decline in population size between 1995 and 1996.  Discuss other trends you see in the graph.

8. Assessment Questions:  What could cause the population decline that occurred between 1995 and 1996?  Based on what you have learned about carrying capacity, what is the carrying capacity of this deer habitat?  Predict what will happen to the population size in 2001.  What circumstances might result in a high birth rate for a population? A low birth rate?  What circumstances might result a high death rate for a population? A low death rate?