 Get yourself into 6 groups of 4-5 students per group  Once you find your group, sit at a table  You have 30 seconds

 Food Station ◦ You will have one piece of “food” to share equally between you and your group members ◦ 3 stations to go to A,B,C-Rotate through them all ◦ Make notes on your worksheet  Shelter Station ◦ On the ground you will see 3 “shelters” ◦ You must stay in the “shelter” for 3 minutes ◦ If you are loud, you’re out ◦ NO SHOVING! You will be out if you shove anyone ◦ Rotate through all 3 stations ◦ Make notes on your worksheet

 Crowded populations mean the individuals have to compete for food, water, space, sunlight, or anything else necessary for survival and reproduction  Some may have enough to survive, but can’t raise offspring  Some may die of starvation  The more individuals in an area, the faster resources are used up  Could be between individuals of the same or different species

 Predator-prey relationships tend to fluctuate (go up and down)  If there is a lot of prey, the predator can eat more, increasing the number of predators  If the prey decreases too much in population, there won’t be enough food for predators and so the population of predators decreases

 Plant and herbivore populations fluctuate just like the predator and prey populations

 Parasites and disease causing organisms feed at the expense of the host  This can weaken or kill the host  The larger the population the easier it is for the parasite or disease to travel through hosts

 Some species will fight amongst each other if they are overcrowded  This fighting can cause stress leaving individuals susceptible to disease  In a few species, overcrowding can cause females to neglect or kill their own offspring

 Organize the following words into 3 categories ◦ Density Dependent ◦ Density Independent ◦ I’m not sure

 A hurricane  Famine  A disease kills half of the population  A forest is cleared by a logging company  The plants that one species really likes has only grown half as much as usual  An early frost kills cherry trees  There is an unusually large population of wolves that eat a lot of rabbits  Territorial lions start fighting each other for habitat space  The weather has been unusually dry so the watering hole has dried up

 A factor that affects all populations in similar ways, no matter the population size or density  It includes things like:  Hurricanes  Droughts  Floods  Natural Disasters

 So what would happen after a drought? ◦ No water so species will compete for the water  WAIT A SECOND MS. JOHNSON! YOU’VE TRICKED US!

 Sometimes a density dependent factor can lead to a density independent limiting factor like competition  What do you think??

 We said that something happens to stop populations from growing.  How do density-independent and dependent factors play into this?

 These limiting factors contribute to what is called carrying capacity  Defined as: the maximum number of individuals of a species an environment can support

 On a sheet of paper, write a paragraph explaining whether or not you think that density independent factors should be considered separate from density dependent factors.  Explain your answer using information from today.