You are a scientist in the Florida Keys working for the Department of Natural Resources. You make sure the wildlife is healthy and thriving. You also find solutions when things are unhealthy. If the water
quality is poor your team helps put systems in place to clean the water. If soil conditions are poor and
plant life is not healthy then you help improve the soil quality. You also monitor the wildlife population
to make sure animals are not overpopulating or becoming endangered.
One day a local from Grassy Key came to your office and told you that his pets got out of their cages. He
told you that they are Giant Gambian Rats. They were imported from Africa. You told him that maybe
his pets will return when they are hungry. He explained that they are vegetarian and they would be
perfectly happy to eat the local vegetation. He then told you that this happened last month and he was
hoping his pets would return. When they didn’t, he figured he should tell someone. He explained that
he had 6 total, 4 were female and 2 were male. This is a problem! First you thought it was just a couple
rats but now there is a chance the rats can bread.
Your team got started with a plan. After all these rats are not from here and this could go either way.
They could die because they were in unfamiliar territory, or they could thrive and hurt the local
environment. You put some traps out and monitored them daily. Within a few days a female and a
male were caught. The female had recently had babies so now you know there are more than just 6 out
there. You also did some research on Gambian Rats and found out that they can have up to 5 litters of
within a 9 month time frame. With each litter they can have 1-6 babies. Now this could be a bigger
problem. So you decided to monitor the population and see how the island can handle the new
inhabitants.
Here is the data that your team collected over the next 5 years.
Years 0 1 2 3 4 5
rats 6 11 20 36 76 130
You now need to figure out the percentage of growth each year the rats are growing to be able to make
an educated decision.
1. Use your calculator to write an equation representing this data. (2 decimal places).
2. Look at the growth factor. What percentage are the rats growing by each year?
3. If this trend continues, how many rats will there be in 8 years from the rat escape day?
4. Grassy Key is only 1.4 square miles. How many rats will there be per square mile at the 8 year
mark? (divide miles by # of rats)
5. Do you think this is sustainable? What did your team decide?
6. What are possible negative effects of letting the rats stay? Do some research on invasive
species. Do the rats need to go or are they ok to stay?
Write a paragraph explaining the action plan of your team. What did you do to figure out all of your
information? Walk me through the process that you used. Then explain the outcome and why you
decided if the rats were ok or needed to go. Include what you found on invasive species.