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Modeling the Impact of Pollution and Predators on a Population of
Northern Leopard Frogs
By Kevin and Zack
Habitat range
• Lakes, streams, ponds, and marshes.
• Green, sometimes light brown.
• Mutated frogs, Minnesota, 1995.
• Turtles, snakes, lizards, birds.
NORTHERN LEOPARD FROG
• Life cycle of frog.
• Damage via pollution.
• Predatory animals.
A MATHEMATICAL REPRESENTATION
MODELING THEFROG LIFE CYCLE
• Three stages.
•Lizards eat only adult frogs.
•Pollution affects all frogs.
• Eggs laid: ~4.1/day/adult
• Eggs hatching: 12 days
• Tadpoles maturing: 60 days
• Population cap: 400 for adults, 1250 overall
MORTALITY DUE TO POLLUTION
Pollution kills:4% tadpoles, eggs.2% adult frogs.
FROGS’ PREDATORS (LIZARDS)
• Lizards live 4 years.• Birth rate based on food.• 2 frogs/lizard/day.
THE COMPLETED MODEL
POPULATIONS DURING A 1,400-DAY TRIAL
• Populations shoot up• Lizards catch up tofrogs• Equilibrium reached
FROG MORTALITIES BY CAUSE
• More deaths due topollution• Lizards eat more,but only adults• Pollution affects all frogs
Conclusion• Pollution affects a population of frogsmore than predators.
Are there any questions? No? Great!
Bibliography
•Dunn, Kyla, “Freaky Frogs”, www.pbs.orgfrontline.online, 1998.
•Oregon State University, “Methroprene”, www.ace.orst.edu/info/extoxnet/pips/methroprene.htm, 1996
•Three Teachers’ Association, “The Northern Leopard Frog”,www.alienexplorer.com/ecology/p146.html, 2000
•Province of Nova Scotia, “Northern Leopard Frog”, http://museum.gov.ns.ca/mnh/nature/frogs/north.htm, 2000