Ratios of body parts or the fact that all squares have the same ratio between perimeter and diagonal. The final product could be a packet with their experimental work and written explanation as to what they did and what they discovered. Look at the phycial characteristics of wildlife in a certain habitat. Look at the physical characteristics of the prey of raptors. Predator and prey relationships.
Snakes are important to keep rodents under control.
One snake can eat 50 mice per year. Example NatureMapping Know when estimation is an appropriate response. Represent this information in a graph, a table, and as a mathematical function. Count individual birds vs flocks of birds. Sketch the curve.