Protected Predators Keep the Balance

Don't get caught believing that hawks are eating all the game birds!

Here's what Red-tailed Hawks really eat.

75% of the Red-tail diet is small mammals
This graph illustrates that a red-tail diet is 75% small mammals such as rabbits
mice, rats, ground squirrels etc. 16% of their diet is insects, 6% reptiles, 2% birds and
1 % fish.

Food Webs

You can think of a food web as a balancing act in the shape of a pyramid

food web

The base of the pyramid is habitat. The middle of the pyramid is the prey species, ground squirrel, snake, rabbit.
The top of the pyramid is the predator, the hawk.

If you remove the predators at the top of the pyramid, will there be more room for prey in the middle?

No. But removing a predator could temporarily allow a higher survival of more young, old, or sick individuals.
Temporarily is the key word here. What happens if you try to squeeze another person or block into the prey/rabbit
level of the pyramid? The addition destablizes the pyramid - something will crash.

This illustrates how prey species can "eat themselves out of house and home" and
experience population crashes. The habitat can support only a limited number of rabbits. This is the
habitat's carrying capacity for rabbits.

Predators keep prey in balance at or near the carrying capacity of their habitat. Without a balancing predator,
prey populations can go through huge number fluctuations.

What might happen to the system if hawks were removed?

Just like removing a part from an engine can cause it to stall, removing a player from a working food
pyramid can cause an unpredictable chain reaction of events. Here's some possible reactions.

Mice are the main ingredient in a Red-tailed Hawk's diet. Rodents have an amazing reproductive potential.
With an average litter size of eight and becoming mature at eight weeks, two mice can turn into more than
2,000 in only six months. This can happen only when all limiting factors are removed.

What might happen if rodents were temporarily out of balance?

pheasant and mice both like to eat corn. More rodents could compete with game birds and other animals for a limited food supply of seeds,
especially in the winter.

What might happen if egg predators like snakes and ground squirrels were temporarily out of balance?

Ground-nesting birds could experience a higher rate of egg loss. They may need to mke more renesting attempts or they might not bring off a
successful brood.

What could you do to the pyramid if you wanted to increase the number of prey animals in the middle
(rabbits, etc.) AND keep the pyramid stable and balanced, avoiding any undesirable chain reactions?

The answer is to expand the habitat base, keeping the predators in place. With a larger base,
more prey can be added and more predators too - to


	The Migratory Bird Treay Act and state laws make it illegal to kill, capture, possess, harass, or harm any bird of prey. Violations are punishable by fines of $5,000 to $250,000 or more, jail sentences, confiscation of possessions, and revocation of licenses.
	.. Poaching is a crime! ................. Turn in Poachers .................... 1-800-532-2020 ....................
			Red-Tailed Hawk Buteo jamaicensis Red-tailed Hawks are the most regularly seen, large, sit-and-hunt, small mammal predator. They seem to be everywhere in the fall as young disperse and northern birds move in to take advantage of open hunting ground. This changes by late February. The resident nesting pairs clean house by chasing all other hawks out of their territories.




	Don't get caught believing that hawks are eating all the game birds! Here's what Red-tailed Hawks really eat. This graph illustrates that a red-tail diet is 75% small mammals such as rabbits mice, rats, ground squirrels etc. 16% of their diet is insects, 6% reptiles, 2% birds and 1 % fish. Food Webs You can think of a food web as a balancing act in the shape of a pyramid The base of the pyramid is habitat. The middle of the pyramid is the prey species, ground squirrel, snake, rabbit. The top of the pyramid is the predator, the hawk. If you remove the predators at the top of the pyramid, will there be more room for prey in the middle? No. But removing a predator could temporarily allow a higher survival of more young, old, or sick individuals. Temporarily is the key word here. What happens if you try to squeeze another person or block into the prey/rabbit level of the pyramid? The addition destablizes the pyramid - something will crash. This illustrates how prey species can "eat themselves out of house and home" and experience population crashes. The habitat can support only a limited number of rabbits. This is the habitat's carrying capacity for rabbits. Predators keep prey in balance at or near the carrying capacity of their habitat. Without a balancing predator, prey populations can go through huge number fluctuations. What might happen to the system if hawks were removed? Just like removing a part from an engine can cause it to stall, removing a player from a working food pyramid can cause an unpredictable chain reaction of events. Here's some possible reactions. Mice are the main ingredient in a Red-tailed Hawk's diet. Rodents have an amazing reproductive potential. With an average litter size of eight and becoming mature at eight weeks, two mice can turn into more than 2,000 in only six months. This can happen only when all limiting factors are removed. What might happen if rodents were temporarily out of balance? More rodents could compete with game birds and other animals for a limited food supply of seeds, especially in the winter. What might happen if egg predators like snakes and ground squirrels were temporarily out of balance? Ground-nesting birds could experience a higher rate of egg loss. They may need to mke more renesting attempts or they might not bring off a successful brood. What could you do to the pyramid if you wanted to increase the number of prey animals in the middle (rabbits, etc.) AND keep the pyramid stable and balanced, avoiding any undesirable chain reactions? The answer is to expand the habitat base, keeping the predators in place. With a larger base, more prey can be added and more predators too - to