"I've seen an awful lot of hawks sitting in power lines with no problems"
That and $5 will get you into a lecture about how many raptors get electrocuted every year.
"you're okay with killing raptors."
I know you'd like me to be, but I'm not. Here's what's killing most of them.
Raptor Conservation Issues
The Danger of Roads
Raptors are hit by cars more often than one might imagine. One of the reasons a raptor may be crossing low over a road is that it is hunting. When roads are built, there is often a change in the habitat around the new road. In forested areas there is an "edge effect" where the area closest to the road has been changed from forest to shorter grasses and shrubs. These grasses may attract more prey species closer to the road. When a raptor dives after its prey it may have to cross the road and risk being hit by a car. Also, after the raptor has caught its prey it is still very near to the road and may be hit as it is eating or taking off after feeding. The same edge effects can happen in open plains, agricultural areas, and many other habitats.
Hunting Raptors Is IllegalAccording to the Migratory Bird Treaty Act (Title 50, Parts 10, 13, 14, 17, 21 and 22) it is unlawful to kill, capture, collect, possess, buy, sell, trade, ship, import or export any migratory birds, including their feathers, eggs, and all other parts. Permits are granted by the U.S. Fish and Wildlife Service, and the state in which the permitee resides. Permits are granted for research, rehabilitation, education, religious purposes, and falconry. Other laws that protect raptors are the Eagle Protection Act, the Endangered Species Acts, and other state laws. Violations of these laws are punishable by fines and imprisonment. While it may seem extreme to punish someone who has found a raptor feather and kept it, it is necessary. Without this extension of the law it would be easier for a poacher to lie and claim that he or she had found the feather on the ground, while in reality they had shot a raptor to obtain the feather.
Flight MechanicsFeathers allow birds to fly. Raptors have 10 primary flight feathers and 13 secondary flight feathers. Raptors are able to soar and glide by angling their wings during flight. Air flows faster over the top side of the wing and slower underneath the wing. Because the air molecules are moving slower under the wing there are more air molecules moving in different directions. With more molecules available to move upward more lift is created and allows the bird to soar. The wing and feathers can be angled more or less to create more or less lift. A bird that is missing all of its primaries would not be able to control this flow and could not fly.
ElectrocutionRaptors are threatened more by power lines than many of the small birds we often see perched on them. The reason is that raptors have such a large wingspan (up to 7-8ft for eagles) that when they land or take off from the poles they may touch two wires at the same time and therefore complete the circuit. Smaller birds cannot touch both wires at the same time and so do not get electrocuted. HawkWatch International has joined forces with Utah Power to begin a program called the Raptor Electrocution Reduction Program (RERP). In surveying 11,000 poles the team found 150 electrocuted raptors at their bases. RERP has worked to identify high-risk poles and retrofit the poles to prevent raptors from being electrocuted. The retrofitting included the placement of triangles to prevent raptors from perching near the lines and the installation of a higher perch that allows raptors to open and close their wings above the wires so there is no threat of electrocution.
ImprintingWhen a bird is taken from the nest and raised by humans it may be physically healthy, but it will not be mentally healthy; it will be an imprint. Imprinting is the process where baby birds look to their parents to learn how they should behave. Imprinting on humans can be especially detrimental to raptors. Raptors must learn to hunt from their parents. It is possible to train a raptor to hunt, i.e. falconry, and it is possible that a falconry bird, which flew away from its trainer will be able to hunt and survive on its own. However, most imprint raptors are not taught to hunt by the people who take them from the nest to keep them as pets. If this is the case, even if they are trained later by a falconer to hunt, they may still decide not to hunt and instead come back to beg humans for food. When a raptor refuses to hunt it is impossible to release it as it is a danger to itself as well as to humans. Also, if the raptor is not fed a proper diet it will become very emaciated; for instance, raptors fed only hamburger are often malnourished and starving by the time they are in the hands of a rehabilitator.
Human Created DangersMost of the dangers raptors face have been created by people. Aside from the dangers discussed on this page (roads, hunting, electrocution, and imprinting) there are other dangers such as barbed wire fences, habitat loss, habitat degradation, lead poisoning due to lead shot or sinkers, and wind powered generators.
- Raptors flying low to the ground during hunting risk becoming entangled in a barbed wire fence. Many, like Calurus, will injure their wings while trying to pull free of the fence.
- Habitat loss affects many raptors as well as other animals. The Spotted Owl of the Northwest is the most famous raptor affected by habitat loss. Spotted Owl's live in old growth and late succession areas in northwestern Pacific forests. In the lower 48 states of the U.S. only 5% of the original old growth forests remains and most of that is in the northwest. In the Pacific Northwest 90% of logging that occurs on National Forest land occurs in areas with older growth areas. In order to ensure the survival of the Spotted Owl, not only do old growth forest areas need to be protected but there must also be corridors of the forest for the Spotted Owls to disperse into new territories.
- Habitat degradation also affects the survival of raptors. A prime example of this is Prairie Falcons. Prairie Falcons prey on the rodents and animals that live in sage habitats. However, because more and more cows are being grazed on public lands more areas with sage are overgrazed, and invasive species such as Cheatgrass Bromus tectorum are able take over the plains. The prey of the Prairie Falcon does not eat the Cheatgrass (neither do the cattle) and therefore Prairie Falcons have a harder time finding food.
- Lead poisoning occurs either directly or secondarily. An example of direct lead poisoning is if a fisherman using lead sinkers loses the sinker in the water and a fish swallows it or if it or a lead bullet washed up on shore and a small bird swallows it mistaking it for a rock. Secondary lead poisoning would occur if a raptor, such as an osprey, (or a human) caught and consumed a fish that had swallowed a lead sinker. Another example would be if a hunter shot a deer but could not find the kill, then the lead bullet could be eaten be scavengers such as the Bald Eagle and other animals.
- Wind-powered generators are often placed on the side of mountain ridges. They are so placed in order to maximize the use of updrafts (when the wind is forced up by mountains or ridges). Unfortunately, migrating raptors also use updrafts to soar along north-south mountain ranges during migration. The danger is that the raptors may fly into the generators and be killed.
What To Do If You Find an Injured RaptorIn general a raptor will not let a human approach it while on the ground unless it is injured or guarding a kill. If you find an injured raptor it is important to keep your distance from the bird. Raptors have extremely sharp talons and powerful feet (a Red-tailed Hawk can squeeze its foot with 160 lbs. of pressure compared to a person who can squeeze their hand with 35-40 lbs. of pressure), and so they can do quite a bit of damage. For more detailed information about dealing with injured wildlife, click here.
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