The July 22 "Birder's View" commentary by Lars Fladmark, regarding his frustrating inability to raise pheasants in North Dakota, seemed based on incorrect beliefs ("Hawks are eating all the songbirds").
A review of pen-reared pheasant release programs for eight U.S. states from North Dakota to Washington concluded this is an inappropriate management tool for increasing pheasant numbers. Stocking 200 to 300 adult pheasants on a 320-acre farm created a feast for natural predators like foxes, coyotes, raccoons, badgers and even raptors. Research revealed that mortality of these naïve pheasants was very high, with few surviving to breed the following spring.
Game farms typically wait to release pheasants until just hours before hunters are ready to shoot them. They realize most pen-raised pheasants are unable to cope with the natural world and many die within days.
Despite these known problems with rearing and releasing pheasants, Fladmark determined hawks were to blame for the deaths of pheasants and other birds.
Large hawks are among the most visible predators and will take pheasant. The hawks in North Dakota that Fladmark wrote about probably were red-tailed and Swanson's hawks, which prey primarily on smaller mammals such as rodents and rabbits. The food habits of these hawks are well-documented; the birds are helpful in keeping small mammal populations in check.
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Any predator would take advantage of an easy, excess food source like newly released pheasants. Even hawks that prefer rabbits, gophers or mice will not pass up a chance at such an easy dinner.
The known major limiting factor for pheasant breeding populations is the amount of suitable habitat available, primarily grasslands. Prime ring-necked pheasant habitat is found in agricultural regions with hay and grain, especially areas with grassy field borders, wetlands and numerous small patches of idle land with tall grass, forbs and lesser amounts of brush and trees, according to the 2001 series, "Birds of North America" (No. 572). These habitats mostly have been reduced by increased and intensive agricultural activity throughout the current pheasant range.
I appreciated Fladmark's concerns with native wildlife, including songbirds. Many North American grassland bird species have been declining for years. Their problems are similar to the pheasant, including the loss and fragmentation of native grasslands and prairies, invasion of exotic species, predation, weather and climate, and agricultural activities.
Although predation does play a role in reducing many wildlife populations, singling out hawks as the sole culprit, as Fladmark did, is not supported by scientific evidence. Predator-prey dynamics are extremely complicated, but the major point is there are many predators, and they need to stay in balance with their prey to survive.
Predators like hawks are an essential component of a healthy and balanced ecosystem. Their massive population declines in the 1940s through 1970s, with the increased use of DDT in the environment and its subsequent banning in 1972, served as a clear warning signal to humanity, causing our reassessment on safe pesticide use.
Finally, the writer developed a connection between his failed efforts in North Dakota and Hawk Ridge and recommended shooting hawks there. This was an alarming and unreasonable proposal. The shooting of hawks at Hawk Ridge was stopped in the 1940s by the efforts of the Duluth Audubon Society. The annual fall migration of raptors over Duluth is one of the most outstanding biological phenomena of the region. Hawk Ridge Nature Reserve was created by the city in 1972 to honor that phenomenon. Each fall more than 80,000 raptors are counted and more than 18,000 people visit Hawk Ridge Nature Reserve to observe this natural spectacle; it is one of the gems in this fine city of Duluth.
Gerald J. Niemi is a professor of biology who teaches ornithology at the University of Minnesota Duluth. He also is a pheasant hunter; is on the board of the Hawk Ridge Bird Observatory, which is responsible for managing the Hawk Ridge Nature Reserve; and has been studying birds for more than 35 years.
