Multiple examples of how wildlife is managed by itself and nature! The only thing man does is mess things up. #hunterslie #trapperslie #pestcontrollies #zooslie
Wildlife Services’ deadly force opens Pandora’s box of environmental problems
Like the prow of a ship, the Granite Mountains rise sharply from the creamy-white playa of the Black Rock Desert in Nevada.
Here, in rugged terrain owned by the American public, a little-known federal agency called Wildlife Services has waged an eight-year war against predators to try to help an iconic Western big-game species: mule deer.
With rifles, snares and aerial gunning, employees have killed 967 coyotes and 45 mountain lions at a cost of about $550,000. But like a mirage, the dream of protecting deer by killing predators has not materialized.
“It didn’t make a difference,” said Kelley Stewart, a large-mammal ecologist at the University of Nevada, Reno.
For decades, Wildlife Services, part of the U.S. Department of Agriculture, has specialized in trapping, poisoning and shooting predators in large numbers, largely to protect livestock and, more recently, big game.
Now such killing is coming under fire from scientists, former employees and others who say it often doesn’t work and can set off a chain reaction of unintended, often negative consequences.
In biological shorthand: Kill too many coyotes and you open a Pandora’s box of disease-carrying rodents, meadow-munching rabbits, bird-eating feral cats, and, over time, smarter, more abundant coyotes. You also can sentence the deer you are trying to help to slow death by starvation.
“There is a widespread perception that predators are the root of all evil and I’m tired of it,” said Stewart. “More often than not, if you have predation on a mule deer population, you’re going to have a healthier population.”
Agency officials say controlling predators is a must, especially in the West where livestock graze large tracts of unfenced land. “The intent is not to prevent predation,” said William Clay, deputy administrator of Wildlife Services. “All we’re trying to do is remove the problem animals.”
Killing predators is part of Wildlife Services’ DNA, a mission it pursues – along with a wide range of other animal control work – largely outside public view.
Some details, though, can be gleaned from the agency’s Web page, where it posts a sea of data showing – species by species – the millions of birds and mammals its employees kill each year. Sift through the numbers and you find that about 560,000 predators were killed across America from 2006 to 2011, an average of 256 a day.
The body count includes more than 25,000 red and gray foxes, 10,700 bobcats, 2,800 black bears, 2,300 timber wolves and 2,100 mountain lions. But the vast majority – about 512,500 – were coyotes.
“When they see a coyote, all they got is one thing in mind: killing it,” said Gary Strader, a former Wildlife Services hunter in Nevada. “They don’t know if it was a coyote that killed a sheep. It’s just a coyote, and it’s got to be killed.”
While fewer bobcats are killed today, the numbers of three other major predators shot, trapped and snared by the agency have risen. In 1970, agency employees killed 73,100 coyotes, 400 black bears, 120 mountain lions. By 2011, the tally had climbed to 83,200 coyotes (up 14 percent), 565 black bears (up 41 percent) and 400 mountain lions (up 230 percent).
“If you look at their mandate, we could not have written it better for them,” said Suzanne Stone, Northern Rockies representative for Defenders of Wildlife, who has worked with Wildlife Services employees to promote nonlethal control. “It’s all about supporting wildlife conservation and promoting humane tools.
“That’s not what is happening on the ground,” Stone said. “Unfortunately, in parts of the western United States it just seems like they are still in the Dark Ages. They go at this as a kill mission. They are at war with wildlife.”
Most surprising may be the fate of the agency’s longtime adversary, the coyote, an animal that Mark Twain once called “a living, breathing allegory of Want.”
After several decades of intense federal hunting, there are more coyotes in more places than ever.
“I call it the boomerang effect,” said Wendy Keefover, a carnivore specialist with WildEarth Guardians. “The more you kill, the more you get.”
In California, researchers have found that having coyotes in the neighborhood can be good for quail, towhees and other birds. The reason? They eat skunks, house cats and raccoons that feast on birds.
“The indirect effects (of predators) are often more important than the direct effects,” said Reg Barrett, professor of wildlife ecology and management at the University of California, Berkeley. “We just don’t know enough about what’s going on.”
The most dramatic example of how predators shape the land is playing out in Yellowstone National Park where wolves, after a 70-year absence, were returned in 1995 and began preying on one of the densest populations of elk in North America.
Before long, aspen, willows and cottonwoods that had been overgrazed by elk began to thrive again, attracting beavers, migratory songbirds and other wildlife.
Ravens, magpies, eagles and grizzly bears benefited, too, from a smorgasbord of elk carcasses.
But tracking the ecological effects of predators is a fine art not widely practiced. “We could sure use more research,” said Barrett.
Last year, something curious caught Stewart’s attention in Nevada: an email informing her that a mule deer had tested positive for the plague – a disease sparked by rodent outbreaks and potentially deadly to humans – in an area where Wildlife Services was killing predators.
“It makes you wonder,” said Stewart. “In this area where we’ve been doing rampant predator control, we’re seeing a disease show up. Frankly, I’d rather see a deer get eaten by a coyote than show up symptomatic for a disease like plague.”
A few years back, Nevada rancher Marti Hoots noticed that jack rabbits were out of control. Then, while rounding up cattle on horseback, she spotted a Wildlife Services plane over her pasture. A man leaned out and began shooting coyotes.
“I was irate,” said Hoots. “It was the dead of winter, and I found no reason for them to be shooting because the coyotes weren’t bothering anything.
“The jack rabbits were everywhere,” Hoots said. “So the coyotes were doing some good, and they were shooting them.”
From the air
Aerial gunning is the agency’s most popular predator-killing tool. Since 2001, more than 340,000 coyotes have been gunned down from planes and helicopters across 16 Western states, including California – an average of 600 a week, agency records show.
“When they take that plane up, they kill every single coyote they can,” said Strader, the former Wildlife Services hunter who worked with aerial gunning crews in Nevada. “If they come back and say, ‘We only killed three coyotes,’ they are not very happy. If they come back and say, ‘Oh, we killed a hundred coyotes,’ they’re very happy.
“Some of the gunners are real good and kill coyotes every time. And other ones wound more than they kill,” Strader said. “Who wants to see an animal get crippled and run around with its leg blown off? I saw that a lot.”
The agency does not disclose the specific locations where aerial gunning takes place, but records show coyotes are killed on public land in Nevada, including the Humboldt-Toiyabe National Forest. In California, coyotes are hunted from the air in Calaveras, Glenn, Kern, Lassen, Madera, Merced, Modoc, San Joaquin, San Luis Obispo, Shasta, Siskyou and Stanislaus counties.
Clay, the agency’s deputy administrator, defended the practice, calling it is a valuable preventive strategy to clear swaths of land of predators in the winter before livestock arrive to graze in the spring.
“If you can remove the predators, you can reduce the losses,” Clay said.
But Carter Niemeyer, a former Wildlife Services district manager who scheduled coyote-killing flights in Montana, said the cost exceeds the value of livestock protected.
“It absolutely calls for a cost-benefit study,” said Niemeyer. “Aerial gunning is very, very expensive. You are talking $700 to $1,000 an hour to be hunting these coyotes.
“If private landowners want every coyote on their property shot, you got no bone to pick with me. But go hire your own helicopter at 700 bucks an hour and do it yourself.”
The practice remains popular, he said, because it keeps hunters busy during the slow winter months. “These guys don’t have a heck of a lot to do in the winter, so to stay employed, they need to go fly around in a helicopter and shoot coyotes that might kill a sheep next spring,” Niemeyer said.
“There is not enough money on earth to kill all the coyotes that might kill a sheep out there.”
There is something else about the effort that made Niemeyer skeptical: the coyote itself. No matter how many were killed, there were always more of them.
The problem, not the cure
Coyotes are known for their cunning. But their response to hunting takes craftiness to a new level: They are expanding their numbers and colonizing new territories.
“The more you shoot, the more you need to shoot,” said Steve Searles, wildlife management officer in Mammoth Lakes. “We go easy on the gun because if you start shooting up the population, you’re not part of the cure. You’re part of the problem.”
In Nevada, scientists found that when Wildlife Services began killing coyotes to protect deer south of Ely in 2004, the average coyote litter size jumped from one pup to 3.5. In 2007, one coyote killed by a Wildlife Services hunter in Nevada had 13 fetuses in its uterus.
Just how coyotes prosper amid persecution remains a mystery. But many believe they benefit from better dining opportunities that emerge over time as coyotes are killed and rabbits and mice begin to multiply.
“A lot of it comes down to nutrition and competition. When you have fewer animals (coyotes) on the landscape, you have more food available per individual. There is a ton of food on the landscape. Why not have a bigger litter?” said Stewart, the Nevada ecologist.
Many also believe killing coyotes en masse only makes them smarter, through natural selection. “I’m sure of it,” said Barrett, the UC Berkeley professor. “How can an animal like that be so successful if there wasn’t strong selection for individuals that take care of themselves under intense pressure? You’ve got to hand it to them. It’s pretty amazing.”
“We’ve raised a super race of coyotes,” said Bill Jensen, a sheep rancher in Marin County. “There is nothing more cunning than these things now.”
At what cost
Wildlife Services spends about $30 million a year to protect livestock from predators – mostly coyotes. On its Web page, it says losses to predators top more than $127 million a year.
But Niemeyer said those losses, which are based on unverified reports from ranchers, are exaggerated. “To paint this picture that the whole livestock industry is under siege by predators is grossly misrepresented,” he said. “There are individuals who sustain losses, but not everyone.”
Sheep and lambs are most at risk. “They are easy to kill, and lots of animals key on them,” Niemeyer said.
But cattle are less in danger.
“Calves, when they’re small, are vulnerable,” said Niemeyer. “But it doesn’t take very many weeks before they outgrow coyotes. In my 33-year tenure, I have less than 20 calves that I would attribute to being killed by coyotes.”
Like a crime scene investigator, Niemeyer journeyed into the field to inspect sheep and cattle that ranchers said had been killed by predators. Often, his verdict was not guilty.
“You start looking and you realize nothing killed this,” said Niemeyer. “They died from a multitude of things: birthing problems, old age, bad hooves, cut by barbed wire. There were an awful lot of things attributed to predation that really were not.”
Niemeyer is not the only former Wildlife Services employee to raise questions about agency practices. In California, biologist Mike Jaeger did, too, with studies in Mendocino County that showed most coyotes don’t prey on sheep at all and those that do are the hardest to kill with nonselective traps and poison.
“The research showed quite clearly that nonselective control doesn’t work,” said Jaeger, who has since retired. “You can remove a lot of coyotes and have no effect at all. Absolutely none.”
But his calls for more selective control often went unheeded, he said, because of a disconnect between the agency’s scientific and field personnel – and its close ties to the livestock industry, which helps fund predator control.
“I think there is a lot of political pressure,” Jaeger said. “They have to make the landowners happy. And many of them perceive the solution of the problem as population reduction.”
Federal officials decline to disclose the ranches on which Wildlife Services employees work. Such information “would cause a clearly unwarranted invasion of personal privacy,” wrote Tonya Woods, director of the Freedom of Information & Privacy Act office for the USDA’s Animal and Plant Health Inspection Service. “Also, disclosing this information will not shed any light on (federal) duties and responsibilities.”
But a document obtained by The Bee provides a look at one Wildlife Services job in Nevada where predators were targeted indiscriminately, and innocent animals died.
The email by a Nevada Department of Wildlife biologist details work on the 3,200-acre Rafter 7 Ranch on the East Walker River in Nevada. “With no evidence of any kind that any predation had occurred Wildlife Services set snares around the area to kill any predators that may wander through,” the biologist, Russell Woolstenhulme, wrote.
Officials concluded the snares killed at random, taking the lives of four bears and four mountain lions that had not harmed sheep.
The state is now demanding that Wildlife Services target predators more selectively. “We realize some of this stuff is not publicly acceptable,” said Rob Buonamici, chief game warden for the Nevada Department of Wildlife.
Mule deer fallacies
But Wildlife Services continues to kill nonselectively in many places, including the Granite Mountains north of Reno where the goal is protecting a big-game species – mule deer – and is funded by a predator control fee assessed on hunters.
Stark, majestic and isolated, the Granites loom like an island over the desert terrain. But that beauty is deceiving because the range is a place of rough justice for predators, internal Wildlife Services records show.
After slicing open a mountain lion killed in a federal neck snare in 2008, one agency hunter filled out a handwritten report: “Stomach contained deer hair and bone fragments,” he noted. Eleven days later, he cut open another lion with different results: “He had nothing in his stomach.”
In some cases, animals had rotted away by the time the agency hunter found them. “Only the skull was saved due to decay. Pelt not saved due to decay/slippage. Decomposition did not allow for accurate weight estimate,” he wrote in a series of reports about mountain lions.
In 2009, the hunter found two lions dead in snares close to each other, “most likely” a mother and daughter, he wrote. Coyotes were targeted routinely, including four pups killed in their den in May 2011.
Has the killing been worth it? That is what scientists have asked as they’ve flown over the Granites, comparing the size and growth of deer herds where predators were killed with places where they were not.
The scientists have packaged their data and findings into reports and presentations filled with biological jargon and complex statistical analysis. But in plain English, it hasn’t worked.
“There was no discernible difference,” said Tony Wasley, a mule-deer biologist with the Nevada Department of Wildlife. “There were several different (population) variables we tested, and none were significantly different than adjacent areas with no predator control.”
Two other factors generally have bigger impacts: harsh weather and poor forage conditions. When there is not enough to eat, saving a deer from predation may only delay death by starvation later.
“The simplicity of predator control has broad appeal,” Wasley said. “The complexity of the problem is far greater.”
A recent study in “Wildlife Monographs,” a scientific journal published by the Wildlife Society, reported that most years, coyotes don’t prey on deer at all. They’re busy eating mice and rabbits. And even when a coyote does kill a mule deer, it generally doesn’t have an impact.
“There is a contingent of mule deer that are going to die every year anyway. Often those are the first ones coyotes prey on,” said Mark Hurley, a mule-deer biologist with the Idaho Department of Fish and Game and author of the study.
“The silver bullet isn’t to run out there and kill all the coyotes or all the lions and boom – you get all the deer back,” said Ken Mayer, director of the Nevada Department of Wildlife. “It’s way, way more complicated than that.”
On occasion, Wasley has presented his findings to Wildlife Services managers in Reno. “I’ve been told my analysis is a morale breaker, that they don’t like me because I’m doing objective analysis,” he said.
“The director told me he’s got a tough time keeping his guys’ spirits up when they read what they’re doing has yet to demonstrate any measurable benefit,” Wasley said.
[piece regarding how prairie dogs are necessary for the environment]
Prairie Dogs and Soil Impacts
- Much of the degradation of soils in the urban environments that have prairie dog colonies is the result of considerable human disturbance over long periods of time.
- The soil erosion we tend to see is often due to overgrazing by cattle, which has been well demonstrated by numerous studies (Schlesinger et al. 1990, Van Auken 2000, Reynolds et al. 2007). It is important to keep in mind that black-tailed prairie dogs prefer open patches of grassland, and will move into heavily grazed patches of grassland. This tends to cause the observer to blame the prairie dogs for the degraded state, when in fact the conditions were present prior to the presence of prairie dogs.
- Prairie dogs and bison co-existed for thousands of years throughout the central grasslands of North America (Forrest 2005, Miller et al. 2007).
- Current research at Janos, Mexico by researchers at the University of New Mexico and University of Mexico (Davidson et al., unpublished data) involves an exclosure experiment where they are comparing grassland in areas where prairie dogs are present to where they have been removed. The effects of prairie dogs on soil stability (a measure of soil erosion) are measured for this study, which shows absolutely no difference (statistically or even qualitatively) in soil stability where prairie dogs are absent versus where they are present over the 2 years (4 seasons) of the study.
- Prairie dog burrows act as aquifers that prevent water from eroding land while helping to cool it.
- Recent studies have shown that ‘managed’ grasses and forbs atop a prairie dog town are higher in protein and nitrogen and are favored for grazing by bison, elk, and pronghorn.
- a [Prairie dog] burrowing can be beneficial to the soil because mixing soil types and incorporating organic matter enhances soil formation. It also helps to increase soil aeration and decrease compaction.
- In short-grass prairies, the number of plant species, particularly forbs, increases because of the digging and scratching activities of prairie dogs that disturb the soil. These patches of bare soil provide excellent sites for annual forbs to become established. . . . Long-term use of an area by prairie dogs appears to promote buffalograss and grama grasses (Foster & Hygnstrom).
- Prairie dogs do more than just serve as prey, they also perform a valuable service for the prairie – they disturb it. In addition to digging up the soil, prairie dogs clip the vegetation around their burrows, enhancing nitrogen uptake by these plants. Natural disturbances are an important part of maintaining the prairie ecosystem (Kotliar, 2001).
Prairie Dogs, Cattle and Soil Impacts:
The overgrazed conditions that we see when both prairie dogs and cattle co-occur are largely due to cattle being confined to a fenced landscape that no longer reflects the large roaming herds that historically grazed the grasslands.
- Large ungulates are known to preferentially graze on prairie dog colonies because of the more nutritious forage (Whicker and Detling 1988, Miller et al. 2007). This is a counterintuitive phenomenon made logical by the prairie dog’s penchant for clearing shrubs that cattle shun, while stimulating weeds they savor (Stolzenburg, 2004).
- Widespread soil erosion is largely caused by overgrazing by cattle, and prairie dogs are known to move into the overgrazed grassland patches.
- Prairie dogs from urban populations provide a key source of prairie dogs for grassland conservation and restoration.
- Like giant earthworms, their excavations were loosening and turning, fertilizing and aerating nearly six tons of hard-baked desert soils per acre, more than eight times the combined output of all kangaroo rats, badgers and other burrowing mammals of the grasslands (Stolzenburg, 2004).
- Efforts to simply eradicate prairie dogs from urban areas are short-sighted and do not contribute to the conservation of our native grassland ecosystems.
- Extermination efforts require 72 hours of poisoning to kill the animals. It is an extremely long, inhumane death, and is not something that should be condoned in a civil society. Additionally, extermination efforts indiscriminately kill not only prairie dogs but also other native wildlife.
- A model way to think about prairie restoration would be to utilize displaced urban prairie dog populations as a source to repopulate grassland areas being restored for prairie wildlife. In these restoration areas, animals can be released so they can repopulate areas where they were historically abundant, prior to mass extermination efforts and play their keystone role in grassland ecosystems, which is critical to maintaining grassland biodiversity.
Aschwanden,C. 2001. Learning to Live with Prairie Dogs. National Wildlife. p. 26
Forrest, S. 2005. Getting the story right: a response to Vermeire and Colleagues. Bioscience 55:526-530.
Foster, N.S., S. E. Hygnstrom . 1990. Prairie Dogs and Their Ecosystem, University of Nebraska-Lincoln
Department of Forestry, Fisheries and Wildlife pp. 2-6
Schlesinger, W. H., J. F. Reynolds, G. L. Cunningham, L. F. Huenneke, W. M. Jarrell, R. A. Virginia, and W. G. Whitford. 1990. Biological feedbacks in global desertification. Science 247:1043-1048.
Stolzenburg, W. 2004. Nature Conservancy, Understanding the Underdog.pp 28-31.
Whicker, A. D., and J. K. Detling. 1988. Ecological consequences of prairie dog disturbances: prairie dogs alter grassland patch structure, nutrient cycling, and feeding-site selection by other herbivores. Bioscience 38:778-785.
Van Auken, O. W. 2000. Shrub invasions of North American semiarid grasslands. Annual Review of Ecology and Systematics 31:197-215.
Young, M.T. 2006. A Prairie Dog Ecosystem. Colorado Division of Wildlife: p.1
PRAIRIE DOGS ARE A KEYSTONE SPECIES OF THE GREAT PLAINS
By Nicole Rosmarino/Southern Plains Land Trust
Editor’s note: (The following studies show unequivocally that prairie dogs are a keystone species of the Great Plains, that is, their presence –including their colonies, burrows structure and grazing habits– is central to the survival of a multitude of other wildlife)
Prairie Dogs as Prairie Restorationists:
Although there is tremendous documentation of the benefits that prairie dogs provide to wildlife species, both as a prey base and for creating extensive habitat for prairie creatures, it is also important to recognize that prairie dogs may help to redress the damage to the land caused by reckless humanity.
First, prairie dogs act as water conservationists. While humans have devastated the water features of the Great Plains –by damming up rivers and streams for crop and livestock agriculture, and by overgrazing of riparian areas by livestock– prairie dogs increase the ability of an arid region to conserve what little water falls from the sky. One author (Outwater 1996) has remarked on the extensive megapore system prairie dogs can provide for channeling precipitation into the water table. Imagine 100-700 million acres of these megapores diligently directing the scant Great Plains rainfall to underground storage. Imagine also what the reduction of those millions of acres to less than 700,000 acres might mean in terms of increased flooding (where there isn’t meant to be flooding) and increased runoff in general.
In addition, prairie dog clipping and digging activities lead to decreases in transpiring leaf area, conservation of soil moisture, changes in soil physical properties, and the promotion of water infiltration to deeper soil depths. All of these factors probably account for the improved soil moisture availability and plant water status on prairie dog colonies (Day and Detling 1994). This improved water status and the higher ratio of green forage on colonies later in the season may explain preferential grazing by bison and antelope (Day and Detling 1994), and, of course, by domestic cattle. In other words, prairie dogs increase the ability of the soil and vegetation in the arid Great Plains to conserve the region’s scant precipitation.
Prairie dogs might also redress some of the problems with overgrazing. For instance, prairie dogs can control noxious weeds and native invaders which proliferate on overgrazed rangeland. An example is prairie dog control of mesquite (Miller et al. 1996; Miller and Ceballos 1994). They remove pods and seeds and nip and strip bark from young seedlings, which contributes to seedling mortality. The extermination of the prairie dog may therefore explain the proliferation of honey mesquite from the late 19th century (“Suffering From a Prairie-Dog Shortage,” 1991). Where mesquite proliferates, prairie dogs could serve to control it.
Finally, prairie dogs may also reverse processes such as soil compaction caused by cattle grazing. For example, Ellison and Aldous (1952) provide an early report of the soil aeration effected by burrowing rodents. These rodents produce soil which is substantially softer and looser than soil in uncolonized areas. Such rodents consequently represent a range improvement, which can undo some negative effects on rangeland (e.g. soil compaction) that are caused by domestic cattle.
In the debate over whether or not prairie dogs are a keystone species of the Great Plains, there is no mention of the fact that all studies reviewed took place after prairie dogs had been reduced by 98% (by 1960). How can we assume wildlife has not made significant adjustments in the face of prairie dog scarcity? Our science may very well have totally missed important, close relationships between prairie dogs and a given bird, mammal, or what have you, only because that bird, mammal, or what have you flew or skittered off to greener pastures in the wake of guns and poisons.)
Many of the earlier studies (e.g. Reading/Miller/Whicker/Detling) have been very clear that the biodiversity contributions of prairie dog colonies should be perceived in terms of a grassland mosaic – e.g. a mix of colonized and uncolonized areas, colonized for different lengths of time. If one looks at biodiversity that way, it makes good sense to observe species near or flying over a prairie dog colony, as well as those species on a colony. Prairie dog colonies don’t operate in isolation from uncolonized areas, so why should their value to biodiversity levels/associated wildlife be judged in isolation? Landscape-level dynamics should be judged at the landscape-level, not acre by acre.
PRAIRIE DOG ASSOCIATES/DOCUMENTED RELATIONSHIPS
1. Black-footed ferret. This species is an obligate associate of the prairie dogs (Russell et al. 1994). Black-footed ferrets depend on prairie dogs as a primary food source and upon their burrows for shelter from weather and predation. The ferret is completely dependent upon prairie dogs for survival (Henderson et al. 1969). Prairie dogs constitute about 90% of the ferret’s diet.
2. Swift Fox. A major portion of the swift fox diet is prairie dogs (Uresk and Sharps 1986). Also of importance is the ability of prairie dogs to provide cover for swift fox. Swift foxes den on or within .8km of prairie dog colonies (Hillman and Sharps 1978).
3. Ferruginous Hawk. That the ferruginous hawk is closely associated with prairie dogs is apparent from research which suggests that ground squirrels and prairie dogs are the top food source for the ferruginous hawk (Olendorff 1993). In addition, researchers have reported the ferruginous hawk’s relative abundance in areas with prairie dog acreage (Knowles and Knowles 1994; Cully 1991), and Canada has emphasized the importance of prairie dogs and burrowing mammals associated with prairie dog colonies in the recovery of ferruginous hawk populations (Canadian Ferruginous Hawk Recovery Plan 1994).
4. Mountain Plover. The mountain plover may be a prairie dog obligate (Knowles and Knowles 1994), and is, at minimum, highly dependent on prairie dogs for survival. Knowles and Knowles (1998) report that mountain plovers select prairie dog colonies for nesting, breeding and feeding. Other reports concur, showing, for example, that mountain plovers use prairie dog towns as nest sites (BLM 1979, cited in Clark et al. 1982), and they strongly prefer the short-cropped vegetation on prairie dog towns (Knowles et al. 1982), which facilitates their insectivorous feeding (Olson 1985).
5. Burrowing Owl. Prairie dog colonies provide the burrowing owl with both shelter and increased prey abundance (Agnew et al. 1987). Consequently, the decline in prairie dog habitat causes declines in burrowing owl numbers (Knowles and Knowles 1994).
6. Golden Eagle. The golden eagle has long been described as an important prairie dog predator, with current predation probably “second only to badger predation” (Campbell and Clark 1981, 273). More recent reports echo the importance of the golden eagle as a prairie dog predator (Hanson 1993), with some researchers declaring that, in the Northern Great Plains, “wherever prairie dogs are found, golden eagles can also be found” (Knowles and Knowles 1994, 35). When golden eagles nest near prairie dog towns, prairie dogs comprise 50-62% of their diet (Tyus and Lockhart 1979).
7. Badger. Badgers are commonly associated with prairie dog colonies. Knowles and Knowles (1994) write “Generally, the more abundant prairie dogs are in an area, the greater the chances of encountering badgers.” According to Campbell and Clark (1981), badgers are possibly the most significant predator of prairie dogs. Lindzey (1982) concurs. 8. Coyote. Coyotes have been named as important predators of prairie dogs by some researchers (Tyler 1968; Koford 1958; Longhurst 1944; Sperry 1941).
9. Prairie Falcons. One researcher reported the majority of predation on prairie dogs was done by prairie falcons (Knowles 1982). Knowles and Knowles (1994) expect that, should good nesting habitat exist for prairie falcons near prairie dog towns, a significant portion of the falcons diets would be prairie dog.
10. Bison. The preference of bison (buffalo) for grazing, breeding, and resting in prairie dog towns has been demonstrated by other researchers (Whicker and Detling 1993; Coppock et al. 1983b). Even more interesting, Krueger (1986) found that bison and prairie dogs have a mutually positive relationship, as the foraging efficiency of prairie dogs increases in the presence of bison, and bison, in turn, prefer the vegetative conditions caused by prairie dogs.
11. Pronghorn. This ungulates preferentially grazes on prairie dog colonies, on account of the abundance of forbs that typify colonized areas (Whicker and Detling 1993; Krueger 1986; Wydeven and Dahlgren 1985). 12. Elk. This ungulate preferentially grazes on prairie dog colonies in the summer months (Wydeven and Dahlgren 1985).
13. Mule deer. This ungulate also preferentially grazes on prairie dog colonies (Foster and Hyngstrom, n.d.).
14. Horned Lark. This bird has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986).
15. Mourning Dove. This bird has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986; Clark et al. 1982).
16. Killdeer. This bird has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986; Clark et al. 1982).
17. Barn Swallow. This bird has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986).
18. Long-billed Curlew. Prairie dog colonies are reported to benefit this bird (Clark et al. 1982; BLM 1979).
19. Eastern Kingbird. Prairie dog colonies are reported to benefit this bird (Clark et al. 1982; BLM 1979).
20. Upland Sandpiper. Prairie dog colonies are reported to benefit this bird (Clark et al. 1982; BLM 1979).
21. McCowns Longspur. Prairie dog colonies are reported to provide nest sites for this bird (Clark et al. 1982; BLM 1979).
22. Snowy Owl. This bird has been documented utilizing prairie dog colonies in the winter months (Sharps and Uresk 1990).
23. Bald Eagle. This bird has been documented utilizing prairie dog colonies in the winter months (Sharps and Uresk 1990), as prairie dogs can provide a portion of this birds diet (City of Boulder, CO, Open Space Dept. 1996).
24. Red-tailed Hawk. This bird has been documented utilizing prairie dog colonies in the spring, summer and fall months (Clark et al. 1982), as prairie dogs can provide a portion of this birds diet (City of Boulder, CO, Open Space Dept. 1996)
25. Kestrel. This bird has been documented utilizing prairie dog colonies in the spring, summer and fall months (Clark et al. 1982).
26. Rough-legged Hawk. This bird has been documented utilizing prairie dog colonies in the spring, summer and fall months (Clark et al. 1982).
27. Harrier. This bird has been documented utilizing prairie dog colonies in the spring, summer and fall months (Clark et al. 1982), as prairie dogs can provide a portion of this bird’s diet (City of Boulder, CO, Open Space Dept. 1996).
28. Short-eared Owl. This bird has been documented utilizing prairie dog colonies in the spring, summer and fall months (Clark et al. 1982). 29. Deer Mouse. This small mammal has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986).
30. Northern Grasshopper Mouse. This small mammal has been reported to be found in higher abundance on prairie dog colonies than in surrounding mixed-grass prairie (Agnew et al. 1986).
31. Desert Cottontail. Prairie dogs enhance habitat for desert cottontails. In one study, no cottontails could be found prior to the
establishment of a prairie dog town, but after the dogtowns were established, cottontails were present in densities of .81-1.33/ha on
colony, in contrast with .03-.05/ha off-colony. (Hansen and Gold 1977).
32. Prairie rattlesnake. The greater abundance of small mammals in prairie dog colonies (Agnew et al. 1986), and the availability of prairie dog burrows for shelter, have been cited as factors for rattlesnakes to utilize prairie dog towns (Knowles and Knowles 1994).
33. Great Plains Toad. The greater availability and abundance of insects on prairie dog towns, and the availability of prairie dog burrows for shelter, have been cited as factors for this toad to utilize prairie dog towns (Knowles and Knowles 1994).
Weighing up to 60 pounds on average, beavers are the largest rodent found in North America. Well-known for building dams, these creatures make more of a difference to their ecosystem than many people realize. In fact, they’re commonly referred to as ecosystem engineers, because of all they do for their surrounding environment.
When beavers make a dam, they slow the flow of water in the stream and, subsequently, a pond or area of wetland is formed. Roughly 85 percent off all native North American fauna rely on wetlands, so they’re extremely important to the ecosystem. These wetlands also slow the runoff of rains, thereby storing water that would otherwise be lost.
When beavers fell trees to make dams and lodges, they have a positive effect on their ecosystem. After felling aspens — beavers’ tree of choice — the stumps grow new shoots, which are unappetizing to beavers but are the ideal food for moose and elk populations. When they cut down trees, they also bring more light to the forest floor, which allows trees that need a lot of light to grow — such as hazels and alders — an opportunity to thrive. This encourages diversity of plant life.
Sediment and Water Filtration
When a dam slows the water and creates a pond or wetland, it also slows the movement of the sediment in the stream and causes it to build up in the pond. This nutrient-rich sediment either provides food for those creatures who live at the bottom of the pond or slowly seeps into the surrounding soil. Once the beavers move on and their dam breaks down, the water will drain, leaving behind an extremely lush meadow full of rich soil. Dams also filter the water that runs through, improving its quality.
The ecosystem engineering that beavers carry out in their habitat has a positive influence on local flora and fauna and greatly increases biodiversity. Studies have shown there is likely to be a greater abundance of birds, reptiles and plant life in areas modified by beavers. Beavers tend to make their ecosystems more complex, and therefore a number of species may rely on them and the way they engineer the environment.
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Opossums are an intricate part of our environment
The next time you see an opossum playing dead on the road, try your best to avoid hitting it, or if you are a hunter or trapper please don’t kill them. Because it turns out that opossums are allies in the fight against Lyme disease. Possums, like many other small and medium-sized mammals, are hosts for ticks looking for a blood meal. But opossums are remarkably efficient at eliminating foraging ticks. “In a way, opossums are the unsung heroes in the Lyme Disease epidemic.” Rick Ostfeld, author of a book on Lyme disease ecology and a senior scientist at the Cary Institute of Ecosystem Studies, explains…
“Because many ticks try to feed on opossums and few of them survive the experience. Opossums are extraordinarily good groomers it turns out – we never would have thought that ahead of time – but they kill the vast majority – more than 95% percent of the ticks that try to feed on them. So these opossums are walking around the forest floor, hoovering up ticks right and left, killing over 90% of these things, and so they are really protecting our health.”
So it’s in our best interest to have opossum neighbors. This means keeping their habitat intact with thoughtful land use planning, tolerating them in our yards, and, whenever possible, avoiding opossum collisions.
They are beneficial to gardens. By eating snails, slugs, insects, and small rodents, they destroy the true culprits that feed on your beautiful vegetable plants.
They clean up spilled garbage. Therefore, if you are too lazy to take your trash to where it belongs and you sit it out on your porch, and then awake to find it gone? Perhaps you should write the opossum a thank you note.
They eat spoiled and rotten fruit that has fallen from trees. This will keep other pests, flies, beetles, and creepy crawlers from invading your orchard or lawn.
TICKS! It’s true! They hoover up ticks like they are candy while they obsessively clean their coats. According to an intense study at the Cray Institute of Ecosystem Studies, “one opossum can kill about 5,000 ticks in one season.”
Oh and opossums are very clean, they actually groom themselves meticulously and precisely, much like cats.
Opossums are very necessary to the environment and beneficial to our health.
Bobcats, scientific name Lynx rufus, are the most widespread predator in North America, ranging from Mexico to Canada. Some researchers have suggested that the bobcat is a “keystone species.” A keystone species is one that has a disproportionate effect on the ecosystem that it lives in, relative to its biomass. Predators are commonly named as keystone species because their populations are relatively sparse, yet they exert considerable influence on lower levels of the food chain.
The bobcat is a generalist predator — this means that it has the ability to prey on a diverse range of prey species. This is due, in part, to its versatile size. The bobcat, roughly the same size as a coyote, is big enough to take down small deer and pronghorn antelope, but small and agile enough to capture small prey. A study carried out by Idaho Fish and Game staff, published in a 1988 issue of “Northwest Science,” found that bobcats ate a total of 42 different species within a year in Oregon’s Cascade Ranges. Hares, black-tailed deer and beavers made up the bulk of the annual diet, but bobcats also ate a range of small mammals, birds, reptiles and even insects.
Top-down Ecosystem Control
As a top predator the bobcat is at, or near, the top of the food chain. This position is a critical one, because the bobcat exerts what is known as “top-down control” of ecosystems. Bobcats and other predators help to keep ecosystems balanced. In ecosystems that are short on predators, consumers lower in the food chain rapidly increase in population size. This over-taxes food resources, leading to poorer condition of individuals and higher rates of starvation. Eventually, low birth rate and high mortality will cause consumer populations to crash, but in the meantime, the effects have filtered down to plant communities. Over-grazing by herbivores can result in very low biomass of some plant species. This in turn affects invertebrate communities, and can inhibit nutrient cycling.