Plans needed to deal with invasive speciesHardly a day goes by that a new invasive species introduction doesn’t make the news. In this day and age of worldwide travel and international trade, something that took hundreds of years to move a short distance by natural distribution can occur in a matter of hours or days hitching a ride in a motor vehicle or in the bilge of a boat.
Hardly a day goes by that a new invasive species introduction doesn’t make the news. In this day and age of worldwide travel and international trade, something that took hundreds of years to move a short distance by natural distribution can occur in a matter of hours or days hitching a ride in a motor vehicle or in the bilge of a boat.
Once it reaches a destination, if there is no competition or predations in its new home territory, the non-native plant or animal can set up shop and outperform its native counterpart, reproducing without any interference. Once established its eradication is almost impossible. Less opportunistic native species can be totally eliminated.
Some non-native species have been brought into an area by well-meaning folks as a perceived valuable addition to the native flora and fauna. The introduction of common carp to our waters was thought to provide an additional food and game fish species, while buckthorn was viewed as desirable ornamental shrub to adorn our urban yards. These are but two examples of hundreds that have gone astray.
Success stories like the introduction of the pheasant in upland areas or salmon in the Great Lakes to replace the devastated lake trout fishery are few and far between. It is amazing the number of species, of both plant and animal origin, that were not native to the landscape 100 years ago.
Even our ever present dandelion is non-native having been introduced by early European immigrants. Escapes from aquariums or flower gardens add greatly to our ever changing landscape.
How can all this happen? One needs to realize that all this is the natural selection process. Survival of the fittest will dictate what species will succeed and what species will be suppressed or eliminated. Specialized plants and animals are at a distinct disadvantage to those less specialized. Life forms that are adaptive to a variety of situations will out-compete less adaptive ones every time.
Humans are a great example of this, being an extremely non-specialized, adaptive species. The human population has expanded to every corner of the earth because of these attributes. Humans can also modify their environment in a short period of time to suit their needs. These activities can adversely affect other populations and species.
Hunters get too much credit for the reduction of the great bison herds. The railroad and farming practices, including the invention of barbed wire, had much more to do with that. The free roaming bison were no longer allowed to roam free.
Land modification, both natural and manmade, can also tip the scale in favor of opportunistic invasives. Disturbed soil is a prime location for a few stray seeds that will soon reproduce into an army of uninvited guests.
Domesticated hogs that escape into the wild will become feral pigs and modify the landscape to suit themselves and their offspring. The extensive damage they do to the environment is not offset by the hunting opportunities they provide.
Millions of dollars have been spent preventing the spread of invasives and millions more have been expended in trying to eradicate them. Kneejerk reaction to the spread and extermination of them can be money down the proverbial rat hole.
What needs to be in place is a plan on how to prevent their arrival. Prevention is the key but it is almost inevitable that their expansion will occur. Once they arrive, a plan needs to be in place to control them. We need to be proactive and not reactive when they come. In some cases, the invasive’s impact can be modified and it can become part of the biological community.
Natural biological control measures can be used when available to lessen their impact. Certain insects have been used successfully to help control purple loosestrife and Eurasian milfoil. Many other examples are available for a variety of other intruders.
Chemical control is also an option but should be used with care because more than just the target organism will be affected. Continued monitoring and follow up treatments are a necessity. Once established any invasive needs to have follow up monitoring and control or it will return in force. Physical control and removal works but is labor intensive.
Bottom line is that a cost effective invasive species plan should be in place for each invasive species, not if they come but when they come.
Earlier this year I received a hardcopy of “Wisconsin Wildlife Surveys April 2012.” These reports are published in April and August each year and contain information and data from a variety of sources over the previous six-month period. It is made possible from Pittman-Robertson funding. Data is accumulated and analyzed for small game, big game, waterfowl and nongame species in Wisconsin. It contains a wealth of information.
According to the “Rare Mammal Observations” section, in 2011, seven reports of verified and possible American marten were received. Six reports of possible wolverines, one report of a possible Frankin’s ground squirrel and one report of a possible Canada lynx were received. Only 25 reports of moose were received. A cow moose was reported with a calf in Washburn County. This is the first calf reported from northwest Wisconsin in recent history. Three young bull moose, one large bull and one dead bull were detected in northeast Wisconsin.
From the “Bird Banding Accomplishments 2011” section by Rich Kahl, through the cooperative efforts of Wisconsin Department of Natural Resources biologists within the Bureaus of Wildlife Management, Endangered Resources and Science Services, a total of 11,880 birds were banded in Wisconsin under the DNR Master Permit. Fourteen species of birds including ducks, geese, swans, loons, osprey, bald eagles, woodcock, mourning doves, terns and song birds were banded at more than 220 sites across the state.
As indicated by the “Wild Turkey Landowner Brood Survey” by Brian Dhuey, 51 percent of hen turkeys observed were accompanied by poults during 2011 compared to 37 percent in 2010. The long term average is 51.2 percent.
The “Fall Turkey Hunter Questionnaire” noted that the fall turkey hunting season was extended 34 days in most of the state in 2011. Most (72 percent) turkey hunter’s feelings on the extended season were “I liked it” or “I liked it a lot.”
Fall turkey hunting with the aid of dogs was allowed statewide in 2011.
Sixty-nine percent of fall turkey hunters receiving a permit hunted turkeys during the 2011 fall turkey season. The overall success rate of active hunters was 20.7 percent.
Statewide, the average number of days spent hunting for fall turkeys was 6.6 with hunting pressure highest on weekends. The most common method of hunting was ambushing from concealment. Despite the larger hunting areas, fewer hunters (9.2 percent) were interfered with during their fall hunt.
Overall satisfaction with the Wisconsin Wild Turkey Program remains high.
(To be continued…)