Mammals as BioContol
Biological control is a method of decreasing the population of pests that compete with vegetation. There are different methods of bio-control. Farmers use parasites, diseases, and predators as forms of bio-control in their fields. Sheep, goats, bats, cats, and mice are among the different mammals used for pest control. Sheep are used to control leafy spurge on many rangelands, and bats for controlling insects. We will discuss the benefits and downfalls of sheep and goats controlling unwanted weeds, and how a study has been done to prove that bats have made a huge difference in the population of insects that harm agricultural crops.
Sheep and goats have both been used to control leafy spurge. Leafy spurge is very unpalatable for most animals, and therefore is only consumed by sheep and goats. This weed produces a large amount of seeds and reproduces quickly. Since it is a noxious weed, and isn’t useful for the production of crops, this becomes a problem that needs to be controlled. Sheep and goats will graze leafy spurge to decrease the spread of the plant, but won’t completely rid the population. The seeds can live through the digestive process and return to the soil in the form of feces. Not all seeds returned to the ground will germinate, but some will. Sheep are more effective than goats only because the seeds can travel through the goat’s system faster. Since the seeds have the potential to germinate after they have been eaten, the sheep and goats should be kept from areas that are free of leafy spurge for about five days to ensure they won’t be spreading it.
Studies have also shown that lambs are useful in minimizing the weeds that may be growing among the alfalfa in a hay field. Because these weeds will decrease the nutritional value and economic value of the hay, it is important that ranchers clear their fields of weeds. “Using sheep to graze out the weeds would be a better alternative than herbicides, because the chemicals can cause the development of ‘super-weeds’ and also could harm the ground water. Even though sheep will eat alfalfa too, the amount of hay produced will not be affected by the grazing” (Guerroro et al. 29-32).
“Steven Seefeldt did a study on controlling forage growth after rangeland fires. After a fire, the first plants to grow back are going to be mainly unwanted weeds that are very competitive with the native vegetation. If the sheep are put in the burnt area to graze those invasive weeds down before the other vegetation a chance to grow, it will minimize the competition and therefore create more valuable forage for the freshly re-grown field” (Ausmus, 2003).
“Putting sheep out to graze a weed infested field is not only beneficial to the farmers who own the fields, but it’s beneficial to the ranchers who own the sheep. The field is getting cleared of weeds and the...