Each year, the pheasant population fluctuates and here at Mitchell County Conservation Board, we hear all sorts of interesting theories as to why the numbers have changed this year.
These stories can hold plenty of merit blaming the bird numbers on a hard winter, wet spring or other common natural events which impacts a bird’s survivorship on a yearly basis. Like any story, the end is always the best part, and all of these stories seem to end the same way “there used to be thousands of birds, you could flush hundreds from a single field, shoot your limit every time you went out.”
I get excited every time I hear one of those stories and having never seen such numbers, imagine what it might look like.
Then the storyteller will guess again at the cause. “Maybe there are just too many hawks now days.” Maybe I respond…Maybe.”
Then, unfortunately, my mind snaps quickly back to reality and I remember there is a very simple explanation, one that requires little guessing and only common sense to grasp in fact two words can say it all, carrying capacity.
For a given region, carrying capacity is the maximum number of individuals of a given species that an area's resources can sustain indefinitely without significantly depleting or degrading those resources. Put simply, every species, including humans, depend on resources to survive and ultimately, the amount of resources available determines the upper limits of a population.
In the case of the pheasant habitat, it is the resource which determines the upper limit of their population, regardless of any other variables, such as weather or predators. Pheasants require grasslands to live and the more grasslands we have, the more pheasants we will have. The current numbers of pheasants can then be easily explained by the loss of 1.7 million acres of grasslands in Iowa since 2008. In ecology terms, that equates to 1.7 million acres of habitat loss. Common sense then tells us the carrying capacity for pheasants has dropped significantly.
This doesn’t mean the story is over and it doesn’t mean the other theories, like predation, weather and overspray do not factor into the equation. Unfortunately, it means those factors compound the problem. The fact our remaining grasslands are fragmented in small chunks, across the State, yields them more susceptible to predation and other natural or unnatural limiting factors.
The Conservation Reserve Program CRP provides landowners with cash incentive to convert qualifying land back into native grassland habitats. The latest program has had a strong focus on pollinators providing habitat that specifically attracts bees, butterflies, and other pollinating insects, while simultaneously improving water quality and providing habitat for Pheasants and other wildlife.
This has been a popular program in Mitchell County. MCCB has assisted in planting almost 3,000 acres of pollinator habitat over the last three years. Though this is a tiny number compared to the 1.7 million acres of habitat loss over the State, it, should lead to a few more birds locally over the next 5 to 10 years. Currently, the USDA has stopped the pollinator program due to the fact the program was in such high demand, it ran out of funding.
Hopefully, the 2018 farm bill will provide landowners with attractive incentives and make participating in the CRP an affordable option. If we do not continue to put more native prairie on the landscape, our pheasant numbers will not have a significant increase, the incredible stories of a healthy and vigorous pheasant population will remain just stories.