Data on Mill Creek Park deer under fire
YOUNGSTOWN — Mill Creek MetroParks has completed a survey of the deer population in Mill Creek Park and its other properties and has found that it is 19 times higher than the “carrying capacity of the land.”
Nick Derico, MetroParks natural resources manager, said having an average of 387 white-tailed deer per square mile in the park system, including 355 per square mile in Mill Creek Park, indicates “a very serious problem.”
Derico said the recommended density of white-tailed deer is 10 to 20 deer per square mile.
“We have too many deer in relation to available MetroParks property in terms of habitat,” he said.
Derico talked with the MetroParks board and public about the matter Feb. 13, and it will be discussed again March 13, when Derico will make recommendations to the park board on what to do.
In the meantime, the public is encouraged to provide its input on the issue at the www.millcreekmetroparks.org/white-tailed-deer-in-mill-creek-metroparks page on the MetroParks website.
Derico said overpopulation of deer has “significant negative impacts to both the health of the deer population and the ecological biodiversity of the land as well as increased human conflicts,” such as coming into contact with motor vehicles.
A key part of data collection was an aerial, infrared survey carried out at night from an airplane Jan. 21, 2022, in Mill Creek Park and Jan. 26, 2022, in the rest of the MetroParks’ facilities.
The MetroParks has published the results in detail, including specific information on Mill Creek Park — from Fellows Riverside Gardens south to U.S. Route 224 in Boardman. It also includes specific results for the Hitchcock Woods and Huntington Woods areas south of Route 224, and 12 other MetroParks properties throughout the county.
The results show that the highest densities are in the Huntington Woods just south of Route 224 at 592 deer per square mile, Yellow Creek at 674 deer per square mile, Sebring Woods at 607 deer per square mile, Sawmill Creek at 540 deer per square mile and Cranberry Run headwaters at 450 deer per square mile.
Derico said no decision has been made on what to do about the high numbers of deer, but MetroParks officials are discussing that with the Ohio Department of Natural Resources, which is “the managing authority for wildlife in the state.”
ODNR has indicated options for reducing the deer population include allowing hunters to reduce the population or another type of “targeted removal beyond hunting.”
THE WHITE DEER
Aaron Young, MetroParks executive director, said whatever decision is reached, he does not anticipate any herd-reducing activities to affect the three white deer that have been identified in Mill Creek Park, two females and a male.
Derico said two conditions can cause either a full or partial lack of pigment in white-tail deer. One is albinism, in which a deer has an all-white coat, white or see-through hooves, an all-pink nose and pink or pale blue eyes.
He said the three white deer in Mill Creek Park can be described that way.
The second condition is what are called leucistic deer, which have a “partial loss of pigment. They can have an all-white coat, but they commonly retain some level of normal pigmentation in their hooves, noses or in their eyes,” Derico said.
“They would be white deer with normal looking brown eyes,” he said. “That is not the case we are seeing.”
But without genetic testing, which the MetroParks has not done, the park system cannot say for sure whether Mill Creek Park’s white deer are albino, Derico said.
Both types of white deer have “recessive genes and should be very rare” and indicate a problem with the deer population, Derico said.
“The frequency with which that recessive gene is being seen in our herd points to poor genetic diversity, which is caused by inbreeding over time.” It is not an indication that the white deer in the park are unhealthy, Derico said.
The typical prevalence of white deer in a herd is 1 in 20,000 to 1 in 30,000 deer, but for Mill Creek Park to have three of them in a population of about 903 suggests poor genetic diversity, Derico said.
The survey indicated 2,935 deer roamed the MetroParks in January 2022.
Derico said overpopulation of deer in the park is “not necessarily” to blame for possible poor genetic diversity. “It’s more showing there may not be a lot of immigration or emigration in the population at the north end of the park.”
He said, “As the population grows and there is no new genetic material coming into the population, inbreeding is taking place and these rare recessive genes are being seen more frequently.”
Derico has a bachelor’s degree in wildlife and fisheries science from the former California University of Pennsylvania, now known as Pennsylvania Western University, in California, Pa., south of Pittsburgh.
He said the point is that the “frequency of these rare genetic conditions is concerning in terms of genetic diversity.”
He said the park has had “numerous” white deer over the years and generally has had one or two born each spring.
Young said a concern is that with the lack of genetic diversity in the north part of Mill Creek Park, inbreeding may be affecting the health of the deer. “Inbreeding over time can cause other genetic issues,” Derico said. Among them are chronic wasting disease, epizootic hemorrhage disease, Lyme disease and other tick-born pathogens, according to a MetroParks presentation.
Jamey Emmert, spokeswoman for the Ohio Division of Wildlife, told this newspaper last summer that “White deer are a product of a recessive gene in both the mother’s and father’s DNA, which result in white offspring. This recessive genetic trait is found in about 1 percent of all white-tail deer.”
But other factors suggest overpopulation of deer in MetroParks properties, Derico said.
A big one is the ecological damage to plants. Deer feed on a variety of woody and herbaceous plants but have preferred species they like to eat, like spring wildflowers, Derico said.
“When deer are overabundant, they gravitate toward those preferred species and disproportionately impact those species, effectively removing them from the landscape,” Derico said. “Oftentimes what are left are plants that are unpalatable to deer.”
It leads to a high prevalence of invasive species, he said. Overpopulation of deer also leads to a “browse line” where the deer have eaten the vegetation from about 5 feet down.
“They can strip the forest understory of growth,” Derico said. “As sapling trees begin to grow, they get browsed to the ground and killed immediately, so there is no intermediate story of succession coming up through our forest right now. So we are missing an entire generation of forest growth right now due to deer browsing.”
The MetroParks has been experimenting in Hitchcock Woods for five years with a deer-proof enclosure to show what the park would look like if deer were not able to browse.
“We’re seeing ecological damage throughout all of our properties,” he said. “As the MetroParks, we’re stewards of the land. It’s our responsibility to manage these properties in the best interest of all species to promote biodiversity and encourage native species.”
He said deer overbrowsing is a problem throughout the nation, “so many people think that is completely normal and they just don’t realize what it really should be like.”
When plant life is negatively affected, it “affects a multitude of other species, mammals, birds, infections, amphibians … because they’re missing habitat,” Derico said. A bird called the wood thrush used to nest in the MetroParks, but they don’t anymore “because their habitat is gone,” he said. “That’s just one example.”
When Derico was asked about the point of view some people may have that enjoying the deer is the most important thing, Derico said “It’s our job … to protect these parcels and it’s important now for future generations. What will happen to future generations if there is no forest succession?” Derico said.