JEFFERSON CITY — Missouri has an abundance of deer, according to Emily Flinn, a resource scientist with the Missouri Department of Conservation. She says the key to understanding this year’s deer forecast is regional and even local differences in deer number.
Flinn specializes in managing Missouri’s economically valuable white-tailed deer herd. She says the state’s deer harvest has been stable for the past 10 years. However, she expects a below-average harvest this year.
She says the past 10 years have seen short-term and long-term changes in deer abundance across the state. For example, changes in hunting regulations have achieved the long-term goal of reducing deer numbers in parts of northern, western, and central Missouri.
During the same period, less liberal harvest regulations have allowed deer numbers in the Ozarks, southwest, and southeast regions of the state to increase slowly but steadily.
Flinn says differences in how Missouri’s estimated 1.4 million deer are distributed across the state also occur at much smaller scales than regions. The most dramatic differences often occur in surprisingly small areas.
To illustrate this, Flinn points to the differences in deer population densities that resulted from last year’s unusually severe outbreak of hemorrhagic diseases, commonly called blue tongue or EHD (epizootic hemorrhagic disease).
These diseases occur annually, but they are more prevalent in drought years. The extraordinarily severe drought of 2012 led to the worst hemorrhagic disease outbreak ever recorded in Missouri.
Reports of deer deaths come to the Conservation Department from its field staff and from citizens. Last year, the number of reports topped 10,000.
Regions with the highest prevalence of deer deaths from hemorrhagic disease were northwest, west-central, and east-central Missouri.
Southeast Missouri had relatively low rates of hemorrhagic disease reports. A map showing county-by-county hemorrhagic-disease reports is available at mdc.mo.gov/node/16479.
Even within counties and regions, the distribution of hemorrhagic disease losses was uneven.
“That is the nature of hemorrhagic diseases,” says Flinn. “You can have significant losses in a particular locality, and almost none in another part of the same county. This is one case where hunters and landowners are in the best position to know how deer populations in their areas are doing.”
That, says Flinn, brings up an important point about the challenge of managing deer in the wake of a severe hemorrhagic-disease outbreak.
Past experience shows that deer numbers often continue to decline in a particular area for as much as three years after an outbreak. That is because hunters continue to harvest about the same number of deer – including does – even though they are not seeing as many deer.
“Most hunters don’t shoot more than one deer a year,” says Flinn. “If deer numbers are down in a particular area, and everyone in the area continues to shoot as many does as they have in the past, what starts out as a moderate reduction in deer numbers can turn into a big reduction. By the time hunters realize what has happened, deer numbers are down so much that it may take a few years to get back to where they were.”
The lesson here is that hunters who noticed lots of deer dying from hemorrhagic disease in their area last year should consider the numbers of deer they are seeing this year and potentially pass up shots at does to allow local populations to recover.
Flinn says Missouri’s deer harvest also is significantly affected by acorn abundance. This is most important in southern Missouri, where the landscape is heavily forested, and acorns outweigh all other deer food sources in the fall.
When acorns are scarce, deer must move around to find food, and that makes them more visible to hunters. Deer behavior and deer harvest are much less dependent on acorn availability in northern Missouri, where acorns make up a smaller percentage of their diet.
The severe shortage of acorns last year due to drought is part of the reason that southern Missouri had a larger-than-usual deer harvest in 2012.
Southern Missouri should have higher acorn production this year, so hunters will need to be more active to find deer.
The combined effects of reduced deer movement, a strong deer harvest in 2012, and losses to hemorrhagic diseases in a few Ozarks counties are likely to result in lower harvest totals this year.