Report – 2011/2012 Deer Management Plan Implementation, Report to Board of Commissioners
HURON-CLINTON METROPOLITAN AUTHORITY, Meeting of September 13, 2012
It is the consensus of natural area managers that controlling excessive deer populations is critical to the long term health and viability of the native ecosystems that these animals are a component of. The management efforts the Metroparks established has had a direct impact on insuring that the parks’ high quality natural areas remain intact for future generations to enjoy.
“Dramatic” response by flora & fauna to climate change, USGS WUWT, Jan 11, 2012
The U.S. Geological Survey and University of Montana study not only showed that the abundance of deciduous trees and their associated songbirds in mountainous Arizona have declined over the last 22 years as snowpack has declined, but it also experimentally demonstrated that declining snowfall indirectly affects plants and birds by enabling more winter browsing by elk. Increased winter browsing by elk results in trickle-down ecological effects such as lowering the quality of habitat for songbirds.
Climate impacts on bird and plant communities from altered animal–plant interactions
Thomas E. Martin & John L. Maron
Nature Climate Change, Jan 10, 2012
Effects of climate on plant communities may provide an alternative, but particularly powerful, influence on animal populations because plants provide their habitats. Here, we show that abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona, USA. We experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk (Cervus canadensis). We excluded elk from one of two paired snowmelt drainages (10 ha per drainage), and replicated this paired experiment across three distant canyons. Over six years, we reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Moreover, predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment.
Deer Problem in Washtenaw County
AboutLearyJournalism, Dec 11, 2011
Jeff Plakke, Natural Areas Manager for the University of Michigan Botanical Gardens and Nichols Arboretum, says that ten-foot high fencing now protects the Gardens’ formal beds, an expensive solution that involved clearing for and installing the fence, and will require continuous monitoring and repair. Before that, Horticulture Manager Mike Palmer said, the deer devoured yews, perennials, and even whole plants like hens and chicks in the rock garden. In fact, the deer defied urban myths and stepped right up to the concrete porch to sneak into the perennial garden.
Metroparks 2010 – 2011 Deer Management Plan Implementation Report, Meeting of Oct 11, 2011
“This year, 2010, was the first time since 1993 that (Trout Lily and) Michigan Lily were observed in blossom. Deer seem to have a special affinity for members of the lily family, and this plant is no exception. We have been anticipating the return of this species ever since the deer culls began in 1999.”
Growing Deer Population Hurts Survival Of Forests
NPR, June 15, 2011
The deer side of the fence has a carpet of grass, a shrubby looking thing, and some large trees – things that are either too big for deer to eat, or are among the very few plants they don’t like to eat. Inside it is practically a jungle. Dozens of different almost exotic looking plants are tumbling over one another. Many of them are young trees.
You have the old trees. And when the old trees go, there is something here [in the enclosure] to take its place. Out there, I don’t see anything out there that’s a small tree.
One of the surprising things they’ve found with this experiment is that deer allow invasive species to flourish. And with fewer native plants, there are fewer birds who depend on them for nests and food. There are fewer mice and fewer chipmunks here when they have to compete with deer.
White-Tailed Deer, Their Foods and Management in the Cross Timbers (Texas),
Kenneth L. Gee, Michael D. Porter, Steve Demarais and Fred C. Bryant
A Noble Foundation Agricultural Division publication, NF-WF-11-02, 2011 (3rd Edition)
While deer were present in the Cross Timbers historically, man’s manipulation of much of the Cross Timbers habitat probably has improved its quality and suitability as white-tailed deer habitat in many ways. Since the late 1800s, land use practices and, consequently, the landscape in the Cross Timbers have changed dramatically. In many situations, the net result has been an increase in habitat diversity. The suppression of naturally occurring wildfires, the erection of fences and the prevailing livestock grazing practices have enabled woody vegetation to encroach into many open areas. On the other hand, many wooded areas have been cleared for planting crops and/or pasture. These types of land use practices have created many openings and woody patches of various sizes and in various stages of succession or regrowth. Additionally, numerous plant species have been introduced and have readily naturalized in the region, adding to the vegetational diversity. All in all, many of the landscape changes have been favorable to deer.
The Responses of Rare and Common Trilliums (Trillium reliquum, T. cuneatum, and T. maculatum) to Deer Herbivory and Invasive Honeysuckle Removal (abstract)
Bione, Castanea 75(4):433-443. 2010
Our results show that the long-term management of white-tailed deer will be important to the conservation of spring ephemeral herbs such as T. reliquum, T. cuneatum, and T. maculatum.
Appetite for trouble
Wisconsin Natural Resources Magazine, Oct 2007
Even small numbers of deer can have dramatic consequences where the land can’t support a larger herd. At a deer density of 12 to 15 animals per square mile of range, herbaceous plants like trillium, Indian cucumber, showy lady’s slipper and white fringed orchid decline. When deer densities reach 20 to 25 animals per square, species like pines, white cedar, hemlock, oaks and Canada yew can stop regenerating and small mammals like red-backed voles, an important prey species, starve out without the forest floor vegetation they need. At 25 to 35 animals per square mile of range, birds like hooded warblers decline from lack of needed ground, shrub and tree layers.
The impact of deer on relationships between tree growth and mortality in an old-growth beech-maple forest
Zachary T. Long, Thomas H. Pendergast IV, Walter P. Carson, Department of Biological Sciences, University of Pittsburgh
Forest Ecology and Management 252 (2007)
White-tailed deer have been at high levels in the northeastern forests of the United States for decades and have strongly influenced forest dynamics. In this long-term study, we found that the composition of the overstory and understory assemblages of an old-growth beech-maple forest differed significantly. We used exclosures to test the hypothesis that deer contributed to these differences by differentially influencing the relationship between growth and mortality among seedlings of the six most abundant tree species. In the absence of deer, we found that the mortality of the six species decreased with increased growth and that interspecific differences in the relationships between growth and mortality coincided with previously observed shade-tolerance rankings. In the presence of deer, mortality decreased with growth only for the browse tolerant species (American beech, black cherry, and sugar maple). Mortality did not decrease with growth for preferred browse species (oak species, ash species, and red maple), rather, this relationship was eliminated in the presence of deer. The changes in growth and mortality relationships in the presence of browsing generally corresponded to observed changes in seedling density following the removal of deer. Sugar maple, ash, black cherry, and total stem density increased in the absence of deer. Our results suggest that the relationship between survival and growth in the understory, a metric of shade tolerance, is a fairly plastic response that varies depending upon the presence and absence of herbivores. Our results indicate that deer have contributed to the differences between understory and overstory vegetation, with browse tolerant species increasing in abundance at the expense of preferred browse species.