Attracting Woodland Wildlife: A Primer - Gary R. Goff
Department of Natural Resources, Cornell University. Ithaca, NY
Most NY forest owners value the wildlife on their land more highly than its sawtimber potential. Fortunately, management for either objective can be quite compatible for the other. That is, with careful planning both objectives can be enhanced simultaneously. The purpose of this paper is to introduce a few key concepts that can be the basis for further study. Fortunately, scores of excellent publications are available to forest owners interested in improving their lands for wildlife.
The key to viable, sustainable wildlife populations is HABITAT
Most wildlife management is based on creating or preserving habitat. Habitat equates to "home" and consists of the necessities of life -- food, water, and cover. Technically there is no such thing as "good" or "bad" habitat per se, as some wildlife species will use even the most "barren" looking areas. Habitat has little meaning as a general term, but is best associated with a single species or perhaps with a community of species that live in the same ecosystem. Examples include wildlife that live in a wetland or in a mature northern hardwood forest.
As a woodland owner, your goal may be to supply quality habitat for a favored wildlife species. The quantity, quality, spacing, and availability of food and cover will determine how good or suitable the habitat is for specific species of wildlife. Let's use the gray squirrel as an example of a species that you might wish to provide with "good habitat". Squirrels need adequate food supplies year-round. Spring foods can consist of sap, and flower and leaf buds of selected tree species; summer foods might be mushrooms, seeds and berries; and favorite fall and winter foods are apples and nuts. Stable squirrel populations are dependent on a variety of different foods in each season, as the quantity of any one food item will vary year by year. Water is seldom a problem for squirrels, but the provision of a pond, a stream pool, or the deepening of a seep can help ensure an adequate supply. Squirrels need nesting and winter denning cover. Hollow trees supply both of these. The last factor to consider is the spacing or juxtaposition of food, water, and cover throughout your woods. The more interspersed these habitat components are, the larger the population of squirrels the woodlot can support, as each squirrel have all his habitat needs within a relatively small home range.
All habitats have a carrying capacity
A common goal of forest owners is to optimize the number of "favored" wildlife species on their land. That generally means they want to increase the population size, or have their favorite species spend more time on their land. To accomplish this, the habitat needs to be improved to support more individuals. Just as a pasture will support only a certain number of livestock, a woodlot will only support a limited number of any one wildlife species. This concept is called the carrying capacity, or the number animals of a species that an area of land can support over a period of time. The focus of management should be on limiting factors, i.e., the habitat components that are limiting the growth of the population, or not allowing the carrying capacity to increase. Using squirrels once again as an example, winter dens are often the limiting factor in relatively young woodlots because there are few old, mature trees with suitable cavities. In such woodlots, squirrels frequently build leaf nests that are inferior to cavity dens. In this circumstance, the owner might decide to build artificial dens out of wood or provide other structures that serve as cavities.
It is often impossible to supply all the habitat requirements of a species on one ownership parcel. Deer have a home range of at least 600 acres, a flock of wild turkeys may range over 10 sq. miles in search of food and cover, and mated pairs of barred owls defend a home territory of 675 acres. Therefore, it is best to focus on providing the habitat component that is in shortest supply in the "neighborhood". To identify the missing component, conduct a driving or walking tour of adjacent ownership parcels and/or obtain an aerial photo of the area and look for missing or limited habitat components, such as conifer cover, open grasslands, wetlands, mature forests, etc.
Forests are an ever-changing ecosystem
In the previous example, the woodlot would in time grow large, old trees. This points out another important factor to consider when choosing appropriate habitat management practices. All woodlots are part of an ever changing ecosystem, i.e., an interacting system of plants, animals, soil, microorganisms, and climate. Nature generally follows a fairly orderly and predictable process whereby one plant community is gradually replaced by another over time. This process is called natural succession. In time as young forests become older, more and more trees will become larger and start to decay, thereby supplying cavity dens for squirrels and a multitude of wildlife species dependent on tree dens. Here, time works well for the person interested in squirrels. However, the owner interested in wildlife such as ruffed grouse and cottontail rabbits that use early-succession-stage vegetation, would not be pleased with the transformation of a brushlot (good grouse habitat) to a mature forest. The ownership objective might be to hold succession at its current stage or even to set it back to a combination of brush and grasslands. Its true that everything a forest owner does, or doesnt do, affects wildlife because even unmanaged woodlands change over time.
Natures way of setting back succession is commonly through what people consider natural disasters, i.e., floods, wind and ice storms, fire, and insect or disease epidemics. Flooding by beavers is perhaps a bit more acceptable to our way of thinking, but the results are the same. Each of these forces can rapidly transform a mature forest to a brushlot or a wetland. Such vegetative changes are followed by a corresponding change in the wildlife community inhabiting the area. Similarly, landowners use chainsaws, brushhogs, controlled burns, or perhaps herbicides to set back succession in plant communities with the goal of providing improved habitat for desired wildlife species.
Obtaining adequate regeneration is critical to successful habitat manipulation
Regeneration is the process by which forests are replaced or renewed by natural or artificial means. Cutting or planting vegetation is undertaken to change the age, size, vigor, species, or form of the vegetation that makes up the current land cover. The goal is to provide better cover or food for desirable wildlife species. While the goal is usually laudable, success is often difficult to achieve. A multitude of factors may intervene and lay waste to the best-laid plans. Deer, rabbits and voles typically munch young seedlings. Droughts raise havoc with new tree plantings. Tree and shrub species must be well matched to site characteristics, such as soil type and moisture, growing seasons, and sunlight availability. Natural regeneration, through seeds or sprouts is greatly influenced by deer populations, site characteristics, availability of seed sources, competition with other vegetation, timing or season of the cutting or harvest, and existence (or absence) of advanced desirable or undesirable regeneration. Luck will not carry the day, as there are just too many variables that must be controlled and correctly factored into a management plan. Do everything you can to ensure successful tree or shrub regeneration, as failure is just too expensive in terms of squandered time, money, resources and opportunity.
Whats a forest owner to do?
As I stated at the beginning of this article, help is available through scores of affordable publications and videos written for private forest owners. Some good references are listed at the end of this article. Landowners should work out a simple, inexpensive, management plan. Its important to determine habitat limiting factors and devise a management strategy to activity to supply the missing component(s). Always work with nature in a manner that complements natural succession rather than attempting to overpower it. Once experience breeds confidence, the complexity, and investment of time and effort can increase to address more demanding goals. An example of a relatively high-success, low-input habitat improvement project is the building of bluebird houses. Most "bluebird" project references describe the habitat needs of bluebirds and provide some excellent construction designs for safe, species-specific houses. Projects involving the creation of water or wetland habitats are usually moderately complex and "expensive", but often bring immediate, dramatic, and rewarding results as a different wildlife community moves into the newly established ecosystem.
Finally, perhaps the most ambitious and challenging endeavor is coordinating sawtimber management and eventual harvests with wildlife management goals. The scale of the operation and the magnitude of change will bring about a significant change in the appearance of the woodlot and its suitability for various wildlife species. Still, the change can bring about some great opportunities to diversify woodland vegetation (age, size, species, vigor, spacing, and form), and thereby provide a variety of habitats suitable to more wildlife species. Also, many wildlife species depend on several successional stages through their life cycle and seasons. As an example, wild turkeys benefit greatly from having a combination of open fields, brush, and mature woodlots composed of mixed hardwood species in their home range.
Bluebirds in New York. Silverman, B.G. and M.E. Krasny. 1989. 4-H Member's Guide. 21 pp. Cornell Cooperative Extension, Dept. of Natural Resources, Fernow Hall, Ithaca, NY 14853. $2.50. (607/255-2814)
Enhancing Wildlife Habitat: A practical guide for forest landowners. Hobson, S.S., J.S. Barclay, and S.H. Broderick. 1993. NRAES-64. 172 pp. NE Reg. Agr. Eng. Service, Cornell Cooperative Extension, 152 Riley-Robb Hall, Ithaca, NY 14853. $30.00. (607/255-7654)
Enhancement of Wildlife Habitat on Private Lands. Decker, D.J. and J.W. Kelley. 1998 (rev.). IB #181. 42 pp. Cornell Cooperative Extension, Distribution Center, Ithaca, NY 14850. $7.50 (607/255-2080)
Managing Small Woodlands for Wildlife. Gutierrez, R.J., D.J. Decker, R.A. Howard, Jr., and J.P. Lassoie. 1987. IB #157. 32 pp. Cornell Cooperative Extension, Distribution Center, Ithaca, NY 14850. $3.00. (607/255-2080)
Managing Woodlands for Wildlife. Baughman, M., J. Kitts, and L. Wenner. 1993. Item #VH-6214-GG. 24-min. video. Univ. Minn. Extension Service Dist. Center, 20 Coffey Hall, 1320 Eckles Ave, St. Paul, MN 55108-6069. $35.50. (1-800/876-8636 or 612/625-8173)
Wildlife Notebook: Sketches of selected wildlife in New York. Decker, D.J. 1988. IB #210. 76 pp. Cornell Cooperative Extension, Distribution Center, Ithaca, NY 14850. $5.50. (607/255-2080)
Wildlife and Timber from Private Lands: A landowner's guide to planning. Decker, D.J., J.W. Kelley, T. Seamans, and R. Roth. 1988. IB #193. 55 pp. Cornell Cooperative Extension, Distribution Center, Ithaca, NY 14850. $5.50. (607/255-2080)
*All prices include tax, shipping and handling. Make checks payable to either "Cornell University" or "University of Minnesota".
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