The first part of this series focused on food and water considerations in habitat management.
The following components—shelter and space—comprise the more “management intense” aspects of creating usable land for wildlife.
Shelter and cover are used to define habitat structure including vegetative, hydrologic and geologic attributes and the way in which wildlife utilize them. The use of shelter and cover is accomplished in a variety of ways, such as feeding, resting, nesting, reproduction, and escape or hiding from predators and weather.
Each use by wildlife is specific to its own natural history. Pronghorn antelope (Antilocapra americana) avoid tall woody vegetative cover preferring open range for predator detection and flight, while ruffed grouse (Bonasa umbellus) prefer heavy horizontal and vertical early successional vegetative cover for predator protection while feeding and raising their young. Both of these examples show that by providing the proper quantity, type and arrangement of cover and shelter, it will attract the wildlife of the selected habitat specific to the species managed.
Providing shelter and cover by the landowner is key in habitat management. Certainly the success of the eastern bluebird (Sialia sialis) and wood duck (Aix sponsa) populations in rebounding from near population crashes can be linked to artificial nest box placement in each bird’s habitat. Conversely, the reduction of snags (dead standing trees) by forestry practices decreased the available natural nesting sites for bluebirds and wood ducks (not to mention decreasing key nutritional and habitat components for numerous other wildlife), thereby reducing shelter and cover components essential to these specific birds survival.
Providing young conifer stands intermixed with early successional hardwood creates ideal ruffed grouse habitat for both shelter from weather, especially in winter, and concealment from predators. However, the older the conifer stand, the more likely hawks and owls are to occupy them for their own cover and shelter making the predation of grouse beneath easier. These predators are concealed by the nature of the conifer branch and needle density and the grouse are exposed by the thinning understory below. Thus, as the age of the conifer stand increases, the habitat suitability for ruffed grouse decreases.
Often, the type of vegetation chosen for cover can also double as a food component within the habitat. Wild turkeys (Meleagris gallopavo) utilize tall mature trees, usually oak and beech, within its range as roosting sites to escape predation. These trees in turn provide large quantities of mast, which the turkeys use as a principle food source. Also, wild turkeys use open fields as nest sites providing ground nesting with maximum protection from edge-stalking predators, and in turn the fields provide high densities of insects which comprise the bulk of a poult’s diet.
Snowshoe hare (Lepus americanus) have shown to prefer cover availability to food availability and have adapted to eat a wide variety of food types to compensate for periods of poor browse, all the while ensuring protection from predators. Knowing what shelter and cover requirements the intended wildlife the landowner wishes to support will dictate the practices needed. In general, go with the native plant types and ages the wildlife have evolved with and again, the more diverse, the better.
Space is the most defining capacity in habitat management for the landowner, as it is difficult and expensive to obtain, as well as maintain.
The size of the property will dictate what management techniques are available for use. The larger the property is, the more tools there are available. However this should not discourage the smaller landowner. Enlisting adjacent property owners with similar habitat management objectives increases connectivity within habitats and discourages fragmentation, regardless of property size.
In terms of habitat management, the space needed for wildlife often translates to home range. The home range of an animal is described as the area covered in daily, seasonal and yearly movements. As food, water, shelter and cover requirements are indicative of each species, so is the space required. Typically, the larger the species, the larger the home range. Moose (Alces alces) occupy a home range of 6,000 acres, whereas New England cottontail rabbits (Sylvilagus transitionalis) vary from half to three quarters of an acre. Topographical factors can also change the overall size in terms of home range for wildlife. Large slopes, rock outcrops, and waterbodies all may interject into minimum space requirements of wildlife species making them unusable. These features may also prove to be barriers impeding movement and furthering isolation from breeding and feeding grounds.
The density of wildlife on a parcel can also change the dynamic of space requirements. Managing the carrying capacities of each species in regards to the habitat provided will prove the most successful if the maximum is not exceeded. Keep in mind more rabbits can occupy an acre than moose. Once again, the more diverse the populations are, the more successful and healthier they will be.
Habitat management should be an enjoyable and hopefully productive investment into the dynamics of property ownership. The rewards of wildlife, be it their recreational or intrinsic values, can be a priceless asset for current and future generations of landowners. Balancing the needs of the wildlife, the components of the land and the desires of the owner is just as much an art as it is a science. The dynamics of habitat require careful planning, constant monitoring and the ability to let be, as soon adjust. Create land use goals and reevaluate them as management progresses, and above all, maintain diversity and patience.