Spring is in the air—thank goodness! As you get ready to head out to your favorite Land Trust Preserve for an early spring hike with your furry friend, we offer this reminder about the importance of keeping dogs on leash.
When humans walk on trails with dogs, they affect their surroundings in various ways. When both human and pet remain on the trail, their impact is restricted to a narrow zone of influence. When dogs are allowed off-leash, they extend this zone of influence in ways that can have negative impacts on wildlife and their habitat.
At Land Trust Preserves where dogs are allowed, our goal is to keep that influence minimal so wildlife can thrive. Impacts of off-leash dogs include:
Direct Predation. Most domestic dogs still maintain instincts to hunt and/or chase when the opportunity arises. Dogs that are not under direct leash control have more opportunities to encounter and kill or injure wildlife. Even if a dog responds quickly to voice commands, their human companion is unlikely to be able to prompt a dog to cease its behavior until after an attack is underway and wildlife has already been injured.
Indirect Predation. Even when dogs are unsuccessful in catching the wild animals they chase, the potential prey has to expend significant energy in order to avoid being caught. Most wild animals live at the edge of their energetic needs; they are just barely surviving. Spending extra energy to escape an off-leash dog can lead to exhaustion and malnutrition, leaving them with no reserves to fend off the next predator. As you can imagine, pregnant wildlife and newborn animals are particularly vulnerable. The mere presence of the roaming dog can elicit a wild animal’s flight response. Mothers can be separated from young and chicks can be prematurely flushed from their nests.
Territory disturbance. Native carnivores and domestic dogs both communicate indirectly through scat / scent marking along trails. Carnivores often define territory with scat / scent. The presence of dog waste may deter native wildlife from utilizing an area; pushing them out of their home range and into the home range of an animal with whom they must compete with for resources. Conversely, new scents from dogs may draw a carnivore in to investigate, bringing them in close proximity to humans, which could be dangerous for both the human and the wild animal.
Vegetation disturbance. Dog activities such as roaming, digging and bed-making all change the ground on which dogs walk and in which some wild animals live. The burrows of animals that live below ground and between the snow and soil can be physically damaged as a result of these activities. Furthermore, damaged vegetation and disturbed soils can take a long time to recover from disturbance by dogs in our very short growing season.
Human disturbance. Let’s not forget our species. Not all people like dogs. In fact, many people dislike dogs and/or are frightened by them. Off-leash dogs can jump and/or knock people over. Please remember that trails at Land Trust Preserves are shared by all kinds of users.
Then there is the issue of dog waste. Let’s talk about dog poop. Dog poop can have the following impacts:
Changing soil composition. Dog waste adds significant nitrogen to the soil, contributing to the destructive effects of invasive weeds on our landscape. Nitrogen is an important soil nutrient which, in arid climates, encourages the growth of non-native plants at the expense of native vegetation.
Disease Transmission. Domestic dogs can be vectors for transmission of diseases to wildlife. Many of these pathogens are transmitted through the abundant waste that dogs leave on trails and in the areas they visit when off-leash. Some diseases commonly transmitted from domestic dogs to wild animals include: distemper, which affects wild carnivore species.Parvovirus affects other canines, and was the source for wolf pup mortality in Glacier National Park area in the early 1990s. Muscle cysts (Sarcocystis spp.) can affect ungulates like deer and elk. Parasites such as ticks, tapeworms, and fleas are well-known problems in dogs that can be passed to other wildlife. Rabies can affect any mammal species.
When you hike, recreate, and generally enjoy the vast landscapes that Central Oregon has to offer, with or without a dog, keep in mind that your human perception of space is in stark contrast to the needs of wildlife. Many of these species require a high degree of habitat specificity; requirements that are far more limited than most of us realize. Please help us keep our wildlife populations healthy and thriving by keeping your dog on a leash and decreasing the impact of your pet on the landscape. Thank you!
Please note, dogs are allowed on leash at the following Land Trust Preserves: Indian Ford Meadow Preserve, the Metolius Preserve, and Whychus Canyon Preserve. Dogs are not allowed at Camp Polk Meadow Preserve. We ask that you observe posted signs regarding dog use.
References and further reading:
Hughes, J., and D.W. Macdonald. 2013. A Review of the interactions between free-roaming domestic dogs and wildlife. Biological Conservation. 157:341-351.
Lenth, B.E., Kinght, R.L. and M.E. Brennan. 2008. The effects of dogs on wildlife communities. Natural Areas Journal. 28(3):218-227.
Sime, Carolyn A. 1999. Domestic dogs in wildlife habitats: Effects of recreation on Rocky Mountain wildlife: Summary of the September 1999 review for Montana). Montana Chapter of the Wildlife Society.