Rare and endangered native plants are at great risk from interference with fruiting ability or seed germination. Wildlife is adversely affected by forestry herbicide applications in many ways. During the first year after herbicide application, a very limited number of species regenerate, and wildlife population densities are drastically reduced. Avoidance of sprayed areas is reported for a number of years after herbicide treatment. As species that return to a given area seasonally are forced to re-locate, territorial boundaries are compromised and breeding and nesting behaviors are disturbed.
Small mammals are more subject to predation due to loss of ground cover.
Wildlife is also directly affected by exposure to toxic chemicals. Although efforts are usually made to ensure that humans are not in target areas during spraying, other species are afforded no such protection. Exposure occurs through herbicide mixtures contacting fur and skin, through inhaled mist, and through eating sprayed foliage. Aquatic organisms are exposed to herbicides when water contamination occurs through drift or runoff from spray areas after rainfall. Exposure to diesel fuel reduces bird egg hatchability to almost zero.