Improving restoration of breeding sites to increase recruitment of anaxyrus boreas in western montana

Abstract

The Montana native western toads (Anaxyrus boreas) have, like most amphibians, been declining in recent years. Although it is endangered and at high risk of extirpation in many states, there are still several healthy breeding populations in Montana. Montana can increase recruitment of this increasingly rare anuran species through habitat restoration. However, using habitat restoration to addressing the decline of this species is not well researched. Here, I evaluate potential restoration methods that could increase recruitment. I provide an overview of the habitat requirements and preferences of A. boreas as well as effective restoration methods for this and other anuran species. To increase recruitment, restoration efforts should include construction of permanent ponds with low turbidity and extensive shallows that gradually increase to a maximum depth of 40 cm. Trees should be removed along the pond perimeter if they shade the water. Active management measures such as sediment removal in ponds, strict regulation of livestock grazing, periodically prescribed burns, and removal of invasive species such as the American bullfrog (Lithobates catesbeianus) should also be implemented. Farther from the breeding site, native deciduous shrubs should be planted, if they are not otherwise present. For existing breeding sites, the area within a 3-km radius should be protected from development and clearcuts. Introduction of beaver (Castor canadensis) to their historical range will also have a significant beneficial impact on the restoration of A. boreas. The locations of these efforts should also be carefully chosen to take into account the continuing effects of climate change. Taking these actions now, based on the data that are available, will help increase recruitment and improve the chances of this species recovering.