The Wildlife in the Willows
Every spring before the crocuses have poked above ground or other plants have sprung fresh green leaves, willows are already hard at work. In Alberta there are about 40 species that fall under the family Salicaceae including both poplar trees and the more familiar willow shrubs. In addition to being classified in the same family, these trees and shrubs have something else in common, they are all wonderful for wildlife! Willow shrubs in particular are spectacular for birds, bees, butterflies and other bugs. From subalpine slopes to lowland riverbanks, willows thrive in a variety of habitats so there is bound to be one that suits your yard. Some species like Beaked Willow (Salix bebbiana) will tolerate disturbed soils that come with fires or floods, can survive in moist, riparian habitats as well as tough clay soils making it a flexible choice. In addition, beaked willow reportedly plays host to a shocking 312 species of butterfly and moths throughout it's range! In Alberta this includes the early season Milbert's Tortoiseshell (Aglais milberti) and Mourning Cloak (Nymphalis antiopa) butterflies as well as the stunning later season White Admiral (Limenitis arthemis). These butterflies are not overly specific in their host plant and will use other willow species as well as some perennials. In addition to playing host to butterflies and moths, willows flower as early as February if the weather is mild or as late as June, providing ample food for native bees.
All of the caterpillars supported by willows make a great food source for migrating and nesting birds. Many of them not only take advantage of the caterpillar buffet for raising their chicks but they also depend on the safety of willow branches for their nests. Willow thickets provide shelter and safety for many birds including robins, warblers and hummingbirds. Although thickets are where birds can be found in our natural areas, even one willow shrub in an urban backyard can make a huge difference in the biodiversity you see. When we think about bringing birds to our yards, often the first thought is given to those plants that provide fruit but even more important are the insects and insects need native plants, shrubs and trees to thrive. Willows are also a favorite food source for deer, moose and beavers. While you and your neighbours may be okay with that, it is something to consider if you want to limit who is coming to your yard.
With their remarkable versatility and ability to provide food and shelter to so many insect and bird species, willows are an important keystone plant to add to your wildlife garden!
Beaked Willow (Salix bebbiana) in flower. Photo credit https://www.greenup.on.ca/