I have to admit that one of the things I love most about street trees is the wildlife they attract. There is something so wonderful about seeing a hummingbird zip around looking for nectar or hearing bees buzzing furiously as you pass under a particularly tasty tree. It feels extra special to see sites like these in urban environments, where contact with wild animals is relatively uncommon. But not all trees are equal when it comes to acting as sources of shelter or food.
For attracting birds, which are I think the most desirable type of urban wildlife (what, no one but me wants to attract raccoons?!), Morton Arboretum makes the following recommendations:
- Create a bird “pantry” by selecting tree species that provide food for birds from their buds, flowers, and nectar.
- Select plants to provide food for birds throughout the entire year.
- Emphasize the use of native species, as plants and animals have evolved side by side over millenia — in other words, native species are necessarily going to provide “the right mix, size, and nutritional value that birds in our area require.”
- Incorporate native habitats to create corridors for birds between urban areas and their natural ranges, or for birds who are migrating.
- Plant in drifts to encourage cross-pollination and boost fertility (and, therefore, fruit yield).
- Plant a variety of tree heights to create vertical “layers” so that birds with different perching and nest-building preferences have options.
- Where possible, plant groupings of conifers to act as year-round windbreaks, shelter, and nesting sites.
In ultra urban environments, chances are good that there is already a list of city-approved street tree species that were picked for characteristics completely unrelated to their attractiveness to birds. Still, if you have the option of picking what kind of tree you want for your site, its serviceability to wildlife — particularly in very developed areas — could have a very positive effect on your local ecology. With over 50% of the world’s population now living in cities, considering how our urban areas are functional for wildlife is increasingly important.
For a more thorough list of some of the birds’s favorite trees and shrubs, visit Morton’s website.