- Author: Anne Schellman
- Contributor: Karey Windbiel-Rojas
People in urban and suburban areas often use the term “invasive” to describe plants or weeds that appear to take over a garden or landscape. However, true invasive plants are weeds that infest ecosystems, rangelands, and pasture—places common garden weeds don't thrive.
Invasive plants can reduce native plant and animal diversity, threaten endangered species habitat, and increase wildfire and flood danger. Most invasive plants were introduced as ornamentals from the retail nursery industry, or for the purposes of soil stabilization, animal forage, human food, fiber, or medicinal plants. Some may still be found for sale at retail nursery and garden centers, including the following:
![Mud nests made by a colony of cliff swallows. [W.P.Gorenzel]](https://ucanr.edu/blogs/UCIPMurbanpests/blogfiles/36152small.jpg)
World Migratory Bird Day (May 10) is a yearly event to help promote awareness about migratory birds and their habitats. The campaign celebrates the migration of birds across countries and continents and focuses on their conservation.
However, during their migration, these birds may cause problems for occupants in urban areas. The birds may nest in colonies on buildings and other structures and their activities can be a nuisance.
Laws that Protect Birds
If migratory bird activities are causing issues in your building, make sure you know the law before you take any action. Certain birds that nest on dwellings may be protected under the
