Parrot’s Feather

Parrot’s feather leaves are arranged in whorls throughout the stem with 4-6 feather-like leaflets per whorl. Emergent leaves grow densely and appear fuller, shorter, and bright green, whereas submerged leaves are less vibrant, longer, and thinner, with whorls that are sparser and more spaced out (Becker & Wong, 2023). In addition, the emergent section of the stem is light green, and the submerged section will appear more brownish red. This species grows laterally and can reach total lengths (root & stem) of 2 to 5 meters. Most of this species’ biomass grows below the water’s surface, with stems capable of extending downward up to 2 meters long, where a rhizome is anchored by thin roots into the sediment below (Becker & Wong, 2023).

During the late 1800s, Parrot’s feather was introduced into North America because of its appeal as an aquatic garden and aquarium plant. Unfortunately, this led to its eventual escape into natural waterways through intentional and unintentional releases. Today, Parrot’s feather is a widely distributed invasive species that has since become established throughout North America, Europe, Australia, Africa, and Asia. In the United States, Parrot’s feather is established in at least 26 states, and although a few detections have taken place in Canada, such as British Columbia and Ontario, there are currently no established populations of Parrot’s feather in Canada (Ontario’s Invading Species Awareness Program, 2021). Parrot’s feather is a relatively delicate aquatic plant and grows only in stagnant or slow-moving water in ponds, ditches, along the shore of lakes, and streams. Shallow aquatic ecosystems that are prone to disturbances are more at risk of Parrot’s feather invasions. This is because reoccurring mechanical disturbances facilitate stem fragmentation and create conditions that allow this species to spread and succeed quickly (Becker & Wong, 2023).

Distribution map retrieved from EDDMapS.org https://www.eddmaps.org/distribution/viewmap.cfm?sub=3054 (August 2023)

Parrot feather is a prohibited species under the Ontario Invasive Species Act. In places where Parrot’s feather is heavily established, this invasive species can cause tremendous ecological damage, disrupting the growth and health of native aquatic plant species, and displacing native biodiversity. Although individual Parrot’s feather plants are relatively small, this species is usually very easy to spot in the aquatic ecosystems it inhabits due to its ability to multiply quickly and form dense mats of vegetation. Once these mats have taken over stagnant waters, they quickly become a hazardous nuisance for people out on the water by getting tangled in paddles, gear, boat motors, and docks.  In extreme cases, they can clog drainage ditches. Aside from these dense mats of vegetation, which will be the most obvious sign of establishment, a reduction in species biodiversity is a common symptom of establishment.

The establishment of Parrot’s feather in streams, wetlands, creeks, and lakes can lead to habitat degradation as countless species of native fishes, aquatic invertebrates, amphibians, reptiles, waterfowl, and insects rely on habitats with native aquatic vegetation for food, protection from predators, nesting sites, and shelter. Parrot’s feather is an adaptable plant that can suffocate and outcompete native freshwater plants, becoming the most dominant species within an area of stagnant water. Therefore, the introduction of this invasive species not only puts the health of native aquatic plant life at risk but also the countless wildlife species that rely on these necessary resources for survival. In the fall, when large quantities of Parrot’s feather die off, the decaying plants can reduce oxygen levels within the water. Aside from the ecological impacts of Parrot’s feather, the dense mats they produce are strenuous and expensive to remove and impedes recreational activities such as swimming, boating, and fishing.

• Learn the key ID features of Parrot’s feather and how to differentiate it from look-alike-species.
• When boating, avoid infested areas or reduce your speed when travelling near Parrot’s feather infestations. Your propeller and the waves you create can break off fragments and spread the pieces to new areas. 
• Inspect your boat, trailer, and equipment after each use. Remove all plants, animals, and mud before moving to a new water body. Learn more about the process of Clean, Drain, Dry. 
• Do not plant Parrot’s feather in your aquarium or water garden. Aquarium hobbyists and water gardeners should only use native or non-invasive plants and are encouraged to ask retailers for plants that are not invasive.
• Never release unwanted aquarium plants. Return or donate unwanted plants to a garden centre or pet store or put them in the garbage. Do not put them in the compost or discard them in natural areas.
• Report all sightings of Parrot’s feather to the Invading Species Hotline at: 1-800-563-7711 or to www.eddmaps.org