Two conservation employees monitoring deerberry population.
Thousand Islands National Park resource conservation staff monitor existing deerberry populations.

Deerberry is one of Canada’s most rare plants. Though common in the United States, deerberry occurs in Canada in two regions of Ontario. Three of the sites where deerberry occurs are in protected areas, however it is crucial that Parks Canada manages visitor use at an ecologically sustainable level to promote deerberry’s survival and recovery.

What is Deerberry?

Close-up of a small deerberry seedlings.
Seedlings planted as part of the deerberry reintroduction program at Thousand Islands National Park.

Deerberry is a low slender shrub belonging to the heath family. It is one of twelve species in the genus Vaccinium which also includes blueberries, bilberries and cranberries. Deerberry is an upright, spreading shrub that rarely grows over a meter tall. Pendant white flower clusters appear in the early summer on long slender stalks. The pistils of the flowers are straight and extend beyond the stamens. Berries appear in late summer and tend to be green to blue in color.

Where is Deerberry found?

Deerberry is usually considered to be unpalatable, although certain shrubs can yield delicious fruit. In the southern Appalachians, deerberry is used for pies, jams and jellies.

Deerberry is located within two regions in Ontario. Existing and historical populations are found in the Niagara and the Thousand Islands areas, where temperatures are milder due to the moderating effect of the great lakes. Three of the populations are protected by Thousand Islands National Park and the Niagara Parks Commission. The Thousand Islands population is found only on islands in the St. Lawrence River, while the population found in the Niagara area is in a semi-developed area. Both these populations are disjunct, along with a small population in Ithaca, New York. The next known closest population of deerberry occurs in Albany, New York.

The preferred habitat for deerberry is dry open woodlands with sandy, well-drained soil.

What is the status of Deerberry?

Deerberry was listed as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in November 2000. Deerberry is listed on Schedule 1 of the Species at Risk Act, which provides protection under federal law.

Deerberry is listed as S1 in Ontario by the Natural Heritage Information Centre, meaning that it is extremely rare and especially vulnerable to extirpation.

Why is Deerberry in danger?

View of the fenced enclosures used to assess the affect of deer browsing on deerberry populations.
Fenced enclosures used to assess the effect of deer browsing on deerberry populations at Thousand Islands National Park.

The major threat to deerberry in Canada is habitat loss, which resulted in an ecosystem function imbalance. This has led to the lack of deerberry seedling establishment. Deerberry seedlings have not been observed in Canada. It is believed that natural fires assisted in providing open woodland habitat that provided the ideal conditions necessary for germination of deerberry in the past. This, combined with the isolation of existing deerberry populations, has led to low genetic diversity of some plants and lack of abundance of plants in Canada.

In the Thousand Islands region deerberry is also at risk from trampling and browsing. Park visitors who stray from established trails can impact remaining deerberry plants. Browsing by deer and other fauna also can impact the individual plants.

In the Niagara region the deerberry population has been adversely affected by development due to tourism. Although it is believed that there were a number of plants in the Niagara area in the past, only one clump exists today.

Why protect Deerberry?

Deerberry is a part of a unique and healthy ecosystem and contributes to the overall biodiversity in Canada. In the Thousand Islands Ecosystem deerberry is found in association with other uncommon species in Canada such as pitch pine (Pinus rigida).

It is important to protect and recover deerberry populations to ensure that a healthy environment is available for future generations.

Close-up of deerberry flowers. Pendant white flower clusters appear in the early summer on long slender stalks.

There are also genetic differences between deerberry found in Canada and deerberry found in more temperate areas in the United States. Being at the northern end of its range, and disjunct from other populations, deerberry in Canada has had to adapt to a colder climate and to more competition than in other populations This has resulted in Canadian deerberry populations that are unique and are of high conservation value.

Deerberry plays an important ecological role where it occurs. The fruit of deerberry plants provide a source of nutrition for numerous birds. The flowers of deerberry provide a source of nectar for various bees.

What is Parks Canada doing to save Deerberry?

There are five ways that Parks Canada is assisting in the recovery of deerberry populations in Canada: through seedling introduction, plant monitoring, protection, education and collaborating with other organizations on recovery.

  • A deerberry reintroduction program has been ongoing at Thousand Islands National Park. Because deerberry plants in Canada have not been known to germinate from seed, park staff have partnered with universities to establish new deerberry seedlings in greenhouse environments. These seedlings are then introduced to areas that have been shown to provide similar habitat.
  • Thousand Islands National Park monitors existing plants that helps to assess plant health and identify possible stressors. Monitoring is done annually.
  • Thousand Islands National Park educates visitors and regional residents about the importance of deerberry and its function in the Thousand Islands Ecosystem. It is important for these audiences to be aware of deerberry so that impact can be minimized where it occurs.
  • Thousand Islands National Park is represented on the Deerberry Recovery Team, a group consisting of government organizations and universities that develops and implements recovery plans and contributes status reports to COSEWIC.

How can I help?

Close-up of the deerberry flowers.
The pistils of the flower are straight and extend beyond the stamens.

It is important that visitors to national parks stay on established trails in order to help protect sensitive plants. Having a small footprint on the land promotes biodiversity and sustainability. It is also important to be good stewards of your land. Management choices on single properties can have a positive or negative impact on the entire ecosystem. By adopting better management practices you can contribute to a healthy environment.

Stay informed of what environmental projects and programs are occurring in your area. Some programs can assist you in knowing more about the environment around you and what you can do to make a difference.