The eastern massasauga, Sistrurus catenatus (Photo credit: Peter Paplanus, used under Creative Commons license CC BY-SA 4.0).
There are a variety of potential conservation strategies, complicating decision-making when time and budgets are limited. The umbrella species concept has been proposed as a form of short-cut to guide conservation management because this strategy in theory can address the needs of multiple species.
What is an umbrella species?
An umbrella species is a plant or animal chosen to guide conservation decision-making, as protecting this species and its habitat confers “an umbrella of protection” to other species inhabiting the same ecological community. Species chosen often have large home ranges or have similar habitat needs to a variety of species. Generally speaking, the higher the diversity of microhabitat requirements a species has, the greater the “umbrella effect” that it will have on other plants and animals.
Why is the eastern massasauga an umbrella species?
The eastern massasauga is an umbrella species, first and foremost, because it is in dire need of protection. Massasaugas in Canada are entirely restricted to the Province of Ontario. The snakes found furthest south in Ontario are part of the “Carolinian” population, which is listed as Endangered provincially and federally. A combination of factors including intensive agriculture, habitat fragmentation, road mortality, urban development, and intentional killing has led to the collapse of the Carolinian massasauga population. These animals can now only be found in two very small subpopulations, at Wainfleet Bog and at Ojibway Prairie, triggering the need for immediate protection and recovery actions.
The second reason is that the eastern massasauga requires a diversity of habitats and microhabitat features to complete all aspects of its life history. Therefore, protecting massasauga habitat affords protection to an assortment of other creatures. In general, these rattlesnakes can be found in a variety of habitat types such as prairies, rock barrens, and forest-wetland complexes. They rely on areas of open canopy for thermoregulation, foraging, and reproduction, often using discrete microhabitats therein, such as rock piles or brush piles. Additionally, they tend to migrate to forested habitats near aquatic features for overwintering, using animal burrows or other access points to get underground into water-saturated soils and away from freezing temperatures. In brief, massasaugas use both upland and wetland habitats, closed canopy and open canopy habitats, and above ground and below ground habitats, thus casting their umbrellas quite widely.
Who fits under the massasauga’s umbrella?
Tallgrass prairies are one of the rarest ecosystems in Canada and are characterized by tall grasses, low tree cover, and seasonal fires that limit the growth of woody plants. Most Canadian prairies have been converted to agricultural uses, with only about 1% of tallgrass prairies remaining in Ontario, thus many prairie species are struggling due to a lack of habitat. At the Ojibway Prairie, in particular, there are a number of plants and animals that fit under the massasauga’s umbrella, and benefit from its protection:
Eastern Chipmunk
The eastern chipmunk (Tamias striatus) is a small ground dwelling squirrel that is locally rare in the Windsor-Essex region. This small mammal is not only an important food source for various animals, but chipmunk burrows provide overwintering habitat for snakes, including the massasauga. Chipmunks rely on species-rich deciduous forests to provide them with a high variety of food sources. Thus conserving massasauga hibernation habitat will in turn protect the forested habitats chipmunks require to flourish.
Milkweed and Monarchs
The Ojibway Prairie is host to a unique variety of plant species, some of which are species at risk (e.g., dense blazing star and colicroot), and others that are rare in Canada. Many species of milkweed occur here, such as the purple milkweed, Sullivant’s milkweed, whorled milkweed, and the tall green milkweed, which is found nowhere else in Canada (see our related blog post). Milkweeds thrive in open sunny areas and are an important plant host for monarch butterflies. Monarch butterflies exclusively lay their eggs on milkweed plants and the caterpillars rely on the milkweed for food and shelter. The monarchs is considered “Endangered” in Canada due to habitat fragmentation and lack of milkweed distribution. Thus, protecting and restoring the open prairie habitats used by massasaugas for foraging, basking and gestation also protects monarchs and their food source.
A monarch butterfly, Danaus plexippus (Photo credit: Metisse Arseneault, 2022).
Terrestrial Crayfish
While many people think of crayfish as being fully aquatic, terrestrial crayfish play an important role in the Ojibway Prairie ecosystem. The digger crayfish (Creaserinus fodiens), devil crayfish (Lacunicambarus diogenes) and the painted mudbug (Lacunicambarus polychromatus) can all be found locally. These species of crayfish dig burrows on land which can descend over 50 cm deep in order to reach the water table. These burrows provide excellent overwintering habitat for massasaugas because they provide access to the groundwater, which is critical to prevent snakes from drying out during the winter.
Other Snakes
The Butler’s gartersnake and the eastern foxsnake are both species at risk in Ontario. These species overlap in distribution with the massasauga and share many behavioural traits. Habitats used by massasaugas such as edge habitats, wetlands, forests, prairies, and old fields also support these snake species. Additionally, both types of snakes also use crayfish and mammal burrows for hibernation. Due to their similar life histories, protecting and restoring massasauga habitat in turn helps support other at risk snakes.
Butler’s gartersnake, Thamnophis butleri (Photo credit: Patrick Leggitt, 2022).
Why conserve umbrella species?
Umbrella species can provide a point of focus for conservation efforts while maximizing environmental benefits. Additionally, supporting a target species can streamline funding applications and decision-making, allowing for quicker action. Protecting the variety of habitats used by massasaugas including prairies, closed and open canopy forests, and wetland-forest complexes will directly help a variety of species already using those habitats. For a relatively small animal, the massasauga casts a relatively large “umbrella” of protection on the neighbouring animals and plants in its vicinity.
Authorship note: This blog post was originally drafted by Patrick Leggitt, and revised and edited by Natasha Dobos and Jonathan Choquette.
References
COSEWIC. 2012. COSEWIC assessment and status report on the Massasauga Sistrurus catenatus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii + 84 pp.
Eastern Foxsnake Recovery Team. 2010. Recovery strategy for the Eastern Foxsnake (Pantherophis gloydi) – Carolinian and Georgian Bay populations in Ontario. Ontario Recovery Strategy Series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. vi + 39 pp.
Ontario Ministry of Natural Resources and Forestry. 2016. Recovery Strategy for the Massasauga (Sistrurus catenatus) – Carolinian and Great Lakes – St. Lawrence populations in Ontario. Ontario Recovery Strategy Series. Prepared by the Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario. v + 9 pp. + Appendix ix + 37 pp. Adoption of the Recovery Strategy for the Massasauga (Sistrurus catenatus) in Canada (Parks Canada Agency 2015).
Paiero, S. M., S. A. Marshall, P. D. Pratt, and M. Buck. 2010. Insects of Ojibway Prairie, a Southern Ontario Tallgrass Prairie. In Arthropods of Canadian Grasslands (Volume 1): Ecology and Interactions in Grassland Habitats. Biological Survey of Canada.
Roberge, J.M. and Angelstam, P. (2004), Usefulness of the Umbrella Species Concept as a Conservation Tool. Conservation Biology, 18: 76-85. https://doi.org/10.1111/j.1523-1739.2004.00450.x
