Mottled Duskywing government response statement

Protecting and recovering species at risk in Ontario

Species at risk recovery is a key part of protecting Ontario’s biodiversity. Biodiversity – the variety of living organisms on Earth – provides us with clean air and water, food, fibre, medicine and other resources that we need to survive.

The Endangered Species Act, 2007 (ESA) is the Government of Ontario’s legislative commitment to protecting and recovering species at risk and their habitats. As soon as a species is listed as extirpated, endangered or threatened under the ESA, it is automatically protected from harm or harassment. Also, immediately upon listing, the habitats of endangered and threatened species are protected from damage or destruction.

Under the ESA, the Ministry of Natural Resources and Forestry (the Ministry) must ensure that a recovery strategy is prepared for each species that is listed as endangered or threatened. A recovery strategy provides science-based advice to government on what is required to achieve recovery of a species.

Government response statements

Within nine months after a recovery strategy is prepared, the ESA requires the Ministry to publish a statement summarizing the government’s intended actions and priorities in response to the recovery strategy. The recovery strategy for the Mottled Duskywing (Erynnis martialis) in Ontario was completed on June 25, 2015.

The response statement is the government’s policy response to the scientific advice provided in the recovery strategy. All recommendations provided in the recovery strategy were considered and this response statement identifies those that are considered to be appropriate and necessary for the protection and recovery of the species. In addition to the strategy, the response statement is based on input from stakeholders, other jurisdictions, Aboriginal communities and members of the public. It reflects the best available traditional, local and scientific knowledge at this time and may be adapted if new information becomes available. In implementing the actions in the response statement, the ESA allows the Ministry to determine what is feasible, taking into account social and economic factors.

Moving forward to protect and recover Mottled Duskywing

The Mottled Duskywing is listed as an endangered species under the ESA, which protects both the butterfly and its habitat. The ESA prohibits harm or harassment of the species and damage or destruction of its habitat without authorization. Such authorization would require that conditions established by the Ministry be met.

Historically, Mottled Duskywing existed throughout the eastern and central United States and parts of south-central Canada. Populations in many U.S. states have severely declined, and Mottled Duskywing may no longer occur in some states within its core range. In Canada, populations of Mottled Duskywing historically extended into southeastern Manitoba, southern Ontario, and southwestern Quebec. These butterflies are now thought to be extirpated from Quebec, but populations are still present, though declining, in southeastern Manitoba. Mottled Duskywing occupies some of Canada’s rarest ecosystems including oak woodlands, pine woodlands, tall grass prairies, and alvars with dry, clay or sandy soils and early successional habitat.

Mottled Duskywing are non-migratory and use their habitat in Ontario throughout all life stages. Currently, Mottled Duskywing occurs in nine, small, isolated metapopulations in southern Ontario. Each metapopulation is comprised of one to several sites where its larval food plants occur, in the vicinity of: Alderville, Burlington/Hamilton, Borden, Marmora, Niagara, Ottawa, Oakville, Grand Bend, and Stirling. These nine metapopulations occur on lands owned privately, on municipal and federal lands, on lands belonging to First Nations, and in protected provincial parks and conservation reserves. Mottled Duskywing are closely associated with their larval food plants, which in Ontario are Prairie Redroot (Ceanothus herbaceous) and New Jersey Tea (Ceanothus americanus). Adult females of the species lay eggs on the leaves of these plants and when larvae emerge from the eggs, they feed on the larval food plants and form a shelter to live in by sewing leaves together with silk. Larvae continue to feed on leaves of the plants and either cocoon and pupate or enter a state of dormancy during the winter in response to adverse environmental conditions, also known as diapause. Following diapause, larvae that have overwintered then cocoon and pupate.

Observations of Mottled Duskywing in Ontario in the past ten years have been of single or a small number of individuals. In 2013 and 2014, individuals were confirmed to persist at sites in Alderville, Burlington/Hamilton, Marmora, and Oakville. It is unknown if Mottled Duskywing remains present in Niagara, Borden, Grand Bend and Stirling based on the most recent surveys and observations; however, the associated search efforts have likely not been sufficient enough to confirm absence at these locations. Despite annual search efforts of historically known sites in the Ottawa area, Mottled Duskywing has not been observed since 2008. Although the species has always been recorded as occurring in small colonies in Ontario, it appears to have become extirpated from historic sites in the Ottawa area and some sites within the Marmora metapopulation, in the past 20 years.

The threats to the species in Ontario are largely related to habitat alteration and include habitat fragmentation and destruction, natural succession, deer browsing, pesticide use and introduction of invasive species. The metapopulations are located within or near populated areas and as a result, they are vulnerable to disturbances related to development and land conversion. The impacts of threats to Mottled Duskywing are increased by their high degree of habitat specificity. Because Mottled Duskywing uses specific host plants (Prairie Redroot and New Jersey Tea), activities or processes (e.g., succession) that threaten the host plants in turn pose a threat to the species. This includes the threat of invasive species such as Dog Strangling Vine (Cynanchum louiseae and C. rossicum) at the Burlington site which may threaten the host plant’s ability to survive. As well, Mottled Duskywings have limited dispersal ability and extirpated sites do not appear to become recolonized. The relationship between Mottled Duskywing and fire is not well understood at this time although it may provide disturbance to maintain suitable habitat conditions. New Jersey tea is a fire tolerant species, however fire may cause direct mortality of individual Mottled Duskywings.

Protecting and recovering species at risk is a shared responsibility. No single agency or organization has the knowledge, authority or financial resources to protect and recover all of Ontario’s species at risk. Successful recovery requires inter-governmental co-operation and the involvement of many individuals, organizations and communities.

In developing the government response statement, the Ministry considered what actions are feasible for the government to lead directly and what actions are feasible for the government to support its conservation partners to undertake.

Government-supported actions

The government endorses the following actions as being necessary for the protection and recovery of the Mottled Duskywing. Actions identified as "high" will be given priority consideration for funding under the ESA. Where reasonable, the government will also consider the priority assigned to these actions when reviewing and issuing authorizations under the Endangered Species Act. Other organizations are encouraged to consider these priorities when developing projects or mitigation plans related to species at risk. The government will focus its support on these high-priority actions over the next five years.

Focus area: Habitat management and stewardship

Habitat loss and degradation is the primary threat to Mottled Duskywing. Landowners, conservation organizations and First Nations have an important role to play in the protection and recovery of the species. Increasing public awareness and working together to promote local stewardship and effective habitat management are key factors in ensuring that threats to current populations of Mottled Duskywing and their habitat are effectively mitigated.

Actions:

1. (High) Using the best available information, work collaboratively with stakeholders including landowners, conservation authorities, and First Nations, to manage habitat by:
   • implementing appropriate methods to prevent woody succession and to thin the canopy and sub-canopy cover, as needed
   • implementing measures to reduce the threat of deer browsing
   • reducing the usage of pesticides that may harm Mottled Duskywing or its host plants
   • targeting the removal of invasive species threatening Mottled Duskywing habitat
   • evaluating the effectiveness of habitat management activities including prescribed fire, wildfire suppression, and deer management
2. Develop and implement education, awareness, and stewardship programs about Mottled Duskywing and its habitat, incorporating components of the pesticide application awareness program to reduce usage in habitat areas.

Focus area: Inventory and monitoring

With nine isolated metapopulations of Mottled Duskywing occurring throughout Ontario, it is important to have sufficient data regarding the current status, site-specific threats and habitat available for each metapopulation. Further investigation of existing and historical locations will improve our understanding of the Ontario population as a whole and allow us to monitor population trends in the future.

Actions:

3. (High) Collaborate with local partners, community members and First Nations to develop and implement a monitoring program for Mottled Duskywing that includes:
   • developing a standardized survey protocol to confirm presence/absence and estimate population numbers
   • estimating the population abundance of each existing metapopulation
   • conducting surveys of historical locations to determine presence/absence
   • assessing and identifying site-specific threats to populations
   • mapping the extent of the host plants at each existing metapopulation location

Focus area: Research

There are still many knowledge gaps regarding the biology and ecology of Mottled Duskywing in Ontario. In order to effectively mitigate site-specific threats to the species and collectively work to implement recovery actions, it is important to investigate the species' habitat requirements, the species' ability to disperse, and annual growth rates. Investigating the feasibility of appropriately scoped, potential augmentation or reintroduction efforts for the species would also assist in filling knowledge gaps.

Actions:

4. (High) Investigate the habitat requirements of Mottled Duskywing and the responses to habitat management techniques by:
   • determining the minimum patch size and density of larval host plants required to support a viable population of Mottled Duskywing
   • conducting research on preferred nectar sources
   • conducting research on the impacts of climate change on larval food plants
   • mapping the present day extent of larval host plant species
5. Investigate cues/triggers used by Mottled Duskywing larvae to break diapause to better understand the potential implications of climate change on the species.
6. Investigate the ability of Mottled Duskywing to disperse within and between habitat patches and identify any specific requirements to facilitate movement and gene flow.
7. Determine the annual population growth and recruitment rates to contribute to a population viability analysis of existing metapopulations.
8. Investigate the feasibility of augmenting those existing populations that currently have very small populations and the feasibility of reintroducing the species to historic sites with suitable habitat.

Implementing actions

Financial support for the implementation of actions may be available through the Species at Risk Stewardship Fund, Species at Risk Research Fund for Ontario, or the Species at Risk Farm Incentive Program. Conservation partners are encouraged to discuss project proposals related to the actions in this response statement with the Ministry. The Ministry can also advise if any authorizations under the ESA or other legislation may be required to undertake the project.

Implementation of the actions may be subject to changing priorities across the multitude of species at risk, available resources and the capacity of partners to undertake recovery activities. Where appropriate, the implementation of actions for multiple species will be co-ordinated across government response statements.

Reviewing progress

The ESA requires the Ministry to conduct a review of progress towards protecting and recovering a species not later than five years from the publication of this response statement. The review will help identify if adjustments are needed to achieve the protection and recovery of the Mottled Duskywing.

Acknowledgement

We would like to thank all those who participated in the development of the Recovery Strategy for the Mottled Duskywing (Erynnis martialis) in Ontario for their dedication to protecting and recovering species at risk.

For additional information

The government response statement for Mottled Duskywing is available in PDF format upon request. Please email PDF requests to recovery.planning@ontario.ca.