Western toads

Toad migration on the Valley Trail at Lost Lake Park image

Whistler’s Lost Lake Park acts as the breeding ground for Whistler’s largest population of Western Toad (Anaxyrus boreas), a sensitive species native to British Columbia. Every year, thousands of Western Toads migrate from the shores of Lost Lake Park to the surrounding forest.

Western Toad update 2023

August 15, 2023: The 2023 Western Toad migration has come to an end in Lost Lake Park and all park areas have fully reopened. 

Most toads have now dispersed into the surrounding forests, but some can still be found in the park so visitors are asked to continue to watch their step and pay attention to posted signage, especially when walking on single track nature trails near bodies of water.

This year’s migration was a great success, largely thanks to our staff and dedicated volunteers who were at Lost Lake all hours of the day helping thousands of toads make it safely across the park.

We would also like to thank all those who visited Lost Lake Park during the migration for respecting all trail and road closures and taking extra care when walking and biking through the park.  Have you spotted toads outside of Lost Lake Park or on the bike trails? Report sightings of toads to stewardship@whistler.ca, this information helps RMOW Environmental Technicians to track toad dispersal outside of the park.

Western Toads at Lost Lake Park

Lost Lake Park is the breeding ground for Whistler’s largest Western Toad population. We are very lucky to host such a large population of this sensitive species right here in our own backyard. Despite being barely the size of a dime, the Western toadlets are an integral part of the Lost Lake ecology. Tadpoles feed on detritus in the lake, which helps keep our lake water clean, benefiting humans and other species. The dime-sized toadlets have also found a place in the hearts of the many volunteers who have helped them on their journey from the lake to forest.

Western toads are native to British Columbia and are sensitive to changes in their environment. Human activities—especially roads and urban development that compromise forests and wetlands— are leading to the loss of suitable habitat and the creation of migration barriers for amphibians. Western Toad populations are particularly vulnerable during the tadpole and “toadlet” life stages.

How does the municipality help?  

Valley Trail underpass at Lost Lake Park

The RMOW has installed permanent features such as signage, fencing and an underpass to protect breeding and tadpole habitat. Closer to the migration, numerous temporary fences, signs and boardwalks are installed to help protect the migrating toadlets.

Recently, the RMOW has built new infrastructure to help migrating toads pass safely through the park. In 2020, a toad underpass was constructed under the Valley Trail just behind the events lawn. In spring of 2021, a second underpass was installed under the Lost Lake Loop Trail, between the Lost Lake Beach and Barking Bay. Underpasses have been strategically placed to allow toads to follow preferred migration routes without crossing high traffic trail networks. In addition to underpasses, the RMOW installed a new log retaining wall along Lost Lake beach to discourage toads from migrating onto park lawn areas where historic mortality numbers have been very high. 

Once toads begin to migrate across the Lost Lake access road and parking lot, these areas will close to all vehicle traffic. When this happens, the free Lost Lake shuttle will continue to run, but visitors will be dropped off at the entrance to Lost Lake Park on Blackcomb Way and will need to walk the remaining 500 meters to the beach. 

Lost Lake Beach, lawns and docks remain open. We just ask that those visiting Lost Lake Park during this period step carefully and walk bicycles as toads are no bigger than the size of a dime and can be easily crushed under foot. These areas may be subject to closure if they happen to coincide with major toadlet migratory pathways. This is difficult to predict as chosen migratory pathways can vary widely from year to year.

The RMOW’s environmental technicians and volunteers maintain a presence to monitor the migration and help the tiny toads move safely from the beach to the forest areas.

When does the migration happen?

Migration typically takes two to four weeks between the end of July and end of August. 

How many migrate?

It is extremely difficult to estimate exactly how many toads there are migrating. Each female may lay up to 20,000 eggs and this years breeding pair count peaked at 40 pairs. This number is our best indicator of estimating population size. 

Inventory and monitoring

  • The RMOW has been monitoring the Western Toads at Lost Lake Park since 2005.
  • The Western Toad population at Lost Lake, along with other monitored species populations, can provide insight into the broader health of Whistler’s ecosystems.
  • Monitoring the stages and development of the tadpoles throughout the summer enables the RMOW to proactively prepare for the migration and focus on public education.
  • The RMOW observes around 35,000–40,000 toads annually during migration.

Policy and planning

  • The RMOW is working to integrate protection of Western toads and other species at risk and their habitat at a policy level, for example in the Official Community Plan.
  • The RMOW considers Western toads and other species at risk and their habitat when reviewing development proposals.
  • With respect to parks, facilities and events planning, the RMOW occasionally closes the special events area at Lost Lake Park during the migration period to support the passage of Western toads. While this may result in some initial disappointment for those having to postpone their special events, the RMOW is confident that saving the tiny toads makes it worth the wait.

Working with partners

  •  It takes a village to support the toads. 
  • The RMOW works with multiple community partners on Western toad monitoring and migration initiatives, including the Whistler Fisheries Stewardship Group, the Community Foundation of Whistler, the Whistler Naturalists, the Whistler Museum and Archives and many more toadally awesome community members.

On the ground

  • The RMOW has installed permanent features including fencing, signs and an underpass to protect the breeding and tadpole habitat along the shoreline of Lost Lake Park and migration route to the forest.
  • In addition to permanent features, a number of temporary fences, signs, boardwalks are installed closer to migration. 
  • The RMOW may close sections of Lost Lake Park during migration to support the toads’ safe access to the forest areas.
  • To protect the toads during the summer migration period, the RMOW asks residents and visitors to be cautious when biking or walking in the area.
  • Residents and guests are encouraged to be careful, be respectful and help the little guys make their way home.

How can you help?

  •  If you visit Lost Lake Park during the summer Western toad migration, be careful, please be respectful and help the tiny toads journey safely to their forest home.
  • Volunteer to help the toads migrate safely. Contact our Environmental Stewardship team: stewardship@whistler.ca.
  • Learn more about Western toads and other species at risk