Western Toad Migration Project

The Western Toad Migration Project involved surveying thirteen 100 m-length transects, nine of which are on Sylvester Road and four on Hartley Road.

In April 2018, seven surveys were completed and 161 toads were counted, while between June and August 2018, 653 alive and 129 dead toadlets were counted.

In 2020, a drift fence was constructed to guide toadlets to safe crossing areas and more effectively count them. Pitfall traps were used as well in these surveys. In this season, 6060 dead toadlets and 10842 alive were observed.

At Allan Lake thirteen surveys were completed in 2021 and 682 toads were counted. The majority of detections were of adult males. During the spring toad migration an overall total of 585 toads were recorded with an average of 45 toads/night. A hotspot for toad movement was detected at the intersection of Hartley and Sylvester Roads.

Twenty surveys were done in 2022 and 1,632 toads were counted, the majority being adult males.

Fifty surveys were completed for Allan Lake toadlets in 2022 and a total of 195,249 toadlets were observed. 163,794 toadlets were detected along the drift fence, 25,958 were detected during road mortality surveys and 5,497 in pitfall traps. The hot spot found in previous years was magnified due to the high number of toads migrating.

Six surveys were completed in 2023 and 130 toads were counted, the majority being adult males. 

Although there were fewer toads migrating this year the crossing hot spot was still observed. We theorize that the toads prefer to cross at this location because it has the most lamp from streetlights of anywhere in the transect.  

In 2023, 19 road mortality/migration surveys were completed for Allan Lake toadlets and a total of 2983 toadlets were observed. 1948 toadlets were alive and 1035 toadlets were dead. The transect was modified this year to represent toadlet migration patterns. On odd-numbered years toadlets are observed to migrate more frequently east rather than west on even-numbered years.

After multiple years of monitoring, it appears there is a trend at Allan Lake that follows a 2-year cycle of more toads breeding in even years. This likely represents the breeding schedule of females that often only breed every 2nd year. Thus, it is expected that 2024 will be a big year for the migration of adults and toadlets. And ultimately drift fencing for toadlets will be installed and monitored in this year.

Common incidental species found on these surveys are Northern Red-legged Frogs (Rana aurora) and Pacific Chorus Frogs (Pseudacris regilla)