Cowichan Valley Western Toad Project Update for July
14th, 2014
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Adult Western Toad |
Welcome to the
Cowichan Valley Western Toad Project
Blog. We are going to use this blog as a
means to keep all of our volunteers and supporters informed about the Western
Toad populations in the Cowichan Valley. Please feel free to share this blog
with other people who would be interested to learn about or get involved with
this project.
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Adult Western Toad found
in a backyard garden
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We are pleased to announce that studies on Western Toad populations in the Cowichan Valley are continuing in 2014. We are excited to have ongoing support from the Ministry of Transportation and Infrastructure (MoTI) and the Ministry of Environment (MoE).
For more information on Western Toads, please visit:
BC Frogwatch:
http://www.env.gov.bc.ca/wld/frogwatch/
Species at Risk Public Registry:
http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=748
Previous areas of focus for our project include:
- Monitoring the breeding site at Wake Lake.
- Identification of additional breeding sites
throughout the Valley.
- Mid-summer toadlet rescues (salvages at road
crossings) during their dispersal away from Wake Lake (and at other
locations).
- Potential use of existing culverts as a means of
getting toadlets across the road.
- Spring and fall road surveys along Barnjum and
Riverbottom Road to locate road crossing hotspots for adult toads. These
areas may be indicative of the most effective location for the
installation of wildlife underpasses in the future.
- A radio telemetry pilot study tracking the
movements of two adult toads in the fall.
- A controlled experiment using toads from Morrell
Lake in Nanaimo to see which radio transmitter belt design is most
effective for a longer-term field study.
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Educational sign at Wake Lake park installed by the CVRD |
Our primary focus for 2014 includes:
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Directive fencing to encourage wildlife to use culverts as underpasses |
- Tracking adult toad movement patterns;
- Locating winter hibernation sites; and
- Monitoring culvert conditions as potential
wildlife underpasses
When will the toadlets disperse from Wake Lake?
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Thousands of tiny toadlets along a drainage dispersing from Wake Lake in the summer of 2012 |
The tadpoles at
Wake Lake are now tiny toadlets and were observed moving up on to the sphagnum on
July 9th. The front legs have
appeared and the tail is gone. The
toadlets will move in and out of the lake for the next few days as they prepare
to head out into the terrestrial environment.
We will continue to monitor the roadside along Barnjum Rd and
Riverbottom Rd on a daily basis for toadlets and watch to see if they will use
the current directive fencing and culverts.
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A single toadlet crossing a gravel road |
We will not be
installing pit fall traps this summer for the toadlet migration as we have done
in past years (2011 and 2012). However,
we will be monitoring their movement patterns as they disperse from breeding
sites and there could also be an opportunity to try and estimate mortality
rates at road crossing points. Pitfall
trapping is not being conducted in 2014 due to the uncertainty of the impact of
such measures on the toadlets.
Remember
that the onset of the toadlet dispersal often coincides with rain events. One of
the best ways to help this animals’ population success is to avoid driving the
roads where known toadlet migrations occur during summer. The toadlets move
throughout the day during rain events, but during hot, dry weather, movement tends to occur at dawn (5-9am) and dusk (6-10pm) when moisture levels
are higher and temperatures cooler.
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Western toad road crossing sign |
Do you know of a breeding site or road crossing location?
We are very
interested in documenting known breeding locations, road crossing points for
toadlet migrations and sub-adult or adult sightings and BC Frogwatch is a
valuable tool to share this information with other scientists or volunteers. If you are out and about during the summer
and you see a migration of toadlets, please report the occurrence and location
to this project (
shari@vigis.ca) and to BC
Frogwatch (
http://www.env.gov.bc.ca/wld/frogwatch/frogwatching/report/).
Why did the toad cross the road?
In order to better
understand the habitat requirements of Western Toads, we are now expanding the
project to look at fall movement patterns and winter hibernation sites. In the fall of 2012 we conducted a radio telemetry
pilot project and fitted two toads with radio transmitters. Each toad was re-located every 2-3 days and
their movements were plotted on a map. While
we were unable to track the two toads to their overwintering sites (both toads
slipped their belts within 2 weeks of attachment), the pilot study yielded some
interesting information on unique movement patterns. For example, one toad
travelled in an almost straight-line distance of approximately 1379 m over its
16-day tracking period, moving through numerous properties, crossing two roads,
and travelling through relatively open habitat. The second toad remained on the
same private property where it was initially captured, moving less than 40 m
between re-locations (every 3 days), less than 100 m total over the 10-day
tracking period, and no farther than 50 m from its original capture and release
point.
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Radio transmitter belts in a range of sizes |
During the
tracking period both toads showed signs of skin irritation at the belt
attachment location. Ideally, the equipment used for a telemetry study should
not affect the behaviour of the study animal (e.g., via a skin irritation) in
order to have the most accurate results as possible in terms of activity
patterns and habitat use. Therefore, in the spring of 2014, 24 male toads were
collected, fitted with one of three transmitter belt designs, and released into
enclosures. The toads were observed on a
daily basis for three weeks to monitor the effects of the transmitter belts as
well as the toad’s ability to slip out of the belts.
We are now
preparing to tag track adult toads in the fall of 2014 (October onwards) in
order to record their movement patterns and hopefully find some overwintering (hibernation)
sites. Ideally we would like to try to
have 3 toads fitted with transmitters at any given time in the fall (the toads
being tracked will vary over the course of the tracking season) and we would
love help from volunteers to locate toads and to help track them.
How can you help? We need volunteers in several ways:
1. Preparation – we need to find areas where we are
likely to locate an adult toad in the fall and then make a list of the
neigbours in that vicinity. This needs to happen before the end of September so
that we have plenty of time for land owner contact. If you see adult toads in your yard on a
regular basis, please contact us so that we can let you know when to watch for
an adult that we can track this fall.
2. Getting
the word out - Do you know
your neighbours? This is where we need the most help. We could use help
informing people about the telemetry project and getting names and contact
details for land owners in our study areas.
We would like to be able to contact private property owners to ask for
permission to track toads on private land.
Although one of the larger known breeding sites is at Wake Lake which is
in a CVRD ecological reserve, most of the surrounding area is privately owned
properties. We want to respect people’s privacy and do not want to trespass to
locate a toad. It is also helpful to
know what homes have dogs or other livestock and to let land owners know when
to expect us when we are out locating toads.
3. Locating toads with transmitters –Once a
toad is fitted with a transmitter, we attempt to track it for anywhere from 2
to 9+ weeks. Fitted toads need to be
located every 2 to 3 days to record their location and have a health check
(e.g., make sure that their belt is fitting properly). This may require walking
on uneven ground through thick shrubs and forest. One or
two volunteer assistants per toad location trip would be very helpful. Volunteers would never locate toads without a
project lead person.
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Adult toad crossing a road to reach a breeding site in early spring |
We will continue
to post project up dates to this blog, so check back often to see what we are
up to, what we are learning and how you can get involved.
Shari and Elke
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If you have
any information on toad breeding sites, road crossing locations, or are
interested in being involved with the toad telemetry project, please
contact:
Or
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