Ryder Lake Amphibian Protection Project 2015 - 2018 · Amphibians are one of the most common vertebrate species killed on roads (Miklós 2003, Dodd et al. 2004). The seasonal migration

Ryder Lake Amphibian Protection Project 2015 - 2018

July 2018 Sofi Hindmarch

Project Coordinator Fraser Valley Conservancy

Fraser Valley Conservancy RLAPP 2018 Page 2 of 44

ACKNOWLEDGEMENTS

This project was made possible with funding provided by the Habitat Conservation Trust Foundation.

Additional funders who supported this project include: Environment and Climate Change Canada’s Habitat

Stewardship Program, Lafarge Canada, Vancity, TD Friends of the Environment Foundation, and The

Langley Concrete Group.

We would also like to thank the numerous volunteers and staff who assisted with road surveys, fencing

installation, and data analysis. We are grateful to Kendra Morgan, whom has provided ongoing advice and

mentorship.

The support of the local community and the City of Chilliwack was critical to the success of this project. We

are very grateful to the local landowners who allowed us to install directive amphibian fencing on their

properties.

The Fraser Valley Conservancy recognizes the Habitat Conservation Trust Foundation and anglers, hunters,

trappers and guides who contribute to the Trust, for making a significant financial contribution to support

the Ryder Lake Amphibian Protection Program. Without such support, this project would not have been

possible.


TABLE OF CONTENTS Acknowledgements .......................................................................................................................................... 2

Executive Summary .......................................................................................................................................... 4

INTRODUCTION ................................................................................................................................................. 5

Species Information ...................................................................................................................................... 5

History of the Project .................................................................................................................................... 7

GOALS AND OBJECTIVES ................................................................................................................................... 9

STUDY AREA .................................................................................................................................................... 10

METHODS ........................................................................................................................................................ 11

(Objective 1) Time lapse photography in the amphibian crossing structure ............................................. 11

1.1 Time lapse photography of crossing structure for sub-adult emigration from wetland .................. 11

1.2 Time lapse photography of crossing structure for adult emigration from wetland ......................... 11

1.3 Time lapse photography of crossing structure for adult migration to wetland ............................... 11

(Objective 2) Assess directional fencing design for weaknesses ................................................................ 11

2.1 & 2.4 Fence surveys for amphibians (sub-adult and adult) .............................................................. 11

(Objective 3) Assess reductions in road mortality associated with crossing structure and directive fencing .................................................................................................................................................................... 12

3.1 Road surveys for sub-adult Western toads ...................................................................................... 12

(Objective 3.2 & 3.3) Road surveys for adult amphibians .......................................................................... 13

RESULTS .......................................................................................................................................................... 14

(Objective 1) Time lapse photography in the amphibian crossing structure ............................................. 14

Objective 2) Assess directional fencing design for weaknesses ..................................................................... 18

2.1 Fence surveys for sub-adult Western toads ......................................................................................... 18

2.2 Fence surveys for adult Western toads ................................................................................................ 20

(Objective 3) Assess reductions in road mortality associated with crossing structure and directive fencing .................................................................................................................................................................... 21

3.1 Road surveys for sub-adult Western toads ...................................................................................... 21

(Objective 3.2 & 3.3) Road surveys for adult amphibians .......................................................................... 24

DISCUSSION .................................................................................................................................................... 28

CONCLUSION................................................................................................................................................... 32

LITERATURE CITED .......................................................................................................................................... 33

Appendix A: Average number of toad per survey plot 2014-2017 ................................................................. 34

Appendix B: Fencing installation and design for Sub-adult Western toad migration 2017. .......................... 35

Appendix C: Fencing installation and design for adult amphibian migration 2018. ....................................... 41

Appendix D: Migration brochure .................................................................................................................... 44


EXECUTIVE SUMMARY

The Ryder Lake Amphibian Protection Program (RLAPP) was initiated by the Fraser Valley Conservancy in

2008 to address the high mortality of amphibians on Elk View, Ryder Lake, and Huston Roads in Chilliwack,

BC. In particular, local landowners were concerned about the large number of sub-adult Western toads

being run over by cars during their annual mass migration in the summer. Amphibians worldwide are

commonly killed on roads during their seasonal migrations to and from breeding ponds. Consequently, a

diverse range of engineering solutions have been attempted to help amphibians cross safely under roads.

The RLAPP started with toad rescue events and road closures, but a permanent solution that would allow

both people and amphibians to safely use this roadway was quickly identified as the only long-term

solution for this issue. In 2014, 57 permanent road plots were established and surveys were initiated to

count migrating adult and sub-adult toads crossing the road at different locations. An amphibian crossing

structure was designed in 2014, and the final product was installed under Elk View road in 2015. The

location of the crossing structure was based on the criteria from the City of Chilliwack Engineering

Department and on five years of amphibian road survey data. Temporary fencing is set up annually to

direct migrating amphibians to the crossing structure. During the main migration periods (spring: adult

immigration, summer: sub-adult emigration, fall: adult emigration). We have continued the road surveys,

and we install a camera in the crossing structure seasonally, which takes time-lapse photography of its

usage.

When road survey data was compared to 2014 pre-construction results, the 2015 and 2017 data showed a

significant reduction in the number of sub-adult toads found in four of the eight permanent road plots

where fencing was installed, and in 2016 there was a significant reduction in two of the corresponding

plots. After the 2015 field season, the methodology for the time-lapse photography in the crossing

structure changed to a horizontal set-up as this provided a more accurate view of the crossing structure.

This makes it hard to directly compare the number of sub-adult toads in 2015 (n=11,688) versus 2016

(n=34,915) and 2017 (n=7418). Other compounding factors were the much smaller sub-adult emigration in

2016 when compared to previous years, and in 2017 the majority of the sub-adult toads emigrating out the

southern end of the wetland, bypassing the fencing and crossing structure altogether.

The number of adult amphibians found along the fenced sections of roads versus unfenced sections shows

no trends. However, we have noticed consistent migration patterns between years for the adults. The

intersection at Ryder Lake and Elkview Roads appears to be a hotspot for adult mortality. Adults do use the

crossing structure, and to date a total of 198 adult toads have been documented using it.

Research into the effectiveness of the amphibian crossing structure in the community of Ryder Lake will

continue for at least three more years. Initial results appear positive and ongoing adaptive management of

the existing fencing systems will continue. The Fraser Valley Conservancy plans to continue to work with

our partners and the local community to design and install long-term permanent fencing solution.


INTRODUCTION

Roads are a common feature of a human developed landscape and have a variety of impacts on wildlife

including directly causing mortality. Amphibians are one of the most common vertebrate species killed on

roads (Miklós 2003, Dodd et al. 2004). The seasonal migration of amphibians, from foraging habitats to

ponds and wetlands for breeding, often requires them to cross roads. This puts these species at high risk of

mortality from vehicles and can also pose a danger to motorists when they cross in large numbers. In

addition to direct mortality, roads can also fragment habitats and cause genetic isolation both of which

increase the risk of species going extinct (Miklós 2003). A variety of engineering solutions have been

attempted across the world to reduce amphibian road mortality including a variety of crossing structure

systems. These systems typically consist of a culvert and associated fencing guidance system (Osvaka et al.

2004). Studies of these systems have shown various levels of success and recommendations have been

collated for the optimal systems for allowing amphibians safe passage under roadways (Fahrig and

Rytwinski, 2009; Miklós 2003, and Osvaka et al. 2004).

Many Western toads, and other amphibians, are killed on roads surrounding a breeding pond in Chilliwack,

BC. The Fraser Valley Conservancy, in collaboration with a variety of partners, installed an amphibian

crossing structure in 2015. This report aims to analyze the effectiveness of the installed crossing structure

and associated fencing in reducing road mortality of amphibians at this location over the past years.

Species Information The Western Toad (Anaxyrus boreas) is a large warty amphibian that is widespread throughout British

Columbia. Despite widespread occurrence, this species has been listed as of Special Concern by the

Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and pursuant to the Species at Risk

Act (SARA). The Western toad has experienced abrupt and significant declines throughout the United

States and on Vancouver Island. Habitat fragmentation, habitat loss, susceptibility to pesticides and other

chemicals, and disease are all factors that are likely linked to these declines. This species, like all native

amphibians, is protected by the Wildlife Act in B.C. making it illegal to kill or hold this species in captivity

(Wind and Dupuis 2002).

Western toads have dry bumpy skin and usually have a pale cream to yellow stripe down their back. They

also have conspicuous parotid glands behind their eyes that store a mild white poison (Figure 1). These

amphibians have diverse colour morphology and can be green, red-brown, black or any variation in

between (see Figure 2) (B.C. Frogwatch Program 2016). Their ventral surface is pale and mottled and has a

patch of pelvic skin that allows them to absorb moisture from the environment. The life expectancy of this

species is between 9 and 11 years (Wind and Dupuis 2002).


Figure 1: Western toad. Figure 2: Sub-adult Western Toad colour morphology.

Western toads are explosive breeders meaning that they congregate in large numbers in the spring to

compete for mates and breed over a short time, usually 1-2 weeks. Breeding occurs in shallow waters of

ponds, stream or lake margins, ditches and even road ruts. These toads have strong site fidelity and will

return to the same location for breeding year after year. Females mature when they are 4-5 years old and

lay between 5,000 and 16,500 eggs in a long double string (B.C. Frogwatch Program 2016).

Males mature at age three and are generally smaller than females. Males compete with each other to

enter amplexus with females. Amplexus is the mating position of amphibians where a male climbs onto a

female’s back and holds on using nuptial pads on his thumbs, until eggs are released. Male toads may

vocalize a release call, a quiet chirping sound, if he is grasped in amplexus by another male.

Figure 3: Congregated Western toad tadpoles in the breeding pond at Ryder Lake (2017).


Embryos usually develop and hatch in 3-12 days. Metamorphosis from tadpoles is usually complete within 3

months and is dependent on water temperatures. Tadpoles are small and black with a tail fin that does not

extend past the tail which distinguishes this species from other frogs. Tadpoles congregate in large

synchronized schools that swim and feed together (see Figure 3). Near the completion of their

metamorphosis they congregate in warm shallow margins and complete their metamorphosis. Tiny

sub-adults migrate en masse away from the wetland and towards forest, grassland, and other moist

terrestrial habitats where they spend the majority of their lives (Wind and Dupuis 2002).

History of the Project The Ryder Lake Amphibian Protection Program (RLAPP) was created by the Fraser Valley Conservancy

(FVC) in 2008. This program was initiated with the help of local landowners in Ryder Lake who wanted to see

a reduction in road mortality of Western toads during their annual sub-adult emigration from the breeding

pond. The program started with toad rescue events in 2008 and 2009 where sub-adult toads were collected

in buckets and carried across the road. A summary of actions undertaken by the FVC to reduce sub-adult

road mortality are detailed in table 1. Road surveys for adult amphibians were initiated in 2010 and

collected data on the Western toad (Anaxyrus boreas), Northern red-legged frog (Rana aurora), Northern

Pacific tree frog (Pseudacris regilla), Northwestern salamander (Ambystoma gracile), roughskin newt

(Taricha granulosa), and long-toed salamander (Ambystoma macrodactylum). Number and seasons of

surveys are listed in Table 2.

Table 1: A summary of actions undertaken by the Fraser Valley Conservancy (FVC).

Year Migration Dates # Observed Action taken by the FVC

2008 2009 2010 2011 2012

2013 2014 2015 2016 2017

July 21 – 26 July 8 - 13 July 28 – August 6 July 25 - 29 Unknown

Unknown July 8 – 28 June 22 –9 July 7 –20 July 14 - 27

41,931 39,220 10,000s NA Very few

NA ~100,000 >11,9001 >47,2001

>25,0321

Toad rescue event with over 150 volunteers. Toad rescue event and road closures July 11, 12, 13.

Partial road closures July 23-29. Flagger controlled road closure. Ready for road closures but too few sub-adults migrating to warrant closure. Voluntary detour signs installed. Voluntary detour signs and monitoring completed. Toad crossing structure installed (June 1-4) and fencing installed to direct amphibians to crossing structure. Voluntary detour signs installed and monitoring completed. Fencing installed June 15th to direct amphibians to crossing structure. Voluntary detour signs installed and road surveys conducted between July 7 – 20. Fencing installed June 28th to direct amphibians to crossing structure. Voluntary detour signs installed and road surveys conducted between July 14 – 27.

1. # observed includes all sub-adult toads detected during road surveys in addition to the total counted passing through crossing structure

from camera analysis.


Table 2: Summary of adult road surveys from 2010 to 2018 (value in brackets is percent alive).

Year # Spring Surveys # Fall Surveys Total # Amphibians Observed Total # Western toads

2010 2011 2012 2013 2014 2015 2016 2017 2018

17 17 11 2 22 9 6 4 3

0 0 0 0 2 4 2 3 NA

716 (43%) 442 (30%) 371 (43%) 156 (18%) 1122 (37%) 437 (45%) 141 (28%) 594 (33%) 219 (63%)

264 (52%) 127 (35%) 150 (52%) 56 (13%) 268 (47%) 135 (44%) 24 (17%) 36 (28%) 71 (79%) dd

Early in the project, it was recognized that a long-term solution was needed at this location to allow Western

toads and people to exist in harmony. Road closures are expensive to enforce and have strong opponents in

the community. Rescue events were dangerous for volunteers working on the road. In addition, picking up

amphibians and transporting them in a bucket may cause injury to the smaller amphibians and

disorientation from being transported which may result in them going back across the road.

The FVC began exploring alternatives including a permanent amphibian crossing structure. In 2014, an

agreement was made with Lafarge Canada to provide in-kind construction support for a permanent crossing

structure. Engineering drawings were developed and permits acquired from the City of Chilliwack. The

Langley Concrete Group built and donated the culvert pieces. The final design for the crossing structure was

a box culvert (0.91m height x 1.83m width x 12m length) with three man-hole cover grates (0.63m

diameter). These grates are intended to increase the amount of light, moisture, and air passage through the

crossing structure based on recommendations made by other projects (Miklós 2003).

Installation of the crossing structure was completed from June 1-4, 2015, just in time for the summer

emigration of sub-adult Western toads. The location of the crossing structure was determined based on

criteria from the City of Chilliwack Engineering Department and the location where the most adult

amphibians were found on the road based on five years of road survey data. Consideration was also given to

where sub-adult Western toads were seen crossing the road but no scientific data was available.

Directional fencing to guide the amphibians towards the crossing structure is installed in the spring for the

adults immigrating to the wetland and then in the summer for the sub-adults emigrating from the wetland.

Community volunteers assist with the installation of fencing. Details for the design of the fencing for sub-

adult Western toads are in Appendix B, and details for adult fencing are in Appendix C.


GOALS AND OBJECTIVES

The goal of the Ryder Lake Amphibian Protection Project (RLAPP) is to reduce amphibian mortality along

Elk View, Ryder Lake, and Huston Roads through the development of an amphibian crossing structure and

additional safe amphibian crossing routes. This project also aims to maintain and promote community

involvement in this conservation effort. The primary goal of this RLAPP project is to evaluate the

effectiveness of the new crossing structure. Specific objectives of this project include:

Evaluate amphibian use of the installed crossing structure;

Assess directional fencing design for weaknesses;

Assess reductions in road mortality associated with crossing structure and directive fencing.


STUDY AREA

This project is based in the community of Ryder Lake in Chilliwack, BC. Ryder Lake is a small farming

community located on the northern end of the Cascade mountain range. The northern slopes of these

mountains transition down towards the Fraser Valley and the City of Chilliwack. The biogeoclimatic

subzone represented in this area is the Coastal Western Hemlock dry maritime (CWHdm). The study occurs

along a 3 km section of Ryder Lake, Huston, and Elk View Roads in Ryder Lake, BC (see Figure 4). This area

was chosen for study based on local interest in the sub-adult toads emigrating from the productive

breeding pond at the center of the survey route. This breeding pond was created on private land by beaver

dam activity in the 1950’s; it remains wet year-round and is at approximately 230 m in elevation. New for

2017, is that we now have permission from the landowners to access the breeding pond. Hence, we are

now able to monitor the toads’ metamorphism from eggs to sub-adults, making it easier to assess when

the mass emigration will occur.

Figure 4: Map of breeding pond and amphibian survey route in Chilliwack, BC.


METHODS

(Objective 1) Time lapse photography in the amphibian crossing structure To assess the number of amphibians using the crossing structure, a Reconyx PC900 Hyperfire Professional

Covert Camera Trap was installed in the crossing structure. The camera was programmed to take photos

every minute as well as when the infrared sensor was triggered.

1.1 Time lapse photography of crossing structure for sub-adult emigration from wetland

For the sub-adult emigration photos were taken during peak migration periods from 4:00 am to 11:59 am

and from 4:00 pm to 11:59 pm. The camera was set on the ground in the middle of the crossing structure

pointing west towards the wetland. On the ground in front of the crossing structure we placed a white

piece of plastic cloth so that it would be easier to see the toads as they migrated through the crossing

structure. In 2017, the camera was mounted in the crossing structure on July 14th, as this is when sub-adult

toads were observed migrating, and removed on August 4th after the completion of the emigration.

Photographs were analyzed individually; the number of amphibians, species, date, time, and temperature

were recorded for every photo. We also assessed whether the same toad was seen on several pictures and

controlled for this when summarizing the data. A t-test (two sample assuming unequal variance) was used

to compare morning and evening time-lapse monitoring sessions for sub-adult toads.

1.2 Time lapse photography of crossing structure for adult emigration from wetland

For the adult amphibian emigration from the wetland in the fall photos were taken for the entire 24-hour

period. The camera was set on the ground in the middle of the crossing structure pointing west towards

the wetland. The camera was installed from September 30th to November 14th, 2017. Photographs were

analyzed individually and number of amphibians, species, date, time, and temperature were recorded. We

also calculated the length of time each amphibian was observed in the crossing structure, based on the

number of photos taken of each individual (i.e. one photo is taken every minute).

1.3 Time lapse photography of crossing structure for adult migration to wetland

For the adult amphibian migration to the wetland in the spring photos were taken between 5:30 pm and

6:59 am. The camera was set on the ground in the middle of the crossing structure pointing east in order

to capture the adult toads migrating towards the wetland. The camera was installed from March 13th to

April 26th, 2018. Similar calculations as described in 1.2 will also be done for the spring data.

(Objective 2) Assess directional fencing design for weaknesses

2.1 & 2.4 Fence surveys for amphibians (sub-adult and adult)

During road surveys for both sub-adult (objective 2.1) and adult (objective 2.4) amphibians, the fence line

was walked by surveyors to observe behaviour of amphibians approaching or travelling along the fence.

For the sub-adult surveys, short videos were taken of the toads moving along the fence. We also assessed

the fence for weaknesses, where sub-adult toads were escaping underneath the fencing, and mended

fence where needed. At the beginning of the sub-adult emigration, we also assessed daily whether the


0.5m

1m

0.5m

Breeding Pond

Plot 1

Plot 2

fencing needed to be slightly adjusted or moved to accommodate for annual variations in the emigration

route. During the adult fence surveys, species and location was noted.

(Objective 3) Assess reductions in road mortality associated with crossing structure and directive fencing

3.1 Road surveys for sub-adult Western toads

A total of 57 survey plots were laid out along the existing amphibian survey route in Ryder Lake. The survey

route is 3 km long and encompasses parts of Elk View, Ryder Lake, and Huston Roads (Figure 4). Plots are

located 50 m apart. Each plot was permanently marked on the road with paint and given a unique number.

During each survey a 0.5 m x 1 m rectangle frame (made out of wood) was placed at each marker in two

locations. Plots were placed on the breeding pond side of the road 0.5m from the centerline. Two plots

were counted at each survey locations set diagonally from each other (Figure 5).

Figure 5: Plot layout showing road and centerline.

In each plot, all live and dead amphibians were recorded. Live amphibians were moved to the side of the

road in their direction of travel. Any dead amphibians were scrubbed off the road using a barbeque brush

so they would not be double counted. We also counted the number of live toads between each plot and

moved live individuals to the side of the road away from the wetland. Dead sub-adult toads between each

plot were only counted during the first survey as it is hard to discern additional road mortality during

subsequent surveys. Surveys were conducted in the morning and/or evening, starting around 8 am and 6

pm respectively.

A two-tailed t-test was performed comparing the average number of sub-adults found per survey in each

plot between 2014 (before crossing structure) and for each year after 2015 (after crossing structure). Equal

or unequal variance was determined based on an F-test in Excel.


(Objective 3.2 & 3.3) Road surveys for adult amphibians Road surveys for live and dead adult amphibians were conducted following standard Resource Inventories

Standards Committee procedures (MELP 1998). Surveys were conducted in the evening, starting at dusk on

days with appreciable precipitation, where the prior days had been dry, (i.e. we tried to conduct the

surveys on the first day of rain after a dry spell). Preferentially, there would also be precipitation during

the survey. Two to four surveyors walked a prescribed 3 km route, backtracking along all sections (see

Figure 4). Surveyors spread out across both lanes of the road and walked at a medium pace scanning the

road with headlamps. For each amphibian or amphibian carcass observed the following data was collected:

species; whether the specimen was alive or dead; gender (when possible); age class; and direction of

movement (generalized as towards or away from central breeding pond). A GPS point was taken using a

Garmin CSX60. Dead amphibians were moved off the road to prevent double counting as surveyors

returned along the survey route. Live amphibians were carefully transported off the road in the direction

of their travel to avoid double counting and prevent vehicular mortality. A clean nitrile or vinyl glove was

used for each individual to prevent disease transmission and protect the amphibians from oils or lotions on

hands in accordance with Wildlife Permit SU16-227002.

Weather data was collected at the beginning and end of each survey including percent cloud cover (0%, 1-

49%, 50-99%, 100%); precipitation category (Misty drizzle, Light Rain, Rain, Heavy Rain); ranking from

Beaufort Wind Scale, and temperature. Names of the surveyors were recorded as well as start and end

time of the survey.

Data collected was analyzed for number of amphibians identified per survey, percent of each amphibian

species found alive and average number of amphibians per survey and km. In addition, the average

number of amphibians per survey was calculated for the area where fencing was installed and compared

with historical data collected in the same area before the fencing and crossing structure were installed.


RESULTS

(Objective 1) Time lapse photography in the amphibian crossing structure Time-lapse photography was used to monitor the crossing structure in the three migratory seasons. Since this project began, 161,847 photographs have been taken and analyzed (Table 3). Over 160 volunteer hours were spent analyzing the photographs. Table 3: Number of photographs and average number of amphibians from 2015-2017. Field of view refers to the positioning of the camera in the crossing structure, i.e. “Large” horizontal view versus “Small” vertical view (no longer in use).

Field of View

Life Stage Season # Photos # Amphibians

Large Small Small Large

Sub-adult Sub-adult Adult Adult

June 25 to June 30, 2015 June 30 to July 17, 2015 Sept 24 to Oct 16, 2015 Feb 15 to Mar 26, 2016

669 16,771 21,566 30,396

10,886 802 9 36

Large Sub-adult July 7 to July 20, 2016 13,119 34,915

Large Adult Sept 16 to Oct 25, 2016 6392 27

Large Adult March 12 to April 5, 2017 19,363 58

Large Sub-adult July 14 to August 4, 2017 19,345 7498

Large Adult Sept 29 to Nov 14, 2017 34,226 35

Large Adult March 3 to April 27, 2018 40,320 125

TOTAL 161,847 54,391 To date, 54,391 amphibians have been observed passing through the crossing structure, including Western

toads, frogs and salamander species. The majority of amphibians observed were sub-adult Western toads

(Table 4, Figure 6 and 7).

Table 4: Number of amphibians observed in the crossing structure by species 2015-2018.

Species Number Observed

Unknown frog species 40

Northern Red-legged frog 83

Salamander species 25

Tree frog 8

Western toad 198

Sub-adult Western toad 54,037


Figure 6: Sub-adult and adult Western toad meet in crossing structure (Summer 2017).

Figure 7: Sub-adult rough-skinned newt in crossing structure moving away from wetland (Fall 2017).


In 2015, significantly more sub-adult toads were seen between 4am and 12pm (morning) versus 4pm and 12

am (evening). However, in 2016 and 2017 no significant differences were between the two time periods,

2016: t=0.72, P=0.47, df= 34952, and 2017: t=1.12E-11, P=0.99, df=2624, respectively. The number of sub-

adult Western toads seen per day was analyzed and results are shown in Table 5.

Table 5: Number of sub-adult Western toads observed crossing through a crossing structure in 2017.

Date Total # Toads

Total # Minutes

Average Toad/Hour

July 15, 2017 81 525 9

July 16, 2017 2853 969 177

July 17, 2017 1091 966 68

July 18, 2017 963 969 60

July 19, 2017 356 963 22

July 20, 2017 1301 963 81

July 21, 2017 174 960 11

July 22, 2017 131 981 8

July 23, 2017 121 963 8

July 24, 2017 132 966 8

July 25, 2017 90 960 6

July 26, 2017 39 960 2

July 27, 2017 17 970 1

July 28, 2017 8 960 1

July 29, 2017 12 963 1

July 30, 2017 10 963 1

July 31, 2017 20 966 1

August 1, 2017 22 969 1

August 2, 2017 4 963 0

Total 7425 17899


The average time spent in the crossing structure was calculated for adult toads during their migration and

emigration to and from the wetland. For these adults, the field of view for the camera was approximately 7 m

which is 58 % of the crossing structure length. It was not possible to identify species seen as eye-shine at the

furthest point from the camera. Toads were observed in 1–61 photos meaning that they spent between 1

and 61 minutes in the camera’s field of view while crossing through the crossing structure (Figure 8). The

average time spent in the camera’s field of view was 4 minutes. However, 65 % of the toads spent 1-3

minutes in the crossing structure.

Figure 8: Total time individual adult toads were seen in the crossing structure spring 2016-spring 2018 (n=188).

48

44

30

12 11

16

8

3 4 3 2 1 1 2 1 1 1

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11 12 14 18 23 25 61

Nu

mb

er

of

toad

s

Number of minutes in tunnel


OBJECTIVE 2) ASSESS DIRECTIONAL FENCING DESIGN FOR WEAKNESSES

2.1 Fence surveys for sub-adult Western toads Approximately 350 m of directional fencing was installed on June 28th, 2017 to direct sub-adult toads

emigrating from the wetland through two safe crossing routes (Appendix B). This year, we doubled the

number of ground staples along the base of the fencing in order to minimize the chances of sub-adult

escaping underneath the fencing (Figure 9). Emigration of sub-adults was observed on July 14th. However,

this year was an unusual emigration year, as the majority of the sub-adult toads exited the wetland at the

southern end, and not the northern which had been the emigration pattern in the previous two years

(Figure 10). Consequently, the majority of the sub-adult toads were too far south to be guided by the

fencing towards the crossing structure. Instead these sub-adult toads crossed Elk View south of the fencing

and crossing structure, as well as Houston Road which is on the opposite side of the breeding pond from

the crossing structure.

The atypical emigration from the wetland also meant some sub-adults emigrated just beyond the southern

edge of the fence line, but they then changed direction before they reached the road. This resulted in them

being on the wrong side of the fence and unable to access the crossing structure. To alleviate this, we

created an opening in the fence near the crossing structure so that the sub-adults that were trapped on

the wrong side moving north had an opportunity to access the crossing structure.

Overall the relative number of sub-adult toads seen moving along the fence-line versus found dead on the

corresponding section of road indicates that the fencing was working (Figure 13). During the emigration we

walked the fence daily to assess for weaknesses. Fencing was removed on August 4, 2017 after the

emigration of sub-adult toads was completed.

Figure 9: Sub-adult Western toad fencing install on June 28th

, 2017. This

year we doubled the number of ground staples along the base of the

fence to minimize the chances that a sub-adult could get underneath it.


Figure 10: Illustrating the migration routes of the sub-adult Western toad. In 2017, the majority of the sub-adult Western toads

emigrated from the southern end of the breeding pond (red lines), bypassing the fencing and crossing structure. Blue lines

illustrate the more “typical” route the sub-adult take when they emigrate from the wetland.


2.2 Fence surveys for adult Western toads On March 3rd 2018, approximately 200 m of fencing was installed on the eastern side of Elk View road to

direct adult amphibians migrating from their forested habitats to the wetland for breeding (Figure 11,

Appendix C). Three spring road surveys were conducted for adult amphibians after fencing installation. The

timing of the adult spring road surveys seem to have coincided well with the migration of the toads, as we

documented 56 adult male toads, 9 adult female toads, and 6 toads with unknown sex, of which 79% were

alive. In addition, we observed eight adult male and one adult female toad migrating along the fence-line

towards the crossing structure (Figure 12). Interestingly, we also documented four sub-adult sized toads on

the road this spring.

Figure 11: Install of fencing on March 3rd

, stakes are placed in ground and silt material attached using staples and

screws.


Figure 12: An adult male toad moving along the fence towards the crossing structure. Springs of 2018, a total of nine

adult toads were documented on the east side of the fence moving in the direction of the crossing structure.

(Objective 3) Assess reductions in road mortality associated with crossing structure and directive fencing

3.1 Road surveys for sub-adult Western toads

The sub-adult toads started emigrating on July 14, 2017. As of August 2, 2017 the migration was finished

and no surveys were done after this date. In total, 10 road surveys were completed and we documented a

total of 106 dead and one live sub-adult toad(s) within the plots. The average number of live toads seen in

total between plots for each survey was eight toads.

Significant differences (p<0.05) between average number of sub-adult toads per plot in 2014 compared to

2017 were found for 7 of the 57 plots 39, 42-45, 47,48 and 57) (Figure 11, 12, Appendix A). With the

exception of plot 57, the average number of toads found in the plots was significantly lower when

compared to 2014. Four of these plots (39, 42 - 45) area located along the installed fencing route. Figure 13

shows the average numbers of amphibians per plot from 2014 - 2017 while Figure 14 shows the locations

of each sub-adult plot and where fencing was installed for the sub-adult migration.


Figure 13: Comparison of average numbers of sub-adult toads found in permanent plots from 2014 to 2017.


Figure 14: Location of each sub-adult Western toad plot as well as location of directional fencing installed for the sub-adults. * specifies plots which had significant lower average number of sub-adult toads when compared to 2014, and

Χ

specifies plots which had significant higher average number of sub-adult toads when compared to 2014.


(Objective 3.2 & 3.3) Road surveys for adult amphibians In total, 6 amphibian road surveys were completed between September 17, 2017 and April 4, 2018. Thirty-

eight person hours of surveying was completed with the help from 6 volunteers. A total of 686 amphibians,

alive and dead, were identified along the 3 km survey route. On average, 114 amphibians were seen per

survey or approximately 19 amphibians/km of survey. The total number of each species as well as percent

alive is shown in Table 6. Tables 7 and 8 show the total numbers separated by season. Figure 15 shows the

total species composition in percent.

Table 6: Total number of amphibians observed during road surveys in the fall 2017, and spring 2018.

Species # Alive # Dead Total Alive

Long-toed salamander 10 2 12 83%

Western toad 67 39 106 63%

Northern Pacific Tree frog 154 244 398 39%

Common Garter snake 0 12 12 0%

Northern Red-legged frog 41 93 134 31%

Rough Skin newt 2 12 14 14%

Unidentified 0 1 1 0%

TOTAL 280 406 686 41%


Figure 15: Species composition of adult amphibians found during Ryder Lake road surveys between 2015-2018 (n=1184).

Table 7: Total number of amphibians observed during road surveys in spring 2015-2018 (n=16 surveys).


Northwestern Salamander 2 0 2 100%







TOTAL 275 266 541 51%

Northwestern Salamander

1%

Long-toed Salamander

2%

Western Toad 15%

Northern Pacific Tree Frog

52%

Western Red-backed Salamander

0%

Northern Red-legged Frog

22%

Roughskin Newt 5%

Common Garter Snake

3%


Table 8: Total number of amphibians observed during road surveys in fall 2015-2017 (n=9 surveys).


Northwestern salamander 5 2 7 71%




Western Red-backed salamander 0 1 1 0%




Unidentified 0 4 4 0%

TOTAL 203 440 643 32% Directional fencing for the adult immigration was installed along Elk View March 3rd, 2018 (Appendix C).

Surveys completed in February and March of 2016 (n=5), 2017 (n=3) and 2018 (n=2) were compared to

surveys completed in the same months in 2015 (n=6), before the toad crossing structure was installed

(Table 9). Fencing was installed over 200 m of the 3 km survey route which is 7 % of the survey route. The

relative percentage of amphibians detected on the road where fencing has been installed varies annually

and is likely strongly correlated with the size of the annual migration. Figure 16 illustrates the density of

adult Western toads documented along the survey route since 2015.


Figure 16: Density of adult Western toads documented along the survey route for each year (2018 is spring only; n= 145).

2015 2016


DISCUSSION

The sub-adult toads started emigrating on July 14th, 2017, which was 2.5 weeks later than 2015 and one

week later than 2016. This difference is likely correlated with the weather, as we had an unusually warm

spring in 2015, and conversely a later spring warm up in 2017. In general, emigration typically occurs in

July. We installed the sub-adult fencing late June, and given our experiences from 2016, we doubled the

number of ground staples and meticulously ensured that there were no areas where the sub-adult toads

could escape underneath the fencing and on to the road. However, this year the majority of the sub-adults

did not emigrate their “typical” route from the northern end of the wetland but instead they emigrated

out the southern part of the wetland, bypassing our directional fencing and crossing structure (Figure 10).

Consequently, our most effective method to ensure reduction in road mortality this year was to ensure

that the public used the voluntary detour route, which was signed and maps were also available. New for

this year was the use of social media to update the local community on a daily basis. Also in response to

the increasing number of people wanting to come and see the emigration of the sub-adult toads, a

brochure with general information about the sub-adult emigration and special parking spaces north of the

crossing structure were provided (Figure 17, Appendix D).

Figure 17: In response to an increasing number of people wanting to come and see the emigration of the sub-adult toads, a

brochure on how to safely view the migration, including a map of the voluntary detour route was available to the public.

Using time-lapse photography, we documented a total of 7,498 sub-adult toads emigrating through the

crossing structure between July 14th and August 2nd, 2017. This was considerably lower than 2016 when


34,915 sub-adult toads were documented. We attribute the lower number of toads documented to the

switch in their emigration route in 2017. Road surveys for sub-adult toads commenced on July 14th, and 10

surveys documented a total of 106 dead and 1 live individual in the 57 plots. The number of toads found

within plots was significantly lower for four of the eight plots along the fenced section of the road when

compared with 2014 survey results. The last plot (57) had on average significantly more toads when

compared with 2014 data, which may reflect the southern emigration route taken by sub-adult toads. In

addition, at the end of the emigration sub-adult toads were also documented along Houston Road.

The 2017 total number of sub-adult toads documented in plots was substantially lower than 2015 when

212 sub-adult toads (n=9 surveys) were documented and 2014, pre-install of crossing structure, when 1032

sub-adult toads were counted (n=31 surveys). Although, this years’ numbers were higher than 2016 when

38 dead and 0 alive were documented over nine surveys. The low numbers documented in 2016, could be

partly due to a smaller emigration, which was expected based on the low number of migrating adult toads

documented in the spring of 2016. Amphibian populations are known to fluctuate annually, and they are

also vulnerable to stochastic events such as changes in environmental conditions, disease and predation

(Marsh and Trenham 2001). The installation of fencing well in advance of the sub-adult emigration and

continued adaptive management of the fencing to accommodate the sub-adult toads movements also

reduced the number of sub-adult toads on the road.

In the fall of 2017, a total of 39 adult toads were documented emigrating from the wetland (time-lapse

photography n=4, road surveys n=11 alive and n=24 dead) and this spring, road surveys documented a

total of 71 adult Western toads immigrating to the wetland (n=56 alive, n=15 dead). This is the largest

number of migrating adults documented to date relative to number of surveys conducted, which would

suggest a large sub-adult emigration from the wetland this summer. Correspondingly, the total number of

adult toads documented going through the crossing structure to the wetland between March 8 and April

26th was the highest ever documented to date with a total of 98 toads.

Since 2016, we have installed the camera ~ 5cm above the ground in the crossing structure facing

horizontally towards the wetland during emigrations and away from the wetland during adult migration to

the wetland. This along with placing a white piece of plastic cloth on the ground in front of the camera has

increased our ability to detect and count adult/sub-adult toads and other amphibians using the crossing

structure. However, the width of the camera lens still precludes us from getting a good view of the

concrete sides 1-2m in front of the camera, so we likely miss counting smaller sub-adult amphibians

walking right up against the concrete wall. Another potential error when using time-lapse photography is

double-counting sub-adult toads that have not cleared the field of view in the one minute photo

timeframe. Overall, we expect that these errors are minimal relative to the number of sub-adult toads

counted and this should not affect yearly comparisons of the data. The adult Western toads are nocturnal

and their spring migration and fall emigration spans over a much longer time-frame when compared to the

sub-adult emigration. Hence, in addition to road surveys, time lapse-photography, as a method has proven

quite useful for monitoring the adult toads. Time-lapse photography and road surveys will continue

through April to further assess this year’s amphibian populations. In conclusion, we are pleased with the

current camera install, and the results generated from the 2016-2017 monitoring of sub-adult emigration

and adult amphibian migration/emigration to and from the wetland.


The adult fencing for the spring migration was installed on March 3rd, 2018, when there was still snow and

the ground was frozen in some locations. Hence, we had some challenges with the wooden stakes being

pushed out of the ground due to the freezing and thawing continuing through March. Re-digging the ditch

and re-installing the wooden stakes at the end of March seems to have worked. However, for future it

might be worth using heavy duty metal stakes in some strategic locations, as these can be placed deeper in

the ground and less flex makes for a sturdier fence. During road surveys in March (n=2) 30 amphibians

were found on the road within the fenced area (n=181 amphibians across the entire survey route), there

were eight adult Western toads, five adult Northern red-legged frogs, 16 adult Northern Pacific tree frogs

and one adult long-toed salamander. In addition, we observed eight adult male and one adult female toad

migrating along the fence-line towards the crossing structure, which is the first time we have documented

adult toads along the fence-line towards the crossing structure. Overall, we think the adult migration

fencing is working well However, given that one of the migration hotspots for the adult toads is the

intersection of Elk View and Ryder Lake Roads (Figure 16), we will be assessing whether we can extend the

fencing to the north of the intersection. Concurrently, we will also evaluate whether there are other

suitable culverts that are in close proximity to areas where adult and sub-adult toads are consistently being

documented on the road.

The sub-adult fencing was installed on June 28th, 2017, which was well in advance of the emigration which

started on July 14th. To minimize the risk of sub-adult toads escaping underneath the fence we doubled the

number of ground staples during install, and carefully inspected the fence regularly before the sub-adult

emigration occurred. However, since the majority of the sub-adults emigrated out the southern end of the

wetland bypassing the fence and the crossing structure altogether, our assessment of the success of the

fencing was more limited this year versus previous years’. Although, the relative number of dead-sub

adults on the stretch of road where fencing was installed was lower when compared to the relative

number of sub-adult toads seen moving along the corresponding fence-line, suggesting that the fencing

was effective in directing the sub-adult toads that were in this location towards the main crossing structure

(route 1) and culverts north of the crossing structure (route 2, see Appendix B). During the sub-adult

emigration we walked the fence daily to assess for weaknesses and evaluated whether the fencing

alignment and/or design needed to be adjusted. Two days into the sub-adult emigration we ended up

modifying the fence due to the atypical emigration route this year. Fencing was removed on August 4,

2017 after the emigration of sub-adult toads was completed. As in previous years, this year also

highlighted the importance of daily checking the fencing and adopting an adaptive management approach

to the fencing alignment during the initial stage of the sub-adult emigration as there are likely to be slight

annual differences in their main emigration route from the wetland. Building a well-constructed

permanent fencing along the road edge at this site has become a priority for this project. In 2018/19, we

will continue to work with our partners and the City of Chilliwack to try a test prototype of permanent

fencing in this location.

The Ryder Lake Amphibian Project (RLAPP) is becoming increasingly known due to ongoing monitoring and

media attention. This past year, the Fraser Valley Conservancy (FVC) was approached by the District of

Mission, Township of Langley, A Rocha (NGO) and Aimee Mitchell/Athene Ecological regarding other toad


migrations occurring in the region. As a result, the FVC implemented a pilot project monitoring the

emigration of the sub-adult toads at Allen Lake in the Fraser Valley Regional District, using the RLAPP

monitoring methods as a template. We also provided ongoing guidance to A Rocha, a not-for-profit group

that has monitored a toad population on the border between the Township of Langley and Surrey since

2016. The Township of Langley has also been in dialogue with us regarding the installation of a tunnel to

provide a safe road crossing for this population of toads and we provided them with design options for the

directional fencing associated with an amphibian crossing structure. The District of Mission contacted us

after a concerned citizen had seen small sub-adult toads in her backyard and on roads in her

neighbourhood located close to the Silverdale Wetlands on the west side of Mission. As a response to this

request we created a post to landowners on our website summarizing what to do when you find toads in

your yard (http://fraservalleyconservancy.ca/what-to-do-when-you-find-tiny-toads-in-your-yard/). Finally,

in March Purnima Govindarajulu at the BC Ministry of Environment organized a Herps and Roads online

meeting where FVC presented the results and recommendations from the RLAPP project to participants

from around the province.

http://fraservalleyconservancy.ca/what-to-do-when-you-find-tiny-toads-in-your-yard/


CONCLUSION

The atypical emigration pattern of the sub-adults in 2017 resulted in the majority of the sub-adults

bypassing the fencing and crossing structure altogether, making it challenging to compare the 2017 sub-

adult migration data with previous years’ results. Irrespective of this, there was less sub-adult mortality

along the stretch of Elk View Road that is protected by fencing. Also not surprisingly, 4 out of 8 plots along

the fenced section of the road had on average significantly lower number of sub-adult toads when

compared to 2014. The variation in the sub-adult toads’ migration routes and fluctuations in the overall

number of toads migrating highlights the importance of on the ground monitoring as this will help us

identify which actions and designs will optimize the fencing. Daily monitoring and fencing modifications

during the initial phase of the migration helps direct the maximum number of amphibians towards the

crossing structure. Three years of amphibian adult road surveys, confirms that hotspot of the adult

migration is the intersection of Elk View and Ryder Lake Roads. We intend to evaluate whether extra

fencing north of this intersection can be effective at further reducing road mortality at this hotspot.

In summary, the amphibian crossing structure was successfully used by over 54,000 adult and sub-adult

amphibians between April 2015 to April 2018. We have secured funding to continue with the monitoring of

this project. Furthermore, we will evaluate the usefulness of permanent fencing prototype, fencing other

culverts within the study area, as well as advise other stakeholders on methods for monitoring toad

populations and options for reducing amphibian road mortality.


LITERATURE CITED

B.C. Frogwatch Program. 2016. “Western Toad.” B.C. Frogwatch Program Species Factsheets. British Columbia Ministry of Water, Land and Air Protection. 2pp. March 8, 2017. Dodd, C.K., W.J. Barichivich, and L.L. Smith. 2004. Effectiveness of a barrier wall and culverts in reducing wildlife mortality on a heavily traveled highway in Florida. Biological Conservation 118:619-631. Fahrig, L., and T. Rytwinski. 2009. Effects of roads on animal abundance: an empirical review and synthesis. Ecology and Society 14(1): 21. [online] URL: ecologyandsociety.org/vol14/iss1/art21 (accessed March 23, 2016). Marsh, D. M., and P. C. Trenham. 2001. Metapopulation dynamics and amphibian conservation. Conservation Biology 15:40-49. MELP 1998. Inventory methods for pond-breeding amphibians and painted turtle. Standards for components of British Columbia’s biodiversity; no. 37. Ministry of Environment, Lands and Parks Resources Inventory Branch. Miklós, P. 2003. Amphibian Mitigation Measures in Central-Europe. In 2003 Proceedings of the International Conference on Ecology and Transportation, edited by C. Leroy Irwin, Paul Garrett, and K.P. McDermott. Raleigh, NC: Center for Transportation and the Environment, North Carolina State University, 2003. Ovaska, K., L. Sopuck, C. Engelstoft, L. Matthias, E. Wind. 2004. Best Management Practices for Amphibians and Reptiles in Urban and Rural Environments in British Columbia. BC Ministry of Water, Land and Air Protection. Nanaimo. 1-159pp. Wind, E.I. and L.A. Dupuis. 2002. COSEWIC status report on the western toad Bufo boreas in Canada, in COSEWIC assessment and status report on the western toad Bufo boreas in Canada. Committee on the Status on Endangered Wildlife in Canada. Ottawa. 1-21 pp


APPENDIX A: AVERAGE NUMBER OF TOAD PER SURVEY PLOT 2014-2017

Table 10: Average number of toads per survey for each plot in 2014, 2015 and 2016. The p-value from a two sample two tailed t- test is given. Values that were statistically significant (P<0.05) are identified by an asterix. Plot

# 2014 avg

2015 avg

2016 avg

2017 avg

T-test 14 vs 15

P<0.05 (ie sig diff?)

T-test 14 vs 16


T-test 14 vs 17


1 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 2 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 3 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 4 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 5 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 6 0.27 0.22 0.00 0.10 0.88 No 0.34 No 0.36 No 7 0.03 0.22 0.00 0.30 0.42 No 0.59 No 0.40 No 8 0.13 0.44 0.00 0.00 0.51 No 0.49 No 0.47 No 9 0.57 0.33 0.00 0.00 0.51 No 0.09 No 0.08 No

10 0.63 0.11 0.00 0.20 0.07 No 0.19 No 0.15 No 11 0.13 0.67 0.00 0.50 0.37 No 0.37 No 0.39 No 12 0.13 0.56 0.00 0.00 0.48 No 0.49 No 0.47 No 13 0.07 0.00 0.00 0.10 0.59 No 0.59 No 0.80 No 14 0.23 0.11 0.00 0.10 0.47 No 0.31 No 0.41 No 15 0.03 0.00 0.00 0.40 0.59 No 0.59 No 0.38 No 16 0.00 0.00 0.00 0.10 NA NA NA NA 0.08 No 17 0.00 0.00 0.00 0.20 NA NA NA NA 0.08 No 18 0.07 0.00 0.00 0.00 0.44 No 0.44 No 0.42 No 19 0.13 0.00 0.00 0.00 0.37 No 0.37 No 0.34 No 20 0.10 0.00 0.00 0.00 0.47 No 0.47 No 0.44 No 21 0.10 0.00 0.00 0.00 0.47 No 0.47 No 0.44 No 22 0.03 0.00 0.00 0.00 0.59 No 0.59 No 0.57 No 23 0.03 0.00 0.00 0.00 0.59 No 0.59 No 0.57 No 24 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 25 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 26 0.20 0.00 0.00 0.00 0.15 No 0.15 No 0.13 No 27 0.43 0.22 0.00 0.00 0.42 No 0.09 No 0.07 No 28 0.30 0.00 0.00 0.00 0.18 No 0.18 No 0.16 No 29 0.67 0.00 0.00 0.00 0.07 No 0.07 No 0.06 No 30 2.43 0.00 0.00 0.00 0.09 No 0.09 No 0.07 No 31 0.67 0.00 0.00 0.00 0.17 No 0.17 No 0.15 No 32 0.03 0.00 0.00 0.00 0.59 No 0.59 No 0.57 No 33 0.13 0.00 0.00 0.00 0.26 No 0.26 No 0.23 No 34 0.00 0.00 0.00 0.00 NA NA NA NA NA NA 35 0.10 0.00 0.00 0.00 0.47 No 0.18 No 0.44 No 36 0.07 0.00 0.00 0.00 0.44 No 0.16 No 0.42 No 37 0.13 0.00 0.22 0.00 0.37 No 0.71 No 0.34 No 38 0.60 0.11 0.56 0.00 0.02* Yes 0.90 No 0.05 No 39 2.87 0.11 1.11 0.00 0.00* Yes 0.13 No 0.01* Yes 40 1.50 0.22 0.00 0.50 0.02* Yes 0.01* Yes 0.07 No 41 0.10 0.11 0.00 0.00 0.94 No 0.47 No 0.44 No 42 7.00 0.78 0.44 0.20 0.01* Yes 0.00* Yes 0.00* Yes 43 2.00 0.00 0.22 0.10 0.10 No 0.14 No 0.01* Yes 44 1.63 0.56 0.89 0.30 0.09 No 0.34 No 0.03* Yes 45 1.50 0.78 0.00 0.50 0.29 No 0.00* Yes 0.02* Yes 46 2.40 2.56 0.44 1.60 0.88 No 0.02* Yes 0.35 No 47 1.70 4.78 0.11 0.20 0.28 No 0.00* Yes 0.00* Yes 48 1.60 0.78 0.00 0.10 0.39 No 0.08 No 0.00* Yes 49 1.03 0.22 0.22 0.40 0.02* Yes 0.14 No 0.24 No 50 0.37 0.67 0.00 0.20 0.32 No 0.16 No 0.52 No 51 0.20 0.11 0.00 0.20 0.61 No 0.23 No 1.00 No 52 0.20 0.22 0.00 0.00 0.93 No 0.38 No 0.35 No 53 0.10 0.78 0.00 0.20 0.16 No 0.34 No 0.42 No 54 0.23 1.44 0.00 0.00 0.39 No 0.31 No 0.29 No 55 1.40 1.78 0.00 0.00 0.75 No 0.17 No 0.14 No 56 0.10 4.56 0.00 0.80 0.19 No 0.47 No 0.15 No 57 0.00 0.11 0.00 0.90 0.07 No NA NA 0.00* Yes


APPENDIX B: FENCING INSTALLATION AND DESIGN FOR SUB-ADULT WESTERN TOAD MIGRATION

2017.

On June 28, 2017, the FVC installed amphibian fencing to guide emigrating sub-adult Western toads to installed crossing structures. Over 350 meters of directional fencing was installed with the assistance of 8 volunteers from Lafarge Canada and the community along with five FVC staff.

Figure 1: Keen fencing installation volunteers.

The fencing set-up was designed specifically for the mass emigration of sub-adult toads that occurs in this

area every year. The topography and land ownership in this area means that the majority of the directional

fencing is installed and taken down for each emigration. Haying of the field needs to be coordinated with

the land manager prior to fencing installation, and due to a delayed growing season and hay cutting, the

installation occurred later this year. Silt fence material (black plastic fabric material) was attached to

wooden stakes using a staple gun (Figure 2).


Figure 2: Attaching silt fence material to wooden stakes


Figure 3: Using soil (A) and hose/ground staples (B) to attach fence to the ground. Also note how the silt fence material was folded over at the top to prevent amphibians from crawling over the fence (A)

Approximately 15 cm of the material was left at the bottom of the fence and attached to the ground. The

preferred method was running a garden hose along the bottom of the material, which was held in place

using ground staples (Figure 3a), where this was not feasible either soil or gravel was piled on top of the

material (Figure 3b). Both methods prevent sub-adult toads from crawling under the fencing. Extra

material at the top of the fence was folded over in the direction of the wetland and attached to the posts

creating a pocket to discourage amphibians from climbing over the fence.

A Fencing was installed to direct the migrating amphibians towards two culvert systems. Amphibians were

directed through the newly installed amphibian crosing structure (route 1) as well as a system of two

existing culverts (route 2). Both routes allowed the amphibians to safely cross Elk View Road along their

natural migration routes. Route 2 involved two existing culverts: one under Ryder Lake Road and a second

under Elk View Road. Fencing was installed inbetween the two culverts to keep the toads moving towards

the second culvert. Toads migrating between the two road crossing routes could choose to move in either

direction to a safe crossing structure. The ends of the fencing that were not connected to a culvert were

curved to encourage any amphibians moving away from the crossing structures to turn around and head

back towards the safe crossing structures.

A

B

Fencing overlap

Soil attaching fence to

ground

Garden hose and ground

staples attaching fence to

ground

A

Garden hose and ground

staples attaching fence to

ground

A


Figure 4: Map showing where directional fencing was installed in 2017.

The fencing was attached to the culverts using a combination of fence posts, zap straps, and duct tape

(Figure 5), this was one of the more challenging aspects of the fencing and needs to be done thoroughly to

ensure no gaps.


Figure 5: Attaching fencing to culvert using fence post and duct tape.

Figure 6: Fencing to redirect amphibians following fencing towards the crossing structure entrance.

Figure 7: Fencing from wetland to first culvert of route 2.

Attaching fence

to culvert with

duct tape

Fence post installed

adjacent to culvert


Figure 8: Fencing through forest towards the crossing structure (route 1)

Figure 9: Fencing to direct amphibians between first and second culvert along crossing route 2.

A

Silt fencing overlap


APPENDIX C: FENCING INSTALLATION AND DESIGN FOR ADULT AMPHIBIAN MIGRATION 2018.

The Fraser Valley Conservancy (FVC) installed amphibian fencing to guide migrating adult Western

toads, Northern Red-legged Frogs, and other amphibians to the installed crossing structures on March

3rd, 2018. At this location, adult amphibians are known to start migrating to breeding locations at the

end of February. Approximately 200 m of fencing was installed with the assistance of 10 community

volunteers and 2 FVC staff members.

Figure 1: Proud fencing volunteers after completing the install!

The fencing was designed as a temporary measure to guide amphibians migrating towards the breeding wetland to the amphibian crossing structure which allows safe passage under Elk View Road. We installed the fencing along the forest side of the road (opposite the breeding pond) to guide the animals safely through the crossing structure and towards the wetland. The topography and land ownership in this area means that this fencing must be installed and removed every season. The fencing was installed along the road (in the right-of-way). We are currently pursuing more permanent solutions; however, until then we will continue to improve this temporary fencing design.


Figure 2: Digging trench and installing wooden stakes.

Silt fence material (black plastic fabric material) was attached to wooden stakes using a staple gun and

screws. A trench was dug and the bottom 10 cm of the fence was buried in the ground to prevent

amphibians, salamanders in particular, from burrowing under the fence (Figure 2). The fence was

angled away from the road to discourage amphibians from climbing over the top. In addition, the height

of the fence on average is 70 cm to reduce the chance of amphibians crawling over the top (Figure 3).

Figure 3: Fencing angled away from road and silt material attached using staples.


The fencing was attached to the culverts using a combination of fence posts and zap straps (Figure 4).

The ends of the fencing not connected to the toad crossing structure were curved to encourage any

amphibians moving away from the crossing structures to turn around and head back towards the safe

crossing structure. This fencing will help prevent the amphibians from crossing back over the road.

Figure 4: Fencing attached to the crossing structure using fence posts and zap straps.

Figure 5: Map showing where directional fencing was installed in 2018.

overlap


APPENDIX D: MIGRATION BROCHURE

Documents

Ryder Lake Amphibian Protection Project 2015 - 2018 · Amphibians are one of the most common vertebrate species killed on roads (Miklós 2003, Dodd et al. 2004). The seasonal migration