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  • Wetland Amphibian Monitoring Protocol

    Terrestrial Long-term Fixed Plot Monitoring Program

    Regional Watershed Monitoring and Reporting

    November 2011

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

    November 2011

    1

    Report prepared by: Paul Prior, Fauna Biologist

    Sue Hayes, Project Manager, Terrestrial Field

    Inventories

    Reviewed by: Scott Jarvie, Manager, Watershed Monitoring

    and Reporting Section

    This report may be referenced as:

    Toronto and Region Conservation Authority (TRCA). 2011. Wetland

    Amphibian Monitoring Protocol - Terrestrial Long-term Fixed Plot

    Monitoring Program Regional Watershed Monitoring and

    Reporting.

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

    November 2011

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    Table of Contents

    pp aa gg ee

    1.0 INTRODUCTION ...................................................................................... 4

    2.0 STUDY DESIGN ....................................................................................... 4

    3.0 EQUIPMENT & MATERIALS ................................................................... 6

    4.0 PLOT SET-UP METHODOLOGY ............................................................. 6

    5.0 DATA COLLECTION METHODOLOGY .................................................. 7

    6.0 DATA MANAGEMENT AND ANALYSIS ............................................... 10

    7.0 REFERENCES ....................................................................................... 11

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

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    L is t o f Tab les Table 1: Frog and toad species present within the TRCA jurisdiction ............................................... 5

    Table 2: Sample size required to detect a 50% decline based on 90% power for each species ...... 5 Table 3: List of required equipment and materials for plot set-up and seasonal monitoring ............ 6 Table 4: Beaufort wind codes .............................................................................................................. 9 Table 5: Call level codes for amphibians .......................................................................................... 10 Table 6: Background noise codes .................................................................................................... 10

    L is t o f F igures Figure 1: Peek calling periods for frog and toad species in the TRCA jurisdiction ........................... 8

    L is t o f Append ices Appendix A: Marsh monitoring program habitat description form .................................................. 13

    Appendix B: Marsh monitoring program amphibian data collection form ....................................... 14

    Appendix C: Marsh monitoring program amphibian route summary form ...................................... 15

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

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    1.0 INTRODUCTION

    Wetlands are recognized as being highly diverse, productive and dynamic ecosystems that serve

    a vital environmental role. Acting as a water filtration system, they prevent sedimentation, slow

    surface run-off and improve water quality. They also provide valuable breeding and spawning

    habitat for numerous bird, fish, mammal, and amphibian species. Throughout Ontario, there are

    five types of freshwater wetlands, namely, marshes, bogs, fens, swamps and shallow open water.

    The wetland amphibian protocol used by the Toronto and Region Conservation Authority (TRCA)

    has been adopted from the Marsh Monitoring Program (MMP) and focuses on amphibian species

    in marsh habitats. A marsh is defined as a vegetated, wet area, periodically or regularly inundated

    up to a depth of 2 metres with standing or slowly moving water (Bird Studies Canada, 2009).

    Marshes are home to several amphibian species that are extremely sensitive to environmental

    change. The long-term monitoring of the richness and distribution of these species throughout the

    TRCA jurisdiction can aid in the assessment of the overall health of the region.

    2.0 STUDY DESIGN

    Ensuring a sample size that is appropriate to detect region wide trends is the primary objective of

    the monitoring program. However, with additional funds and resources in the future it will also be

    desirable to increase the sample size in order to have the ability to look at differences between

    three land-use zones (urban, urbanizing and rural).

    Program Objective:

    To assess the overall trend of species richness in frog and toad populations in the TRCA

    jurisdiction

    Amphibian surveys are limited to frog and toad species found throughout the TRCA jurisdiction.

    The unique and distinctive territorial and/or mating calls sung by male frogs and toads, in the

    spring and summer, are used as the main means of species identification. Within the TRCA

    jurisdiction there are currently nine frog species and one toad species that can be found (Table 1).

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

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    Table 1. Frog and toad species present within the TRCA jurisdiction.

    Common Name Scientific Name

    American toad Bufo americanus

    Gray treefrog Hyla versicolor

    Spring peeper Pseudacris crucifer

    Chorus frog Pseudacris triseriata

    Wood frog Rana sylvatica

    Northern leopard frog Rana pipiens

    Pickerel frog Rana palustris

    Green frog Rana clamitans melanota

    Mink frog Rana septentrionalis

    Bullfrog Rana catesbeiana

    From previous field inventories it is apparent that some of these species are more common than

    others throughout the jurisdiction. Therefore, in order to detect a 50% decline the sample size is

    different for each species. The more common species require fewer monitoring routes whereas

    the not so common species require more routes (Table 2). These results were determined through

    an a priori power analysis conducted by Zorn (2008). The number of monitoring routes required

    is dependent on four other factors: the minimum trend to be detected (effect size), the variance of

    the data, the probability of not making a false alarm (confidence level) and the probability of not

    missing a signal (power). It was determined that a high power (90%) was required for the

    monitoring program in order to not miss a signal and report no change when in fact there was

    change.

    Table 2. Sample size required to detect a 50% decline based on 90% power for each

    species. Results are based on an a priori power analysis.

    Species Sample Size per Year for 90% Power

    American toad 14

    Bullfrog 46

    Green frog 6

    Northern leopard frog 12

    Pickerel frog 80

    Wood frog 12

    Spring peeper 5

    Gray treefrog 10

    Chorus frog 44

    *Mink frog was not included in the analysis, as only one location is known within the TRCA

    jurisdiction.

    From these results it was apparent that more than 44 sites would be needed for rarer species

    (Chorus frog, bullfrog and pickerel frog). However, only 14 sites were required for 6 of the 9

    species. Therefore, 14 MMP stations will be monitored in order to assess the overall regional

    temporal trend for frog chorus call for those 6 species (American toad, green frog, northern

  • W e t l a n d A m p h i b i a n M o n i t o r i n g P r o t o c o l

    November 2011

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    leopard frog, wood frog, spring peeper and gray treefrog). A 50% decline could be detected in

    sites occupied over 5 years using an 80% confidence level and 90% power.

    3.0 EQUIPMENT & MATERIALS Different materials and equipment are needed depending on whether the plot is being set-up for

    the very first time or if visited for seasonal monitoring (Table 3).

    Table 3. List of required equipment and materials for plot set-up and seasonal monitoring.

    Set-up Equipment Seasonal Monitoring and Maintenance

    Equipment

    Compass Aerial photo of general station area Hand held GPS unit to metre posts of iron rebar Spray paint Flagging tape Pens and pencils Clipboard Habitat description forms

    Compass Map showing plot locations Amphibian data form Habitat Description form Thermometer Flashlight (spare batteries) Bug repellent Watch/ stopwatch Clipboard and pencils Flagging tape

    4.0 PLOT SET-UP METHODOLOGY

    In order to reduce staff travel time during the field season, amphibian stations and wetland bird

    stations were placed at the same locations or were placed in close proximity to one another. Site

    access was also a consideration in order to reduce the amount of travel time between stations.

    Monitoring stations are set-up at the edge of wetlands that are generally large enough to

    accommodate at least one station (needing to be 100 m radius semi-circle in size). As larger

    wetlands are not evenly distributed across the jurisdiction, some monitoring sites are smaller than

    the 100 m radius semi-circle. By allowing smaller sized wetlands to be included, a more even

    distribution of stations is created across the jurisdiction and provides a gradient of wetland types

    and quality to be represented in the TRCAs monitoring program.

    A survey route can consist of one to eight monitorin