Amphibian Surveys In the Dawson Creek TSA, For. Louisiana-Pacific Canada Ltd. Dawson Creek, BC

Transcription

1 Amphibian Surveys In the Dawson Creek TSA, 2009 For Louisiana-Pacific Canada Ltd. Dawson Creek, BC By Sandra Kinsey, B.Sc. Alpine Environmental Services 9860 Alpine Drive Prince George, BC V2N 5W7 December 15, 2009

2 2 Amphibian Surveys in the Dawson Creek TSA, 2009 ABSTRACT Amphibian surveys were conducted for Louisiana-Pacific Canada Ltd. in the Dawson Creek Timber Supply Area in the following Landscape Units: Kiskatinaw, Dawson Creek, One Island, Septimus, Lower Moberly and Upper Moberly. Using approved Resources Information Standards Committee inventory methods (road surveys, auditory (calling) surveys and pond searches) the relative abundance of local amphibians is estimated from the survey results. Each of the eight transects was surveyed three times between May 2 and May 31, Pond searches were conducted between May 3 and June 16, 2009, with most done in May. This was the third year of a three-year project. An estimated 1,024,742 individuals of four amphibian species were detected on the project this year: Western Toad (Anaxyrus boreas formerly Bufo boreas), Boreal Chorus Frog (Pseudacris maculata), Wood Frog (Lithobates sylvatica formerly Rana sylvaticus) and Long-toed Salamander (Ambystoma macrodactylum) Wood Frogs, 2060 Boreal Chorus Frogs and 6 Western Toads were heard on the Auditory Surveys for a total of 4146 calling frogs and toads. Relative abundance on the transects ranged from 5.4 to 43.4 individuals per calling station with an average of 8.0 individuals per calling station for the first round, 5.7 for the second round and 3.4 for the third round. When using only active calling stations, the ranked order of transects was generally similar, with the exception of Moberly Lake, which was ranked higher (fourth), likely due to larger average pond size. On the Road Surveys, 59 Western Toads and 1 Wood Frog were detected. An estimated 1,020,536 individuals, larvae or eggs of all four amphibian species were found during 112 pond searches of 61 different ponds. Most of the egg masses were deposited by Wood Frogs. Comparisons with results from 2007 and 2008 were made for all survey results. Numbers recorded in the calling surveys increased 332% in 2008 from 2007, then declined slightly in 2009 to 200% of the 2007 total. The road surveys followed a similar pattern. The pond searches showed variation between ponds and between years. Nonetheless, total numbers increased each year. Significant findings this year were the resilience of the amphibians this year to the two snowstorms, one during the second week of May and the other less than a week later. The Western Toads laid their eggs later than the previous two years as a result, and the peak of Chorus Frogs breeding activity was delayed. Species distributions remained consistent with previous years.

3 3 TABLE OF CONTENTS ABSTRACT... 2 TABLE OF CONTENTS... 3 LIST OF TABLES... 4 LIST OF FIGURES... 4 INTRODUCTION... 5 PROJECT AND STUDY AREAS... 5 SUMMARY OF EXISTING INFORMATION... 6 METHODS... 6 RESULTS... 9 Auditory Surveys Road Surveys Pond Searches Comparisons with 2007 and DISCUSSION Variation in Surveys Amphibian Detection Issues with Survey Routes CRITIQUE OF INVENTORY PROTOCOLS APPENDICES Appendix I. Coordinates for transects, Dawson Creek amphibian surveys, Appendix II. Sample of Pond Survey results, using estimates of adult equivalents, LITERATURE CITED... 25

4 4 LIST OF TABLES Table 1. Survey Dates and Transect Information from west to east, Table 2. Species Occurrence List, Table 3. Amphibian abundance on auditory surveys for all stations and active stations only, by transect, Table 4. Relative abundance of amphibians (toads) on the Road Surveys, Table 5. Change in amphibian numbers and Coefficient of Variation for auditory and road surveys, LIST OF FIGURES Figure 1. Timing of the auditory, road and pond surveys, Figure 2. Number of Frogs and Toads detected on Auditory and Road Surveys, by round,

5 5 INTRODUCTION The intent of this project was to gather baseline information on the relative abundance of selected amphibian species within forested landscapes in the Dawson Creek Timber Supply Area (TSA) in northeastern British Columbia (BC). Using data from approved Resources Information Standards Committee (RISC) inventory methods (auditory surveys, road surveys and pond searches), the relative abundance of local amphibian species are estimated. To increase efficiency, established roads in forested landscapes were surveyed. This report covers Year 3. Some comparisons are made with Years 1 and 2 of the project (2007 and 2008). Results will be useful in themselves as baseline data, but will also be tied in with other ongoing work investigating amphibian use of wetlands in the TSA before and after adjacent timber harvesting. The information can be used in existing national and international programs set up to monitor amphibian populations, e.g. FrogWatch BC and the North American Amphibian Monitoring Program. These other programs show amphibian populations declining in many areas. Data obtained during this project have been forwarded to academia (Julie Lee-Yaw, University of British Columbia; Mark Thompson University of Northern British Columbia) and consultants (Elke Wind for the Western Toad Monitoring Program, and Brian Slough for an amphibian management plan for the Yukon). Five possible species of amphibians were anticipated for this project. They were Western Toad (Anaxyrus boreas formerly Bufo boreas), Boreal Chorus Frog (Pseudacris maculata), Wood Frog (Lithobates sylvaticus formerly Rana sylvatica), Long-toed Salamander (Ambystoma macrodactylum) and Columbia Spotted Frog (Rana luteiventris). The old Latin names will continue to be used in this report. All five species are Yellow-listed in British Columbia. Western Toad is ranked Special Concern, Schedule 1 by The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and the federal Species at Risk Act (COSEWIC, 2002). Project Coordinator for this project is Mark Phinney, District Biologist for Louisiana-Pacific Canada Ltd. in Dawson Creek, BC. Field surveys were conducted by Sandra J. Kinsey and Laird E. Law. The project was funded by the Forest Investment Account (FIA), Project Number PROJECT AND STUDY AREAS The project area is in the south Peace region of northeastern British Columbia. Dawson Creek and Chetwynd are the major urban centres. The biogeoclimatic zone is Boreal White and Black Spruce, Peace moist warm variant (BWBSmw1). The BC Ministry of Environment Region is Omineca/Peace. The project area was stratified by landscape units as that is how the proponent manages the area at the operational planning level.

6 6 Landscape Units (LUs) are planning areas based on topographic or geographic features, typically watersheds (see Table 1). Six Landscape Units were chosen for the project: Kiskatinaw (KI), Dawson Creek (DC), One Island (OI), Septimus (SE), Lower Moberly (LM) and Upper Moberly (UM). Kiskatinaw LU is west of the town of Dawson Creek. One Island LU is south of Dawson Creek along the BC-Alberta border. Septimus LU is northwest of Dawson Creek towards Chetwynd. Lower Moberly LU is northeast of Chetwynd. Upper Moberly LU is north and west of Chetwynd. Eight transects were surveyed: Bear Mountain, Septimus, Del Rio, North Monias, Swan Lake (near Boudreau Lake), Moberly Lake, Tupper Creek and Halfmoon. The transects fall within three ecosections: Peace Lowlands (PEL), Kiskatinaw Plateau (KIP), and Hart Foothills (HAF) Ecosections (see Table 2). SUMMARY OF EXISTING INFORMATION All five of the possible species in the study area require water for breeding. Adults are terrestrial to varying degrees, depending on the species. General information is available in field guides and handbooks such as Corkran and Thoms (1996) and Matsuda et al (2006). More specific information for each species throughout their range can be found on websites such as NatureServe, AmphibiaWeb and COSEWIC. Very little work has been done on amphibians in northeastern BC. Wildlife use surveys along the Peace River focused on the river valley, which is outside the study area of this project. The Peace/Williston Fish and Wildlife Compensation Program conducted amphibian surveys in the adjacent Lake Williston watershed (Hengeveld, 2000). Results from Years 1 and 2 of this project, conducted in 2007 and 2008, are available from the WSI (Wildlife Species Inventory) database. Collections exist throughout North America. Many have records for northeastern BC. Hodge (1976) lists records in the Tongass Historical Society Museum in Ketchikan, Alaska. METHODS Approved RISC methodology was followed for the three survey methods used: Auditory, Road and Pond Searches (Resource Inventory Committee, 1998a). A variance was granted to allow surveys to extend after midnight due to the long daylight hours in the northern part of BC, and a variance to not collect dead specimens and forward to the government was also granted. The same eight transects established in 2007 (see Table 1 and Appendix I) were surveyed again this year using the same methodologies. Concurrent auditory and road surveys were conducted three times on each transect; all were conducted in May, beginning May 2. At least three of the ponds from each transect searched in the past two years were searched again this year. Most of these searches were done in May. Most ponds were visited more than once.

7 7 The transects averaged 30 listening stations over 15 km for a project total of 243 stations. The number of amphibians heard during a 3 minute stop at each station was recorded. As in the previous two years, the counts of calling amphibians for some stations are estimated due to the difficulty in determining numbers in a chorus of overlapping and continuous calls (Resource Inventory Committee, 1998a). In this report, the number of egg masses and strings will be employed as an estimate of the number of breeding females at a site. One frog egg mass represents one female frog. One set of toad egg strings represents one female. However, the WSI requirements call for a total number of eggs, including frogs and toads. Since both frogs and toads lay eggs in masses or strings, counts of eggs and larvae were estimated due to the sheer numbers involved. To obtain this number, a Wood Frog egg mass was estimated to contain 700 eggs, based on a complete count of a representative egg mass in 2008 (Kinsey, 2008). It was more difficult to evaluate the number of toad egg strings (and female toads), since multiple pairs could be laying eggs at the same time in the same area. To estimate the number of eggs in toad strings, subsets of the strings were counted to determine the number of eggs per 10 cm and multiplied by the estimated length of the egg string to obtain total number of eggs. Boreal Chorus Frogs were estimated to contain 50 eggs per mass; this number is an approximation determined from the egg masses observed in the study area. Long-toed Salamander females were estimated to lay 90 eggs each. This number was obtained through a literature search and takes into consideration the latitude and elevation of the study area (AmphibiaWeb, 2009; Howard and Wallace, 1985; Nussbaum, 1983; Montana Field Guide, 2009). Pond surveys documented amphibians at all life stages. However, previously counted organisms were not added to the final tally for a pond. For example, if eggs were documented on the first visit, tadpoles seen on a later visit were not counted, although they were noted on the field sheets. Each pond was photographed and GPS coordinates recorded (NAD 83). A brief description of the site included size and vegetation present. Air and water temperatures were taken. RISC data forms for Pond-breeding Amphibians were completed in the field (Resource Inventory Committee, 1998b). The surveys were conducted from May 2 to May 31, 2009 (see Table 1). Round 1 of the Auditory and Road Surveys was conducted May 2-9. Round 2 of the Auditory and Road Surveys was conducted May Round 3 of the Auditory and Road Surveys was conducted May 24 - May 31. Pond Searches were conducted between May 3 and June 16.

8 8 Table 1. Survey Dates and Transect Information from west to east, TRANSECT Auditory and Road Survey Dates, 2009 Dates of Pond Searches, 2009 Landscape Unit Average Elevation (m) (range) Moberly Lake May 5, 16, 27 May 6, 11, 28 Upper Moberly 745 ( ) Swan Lake May 4, 14, 26 May 5, 15, Lower Moberly 679 (642-25, ) North Monias May 2, 10, 24 May 3, 11, 25 Lower Moberly 656 ( ) Del Rio May 3, 15, 25 May 4, 16, 26 Lower Moberly 672 ( ) Septimus May 6, 22, 29 May 6, 7, 22, Septimus 884 (824-23, 29, ) Halfmoon May 9, 23, 30 May 9, 10, One Island, 915 (812-23, 30, 31 Kiskatinaw 973) Bear Mountain May 7, 20, 28 May 21, 31 Dawson Creek, 889 (731- (Kiskatinaw) 940) Tupper Creek May 8, 21, 31 May 8, 9, 22, Dawson Creek 894 (830-25, 31 & 940) June 1, 16 Transect Length (km)

9 9 Table 2. Species Occurrence List, SPECIES CODE DESIGNATION BEC Zone Western Toad BUBO (Bufo boreas) Boreal Chorus Frog (Pseudacris maculata) Wood Frog (Rana sylvatica) Long-toed Salamander (Ambystoma macrodactylum) Special Concern (COSEWIC), Yellow (BC), SARA Schedule 1 Landscape Unit BWBSmw1 Dawson Cr., Lower Moberly, Upper Moberly, Septimus, One Island, Kiskatinaw PSMA Yellow (BC) BWBSmw1 Dawson Cr., Lower Moberly, Septimus RASY Yellow (BC) BWBSmw1 Dawson Cr., Lower Moberly, Upper Moberly, Septimus, One Island, Kiskatinaw AMMA Yellow (BC) BWBSmw1 Upper Moberly, Septimus Ecosection Peace Lowlands, Hart Foothills, Kiskatinaw Plateau Peace Lowlands (Kiskatinaw Plateau) Peace Lowlands, Hart Foothills, Kiskatinaw Plateau Peace Lowlands Method(s) Detected Auditory, road, pond Auditory, pond Auditory, road, pond Pond RESULTS Four species of amphibians were recorded again this year on the three survey types (see Table 2 above). They are, in order of frequency of detection: Wood Frog, Boreal Chorus Frog, Western Toad, and Long-toed Salamander. An estimated 1,024,742 organisms (adults, larvae, eggs) were tallied, representing an estimated 7026 female amphibians. Consistent with previous years, Wood Frogs and Western Toads were found on all transects; Boreal Chorus Frogs were found on all transects except Halfmoon and Moberly Lake (though few were found on Bear Mountain and Tupper Creek); and Long-toed Salamanders were found on only the Moberly Lake and Septimus transects (see Table 2). No Spotted Frogs were found.

10 10 An estimated 4146 calling frogs and toads were detected on the Auditory Surveys. On the road surveys, 60 amphibians (59 Western Toads and 1 Wood Frog) were detected. An estimated 1,020,536 (adults, juveniles, larvae, eggs) of all four amphibian species were found on the pond searches. Of this number, 169 were in adult form. The 1,020,367 eggs and tadpoles (larvae) represent 2429 female Wood Frogs, 153 female Long-toed Salamanders, 2 female Chorus Frogs and approximately 68 female Western Toads. Auditory Surveys Three of the four amphibian species found were documented on the Auditory Surveys: 2080 Wood Frogs (50% of individuals heard), 2060 Boreal Chorus Frogs (50% of individuals heard), and 6 Western Toads (<1%) for a total of 4146 calling frogs and toads (see Table 3, below). The peak of the Wood Frog calling this year was the first week of May. The peak of the Boreal Chorus Frogs appears to be the beginning of the third week of May, starting May 14 and tapering off to the end of the month. Relative abundance was calculated two ways: The first divided the number of calling amphibians by the number of stations on the transect. The second method used the number of active stations on the transect (i.e. this method excluded stations where no frogs were heard). Based on the auditory survey results from all stations, the relative abundance by transect ranged from 5.4 to 43.4 (average = 17.1) individuals per calling station (summed for all three counts) with an average of 8.0 individuals per calling station for the first round, 5.7 for the second round, and 3.4 for the third round (see Table 3, below). The Swan Lake transect had the highest abundance for Round 1; Del Rio transect had the highest abundances for Rounds 2 and 3. On the first round, Swan Lake (21.5 individuals per calling station) and Bear Mountain (15.3 individuals per calling station) had the two highest abundances. Nearly all frogs on Bear Mountain were Wood Frogs (only 1 Boreal Chorus Frog); Swan Lake was 58% Wood Frogs, while on Del Rio only 29% were Wood Frogs with the rest being Boreal Chorus Frogs. On Round 2, Del Rio had 24.5 individuals per calling station; 94% of these were Boreal Chorus Frogs, the rest were Wood Frogs. Swan Lake was next highest with a relative abundance of 8.4 individuals per calling station, of which 75% were Boreal Chorus Frogs. On Round 3, Del Rio had 12.7 individuals per station, of which 98% were Boreal Chorus Frogs. The Swan Lake transect had 7.4 individuals per station, of which 95% were Boreal Chorus Frogs.

11 11 The first round of auditory surveys tallied 47% of the total amphibians heard; the second round had 33% and the third round 20%. Thus, the vast majority of amphibians tallied during acoustic surveys in this area continue to be counted in early and mid-may. Late season counts are relatively unproductive. The Del Rio transect was responsible for one-third (35%) of all detections on the auditory surveys. Summarizing for the year, Del Rio transect had the highest abundance, followed by Swan Lake, Bear Mountain, North Monias, Tupper Creek, and Halfmoon. Moberly Lake and Septimus transects had the lowest abundance. Rankings based on active calling stations were generally similar, except that the Moberly Lake transect was ranked fourth rather than tied for seventh (see Table 3). Table 3. Amphibian abundance on auditory surveys for all stations and active stations only, by transect, TRANSECT Round 1 Round 2 Round 3 Total Stations #/station #active stations #/active station Moberly Lake Swan Lake North Monias Del Rio Septimus Halfmoon Bear Mountain Tupper Creek Total #/station Road Surveys During road surveys, 59 Western Toads were found (see Table 4). 69% were documented on Round 3, 12% on Round 2 and 19% on Round 1. One Wood Frog was detected on the road surveys this year (on Round 3). Road surveys are an effective method of counting adult toads, particularly after the breeding season.

12 12 All transects had at least one Western Toad documented on a road survey. Del Rio transect had the most Western Toads with 18 of the 59 total detections (31%). Moberly and Swan Lakes had the second highest at 12 individuals each transect (20% each). Table 4. Relative abundance of amphibians (toads) on the Road Surveys, Transect Toads per Kilometre Total # of TRANSECT Length Round 1 Round Round TOTAL toads on (km) 2 3 transect Moberly Lake Swan Lake North Monias Del Rio Septimus Halfmoon Bear Mountain Tupper Creek TOTALS Pond Searches An estimated 1,020,536 organisms (adults, larvae, eggs) of all four amphibian species were found during 112 pond searches of 61 ponds. Most of the egg/hatchling masses were Wood Frog (777,220 for 76% of pond organisms) and Western Toad (230,260; 23%). The remaining 1% was made up of Long-toed Salamander and Boreal Chorus Frog eggs. The Western Toad and Wood Frog egg masses represent approximately 68 and 2429 breeding females, respectively. The Long-toed Salamanders were detected on the pond searches as eggs (12,787) in eleven ponds on the Septimus and Moberly Lake transects. This represents approximately 153 breeding females. Eggs were first found on May 5 (first day of pond searches in known salamanderoccupied ponds). 754,300 Wood Frog eggs were found on all transects. Newly laid eggs were found from May 3 to 23. Some of the eggs found on May 3 were a few days old. The first hatchlings were found on May 15 (May 18 in 2008) and independent tadpoles on May 18. The eggs as well as 88 adults, 1320 tadpoles, and 2160 neonates were found in 50 ponds. 230,260 Western Toad eggs were found on the pond searches for Swan Lake, Septimus and Tupper Creek transects. The first eggs were found on May 15 when one string was found, but most eggs weren t laid until after May 20 when the second snowstorm ended. Egg strings averaged (mode) 4 metres per pair (2000 eggs). The eggs, one sub-adult and 23 adults were found in 12 ponds.

13 13 Boreal Chorus Frog eggs (two egg masses in two ponds) were documented on the pond searches of North Monias on May 11. They were one day old. Adults were seen and heard, during pond searches, on Del Rio, North Monias, Swan Lake and Septimus transects starting on May 2. Comparisons with 2007 and 2008 Note: Previous years totals relating to egg numbers have been recalculated using current, more accurate estimates of eggs per mass as described under Methods: 700 eggs per Wood Frog egg mass, 50 eggs per Boreal Chorus Frog egg mass, 90 eggs per Long-toed Salamander breeding female. Content of toad egg strings was estimated each year and have not been adjusted. One egg mass is assumed to be one breeding female. One set of toad egg strings is also assumed to be one breeding female. This year 1,024,742 organisms (adults, larvae, eggs) were tallied. This number is much higher than the re-calculated totals of 669,876 organisms in 2008, and 84,023 in However, effort increased each year with 46 visits to 43 ponds in 2007, 62 visits to 43 ponds in 2008 and 112 visits to 61 ponds in Eighteen ponds were new in 2009 and accounted for 45 of the visits and 191,617 organisms. Thus, the combined results of pond searches should not be used to infer an increasing population, since effort also increased. Timing of the surveys was generally at the same each year (see see Figure 1). Pond surveys were started slightly later in 2007 compared to 2008 and Auditory and road survey efforts remained constant with three surveys done in May each year; although the surveys were more spread out in 2007 and extended into June. Results for road surveys and auditory surveys (total numbers detected) generally dropped between 2008 and There was no consistent trend across all species-transect-year combinations (see Figure 2 and Table 5). Numbers of the two common species fluctuated widely and inconsistently between years and between transects. Three of the four amphibian species found were documented on the auditory surveys each year with 4146 amphibians in 2009, 6798 in 2008 and 2047 in 2007 (see Table 3). By species, 50% of the amphibians heard in 2009 were Wood Frogs (compared to 65% in 2008, and 61% in 2007); 50% were Boreal Chorus Frogs (compared to 35% in 2008, and 38% in 2007); and less than one percent were Western Toads each year (see Table 5). Twenty-seven percent fewer toads were detected on the road surveys this year compared to last year, but it was still an increase of 36% over the first year. Moberly Lake transect had the most toads when all years are added together. Toads were encountered on this route on all but one road survey over the three years. Overall, most toads were detected on the third round of surveys in each year (see Figure 2). The pond searches showed variation between ponds and between years, even within transects. Ponds contained zero to four species of amphibians. Some ponds had no eggs while other ponds had many eggs. Some ponds had eggs one year and not the next (see Appendix II).

14 14 The pond survey results include adults detected during pond surveys. This increased the species richness of a pond, but had little influence on overall numbers. Calling was the primary method by which chorus frogs were documented during a pond survey. Figure 1. Timing of the auditory, road and pond surveys,

15 Figure 2. Number of Frogs and Toads detected on Auditory and Road Surveys, by round,

16 Table 5. Change in amphibian numbers and Coefficient of Variation for auditory and road surveys, The toad data (BUBO) is from road surveys, the frog data (PSMA, RASY) are from auditory surveys. BUBO PSMA RASY Grand Total Mean C.V.% Bear Mountain % Del Rio % Halfmoon % Moberly Lake % North Monias % Septimus % Swan Lake % Tupper Creek % Grand Total % Mean C.V. % 36% 48% 63%

17 DISCUSSION Variation in Surveys The results of 2009 continued to show the variability revealed in the preceding two years of the project. Auditory surveys resulted in numbers greater than the first year but less than the second year. Road surveys followed the same pattern. Pond survey results increased each year with increasing search effort. A number of factors can influence the results of a survey. Weather during the peak survey period (cold temperatures, wind, snow, heavy rains) is a key factor that can shorten, extend, or delay the breeding season of some or all species. Other factors are timing and frequency of the surveys, the weather of the year before and experience of the surveyors. External forces can also impact the survey results: road maintenance (particularly any work involving roadside ditches), traffic volume, forest harvesting and other industrial activity. Size of the ponds is also a factor. An analysis of the auditory surveys shows the transects rank differently according to how many stations have amphibians calling. Moberly Lake and Septimus transects were ranked at the bottom when abundance is calculated using total number of stations on the transect, but when only active stations are used in the calculation Moberly Lake ranks fourth, Septimus remains at the bottom. This can be explained by the geography of the transects: Moberly Lake has few wetlands along the survey route, but they are relatively large and attract many amphibians. The Septimus route has many more ponds, but they are relatively small and are inhabited by fewer amphibians. Observer experience was not a factor that contributed to the variable results over the term of this project. The same surveyors conducted the counts in all three years, and had done similar work in the area for two years prior to the initiation of this project. It is important that surveys are scheduled according to local conditions rather than calendar date. Warm temperatures appear to be critical to amphibians in the Peace region. However, the weather was different each year of this project so the initiation of frog calling varied each year. Spring 2007 started relatively normal but was quite wet which could have lead to higher productivity resulting in more amphibians the following year. Spring 2008 started late with winter conditions returning in mid-april. The last snowstorm was the evening of April 30. It took two days for the amphibians to initiate calling in full chorus. The delayed start caused the breeding season to be condensed. In contrast, spring 2009 breeding season was extended due to weather-caused delays. Spring 2009 started relatively normal, but the surveys were interrupted twice by May snowstorms. The two snowstorms of May 2009 show how critical warm temperatures are to amphibians in the Peace region. Both 2009 storms suspended surveys and amphibian breeding activity--for three days each time. The first storm started May 11, the second on May 17. The storms did not seem to affect the Wood Frogs as the first storm hit about when calling activity normally declines. The second storm hit about the time the toads start laying eggs. One set of toad eggs was found on

18 18 May 15, but the rest were not laid until on or after May 22. The Chorus Frogs extended their period of heightened activity to the end of the month, appearing to make up for the time lost during the storms. Between-year results for individual transects could have been affected by road activities during both the non-breeding and breeding seasons. Between 2007 and 2008 the Bear Mountain road was improved to all-weather road status. This negatively impacted some of the ponds close to the road. During the 2008 surveys the Moberly Lake Road had such a high volume of traffic the road required ongoing maintenance. Between 2008 and 2009 the road was improved to all-weather status. Since most of the ponds on this route are relatively large and concentrated near the beginning of the transect, the negative impact of road improvement may be less than on other routes where improvement occurred. However, the reduced number of toads detected on this transect in 2009 may indicate lower habitat quality or increased mortality of adults. Part of the Tupper Creek route was also improved to all-weather status between the 2008 and 2009 surveys. Some ponds were negatively impacted while others were modified to contain a bare, shallow shoreline attractive to egg-laying toads. Unfortunately, the water evaporated before the eggs could hatch. Amphibian Detection Western Toads can be detected using three survey methods (road, pond and auditory). However, auditory surveys are not an effective method as the call can only be heard from short distances (<50m) and is infrequent. There is considerable variation in the calls of Western Toad across its range, and local toads are not particularly vocal. Road surveys can be productive, depending on time of year and weather conditions. On warm summer nights adult toads can be numerous on the road while they forage. The toads can also be detected on the road during breeding season while they move to and from the breeding ponds but results indicate that they are not as numerous at this time. The breeding ponds tend to have a shallow (less than 30 cm deep), poorly vegetated shoreline for egg laying. Eggs laid later in May appear to be deposited on the surface of slightly deeper water where there is enough vegetation to support the adults. Once the eggs are laid, pond surveys can be conducted independent of weather. Eggs can be checked for a couple of weeks after being laid. Once the tadpoles emerge, however, surveys are again influenced by weather conditions. Repeated pond surveys that track tadpole development would give more information on pond quality and survival rate of the tadpoles. Where they occur, Long-toed Salamanders eggs are easily found attached to grasses, sedges and branches in patches of calm water, generally where the water is shallower and warmer than elsewhere in the pond. Salamander eggs have been found on only two transects: Moberly Lake and Septimus. Elevation doesn t seem to be a limiting factor for their distribution as Septimus is one of the higher transects with an average elevation of 884 m (see Table 1). The subspecies present in this study area is the Northern Long-toed Salamander, Ambystoma macrodactylum krausei. Since this subspecies occurs in western Alberta, it is possible that salamanders have colonized the area via the Peace River and then into the Moberly and Pine Rivers. Salamanders can be found during road surveys when they are moving to and from the breeding ponds, but the

19 19 surveyor must drive very slowly and weather conditions must be perfect. No salamanders were found during road surveys on this project. The most effective way to count Boreal Chorus Frogs is with auditory surveys. Even on transects where calling Boreal Chorus Frogs were abundant (Swan Lake, North Monias, Del Rio, Septimus), very few Chorus Frog eggs or tadpoles were found. The egg masses are approximately the size of a quarter and the tadpoles are very small. Eggs are laid in wellvegetated waters, usually on sedges and grasses, and under vegetation or sticks. Wood Frog, Western Toad and Long-toed Salamander eggs are larger, more numerous and tend to be on or near the water surface, hence easier to find. Chorus Frogs may live for only one or two years so a drop in population will be noticed quickly (Matsuda, 2006). Few Chorus Frogs were documented on Bear Mountain, Tupper Creek and Halfmoon transects over the three years of this project. These three transects are in the Kiskatinaw Plateau Ecosection, whereas the four transects with abundant chorus frogs are in the milder Peace Lowlands Ecosection. The peak of Chorus Frog calling occurs nearly two weeks after the peak for Wood Frogs, and calling continues (on a much reduced level) much later into the spring. Wood Frogs are the earliest frog to become active in the spring. They are the most abundant frog in the study area. This species is easy to document on auditory surveys if counts begin early enough in the spring. Timing is critical as they call for about two weeks only. Pond searches are also an effective method to document Wood Frogs. The eggs are usually found as an aggregate of egg masses. Some ponds have contained over 150 egg masses. Like the toads, the ponds can be monitored for a couple of weeks after egg laying, regardless of weather. Once the eggs hatch the surveys are again influenced by weather. Issues with Survey Routes The roads surveyed in this project generally do not see a high volume of springtime traffic. Nevertheless, there were times when amphibian road mortality may have occurred. Both the Moberly Lake Road and Radar Lake Road (Bear Mountain) had periods of heavy night-time traffic (associated with industrial development) during the study period. Traffic was scheduled for late evening hours to avoid inconveniencing public / recreational daytime traffic. Toads foraging at night, after the breeding season, appear to be most susceptible to road mortality. Excessive loss of adult toads may lead to population declines. Adults don t breed until they are several years old and it is thought that females will return to a pond for breeding only once every 4 or 5 years. Toads live to about eleven years old in the wild they have few natural predators after reaching adulthood (Wind, 2002). Road improvements and maintenance can affect amphibian habitat. During the course of this project, one of the ponds being monitored along the Moberly Lake transect was excavated to improve roadside drainage. The pond contained salamander and toad eggs, which were destroyed. Construction of pits and ditches can create breeding habitat as well. However, the newly formed ponds must be left undisturbed during the critical breeding period and contain sufficient water to avoid desiccation if these are to provide any benefit to amphibian populations.

20 20 CRITIQUE OF INVENTORY PROTOCOLS A variety of survey methods must be used, as no single type is best for the four amphibian species found in the Dawson Creek TSA. Auditory and pond surveys work well for Wood Frogs. The auditory surveys are best when large wetlands and lakes are present. Pond surveys are very effective for small wetlands, ditches and puddles. Auditory surveys work best for Boreal Chorus Frogs. A combination of pond and road surveys works well for Western Toad; with the road survey being the best method after the eggs have hatched and the tadpoles dispersed. Pond surveys work best for Long-toed Salamanders; surveys should be started as soon as there is open water and could be extended into July -- but with decreasing effectiveness. The timing of the surveys also needs to be flexible. Although frogs call during the day at this latitude (~56 degrees North), the full chorus does not begin until after dark, and then continues through the night. In early May darkness does not fall until at least 9:30 pm, and closer to 10 pm at the end of May. We found in this project that it was necessary to continue surveys after midnight. It is critical to tailor the details of project design around local conditions, rather than calendar dates, and recognize that there may be year-to-year differences in survey timing. The RISC inventory methods for pond-breeding amphibians are generally flexible. However, one rigid parameter is the requirement to situate calling stations 500m (or less) apart. In the Peace region there can be vast tracts of similar habitat. For management purposes it may be more useful to have the option of surveying a larger study area by locating the listening stations farther apart. This project has established a baseline for future work. Peak calling times differ for the two common frog species, thus there is a need for at least two rounds of auditory surveys. Eight transects were surveyed on this project which supplied a broad geographic baseline to work from. It also meant that peak calling on any one transect for either species could have been missed. To better understand the ecology of the amphibians a smaller number of transects should be surveyed more frequently. The impact of weather and other variables would also be minimized. The result would be more information on the breeding behavior of the frogs, including how they cope with setbacks caused by weather. Continuing pond surveys into July and perhaps August would supply more information on the life history and survivorship of the amphibians. This would work well for the Wood Frog, Western Toad and Long-tailed Salamander.

21 21 APPENDICES Appendix I. Coordinates for transects, Dawson Creek amphibian surveys, Design Component Label Start UTM Easting Start UTM Northing End UTM Easting End UTM Northing Number of call stations UTM Length Study Area Name Zone (km) Moberly Lake ML_tr Swan Lake A SL_trA Swan Lake B SL_trB North Monias NM_tr Del Rio DR_tr Septimus SE_tr Halfmoon A HM_trA Halfmoon B HM_trB Bear Mtn BM_tr Tupper Creek FSR TC_tr

22 22 Appendix II. Sample of Pond Survey results, using estimates of adult equivalents, Coordinates are NAD 83. Moberly Lake Transect Pond 2 Species Pond 4 Species /554714/ AMMA AMMA RASY /563978/ BUBO Total RASY Total Pond 3 Species /556381/ null 0 n/s Total 0 n/s 0 Swan Lake Transect Pond 1 Species Pond 2 Species BUBO BUBO /601927/ PSMA /601338/ PSMA RASY RASY Total Total Pond 4 Species Pond 6 Species BUBO /598068/ PSMA /598092/ PSMA RASY RASY Total Total Pond 7 Species Pond 10 Species /597941/ PSMA /598018/ RASY n/s RASY Total n/s 2 23 Total 0 1 5

23 23 North Monias Transect Pond 1 Species Pond 2 Species /610568/ null frog Total /610568/ PSMA RASY Total Pond 4 Species Pond 5 Species /605721/ PSMA /604736/ PSMA RASY RASY Total Total Del Rio Transect Pond 1 Species Pond 2 Species /613994/ 10/617011/ PSMA PSMA RASY RASY (660m) (672m) Total Total Pond 3 10/611854/ (684m) Species Pond 4 Species PSMA /610713/ BUBO RASY PSMA Total RASY Total Septimus Transect Pond 1 Species Pond 2 Species AMMA AMMA BUBO BUBO /626090/ 10/624158/ PSMA PSMA RASY RASY Total Total Pond 3 Species Pond 4 Species AMMA AMMA /628771/ 10/624111/ BUBO RASY RASY Total Total

24 24 Pond 5 Species Pond 6 Species /629550/ null PSMA /629450/ Grand Total RASY Total Halfmoon Transect Pond 1 Species Pond 2 Species /646351/ RASY BUBO /644679/ Total RASY Total Pond 3 Species Pond 4 Species BUBO /642098/ RASY /644303/ RASY Grand Total Total Bear Mountain Transect Pond 1 10/665736/ Species Pond 2 Species RASY frog/toad Total /667272/ RASY Total Pond 3 Species /667975/ RASY Total Tupper Creek Transect Pond 2 Species Pond 5 Species /673049/ RASY BUBO /672642/ Total RASY Total Pond 7 Species Pond 8 Species BUBO n/s 10 2 BUBO n/s /672369/ 10/672930/ RASY n/s 5 45 RASY n/s Total n/s Total n/s 4 16

25 25 LITERATURE CITED AmphibiaWeb: Information on amphibian biology and conservation [web application] Berkeley, California: AmphibiaWeb. Available: (Accessed: October 20, 2009). B.C. Conservation Data Centre, BC Species and Ecosystems Explorer. B.C. Ministry of Environment, Victoria, BC. Website accessed September 14, 2009: Green, D.M., and R.W. Campbell The Amphibians of British Columbia. British Columbia Provincial Museum handbook series No. 45. Royal British Columbia Museum, Victoria, BC. COSEWIC, COSEWIC assessment and status report on the western toad Bufo boreas in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. Corkran, C., and C. Thoms Amphibians of Oregon, Washington and British Columbia. Lone Pine Publishing, Edmonton, AB. DeLong, C., A. McKinnon, and L. Jung A Field Guide for Identification and Interpretation of Ecosystems of the Northeast Portion of the Prince George Forest Region, LMH No. 22. BC Ministry of Forests, Research Branch, Prince George, BC. Ecosystem Branch, Ministry of Environment Part II: Ecoregion Unit Descriptions. Hengeveld, P.E Presence and Distribution of Amphibians in the Williston and Dinosaur Reservoir Watersheds, Peace/Williston Fish and Wildlife Compensation Program Report No Hodge, R.P Amphibians & Reptiles in Alaska, the Yukon and Northwest Territories. Alaska Northwest Publishing Company, Anchorage, Alaska. Howard, J.H. and R.L. Wallace Life history characteristics of populations of the long-toed salamander (Ambystoma macrodactylum) from different altitudes. Amer. Midl. Nat. 113: Kinsey, S.J Amphibian Surveys in the Dawson Creek TSA For Louisiana-Pacific Canada Ltd, Dawson Creek, BC. Kinsey, S.J Amphibian Surveys in the Dawson Creek TSA For Louisiana-Pacific Canada Ltd, Dawson Creek, BC. Matsuda, B., D.M. Green, P.T. Gregory Amphibians and Reptiles of British Columbia. Royal BC Museum, Victoria, BC.

26 26 Montana Field Guide. Boreal Chorus Frog Pseudacris maculata. Retrieved on October 20, 2009, from Montana Field Guide. Long-toed Salamander Ambystoma macrodactylum. Retrieved on October 20, 2009, from NatureServe NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available (Accessed: October 20, 2009). Nussbaum, R.A., E.D. Brodie, Jr., and R.M. Storm Amphibians and Reptiles of the Pacific Northwest. The University Press of Idaho, Moscow, Idaho. Resource Resources Information Standards Committee The Vertebrates of British Columbia: Scientific and Common Names: Version 3 Errata No. 1. Standards for Components of British Columbia s Biodiversity No.2. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resources Information Standards Committee. 2005a. Inventory Dataforms for Species Inventory Fundamentals: Version 2, Errata No. 1. Standards for Components of British Columbia s Biodiversity No.1. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resources Information Standards Committee. 2005b. The Vertebrates of British Columbia: Scientific and Common Names: Version 3, Errata No. 2. Standards for Components of British Columbia s Biodiversity No.2. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resources Information Standards Committee Inventory Methods for Pond-breeding Amphibians and Turtles: Version 2 (March 1998), Errata No. 1. Standards for Components of British Columbia s Biodiversity No.37. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resource Inventory Committee. 1998a. Inventory Methods for Pond-breeding Amphibians and Turtles: Version 2. Standards for Components of British Columbia s Biodiversity No.37. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resource Inventory Committee. 1998b. Inventory Dataforms for Pond-breeding Amphibians and Turtles: Version 2. Standards for Components of British Columbia s Biodiversity No.37. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resource Inventory Committee. 1998c. Species Inventory Fundamentals: Version 2. Standards for Components of British Columbia s Biodiversity No.1. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC.

27 27 Resource Inventory Committee. 1998d. Inventory Dataforms for Species Inventory Fundamentals: Version 2. Standards for Components of British Columbia s Biodiversity No.1. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resource Inventory Committee Live Animal Capture and handling Guidelines for Wild Mammals, Birds, Amphibians, and Reptiles: Version 2. Standards for Components of British Columbia s Biodiversity No.3. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Resource Inventory Committee The Vertebrates of British Columbia: Scientific and Common Names: Version 3. Standards for Components of British Columbia s Biodiversity No.2. Terrestrial Information Branch, Ministry of Sustainable Resource Management. Victoria, BC. Walker, M., ed. Amphibians Mate Under a Full Moon. Earth News. BBC News 2009/7/14. Wind, El and L.A. Dupuis 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 of Endangered Wildlife in Canada. Ottawa.