Using multiple survey methods to detect terrestrial and mammals: what are the most successful and cost- efficient combinations?

Author G. Garden, Jenni, A. McAlpine, Clive, P. Possingham, Hugh, Jones, Darryl

Published 2007

Journal Title Wildlife Research

DOI https://doi.org/10.1071/WR06111

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Griffith Research Online https://research-repository.griffith.edu.au 1 2 3 4 5 6 Using Multiple Survey Methods to Detect Terrestrial Reptiles and 7 Mammals: What are the Most Successful and Cost Efficient 8 Combinations? 9 10 11 12 Jenni Garden*1,2, Clive McAlpine1,2, Darryl Jones3, Hugh Possingham2 13 1School of Geography, Planning and Architecture, The University of Queensland, St Lucia, Brisbane, 14 Qld, 2The Ecology Centre, The University of Queensland, St Lucia, Brisbane, Qld, Centre for 15 Innovative Conservation Strategies, Griffith University, Nathan, Brisbane, Qld 16 17 * Corresponding Author: C/- School of Geography, Planning and Architecture, The University of Queensland, St 18 Lucia, 4072, Qld, Australia. (Email: [email protected]). Ph: 0403 778 963. Fax: (07) 3365 6899 19 20 21 Running Title: Cost-effective fauna surveys 22 23 24 25 26 27 28 29 30 31 32 33 34

1 35 Abstract 36 The selection of survey methods for wildlife surveys is a critical decision that will 37 influence the accuracy and comprehensiveness of the research outcomes. The choice 38 of methods is commonly based on the species of interest, yet is often limited by the 39 project budget. Although several studies have investigated the effectiveness of 40 various survey techniques for detecting terrestrial mammal and species, none 41 have provided a quantitative analysis of the costs associated with different methods. 42 We compared the detection success and cost efficiency of six survey methods for 43 detecting the occurrence of terrestrial mammal and reptile species in urban bushland 44 remnants of Brisbane City, Queensland. We detected a total of 19 target reptile 45 species (8 families) and 9 target mammal species (3 families). Cage traps or Elliott 46 traps coupled with hair funnels were the most cost-effective methods for detecting 47 ground-dwelling mammals, with the success of cage or Elliott traps dependent on 48 species’ body sizes. Pit-fall traps and/or direct observations were the most cost 49 effective methods for detecting reptiles, with the effectiveness of each method 50 depending of the species’ body-size and behaviour. 51 52 Key words: Cage trap, Elliott trap, pit-fall trap, hair funnel, direct observation, scat 53 analysis, Brisbane 54

2 55 Introduction 56 Managing Australia’s terrestrial habitats for mammal and reptile conservation 57 requires a thorough knowledge of the composition and distribution of species within 58 and across the habitats of interest. Wildlife surveys of species occurrence and 59 abundance have long been used to acquire such knowledge. For terrestrial mammal 60 and reptile species, a variety of survey methods have been used by researchers to 61 determine occurrence and abundance. These methods have been specifically designed 62 to target particular species or species’ groups (Sutherland 1996a; Menkhorst and 63 Knight 2001), and so vary in their applicability and relative detection success for 64 different taxa. Consequently, the choice of survey method(s) is a critical factor 65 influencing the accuracy and comprehensiveness of survey results. 66 Several studies have investigated the relative success of different survey methods 67 for detecting mammal and/or reptile species in Australian landscapes including, but 68 not limited to: pit-fall traps with or without drift fences (e.g. Mengak & Guynn 1987; 69 Friend et al. 1989; Laurance 1992; Catling et al. 1997; Crosswhite et al. 1999; 70 Moseby and Read 2001; Ryan et al. 2002), Elliott traps (e.g. Laurance 1992; Catling 71 et al. 1997; Clemann et al. 2005), wire cage traps (e.g. Friend 1978; Laurance 1992; 72 Catling et al. 1997), direct observations and/or active searches (e.g. Brown & Nicholls 73 1993; Catling et al. 1997; Crosswhite et al. 1999; Ryan et al. 2002), hair tubes or 74 funnels (e.g. Catling et al. 1997; Lindenmayer et al. 1999; Mills et al. 2002) and, 75 vocalisations and/or indirect signs such tracks, scats, diggings or scratches (e.g. Friend 76 1978; Catling et al. 1997; Mills et al. 2002). Across all of these studies, the common 77 finding is that different survey methods are useful for sampling particular fauna 78 species and no single approach accurately samples all species within a community. 79 Therefore, as advocated by numerous previous researchers, surveys aimed at detecting 80 multiple species must employ a suitable combination a survey methods (e.g. Laurance 81 1992; Brown and Nicholls 1993; Catling et al. 1997; Crosswhite et al. 1999; 82 Lindenmayer 1999; Ryan et al. 2002; Doan 2003). The selection of these methods 83 should be influenced by the species or species’ group of interest, but consideration in 84 the survey design must also be given to the dietary and habitat preferences, 85 behavioural attributes and body size of the target species (Mengak and Guynn 1987; 86 Laurance 1992; Catling et al. 1997; Crosswhite et al. 1999; Lindenmayer 1999; Mills 87 et al. 2002).

3 88 In addition to differences in detection success, each wildlife survey method varies 89 in the required degree of effort (person hours) and the cost expended to detect target 90 fauna. Consequently, the choice of survey method is commonly limited by the project 91 financial budget and time frame. It is important, therefore, that the method(s) selected 92 will produce the greatest detection success whilst maintaining low overhead costs. 93 Such information is particularly pertinent for surveys that aim to detect a range of 94 species and species’ groups. Although a small number of authors have qualitatively 95 discussed effort associated with various survey techniques (e.g. Catling et al. 1997; 96 Crosswhite et al. 1999; Mills et al. 2002), we could not find any studies that explicitly 97 examined and compared quantitative costs associated with various survey methods. 98 This paper compares six survey methods for detecting terrestrial reptile and small 99 mammal species in terms of their relative detection success and costs of surveying. 100 Three key questions were posed: (i) What is the relative success of each method for 101 detecting reptiles and mammals? (ii) What is the cost associated with each method? 102 and, (iii) What is the most successful and cost efficient combination of methods? 103 These questions are addressed using results of wildlife surveys conducted within 104 urban remnant habitat fragments of Brisbane City. 105 106 Methods 107 Study area and survey design 108 The study was conducted within the Brisbane City Council (BCC) Local 109 Government Area (LGA) of southeast Queensland (153º2’S, 27ºE; area 1,220 km2, 110 population > 1 million) (Figure 1). A total of 59 survey sites were established within 111 lowland, remnant bushland fragments located in the City’s southern (Karawatha) and 112 south-eastern (Burbank) suburbs (Figure 1). Brisbane is Australia’s fastest growing 113 capital city and has already cleared approximately two-thirds of the pre-European 114 woody remnant vegetation for urban development (Brisbane City Council 2001). 115 This extensive loss and fragmentation of native vegetation has impacted on native 116 wildlife assemblages. Having made significant acquisitions of local forest remnants 117 for conservation, BCC has a strong interest in acquiring sound scientific knowledge 118 that will enhance urban planning, management (both on and off reserves), restoration 119 and, biodiversity conservation decision-making processes. In order to achieve this 120 long-term goal of effectively conserving native wildlife assemblages within remnant

4 121 habitat fragments, it is essential that we first know the distribution of species across 122 the urban landscape and how this relates to habitat loss, fragmentation and condition. 123 124 INSERT FIGURE 1 NEAR HERE 125 126 Survey design 127 To reduce variability in vegetation composition, survey sites were located within 128 the Regional Ecosystem (RE) type 12.9-10.4, which is dominated by scribbly gum 129 (Eucalyptus racemosa) woodland located on sedimentary rocks and sandy soils 130 (Young & Dillewaard 1999). Each site measured 20 m x 45 m and was surveyed 131 using three parallel transects 10 m apart, orientated perpendicular to the natural slope 132 of the land. Each site was surveyed using a combination of live-trapping and passive 133 detection methods. Terrestrial reptile and small to medium mammal species (< 3 kg) 134 were surveyed over three consecutive nights during fine weather days in spring and 135 summer. Initial surveys of all sites occurred in 2004. Repeat surveys of 51 sites were 136 conducted in 2005; nine sites were not repeat-surveyed due to recent fire or human 137 interference. 138 139 Trapping & detection methods 140 Each site was surveyed using a combination of: 8 wire cage traps, 10 Elliott traps, 141 5 dry pit-fall traps (10 L buckets), and 3 hair funnels. Traps were spaced 142 approximately 5 m apart along the three transects (Figure 2) and, wherever possible, 143 were positioned to maximise the chances of being encountered by an by 144 placing traps alongside, on, or in logs, grass runways or possible shelter sites 145 (Sutherland 1996b; Cunningham et al. 2005). Cage traps, Elliott traps and hair 146 funnels were baited with the standard Australian mammal mixture of peanut butter, 147 rolled oats and honey, with vanilla essence also added (Menkhorst & Knight 2001). 148 In addition, a piece of apple was used as bait in the cage traps and Elliott traps. Pit- 149 fall traps were left unbaited. Direct observations and scat collection were also 150 conducted opportunistically during each site visit. 151 152 INSERT FIGURE 2 NEAR HERE 153

5 154 Cage traps were used to detect medium-sized terrestrial mammals such as native 155 rodents (e.g. Rattus fuscipes and Rattus lutreolus) and bandicoots (e.g. Isoodon 156 macrourus and Perameles nasuta), whereas Elliott traps targeted small-bodied species 157 such as dunnarts (Sminthopsis spp.) and antechinus (Antechinus spp.). The hair 158 funnels (Faunatech Pty Ltd, Bairnsdale, Victoria). used to detect both small and 159 medium-sized mammals differed in design from other hair sampling devices (e.g. 160 Lindenmayer et al. 1999; Mills et al. 2000; Scotts and Craig 1988) in having only a 161 single large opening that tapers to an enclosed bait chamber. A specialised wafer was 162 attached to the upper inside surface of the funnel. The wafer was covered with a 163 sticky substance (‘faunagoo’), which replaces the double-sided tape used in previous 164 similar traps to collect hair samples. Dry pit-fall traps were employed primarily to 165 detect small reptile species, with direct observations being used to detect large-bodied 166 reptiles that were unlikely to be detected by other methods. Any scats detected were 167 also collected for ex situ analysis. 168 Cage and Elliott traps were set and baited each afternoon before sunset, checked 169 for captures before dawn the following morning and then closed during the day. 170 Captured were identified to species-level using a field guide (Menkhorst & 171 Knight 2001), photographed, weighed, sexed and immediately released at the point of 172 capture. Hair funnels were set and baited at the start of the three day survey cycle and 173 left undisturbed until collection at the end of the survey cycle. All wafers with hair 174 samples were sent for identification ex-situ by one of two independent experts (Initial 175 surveys: Michiala Bowen; Repeat surveys: Barbara Triggs). Hair samples were 176 identified to species level wherever possible, with identifications being classified as 177 either “definite” or “probable”. Only definite species identifications were used for 178 subsequent data analyses. 179 Dry pit-fall traps were established at least one week prior to site surveys to allow 180 species and habitat to recover from the localised disturbance that occurs during 181 placement of the traps. Dense vegetation and fallen woody debris at most sites 182 prevented the use of drift-fences that have previously been used in conjunction with 183 pit-fall traps to improve capture success (e.g. Mengak & Guynn 1987; Friend et al. 184 1989; Crosswhite et al. 1999; Menkhorst & Knight 2001). Pit-fall traps were open for 185 the duration of the survey cycle and were checked for captures each morning and 186 afternoon. Captured animals were identified to species-level using a field guide 187 (Wilson 2005), photographed, weighed, sexed (if possible) and immediately released

6 188 at the point of capture. Between the initial and repeat wildlife survey periods, lids 189 were securely fitted to each pit-fall trap to prevent captures. Direct observations and 190 scat collections were used opportunistically throughout all site visits to identify target 191 species. All scats collected were identified ex situ by the same independent experts 192 who analysed the hair samples. Only definite species’ identifications were used in 193 subsequent analyses. 194 The relative success of each survey method was determined by evaluating the total 195 number of species detected by each method across all sites. The total number of 196 “unique” species detected by each method was also examined. Unique species were 197 those species detected by only one survey method (sensu Doan 2003). Species’ 198 detections from the initial and repeat surveys were collated for analyses. 199 200 Cost analysis 201 The cost of each survey method was calculated independently based on the cost 202 output required to survey a single site over one survey cycle (i.e. over 3 consecutive 203 nights). Four main areas of cost expenditure were considered for each method: 204 equipment costs, bait/analysis costs, personnel costs and travel costs. 205 Equipment costs included expenditures for acquiring traps as well as additional 206 items required to prepare each trap. Trap acquisition costs for each method were 207 calculated at 2004 purchase prices. Additional preparatory expenses included shade 208 cloth for cage traps, hair wafers for hair funnels and, the hire of a motorised auger for 209 digging pit-fall traps. 210 Bait/analysis costs covered bait expenses as well as ex situ hair and scat analysis 211 charges. The cost of bait was calculated based on the cost of bait ingredients per trap 212 over the three night survey cycle. Cage traps and hair funnels used larger peanut 213 butter balls than Elliott traps and the price was adjusted accordingly. For each survey 214 night, fresh bait was used in cage and Elliott traps, whereas the hair funnel bait was 215 left unchanged during the survey cycle. The charge cost for expert analyses of hair 216 and scat samples differed between the two experts and so an average charge was used 217 to calculate costs of hair and scat analyses. 218 Personnel costs were calculated for two people based on The University of 219 Queensland’s minimum hourly wage for a casual research assistant of $19 per hour 220 plus 15.5% on-costs (all prices are given in Australian dollars). Personnel cost 221 calculations incorporated the time taken to prepare traps, establish traps at a site, set

7 222 and check traps each survey day and, remove traps at the end of the survey cycle. 223 Although observation and scat collection were not standardised, an approximate time 224 for each activity per site was calculated. 225 Travel costs were based on The Ecology Centre’s (The University of Queensland) 226 vehicle hire charge of $0.50/km, with an average of 60 km per return trip, per site 227 visit. The number of return trips was calculated independently for each survey 228 method and included trips to establish, set, check and, remove traps or conduct direct 229 observations/scat collection. 230 231 Cost versus success 232 The most effective survey method or combination of methods was based on both 233 species’ detection success per site and trapping cost per site. The total numbers of 234 individuals and species detected per survey method was averaged across sites to give 235 the average numbers of individuals and species detected per method per site. This 236 average detection success plus the average cost of each survey method per site was 237 compared in order to identify the most effective and efficient combination of methods. 238 239 Results 240 Species Detected 241 A total of 28 target native terrestrial reptile and small mammal species, 242 representing 11 family groups, were detected from the 59 sites surveyed (Table 1). A 243 number of non-target species were also detected, including large terrestrial mammals 244 (wallabies and kangaroos), invertebrates, amphibians, birds, arboreal marsupials and 245 exotic mammal and reptile species. 246 247 INSERT TABLE 1 NEAR HERE 248 249 Survey method success 250 Each survey method successfully identified at least two target species, with 251 certain methods detecting up to 14 species (Figure 3a). As expected, each method 252 was mainly suited to detecting either mammals or reptiles, with no method detecting 253 both mammals and reptiles in equal proportions (Figure 3a). Although there was a 254 degree of overlap in the species detected by each survey method, all methods detected 255 at least one species not detected by another method (Figure 3b).

8 256 257 INSERT FIGURE 3 NEAR HERE 258 259 Cage traps 260 A total of 2664 trap nights produced a total of 277 captures (capture success = 261 10.4%). Target reptile and mammal species comprised 6.9% (n=19) of the total cage 262 trap captures. Collectively, these species represented three family groups and four 263 species (Table 1). With the exception of one reptile capture (carpet python, Morelia 264 spilota), all target species captured by this method were medium-sized mammals. 265 The northern brown bandicoot (Isoodon macrourus) was the most commonly captured 266 mammal (n=14 across 7 sites). Bush rats (Rattus fuscipes) were captured on two 267 nights at a single site and the swamp rat (Rattus lutreolus) and carpet python were 268 trapped at one site each, from a single capture. The bush rat, swamp rat and carpet 269 python were not detected by any other survey method (Table 1). 270 Captures of non-target species included: the common brush-tail possum 271 (Trichosurus vulpecular) (n=124), exotic black rat (Rattus rattus) (n=100), introduced 272 cane toad, Bufo marinus (n=26), Australian magpie (Gymnorhina tibicen) (n=6), grey 273 butcherbird (Cracticus torquatus) (n=2) and, Torresian crow (Corvus orru) (n=1). 274 Overall, cage traps were found closed without captures 6.9% of the time (n=184). 275 276 Elliott traps 277 A total of 3330 trap nights produced 55 captures for an overall trap capture 278 success of 1.7%. Of these captures, 34.5% (n=19) were target species that 279 represented two mammal species from different families (Table 1). Common 280 dunnarts (Sminthopsis murina) were captured more frequently and across a greater 281 number of sites (n=12 across 7 sites) than yellow-footed antechinus (Antechinus 282 flavipes)(n=7 across 4 sites). Both species were detected only by this method (Table 283 1). Non-target species captured by Elliott traps included: cane toads (n=16), house 284 mouse Mus musculus (n=14), giant white-kneed king cricket (Australostoma 285 australasiae) (n=4), centipede (n=1), and a juvenile common brush-tail possum (n=1). 286 Elliott traps were found closed without captures 4% of the time (n=133). 287 288 Dry pit-fall traps

9 289 Of the 568 pit-fall traps used during the survey periods, 105 were successful in 290 capturing target species (18.5%). A total of 12 reptile species (representing three 291 families) and one mammal species were detected (Table 1). The reptile species 292 captured were small-bodied species or juveniles of larger-bodied species (e.g. juvenile 293 bearded dragon (Pogona barbata)). Four reptile species were not detected by any 294 other method: Verreaux’s (Anamalopus verreauxii), scute-snouted 295 skink (Calyptotis scutirostrum), copper-tailed skink (Ctenotus taeniolatus) and, 296 eastern stone gecko (Diplodactylus vittatus) (Table 1). The only mammal species 297 captured in pit-fall traps was the common planigale (Planigale maculata). This 298 species was identified from two captures of individuals at two different sites. The 299 common planigale was detected during surveys only by this method (Table 1). 300 Non-target species’ captures were common in pit-fall traps, with invertebrate 301 species such as ants, spiders, snails and crickets being the most common by-captures. 302 Non-target vertebrate by-captures were all amphibians: cane toads (n=16), ornate 303 burrowing frogs (Lymnodynastes ornatus) (n=7), and copper-backed broodfrogs 304 (Pseudophryne raveni) (n=5). 305 306 Hair funnels 307 A total of 341 wafers were used during the surveys, of which 84 (24.6%) 308 contained hair samples. Of the 84 wafers with hair samples, 17 (20.2%) contained 309 hair that was able to be definitely identified to the species level, with seven of these 310 representing target species. Three target mammal species were positively identified 311 from hair samples: brown antechinus (Antechinus stuartii), northern brown bandicoot, 312 and long-nosed bandicoot (Perameles nasuta). The brown antechinus and long-nosed 313 bandicoot were identified only by this method (Table 1). Although hair funnels 314 specifically target mammal species, a live reptile by-catch of a single garden skink 315 (Lampropholis delicata) was found on a wafer at one site. 316 317 Direct observations and scat analyses 318 Opportunistic species identifications through direct observations and scat 319 collection and analyses respectively identified a total of 14 target reptile species and 320 two target mammal species (Table 1). Direct observations identified six reptile 321 species not detected by any other method (Table 1). Of the two mammals detected 322 from scats (Table 1), the Melomys could not be positively identified to species level,

10 323 although the grassland melomys (M. burtoni) was considered probable. As this was 324 the only detection from this genus, the genus record was included in subsequent 325 analyses. 326 327 Cost of detection methods 328 There were significant variations in cost among the survey methods (Figure 4). 329 Total costs to survey a single site over three nights ranged from $178.86 for hair 330 funnels to $925.66 for cage traps. Elliott trapping was the most expensive method 331 ($815.18) after cage trapping, despite more Elliott traps than cage traps being used to 332 survey a site (n=12 and n=10, respectively). Pit-fall traps, direct observation, and scat 333 analysis were all similar in cost ($626.37, $655.52, $660.52 per site respectively). 334 The main differences in costs resulted from equipment and travel expenses associated 335 with each method (Figure 4). 336 337 INSERT FIGURE 4 NEAR HERE 338 339 Cost vs. success 340 Overall, it appeared that pit-fall trapping was the most effective and efficient 341 survey method, detecting both the highest number of species (n=0.0018) and captures 342 (n=0.003) per dollar (Figure 5a). Direct observations, followed by hair funnels were 343 the next most successful and efficient survey methods (Figure 5a). Elliott traps and 344 cage traps were roughly similar in their cost per species and cost per capture, yet both 345 were substantially less economic than hair funnels (Figure 5a). Comparatively, scat 346 detection/analysis had the lowest detection success for money spent, with 0.0000941 347 species and captures detected per dollar (Figure 5a). 348 For reptiles, the most successful survey methods mirrored those for overall 349 detection costs. Pit-fall traps produced the highest species detection (n=0.0017) and 350 capture success (n=0.0029) per dollar outlay (Figure 5b). Similarly, direct 351 observations were the next most effective and efficient method (Figure 5b), with per 352 dollar values for number of species detected and number of captures equal to those 353 shown in Figure 5a, as mammals were not detected using this method (Figure 3a). 354 The remaining four methods failed to detect reptiles, with the exception of the single, 355 unusual by-catch in a hair funnel and a cage trap.

11 356 For mammals, pit-fall trapping and direct observations were the least successful 357 and most costly methods (Figure 5c). Hair funnels were found to produce the greatest 358 number of species detections (n=0.00066) and captures (n=0.00076) per dollar, 359 implying the lowest cost per species detected and per capture (Figure 5c). Elliott traps 360 were the next most cost efficient and successful method, detecting more species 361 (n=0.00025) and captures (n=0.000395) per dollar than cage traps (0.000165 species 362 and 0.00033 captures per dollar) (Figure 5c). Scat detection/analysis produced more 363 species detections and captures (n=0. .0000941) per dollar than pit-fall trapping 364 (n=0.0000541) (Figure 5c). However, both scat detection/analysis and pit-fall 365 trapping had a higher cost per detection and capture than the other methods, with the 366 exception of direct observations which were not useful for detecting any target 367 mammal species (Figure 5c). 368 369 INSERT FIGURE 5 NEAR HERE 370 371 372 Discussion 373 374 No one survey method independently detected all species recorded during the 375 surveys, yet each method was important for detecting between 1-6 species that were 376 not detected by any other method. There were distinct biases between methods in 377 terms of the species’ group (reptiles or mammals) most successfully detected. Pit-fall 378 traps and direct observations were substantially more successful in detecting reptile 379 species, whereas hair funnels, scat detection/analysis, cage traps and Elliott traps were 380 more useful for detecting mammal species. Such detection biases correspond to the 381 purpose for which each method was designed (Sutherland 1996a). However, it also 382 indicates that, as noted by Laurance (1992), the use of only a single method in fauna 383 community surveys will “…be biased toward a non-random subset of species in the 384 community...” (p. 654). Therefore, when surveying fauna communities, it is essential 385 that combination of survey methods are employed in order to adequately sample a 386 range of species. This finding is consistent with previous studies that have also 387 advocated the use of a combination of techniques for surveying a range of wildlife 388 species (e.g. Mengak & Guynn 1987; Laurance 1992; Catling et al. 1997; 389 Lindenmayer et al. 1999).

12 390 We found a considerable difference among methods in terms of the cost outlay 391 required for detecting ground-dwelling mammal and reptile species. However, these 392 calculations were based on the complement of traps used during the study to survey 393 each site and therefore, such costs may vary for other studies depending on the 394 number of each survey method utilised, the duration of active searches and, the 395 analysis of hair/scat samples relative to the success of these methods. To help provide 396 a direct comparison between the success and cost of each survey method, success was 397 interpreted in terms of ‘value for money’; that is, the number of species and the 398 number of captures per dollar spent for each method. Using these calculations, we 399 found that the methods most successful for detecting various species and species’ 400 groups were also those that produced the most number of mammal and reptile species’ 401 detections and captures at the least cost. 402 403 Reptiles 404 Based on the results of this study, the most effective trapping methods for 405 terrestrial reptile surveys are a combination of pit-fall traps and direct observations. 406 Despite being opportunistic rather than standardised, direct observations detected 407 more overall reptile species, as well as more unique species than pit-fall trapping. 408 However, pit-fall trapping was more cost effective than direct observations, detecting 409 more species and captures per dollar. This suggests that pit-fall trapping would 410 produce the highest species detection and capture success for the least amount of 411 money. However, the unique species detected by each of these methods was 412 significantly biased by body size and behaviour. Large-bodied reptiles such as lace 413 monitors, snakes and dragons that were unlikely to be captured in pit-fall traps were 414 detected by direct observation. The exception was a pit-fall trap capture of a single 415 juvenile bearded dragon that was too small to escape from the trap. 416 Comparatively, the species detected by pit-fall traps were small-bodied, cryptic, 417 nocturnal and/or burying reptiles such as small , eastern stone geckos, and 418 Verreaux’s skinks. The relative species detection success of pit-fall traps is expected 419 to have been even greater than direct observations if it had been possible to use drift 420 fences and larger traps (buckets). Crosswhite et al. (1999), for instance, showed that 421 more reptiles were captured using pit-fall traps combined with drift-fences than 422 through active searches and Catling et al. (1997) concluded that increasing the size of 423 the buckets used as pit-fall traps would likely have increased the capture success of

13 424 larger-bodied species which were able to otherwise escape. However, increasing the 425 trap size and/or incorporating drift fences would also have increased the cost 426 associated with pit-fall trapping. 427 Similarly, given that all direct observations were opportunistic, it may be 428 expected that a dedicated, time-constrained active search period would have identified 429 additional species. However, in accordance with reports by Crosswhite et al. (1999) 430 and Ryan et al. (2002), pit-fall trapping is still likely to have detected the highest 431 number of species and captures. Furthermore, additional costs and limitations 432 associated with personnel time and experience is likely to influence the accuracy of 433 active search results, thereby potentially offsetting any increase in species detections 434 through time-constrained searches (Crosswhite et al. 1999; Silveira et al. 2003). 435 Based on the cost efficiency and detection success of pit-fall trapping and direct 436 observations, we recommend that pit-fall trapping be used as the primary technique 437 for surveys of small-bodied terrestrial reptiles. Where habitats and budgets allow, 438 drift fences should also be used to increase capture success (Friend et al. 1989; 439 Moseby and Read 2001). For surveys focussing on larger-bodied reptiles, time- 440 constrained active searches are recommended as the most cost efficient and 441 productive detection method. However, when attempting to survey a range of 442 terrestrial reptile species, a combination of pit-fall traps and active searches are likely 443 to be the best combination of survey methods for detecting the highest number of 444 species and captures per dollar. Furthermore, when used in combination, the travel 445 costs for each survey method were approximately 50% less, which may compensate 446 for increased expenses associated with the inclusion of drift-fences and even increased 447 search times. 448 449 Mammals 450 Mammal species were detected by five of the six survey methods employed. 451 Optimum trapping methods for terrestrial, small- and medium-sized mammal surveys 452 were hair funnels, followed by Elliott traps and cage traps, as well as scat analysis and 453 pit-fall traps to a lesser degree. Although hair funnels, Elliot traps and cage traps all 454 detected the same number of unique species, the cost effectiveness of these captures 455 varied significantly. Hair funnels were the most economical form of surveying target 456 mammals, detecting more species and captures per dollar than the other mammal 457 survey methods. The relative cost effectiveness of hair funnels is most likely related

14 458 to the advantages this method has over live trapping methods in being less labour- 459 intensive, able to detect more than one species or individual per funnel, and able to 460 capture hair from species of various body-sizes (Lindenmayer et al. 1999; Mills et al. 461 2002). However, unlike live trapping methods, differentiating between individuals of 462 the same species is not possible using hair funnels, thereby limiting the usefulness of 463 this method for surveys aimed at determining species’ abundance. Furthermore, 464 accurately identifying hair samples to the species level is a difficult process that is 465 susceptible to hair samples being incorrectly identified or not able to be identified at 466 all. Lobert et al. (2001), for instance, tested the accuracy of hair identification by two 467 independent experts and found that almost half of the samples analysed involved 468 some degree of identification error. Furthermore, the identification of dog hair from a 469 hair funnel used in Lindenmayer et al.’s (1999) study was questionable given the hair 470 sample was from an arboreal funnel (see also Kavanagh & Stanton 1998). However, 471 the positive species identifications from hair samples collected during this study are 472 reasonable and were considered to be accurate. 473 There were also clear associations between the body size of mammals and the 474 success of various methods for detecting different species. Elliott traps, given their 475 size, detected only small-bodied mammal species, with the exception of a single by- 476 catch of a juvenile brush-tail possum at one site. Similarly, small-bodied species, 477 such as dunnarts and antechinus were not captured in cage traps probably due to the 478 lower sensitivity of cage trap treddles and the light weight of small-bodied species. 479 Cage traps were, however, successful in capturing medium-sized species such as 480 rodents and bandicoots, whose body size prevented captures in Elliott traps. Due to 481 their tapered design and large surface area for capturing hair samples, hair funnels 482 detected both medium- and small-bodied terrestrial mammals, including species not 483 captured by live trapping methods (e.g. long-nosed bandicoot and brown antechinus). 484 Furthermore, although more commonly used for reptile surveys, pit-fall trapping 485 was the only method to detect the occurrence of planigales during this study. This is 486 consistent with previous studies that have found pit-fall traps to be useful for detecting 487 small, elusive mammal species that rarely enter other traps (e.g. Milledge 1991, 488 Laurance 1992, Catling et al. 1997, Menkhorst & Knight 2001). Therefore, unless a 489 project is specifically targeting planigales (or similar elusive, shy species), or has a 490 sufficiently large budget, pit-fall traps are not recommended for mammal surveys. 491 Scat detection and analysis also identified one small mammal (Melomys spp.) not

15 492 detected by any other method. However, these scat samples were not able to be 493 positively identified to the species level, suffering the same analysis difficulties as 494 hair sample identifications. Based on our results, both pit-fall trapping and scat 495 detection/analysis methods would require a substantial cost outlay in order to detect as 496 many species and captures as the other methods. As such, these methods are 497 recommended as supportive methods only if the project budget allows. Alternatively, 498 excess funding could be allocated to increasing the survey-intensity of optimal survey 499 methods or, by exploring the use of additional bait types, such as meat products, to 500 help improve the range of species detected (e.g. herbivores as well as omnivores and 501 carnivores) (Laurance 1992; Mills et al. 2002). 502 Therefore, based on the results from this study, we propose that optimal survey 503 methods for detecting medium-bodied terrestrial mammals are a combination of cage 504 traps and hair funnels. Comparatively, small-bodied terrestrial mammals are best 505 surveyed using Elliott traps and hair funnels. Complementary pit-fall traps should 506 also be used if attempting to detect planigales or similarly elusive mammal species. 507 However, if only planigales or similar species are being targeted, then intensive pit- 508 fall trapping should be adopted as the primary survey method. Like reptile surveys, 509 drift fences may be adopted to increase capture success (e.g. Mengak and Guynn 510 1987). In habitats with sparse ground cover, scat detection may prove more 511 successful than found in this study, although it is best used as a supplementary 512 method with other techniques only if funds permit. 513 514 515 Acknowledgements 516 This research formed part of a collaborative project between The University of 517 Queensland and Brisbane City Council. Fauna surveys were conducted under UQ 518 AEC permits, GSP/030/04/BCC/UQGS, and a Queensland Government EPA 519 scientific purposes permit, WISP01975204. Financial support was provided to JG by 520 Brisbane City Council and a UQ graduate scholarship. We also wish to acknowledge 521 the support of private land-owners and Redland Shire Council’s Water and Waste 522 Division in allowing access to their properties. Thanks also to: the numerous 523 volunteers who assisted with digging holes for pit-fall traps, Michiala Bowen and 524 Barbara Triggs for analysing hair and scat samples and, to the project’s research

16 525 assistants, Michelle Walton and Alison Howes, for dedicated support and assistance 526 during field surveys. 527 528 References 529 Brown, G. W., Nicholls, A. O. (1993). Comparative census techniques and modelling 530 of habitat utilization by reptiles in northern Victoria. In ‘Herpetology in Australia: a 531 Diverse Discipline’. (Ed. D. Lunney and D. Ayers.) pp. 283-290. (Royal Zoological 532 Society of New South Wales: Mosman.) 533 534 Brisbane City Council. (2001). State of the Environment Report: Brisbane 2001. 535 Brisbane City Council. (Brisbane City Council: Brisbane.) 536 537 Catling, P. C., Burt, R. J., Kooyman, R. (1997). A comparison of techniques used in a 538 survey of the ground-dwelling and arboreal mammals in forests in north-eastern New 539 South Wales. Wildlife Research 24, 417-432. 540 541 Clemann, N., Long, K., Skurrie, D., and Dzuris, J. (2005). A trapping survey of small, 542 ground-dwelling vertebrates in the Little Desert National Park, Victoria. Australian 543 Zoologist 33, 119-126. 544 545 Crosswhite, D. L., Fox, S. F., Thill, R. E. (1999). Comparison of methods for 546 monitoring reptiles and amphibians in upland forests of Ouachita Mountains. 547 Proceedings of the Oklahoma Academy of Science 79, 45-50. 548 549 Cunningham, R. B., Lindenmayer, D. B., MacGregor, C., Barry, S., and Wlesh, A. 550 (2005). Effects of trap position, trap history, microhabitat and season on capture 551 probabilities of small mammals in a wet eucalypt forest. Wildlife Research 32, 657- 552 671. 553 554 Doan, T. M. (2003). Which methods are most effective for surveying rainforest 555 herpetofauna? Journal of Herpetology 37, 72-81. 556

17 557 Friend, G. R. (1978). A comparison of predator scat analysis with conventional 558 techniques in a mammal survey of contrasting habitats in Gippsland, Victoria. 559 Australian Wildlife Research 5, 75-83. 560 561 Friend, G. R., Smith, G. T., Mitchell, D. S., and Dickman, C. R. (1989). Influence of 562 pitfall and drift fence design on capture rates of small vertebrates in semi-arid habitats 563 of Western Australia. Australian Wildlife Research 16, 1-10. 564 565 Kavanagh, R. P., and Stanton, M. A. (1998). Nocturnal birds and arboreal marsupials 566 of the southwestern slopes, New South Wales. Australian Zoologist 30, 449-466. 567 568 Laurance, W. F. (1992). Abundance estimates of small mammals in Australian 569 tropical rainforest: a comparison of four trapping methods. Wildlife Research 19, 651- 570 655. 571 572 Lindenmayer, D. B., Incoll, R. D., Cunningham, R. B., Pope, M. L., Donnelley, C. F., 573 MacGregor, C. I., Tribolet, C., and Triggs, B. E. (1999). Comparison of hairtube types 574 for the detection of mammals. Wildlife Research 26, 745-753. 575 576 Lobert, B., Lumsden, L., Brunner, H., and Triggs, B. (2001). An assessment of the 577 accuracy and reliability of hair identification of south-east Australian mammals. 578 Wildlife Research 28, 637-641. 579 580 Mengak, M. T., Guynn, Jr. D. C. (1987). Pitfalls and snap traps for sampling small 581 mammals and herpetofauna. American Midlands Naturalist 118, 284-288. 582 583 Menkhorst, P., and Knight, F. (Eds.) (2001). ‘A Field Guide to the Mammals of 584 Australia.’ (Oxford University Press: Melbourne.) 585 586 Milledge, D. (1991). A survey of the terrestrial vertebrates of coastal Byron Shire. 587 Australian Zoologist 27, 66-90. 588 589 Mills, D. J., Harris, B., Claridge, A. W., and Barry, S. C. (2002). Efficacy of hair- 590 sampling techniques for the detection of medium-sized terrestrial mammals. I. A

18 591 comparison between hair-funnels, hair-tubes and indirect signs. Wildlife Research 29, 592 379-387. 593 594 Moseby, K. E., and Read, J. L. (2001). Factors affecting pitfall capture rates of small 595 ground vertebrates in arid South Australia. II. Optimum pitfall trapping effort. 596 Wildlife Research 28, 61-71. 597 598 Ryan, T. J., Philippi, T., Leiden, Y. A., Dorcas, M. E., Wingley, T. B., and Gibbons, 599 J. W. (2002). Monitoring herpetofauna in a managed forest landscape: effects of 600 habitat types and census techniques. Forest Ecology and Management 167, 83-90. 601 602 Scotts, D. J., and Craig, S. A. (1988). Improved hair-sampling tube for the detection 603 of small mammals. Australian Wildlife Research 15, 469-472. 604 605 Silveira, L., Jácomo, A. T. A., Diniz-Filho, J. A. F. (2003). Camera trap, line transect 606 census and track surveys: a comparative evaluation. Biological Conservation 114, 607 351-355. 608 609 Sutherland, W. J. (Ed.) (1996a). ‘Ecological Census Techniques: a Handbook.’ 610 (Cambridge University Press: Cambridge.) 611 612 Sutherland, W. J. (1996b). Mammals. In ‘Ecological Census Techniques: a 613 Handbook.’ (Ed. W. J. Sutherland.) pp. 260-280. (Cambridge University Press: 614 Cambridge.) 615 616 Wilson, S. (Ed.) (2005). ‘A Field Guide to Reptiles of Queensland.’ (New Holland 617 Publishers Pty. Ltd.: Sydney.) 618 619 Young, P. A. R., and Dillewaard, H. A. (1999). Southeast Queensland. In ‘The 620 Conservation Status of Queensland’s Bioregional Ecosystems’ (Eds. P. S. Sattler and 621 R. D. Williams.) pp. 12/1-12/48. (Environmental Protection Agency: Brisbane.) 622 623 624

19 625 626 627 628 629 630 631 632 Figure 1. Map of study area showing location of (a) Brisbane and central business 633 district (CBD), and site locations within (b) Karawatha area and (c) Burbank area. 634 GIS data provided by Brisbane City Council. 635 636 Figure 2. Site schematic showing trap layout along the three transects. 637  Hair funnels; Elliott traps; Cage traps; Pit-fall traps. 638 639 Figure 3. (a) The total number of species detected by each survey method, and (b) 640 the number of unique species detected by each survey method. Reptiles; 641 Mammals. 642 643 Figure 4. Relative cost of each survey method in isolation as used during this project 644 to survey one site over a three night period. Total cost for each method comprised 645 expenses relating to: equipment, bait/analysis, personnel time and, travel. 646 647 Figure 5. Average success of each survey method per site, per dollar. For clarity, the 648 cost of success is shown as success per thousand dollars for: (a) all target species 649 detected; (b) reptiles detected; and (c) mammals detected. For all graphs: average 650 number of species per site per thousand dollars; average number of captures per site 651 per thousand dollars. 652 653 654 655 656 657 658

20 659 660 661 662 663 664 665 666 667 Table 1. Collated species list and method/s by which they were detected. 668 Species that were detected by only a single survey method; ● species detected by 669 more than one survey method. 670

Survey Method Family Group Scientific Name Common Name CT ET PF HF Obs S Dasyuridae Antechinus flavipes Yellow-footed antechinus  Antechinus stuartii Brown antechinus  Planigale maculata Common planigale  Sminthopsis murina Common dunnart  Native Mammals Muridae Melomys sp. Likely: Grassland melomys  Rattus fuscipes Bush rat  Rattus lutreolus Swamp rat  Peramelidae Isoodon macrourus Northern brown bandicoot ● ● ● Perameles nasuta Long-nosed bandicoot  Agamidae Diporiphora australis Tommy round-head ● ● Physignathus lesuerii Eastern water dragon  Pogona barbata Bearded dragon ● ● Colubridae Dendrelaphis punctulata Common tree snake  Elapidae Pseudechis porphyriachus Red-bellied black snake  Gekkonidae Diplodactylus vittatus Eastern stone gecko  Pygopodidae Lialis burtonis Buton's snake-lizard  Pythonidae Morelia spilota Carpet python  Scincidae Anamalopus verreauxii Verreaux's skink  Native Reptiles Calyptotis scutirostrum Scute-snouted calyptotis skink  Carlia foliorum Tree-base litter-skink ● ● Carlia pectoralis Open-litter rainbow skink ● ● Carlia vivax Storr's rainbow skink ● ● Cryptoblepharus virgatus Fence skink ● ● Ctenotus taeniolatus Copper-tailed skink  Eulamprus quoyii Eastern water skink  Lampropholis amicula Secretive skink ● ● Lampropholis delicata Garden skink ● ● ● Varanidae Varanus varius Lace monitor  671 672

21 673

22 674 Figure 1. 675 676 677

678 Main roads

679 Brisbane CBD

680 Remnant Vegetation (1999) 681 Brisbane river & Ocean 682 Survey sites 683 c. 684

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