A comparison of survey methods for arboreal possums in jarrah forest, Western Australia

2005 ◽  
Vol 32 (8) ◽  
pp. 701 ◽  
Author(s):  
A. F. Wayne ◽  
A. Cowling ◽  
C. G. Ward ◽  
J. F. Rooney ◽  
C. V. Vellios ◽  
...  

Comparative trials of different survey methods were conducted in the southern jarrah (Eucalyptus marginata) forest to determine the most efficient means of detecting koomal (common brushtail possum, Trichosurus vulpecula hypoleucus) and ngwayir (western ringtail possum, Pseudocheirus occidentalis). In particular, we examined different trapping and spotlighting methods and compared these with scat surveys. Six different trapping methods (derived by combining three bait types and two trap positions) were compared at six sites. Significantly fewer koomal were caught on ‘universal’ bait (i.e. peanut butter, rolled oats and sardines) than on flour-based baits using rose oil or Eucalyptus oil as lures. Significantly more individuals of both possum species were caught in arboreal traps than in ground traps (P < 0.001 in both cases). Recapture rates of koomal were high, whereas ngwayir were rarely retrapped. There were no detection differences between six different spotlighting methods (derived by combining three spotlight intensities with two filter colours) for koomal. Significantly more ngwayir were detected using 50-W or 100-W lights than 20-W lights (P = 0.01). There were no significant differences in the detection rates for ngwayir using red or white light. There were, however, significant observer differences in the number of possums of both species detected (koomal, P = 0.025; ngwayir, P = 0.004). Spotlighting detected, on average, only 4.9% of the koomal ‘known to be alive’ by trapping. However, spotlighting with a 50-W or 100-W spotlight detected more ngwayir than did trapping. Koomal abundance measures derived from scat surveys were not related to trapping or spotlight abundance estimates. For ngwayir, however, scat counts were strongly related to spotlight counts and there were no significant observer differences for the former. We conclude that koomal are more effectively surveyed using arboreal trapping with rose or Eucalyptus lures. Ngwayir are best surveyed using scat surveys or 50-W spotlights.

2005 ◽  
Vol 32 (8) ◽  
pp. 689 ◽  
Author(s):  
A. F. Wayne ◽  
A. Cowling ◽  
J. F. Rooney ◽  
C. G. Ward ◽  
I. B. Wheeler ◽  
...  

This paper describes how environmental factors, survey method procedures and differences in forest structure resulting from logging relate to the detection of koomal (common brushtail possum, Trichosurus vulpecula hypoleucus) and ngwayir (western ringtail possum, Pseudocheirus occidentalis). A total of 169 vehicle-based spotlight surveys of possums within native jarrah (Eucalyptus marginata) forest was conducted on three transects over eight years (1996–2003). Up to 5.7 koomal and up to 3.3 ngwayir were detected per kilometre per transect side. Only one ngwayir was detected during the eight surveys conducted between 2001 and 2003. More koomal were seen in spring and autumn (i.e. September–November and March–May respectively) and more ngwayir were seen between October and April. Although surveys were not conducted on very rainy or excessively windy nights, fewer possums were nonetheless seen on nights following rainy days and on cold nights. Cloud cover also affected sightings of koomal. The time taken to complete the surveys increased in conjunction with the number of possums detected, on account of the time required to record data. The importance of standardising travelling speed also is emphasised. Possum spotlight counts differed between recently logged and unlogged areas. However, these findings were not supported by complementary koomal abundance estimates derived from trapping, suggesting that vegetation structure may affect detectability. Factors such as the lunar cycle, wind speed and survey start time after sunset did not significantly affect detection rates of either species. On the basis of these findings, specific survey conditions can be selected to improve spotlight detection efficiency.


2017 ◽  
Vol 47 (2) ◽  
pp. 123-132 ◽  
Author(s):  
Natália Carneiro ARDENTE ◽  
Átilla Colombo FERREGUETTI ◽  
Donald GETTINGER ◽  
Pricila LEAL ◽  
Fernanda MARTINS-HATANO ◽  
...  

ABSTRACT This study was the first to evaluate the efficiency of trapping methods in the study of small mammals in the Carajás National Forest, southeastern Brazilian Amazon. It is an area with a unique vegetation type (metalofilic savannah or Canga). The aims of this study were to compare the efficiency of two trapping methods (i.e. live-traps and pitfalls), the bait types used, and evaluate if trapping success varied seasonally. We used four sampling grids, each with six parallel transects. The trap effort for live-traps and pitfalls was 51,840 trap*nights and 10,800 bucket*nights, respectively. We used three types of bait: a paste of peanut butter and sardines, bacon, and bananas. We placed one type of bait in each trap, alternating between points. We recorded 26 species of small mammals, 11 from the order Didelphimorphia and 15 from the order Rodentia. Pitfalls captured a higher number of species compared with live-traps. The capture rate, the mortality rate and the quantity of juveniles and adults did not differ significantly between methods. Capture rate for pitfalls differed significantly between seasons. The majority of species were captured by a single method. Species were equally attracted to the traps regardless of the type of bait used. Some of our results differed significantly from other studies in Amazonia and such variation should be taken into account when designing survey methods for Amazonian small mammals.


1985 ◽  
Vol 12 (3) ◽  
pp. 461 ◽  
Author(s):  
I Abbott ◽  
PV Heurck

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.


2006 ◽  
Vol 54 (6) ◽  
pp. 571 ◽  
Author(s):  
Melanie A. Norman ◽  
Julie A. Plummer ◽  
John M. Koch ◽  
Greg R. Mullins

Alcoa is undertaking rehabilitation in the jarrah (Eucalyptus marginata D.Don ex Sm.) forest of Western Australia, following bauxite mining. One of the methods used in the rehabilitation program is broadcasting seeds; however, about two-thirds of species require seed-dormancy-breaking treatments. Smoke overcomes dormancy and enhances the germination of many jarrah forest species. Smoke-application methods were investigated to find the best seed treatment for 64 jarrah forest species. The optimum duration of seed imbibition in aqueous smoke and dilution of the aqueous smoke product were also investigated. The method of smoke application was important. Smoke water enhanced the germination of 12% of species, whereas aerosol smoke enhanced the germination of 6% of species. Both Grevillea pilulifera (Lindl.) Druce and Velleia trinervis Labill. had germination enhanced by both smoke-application methods. Aerosol smoke inhibited the germination of Clematis pubescens Endl. and Hypocalymma angustifolium (Endl.) Schauer. A total of 78% of species did not exhibit significantly enhanced germination when smoke treated, including the two species inhibited by smoke treatment. Germination was equivalent following 1- and 12-h imbibition in the aqueous smoke extract. Dilutions of the aqueous extract Regen 2000 Smokemaster from 1 to 3% were optimal for the germination of Marianthus bicolor (Putt.) F.Muell and Stylidium amoenum R.Br., even after subsequent washing with water, demonstrating the irreversible nature of smoke treatments. For species that did not exhibit smoke-enhanced germination, other dormancy-breaking treatments may be required before a response to smoke is elicited. These results have application to a wide variety of natural managed lands, disturbed and designed landscapes.


2019 ◽  
Vol 46 (2) ◽  
pp. 104 ◽  
Author(s):  
Shannon J. Dundas ◽  
Katinka X. Ruthrof ◽  
Giles E. St.J. Hardy ◽  
Patricia A. Fleming

Context Camera trapping is a widely used monitoring tool for a broad range of species across most habitat types. Camera trapping has some major advantages over other trapping methods, such as pitfall traps, because cameras can be left in the field for extended periods of time. However, there is still a need to compare traditional trapping methods with newer techniques. Aims To compare trap rates, species richness and community composition of small mammals and reptiles by using passive, unbaited camera traps and pitfall traps. Methods We directly compared pitfall trapping (20-L buried buckets) with downward-facing infrared-camera traps (Reconyx) to survey small reptiles and mammals at 16 sites within a forested habitat in south-western Australia. We compared species captured using each method, as well as the costs associated with each. Key results Overall, we recorded 228 reptiles, 16 mammals and 1 frog across 640 pitfall trap-nights (38.3 animal captures per 100 trap-nights) compared to 271 reptiles and 265 mammals (for species likely to be captured in pitfall traps) across 2572 camera trap nights (20.8 animal captures per 100 trap-nights). When trap effort is taken into account, camera trapping was only 23% as efficient as pitfall trapping for small reptiles (mostly Scincidae), but was five times more efficient for surveying small mammals (Dasyuridae). Comparing only those species that were likely to be captured in pitfall traps, 13 species were recorded by camera trapping compared with 20 species recorded from pitfall trapping; however, we found significant (P&lt;0.001) differences in community composition between the methods. In terms of cost efficacy, camera trapping was the more expensive method for our short, 4-month survey when taking the cost of cameras into consideration. Conclusions Applicability of camera trapping is dependent on the specific aims of the intended research. Camera trapping is beneficial where community responses to ecosystem disturbance are being tested. Live capture of small reptiles via pitfall trapping allows for positive species identification, morphological assessment, and collection of reference photos to help identify species from camera photos. Implications As stand-alone techniques, both survey methods under-represent the available species present in a region. The use of more than one survey method improves the scope of fauna community assessments.


1984 ◽  
Vol 32 (4) ◽  
pp. 367 ◽  
Author(s):  
IJ Colquhoun ◽  
RW Ridge ◽  
DT Bell ◽  
WA Loneragan ◽  
J Kuo

Land use which reduces tree canopy density and the impact of Phytophthora cinnamomi are believed to be altering the hydrological balance of parts of the northern jarrah forest, Western Australia. In the drier eastern zones of the forest, replacement plant communities must maintain the soil-salt-water balance to prevent significant increases in salinization of streams in water supply catchments. Daily and seasonal patterns of the diffusive resistance of leaves and xylem pressure potential were determined for the major natural dominant of the region, Eucalyptus marginata, and five other species of Eucalyptus used in rehabilitation. Three types of daily and seasonal patterns were observed. E. marginata and E. calophylla exhibited little stomatal control of water loss, and leaf resistances remained low throughout the study period (type 1). E. maculata, E. resinifera and E. saligna exhibited marked stomatal regulation during summer days when xylem pressure potentials fell below -2.O MPa (type 2). E. wandoo (type 3) also controlled water loss but developed xylem pressure potentials far lower than all other species tested (<-3.0 MPa). Although none of the species tested replicated the summer stomatal resistance and xylem pressure potential patterns of E. marginata, it is suggested that total annual water use should be examined before selecting the most appropriate species to rehabilitate disturbed sites in the eastern zones of the northern jarrah forest region.


2018 ◽  
Vol 45 (2) ◽  
pp. 185 ◽  
Author(s):  
Damian R. Michael ◽  
Daniel Florance ◽  
Mason Crane ◽  
Wade Blanchard ◽  
David B. Lindenmayer

Context Artificial refuges (cover boards) are a popular method to survey and monitor herpetofauna worldwide. However, one limitation of using artificial refuges in terrestrial environments is the low detection rates of arboreal species. Furthermore, destructive search techniques can damage critical microhabitat such as exfoliating rock or flaking bark of mature trees. Aim We tested a non-destructive, passive method of sampling arboreal reptiles in fragmented agricultural landscapes in south-eastern Australia. Methods We installed 84 artificial bark refuges consisting of strips of non-toxic, closed-cell foam attached to eucalypt trees in 13 patches of remnant vegetation. We used Bayesian statistics to compare differences in detection rates among artificial bark refuges, terrestrial artificial refuges and active searches of natural habitat over a 4-year period. Key results Active searches combined with terrestrial artificial refuges detected the highest number of reptile species, including several cryptic fossorial species. Artificial bark refuges detected, on average, 132 times more individuals of the arboreal southern marbled gecko, Christinus marmoratus, than did terrestrial refuges. Gecko abundance patterns were related to tree characteristics such as tree size, bark thickness and stand basal area, as well as survey year. Conclusions Traditional survey methods such as terrestrial cover boards, in combination with active searches of natural habitat, may significantly underestimate counts for arboreal gecko species. Implications Artificial bark refuges provide a cost-effective, non-destructive and durable method for surveying and monitoring arboreal reptiles in woodland environments over short to medium time frames. Foil-backed, closed-cell foam has broad application for use in spatial capture–recapture studies and long-term monitoring of arboreal reptiles. This method also may be effective for procuring records of threatened arboreal geckos or as a solution for providing temporary habitat in ecological restoration projects.


2002 ◽  
Vol 50 (1) ◽  
pp. 107 ◽  
Author(s):  
K. L. McDougall ◽  
G. E. St J. Hardy ◽  
R. J. Hobbs

The spatial distribution of Phytophthora cinnamomi Rands at seven dieback sites in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia was determined by the following two baiting techniques: in situ baiting with live Banksia grandis Willd. seedlings and ex situ baiting of sampled soil and root material. Four areas within each site were sampled, reflecting dieback age and position in the landscape. Approximate dieback ages of 50, 20 and 5 years were determined by aerial photography. The 50-year-old age class was divided into wet valley floor and dry gravelly slope. Phytophthora cinnamomi was recovered most frequently from the 5-year-old (dieback fronts) and wet 50-year-old areas by both baiting techniques. It was recovered from more than twice as many areas and about five times as many samples when in situ B. grandis baits were used compared with ex situ soil and root baiting. Almost all recoveries from in situ baits were made between October and December. From both methods, it appears that P. cinnamomi has a patchy distribution within dieback sites in the northern jarrah forest. It is easily detected only on dieback fronts and wet valley floors. On dry gravelly sites affected 20 years or more ago, P. cinnamomi is rare and may even be absent at some sites. This makes confident detection of the pathogen difficult. In situ baiting at least allows a temporal component to the sampling and will be a useful method of detection in areas where P. cinnamomi is rare or transient.


2013 ◽  
Vol 61 (2) ◽  
pp. 119 ◽  
Author(s):  
Jessica Lee ◽  
Hugh Finn ◽  
Michael Calver

Land clearing threatens three black cockatoo species (forest red-tailed black cockatoo, (Calyptorhynchus banksii naso), Carnaby’s cockatoo (Calyptorhynchus latirostris), and Baudin’s cockatoo (Calyptorhynchus baudinii) endemic to south-western Australia, so revegetation is important to their recovery. Over three years we studied cockatoo activity in 7–14-year-old mine-site rehabilitation in the region’s jarrah (Eucalyptus marginata)–marri (Corymbia calophylla) forest to give the most detailed description to date of the use of rehabilitation by the birds. Pits varied floristically and structurally (despite similar rehabilitation prescriptions), but interior and exterior plots (100 m2) were similar within pits. Using feeding traces (e.g. chewed husks), and behavioural observations we confirmed feeding within eight years of revegetation. Plots containing feeding trace were similar to plots without, so factors determining black cockatoo feeding may not be apparent at small scales. Returning food resources reflected vegetation succession, with regenerating marri and fast-maturing proteaceous species providing most food. Carnaby’s cockatoo ate Banksia and Hakea seeds and Baudin’s cockatoo and the forest red-tailed black cockatoo consumed marri seeds. Banksia squarrosa, Hakea undulata, H. prostrata and marri were common foods in all years. Revegetation efforts elsewhere should consider these species, within the constraints of rehabilitation protocols addressing multiple aims.


2008 ◽  
Vol 65 (1) ◽  
pp. 17-26 ◽  
Author(s):  
R Glenn Szerlong ◽  
David E Rundio

We present a statistical modeling method for estimating mortality and abundance of spawning salmon from time-series counts that eliminates the need for separate information about mortality. We model arrival and mortality using differential equations, where mortality can be constant or changing linearly, and estimate mortality and abundance from counts using maximum likelihood when multiple estimates of detection rate are available. We also develop an approximate likelihood to estimate mortality and abundance when only a single value for detection rate is available or to estimate only mortality when detection rates are entirely unknown. We demonstrate our approach using counts of coho salmon (Oncorhynchus kisutch) where mortality, abundance, and detection were determined from tagging at a weir. Our model for nonconstant mortality produced mortality estimates that closely matched the empirical data and were robust to variation in other parameters. It also provided a better fit to the stream counts and a closer abundance estimate to the weir count than the constant mortality model. Monte Carlo simulations indicated that the approximate likelihood provided reasonable estimates of mortality over most of the ranges of parameters explored, particularly under the nonconstant mortality model, and produced relatively unbiased abundance estimates using a single value for detection.


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