Influence of shade covers on pitfall trap temperatures and capture success of reptiles and small mammals in arid Australia

1999 ◽  
Vol 26 (3) ◽  
pp. 341 ◽  
Author(s):  
Trevor J. Hobbs ◽  
Craig D. James

Shade covers for pitfall traps can be used to reduce the amount of solar radiation penetrating to the bottom of pitfall buckets, thereby reducing the number of captured animals dying from heat-stress. We tested the effectiveness of a variety of shade covers for reducing temperatures in pitfalls and trap mortality of small vertebrates, and examined the effect of one cover design on trap success in arid landscapes. Shade covers made of insulation foil were found to reduce core pitfall temperatures by 20–22˚C compared with uncovered buckets, which reached temperatures greater than 66ºC. Other cover types tested (plastic lid or cardboard) were found to be less effective: core bucket temperatures still reached 48–53ºC. While foil covers do reduce temperatures and therefore the probability of heat-stress-related mortality, above-ground foil covers also influence trap success. Traps with above-ground foil covers caught 39–43% fewer small vertebrates and 7–42% fewer species than uncovered traps. Above-ground foil covers had the greatest influence on the sampled abundance of scincid lizards (reduced by 50–52%), reduced the sampled abundance of most other lizard families and mammals, but increased capture success for snakes. If shade covers are required to minimise heat stress and mortality in pitfall buckets we recommend foil covers placed inside the bottom pitfall buckets as they significantly reduce pitfall temperatures and are likely to have minimal influence on trap success. However, regular checking of traps is still one of the most reliable ways to reduce heat-stress- related and other deaths in pitfall traps.

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Reija Ruuhela ◽  
Athanasios Votsis ◽  
Jaakko Kukkonen ◽  
Kirsti Jylhä ◽  
Susanna Kankaanpää ◽  
...  

Urbanization and ongoing climate change increase the exposure of the populations to heat stress, and the urban heat island (UHI) effect may magnify heat-related mortality, especially during heatwaves. We studied temperature-related mortality in the city of Helsinki—with urban and suburban land uses—and in the surrounding Helsinki-Uusimaa hospital district (HUS-H, excluding Helsinki)—with more rural types of land uses—in southern Finland for two decades, 2000–2018. Dependence of the risk of daily all-cause deaths (all-age and 75+ years) on daily mean temperature was modelled using the distributed lag nonlinear model (DLNM). The modelled relationships were applied in assessing deaths attributable to four intensive heatwaves during the study period. The results showed that the heat-related mortality risk was substantially higher in Helsinki than in HUS-H, and the mortality rates attributable to four intensive heatwaves (2003, 2010, 2014 and 2018) were about 2.5 times higher in Helsinki than in HUS-H. Among the elderly, heat-related risks were also higher in Helsinki, while cold-related risks were higher in the surrounding region. The temperature ranges recorded in the fairly coarse resolution gridded datasets were not distinctly different in the two considered regions. It is therefore probable that the modelling underestimated the actual exposure to the heat stress in Helsinki. We also studied the modifying, short-term impact of air quality on the modelled temperature-mortality association in Helsinki; this effect was found to be small. We discuss a need for higher resolution data and modelling the UHI effect, and regional differences in vulnerability to thermal stress.


2002 ◽  
Vol 139 (1) ◽  
pp. 87-93 ◽  
Author(s):  
A. K. SHINDE ◽  
RAGHAVENDRA BHATTA ◽  
S. K. SANKHYAN ◽  
D. L. VERMA

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.


HortScience ◽  
2018 ◽  
Vol 53 (10) ◽  
pp. 1416-1422 ◽  
Author(s):  
Giverson Mupambi ◽  
Stefano Musacchi ◽  
Sara Serra ◽  
Lee A. Kalcsits ◽  
Desmond R. Layne ◽  
...  

Globally, apple production often occurs in semiarid climates characterized by high summer temperatures and solar radiation. Heat stress events occur regularly during the growing season in these regions. For example, in the semiarid eastern half of Washington State, historic weather data show that, on average, 33% of the days during the growing season exceed 30 °C. To mediate some of the effects of heat stress, protective netting (PN) can be used to reduce the occurrence of fruit sunburn. However, the impacts of reduced solar radiation in a high light environment on light-use efficiency and photosynthesis are poorly understood. We sought to understand the ecophysiological response of apple (Malus domestica Borkh. cv. Honeycrisp) under blue photoselective PN during days with low (26.6 °C), moderate (33.7 °C), or high (38.1 °C) ambient temperatures. Two treatments were evaluated; an uncovered control and blue photoselective PN. Maximum photochemical efficiency of PSII, or photosystem II (Fv/Fm) was significantly greater at all measurement times under blue photoselective PN compared with the control on days with high ambient temperatures. Fv/Fm dropped below 0.79, which is considered the threshold for stress, at 1000 hr in the control and at 1200 hr under blue photoselective PN on a day with high ambient temperature. On days with low or moderate ambient temperatures, Fv/Fm was significantly greater under blue photoselective PN at 1400 hr, which coincided with the peak in solar radiation. ‘Honeycrisp’ apple exhibited dynamic photoinhibition as shown by the diurnal decline in Fv/Fm. Quantum photosynthetic yield of PSII (ΦPSII) was also generally greater under blue photoselective PN compared with the control for days with moderate or high ambient temperatures. Photochemical reflectance index (ΔPRI), the difference in reflectance between a stress-responsive and nonstress-responsive wavelength, was greater under PN compared with the control on the day with high ambient temperatures, with no differences observed under low or moderate ambient temperatures. Leaf gas exchange did not show noticeable improvement under blue photoselective netting when compared with the control despite the improvement in leaf-level photosynthetic light use efficiency. In conclusion, PN reduced incoming solar radiation, improved leaf-level photosynthetic light use efficiency, and reduced the symptoms of photoinhibition in a high-light, arid environment.


2021 ◽  
Author(s):  
Gonzalo Martín Rivelli ◽  
María Elena Fernández Long ◽  
Leonor Gabriela Abeledo ◽  
Daniel Calderini ◽  
Daniel Julio Miralles ◽  
...  

Abstract Episodes of heat stress constrain crop production and will be aggravated in the near future according to short and medium-term climate scenarios. Global increase in cloudiness has also been observed, decreasing the incident solar radiation. This work was aimed to quantify the probability of occurrence of heat stress and cloudiness, alone or combined, during the typical post-flowering period of wheat and canola in the Southern Cone of South America. Extended climate series (last 3-5 decades with daily register) of 33 conventional weather stations from Argentina, Brazil, Chile and Uruguay (23ºS to 40ºS) were analysed considering the period from September to December. Two different daily events of heat stress were determined: i) maximum daily temperature above 30ºC (T>30ºC), and ii) 5ºC above the historical average maximum temperature of that day (T+5ºC). A cloudiness event was defined in our work as incident solar radiation 50% lower than the historical average radiation of that day (R50%). The T>30ºC event increased its probability of occurrence throughout the post-flowering phase, from September to December. By contrast, the risk of T+5ºC event decreased slightly, just like for R50%, and the higher the latitude, the lower the probability of R50%. The T>30ºC plus R50% combined stresses reached greater cumulated probabilities during post-flowering, compared to T+5ºC plus R50%, being 42% vs. 15% in northernmost locations, 26% vs. 19% in central (between 31ºS to 35ºS), and 28% vs. 1% in southernmost locations, respectively. A curvilinear relationship emerged between the monthly probability of combined stresses and the number of days with stress per month. In summary, T>30ºC was the most frequent thermal stress during post-flowering in wheat and canola. Both combined stresses had a noticeable risk of occurrence, but T>30ºC plus R50% was the highest. Evidence of the recent past and current occurrence of heat stress individually, and its combination with cloudiness events during post-flowering of temperate crops, serves as a baseline for future climate scenarios in main cropped areas in the Southern Cone of South America.


2018 ◽  
Vol 150 (6) ◽  
pp. 813-820
Author(s):  
H.E. James Hammond ◽  
David W. Langor ◽  
Dustin J. Hartley

AbstractThe depth at which pitfall traps were sunk into the ground and the resulting catches of epigaeic Carabidae (Coleoptera) and Staphylinidae (Coleoptera) assemblages in subhygric to hydric ecosites with very deep organic soil layers was investigated in the upper foothills ecoregion of Alberta, Canada. Traps were installed at seven sites, with six surface traps (the pitfall trap lip <5 cm below soil surface) and six deep traps (the pitfall trap lip >20 cm below soil surface) at each site. A total of 5289 beetles representing 75 taxa were collected. There were no significant effects of trap depth on catch. Rarefaction estimates of species diversity were higher in surface pitfall traps for both taxa. The similarity of pooled catches between deep and surface traps was on average 75%, suggesting that both trap types were collecting similar faunas. We found no advantage to using deep pitfall traps in addition to surface traps to sample the epigaeic fauna of wet forest stands and peatlands.


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.


2009 ◽  
Vol 57 (5) ◽  
pp. 311 ◽  
Author(s):  
Graham G. Thompson ◽  
Scott A. Thompson

The temperature in pit and funnel traps with various shade-cover treatments on the two hottest days in Perth in the summer of 2008/09 were examined. Lethal temperatures for small mammals and reptiles were experienced in pipe and bucket pit-traps and funnel traps without covers on both days. Funnel traps with shade covers provided similar or better protection from solar radiation than buckets, pipes and funnel traps without covers. A breeze reduced temperatures in funnel traps more than it did in bucket and pipe pit-traps. It is recommended that all funnel traps deployed during fauna surveys be protected by a shade cover and during hot conditions a second shade cover should be used.


Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  

AbstractHeat stress decreases human physical work capacity (PWC), but the extent to which solar radiation (SOLAR) compounds this response is not well understood. This study empirically quantified how SOLAR impacts PWC in the heat, considering wide, but controlled, variations in air temperature, humidity, and clothing coverage. We also provide correction equations so PWC can be quantified outdoors using heat stress indices that do not ordinarily account for SOLAR (including the Heat Stress Index, Humidex, and Wet-Bulb Temperature). Fourteen young adult males (7 donning a work coverall, 7 with shorts and trainers) walked for 1 h at a fixed heart rate of 130 beats∙min−1, in seven combinations of air temperature (25 to 45°C) and relative humidity (20 or 80%), with and without SOLAR (800 W/m2 from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature and clothing conditions. Wet-Bulb Globe Temperature and the Universal Thermal Climate Index represented SOLAR correctly and did not require a correction factor. For the Heat Stress Index, Humidex, and Wet-Bulb Temperature, correction factors are provided enabling forecasting of heat effects on work productivity.


2020 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
Noor Farikhah Haneda ◽  
Nisfi Yuniar

Deforestasi atau perubahan fungsi dari hutan menjadi non-hutan berperan dalam perubahan ekosistem dan spesies di dalamnya. Serangga sebagai salah satu fauna di dalamnya merupakan aspek yang menarik untuk dikaji khususnya semut. Tujuan penelitian ini adalah mengidentifikasi peranan-peranan dari genus semut yang ditemukan di ekosistem transformasi. Penelitian dilaksanakan di Desa Bungku, Kecamatan Bajubang, Kabupaten Batanghari, Provinsi Jambi. Metode yang digunakan dalam penelitian ini adalah membuat plot pengamatan secara purposive sampling. Plot pengamatan dipasang di empat eksosistem hutan dengan jumlah masing - masing ekosistem sebanyak empat plot. Setiap plot memiliki lima sub plot yang tersebar di empat eksosistem hutan untuk pemasangan pitfall trap. Teknik pengambilan sampel semut menggunakan pitfall trap di empat ekosistem. Empat ekosistem tersebut yaitu hutan sekunder, perkebunan kelapa sawit, kebun karet, dan hutan karet. Hasil penelitian ditemukan sebanyak 33 genus dari 6 subfamili. Selanjutnya dari 33 genus dikelompokkan berdasarkan peranannya. Berdasarkan peranannya terdapat 46% pencari makan , 36% predator, 3% semut tentara, 3% pemakan bangkai, dan 3% lainnya (semut pemanen/pemetik, omnivora, predator, dan pemakan bangkai). Camponotus sebagai genus dominan memiliki peranan pencari makan, dan Pheidole mempunyai peranan sebagai penghancur biji dan sebagian lainnya adalah omnivora. The Role of Ants in Lowland Tropical Rainforest TransformationAbstractDeforestation or changes functions from forest to non-forest play a role in changing ecosystems and the species within them. Insect as one of the fauna is an interesting aspect to study, especially ants. Aims of this study is to identify the roles of the genus of ants that found in the transformation ecosystem. This study was conducted in Bungku Village, Bajubang District, Batanghari Regency, Jambi. Method used in this study is to make a plot of observation by purposive sampling. Ant sampling techniques use pitfall traps in four ecosystems i.e.. secondary forest, oil palm plantation,rubber plantation, and jungle rubber. This study found 33 genera from 6 subfamilies. Furthermore, 33 genera are grouped based on their roles, i.e. (1) 46% foragers, (2) 36% for predators, (3) 3% for army ants, (4) 3% for scavengers, and (5) 3% for others (harvesting ants, omnivores, predators and scavengers too). Camponotus as the dominant genus has a role for foragers, and Pheidole has a role as a seed destroyer and the other part is omnivorous.


2020 ◽  
Author(s):  
Antoine Gardarin ◽  
Muriel Valantin-Morison

Abstract In arable agroecosystems, arthropod communities often have a reduced abundance and diversity, which represents a challenge for sampling techniques needed to detect small differences among these simplified communities. We evaluated the suitability of pitfall traps for comparing the effects of cropping systems on arthropod communities. In a field experiment, we compared the effects of two pitfall trap diameters, the type of preserving fluid and the sampling effort on three metrics (activity density, taxonomic richness, and community weighted mean [CWM] of body size) for carabids and spiders. Trap size affected the observed composition of communities, with large traps yielding a higher proportion of spiders, and a higher richness and CWM body size for both taxa. The type of preserving fluid had a weaker effect. Simulations with various sampling efforts showed that only very different communities could be distinguished with less than 10 traps per field or less than 30 field replicates. Fewer traps were required to find differences between cropping systems for body size than for other metrics. Carabid activity density and body size, and spider genus richness, were the variables better distinguishing between cropping systems with the smallest sampling effort. A high sampling effort was required for comparing activity density and richness across cropping systems. Selection of the most appropriate trap design, metrics, and crops are the main factors for optimizing the trade-off between sampling effort and the ability to detect arthropod community responses to habitat management.


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