scholarly journals Effects of parasites and predators on nociception: decreases analgesia reduces overwinter survival in root voles (Rodentia: Cricetidae)

2021 ◽  
Vol 38 ◽  
pp. 1-9
Author(s):  
Yuan-Gang Yang ◽  
Guo-Zhen Shang ◽  
Xue-Qin Wu ◽  
Hui-Qing Chen ◽  
Yan Wu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Small Mammals ◽  
Parasitic Infection ◽  
Environmental Stressors ◽  
Thermal Stimulus ◽  
Overwinter Survival ◽  
Defensive Responses ◽  
Live Trapping ◽  
Nociceptive Responses ◽  
Infected Prey

Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.

scholarly journals Long-Term Trends in Small Mammals on a Right-of-Way in Pennsylvania, U.S.

2007 ◽  
Vol 33 (2) ◽  
pp. 147-152
Author(s):  
Richard Yahner ◽  
Richard Yahner ◽  
Russell Hutnik
Keyword(s):  
Small Mammals ◽  
Forest Cover ◽  
Common Species ◽  
The State ◽  
Mammal Species ◽  
Right Of Way ◽  
Live Trapping ◽  
Long Term Trends

The State Game Lands 33 Research and Demonstration Area, Centre County, Pennsylvania, U.S., has been studied since 1953 with the objective of comparing the effectiveness of commonly used mechanical and herbicidal maintenance treatments on vegetation and wildlife on a right-of-way (ROW). Small mammals are important wildlife species on a ROW by consuming tree seeds, thereby reducing invasion of undesirable tree species, and these mammals are important components of a healthy ecosystem. As a follow up to a 2-year study of small mammals conducted 15 years earlier (1989 to 1990) on the State Game Lands 33 ROW, we initiated a 2-year live-trapping study in 2004 on small mammal populations on this ROW. The objectives of our study were to determine relative abundance and species richness (number of species) in six major cover types and in the adjacent forest. One hundred twenty-one individuals of eight species were observed in 2004 and 2005 combined; the most common species was the white-footed mouse (Peromyscus leucopus). One of the most important cover types to small mammals on the ROW was forb-grass, whereas the forest cover type tended to be less diverse in terms of number of mammal species than in cover types on the ROW.

scholarly journals Antinociceptive effect of Pleurotus ostreatus (Oyster Mushroom) Aqueous Extracts in Rattus norvegicus (Albino Rats)

1970 ◽  
Vol 20 (2) ◽  
pp. 483-487
Author(s):  
LF Zitte ◽  
RS Konya
Keyword(s):  
Aqueous Extract ◽  
Rattus Norvegicus ◽  
Pleurotus Ostreatus ◽  
Hot Water ◽  
Oyster Mushroom ◽  
Albino Rats ◽  
Thermal Stimulus ◽  
Aqueous Extracts ◽  
Standard Drug ◽  
Nociceptive Responses

Antinociceptive is reducing sensitivity to painful stimuli for the individual. The objective of this study was to evaluate the antinociceptive potentials of graded doses of Pleurotus ostreatus (Oyster Mushroom) aqueous extract in Rattus norvegicus (Albino Rats) and its chemical pattern by comparing it with a standard drug and a control using the hot water based flick tail test. Thirty five adult rats of both sexes were used for the experiment which, were divided into five groups of seven rats per group. Group one was used as the control (with 1ml normal saline), while groups two, three and four were treated with 100, 200 and 400 mg/kg of Pleurotus ostreatus aqueous extracts and group five treated with 15 mg/kg Aspirin (a standard drug) as positive control. Hot water at 550C was used to determine the nociceptive responses of the animals to detect anti-nociceptive effects of Pleurotus ostreatus extracts as compared to the control in hot water inflicted pain. The results suggested that Pleurotus ostreatus aqueous extract exhibits antinociceptive properties against thermal stimulus at 550C. The diversity of individual animals’ pain tolerance threshold when immersed in hot water was also observed during the experiment. However, the extract indicated a high degree of anti-nociceptive effect at 30, 60, 90 and 120 minutes post treatment period, with a progressively longer threshold time for pain sensitivity. It was also found that at 90 minute period, the control portrayed a relatively short response time.KEY WORDS: Anti-nociceptive, threshold pain, Pleurotus ostreatus, hot water test flick tail.

Habitat selection by two species of small mammals in the Atlantic Forest, Brazil: Comparing results from live trapping and spool-and-line tracking

2010 ◽  
Vol 75 (2) ◽  
pp. 106-114 ◽  
Author(s):  
Jayme Augusto Prevedello ◽  
Renato Garcia Rodrigues ◽  
Emygdio Leite de Araujo Monteiro-Filho
Keyword(s):  
Habitat Selection ◽  
Atlantic Forest ◽  
Small Mammals ◽  
Live Trapping ◽  
Line Tracking

Amplified predation after fire suppresses rodent populations in Australia’s tropical savannas

2015 ◽  
Vol 42 (8) ◽  
pp. 705 ◽  
Author(s):  
Lily Leahy ◽  
Sarah M. Legge ◽  
Katherine Tuft ◽  
Hugh W. McGregor ◽  
Leon A. Barmuta ◽  
...  
Keyword(s):  
Small Mammals ◽  
High Intensity ◽  
Direct Evidence ◽  
Population Decline ◽  
Ground Cover ◽  
Ground Vegetation ◽  
Northern Australia ◽  
Feral Cats ◽  
Live Trapping ◽  
Rodent Populations

Context Changes in abundance following fire are commonly reported for vertebrate species, but the mechanisms causing these changes are rarely tested. Currently, many species of small mammals are declining in the savannas of northern Australia. These declines have been linked to intense and frequent fires in the late dry season; however, why such fires cause declines of small mammals is unknown. Aims We aimed to discover the mechanisms causing decline in abundance of two species of small mammals, the pale field rat, Rattus tunneyi, and the western chestnut mouse, Pseudomys nanus, in response to fire. Candidate mechanisms were (1) direct mortality because of fire itself, (2) mortality after fire because of removal of food by fire, (3) reduced reproductive success, (4) emigration, and (5) increased mortality because of predation following fire. Methods We used live trapping to monitor populations of these two species under the following three experimental fire treatments: high-intensity fire that removed all ground vegetation, low-intensity fire that produced a patchy burn, and an unburnt control. We also radio-tracked 38 R. tunneyi individuals to discover the fates of individual animals. Key results Abundance of both species declined after fire, and especially following the high-intensity burn. There was no support for any of the first four mechanisms of population decline, but mortality owing to predation increased after fire. This was related to loss of ground cover (which was greater in the high-intensity fire treatment), which evidently left animals exposed to predators. Also, local activity of two predators, feral cats and dingoes, increased after the burns, and we found direct evidence of predation by feral cats and snakes. Conclusions Fire in the northern savannas has little direct effect on populations of these small mammals, but it causes declines by amplifying the impacts of predators. These effects are most severe for high-intensity burns that remove a high proportion of vegetation cover. Implications To prevent further declines in northern Australia, fire should be managed in ways that limit the effects of increased predation. This could be achieved by setting cool fires that produce patchy burns, avoiding hot fires, and minimising the total area burnt.

Infection with acanthocephalans increases the vulnerability of Gammarus pulex (Crustacea, Amphipoda) to non-host invertebrate predators

Parasitology ◽  
2008 ◽  
Vol 135 (5) ◽  
pp. 627-632 ◽  
Author(s):  
N. KALDONSKI ◽  
M.-J. PERROT-MINNOT ◽  
S. MOTREUIL ◽  
F. CÉZILLY
Keyword(s):  
Host Species ◽  
Parasite Species ◽  
Parasitic Infection ◽  
Gammarus Pulex ◽  
Intermediate Hosts ◽  
Trophic Transmission ◽  
Orconectes Limosus ◽  
Phenotypic Changes ◽  
Invertebrate Predators ◽  
Infected Prey

SUMMARYPhenotypic alterations induced by parasites in their intermediate hosts often result in enhanced trophic transmission to appropriate final hosts. However, such alterations may also increase the vulnerability of intermediate hosts to predation by non-host species. We studied the influence of both infection with 3 different acanthocephalan parasites (Pomphorhynchus laevis, P. tereticollis, and Polymorphus minutus) and the availability of refuges on the susceptibility of the amphipod Gammarus pulex to predation by 2 non-host predators in microcosms. Only infection with P. laevis increased the vulnerability of amphipods to predation by crayfish, Orconectes limosus. In contrast, in the absence of refuges, the selectivity of water scorpions, Nepa cinerea, for infected prey was significant and did not differ according to parasite species. When a refuge was available for infected prey, however, water scorpion selectivity for infected prey differed between parasite species. Both P. tereticollis- and P. laevis-infected gammarids were more vulnerable than uninfected ones, whereas the reverse was true of P. minutus-infected gammarids. These results suggest that the true consequences of phenotypic changes associated with parasitic infection in terms of increased trophic transmission of parasites deserve further assessment.

scholarly journals Modified live traps increase capture success of semifossorial voles in Alpine meadows

Mammalia ◽  
2020 ◽  
Vol 84 (4) ◽  
pp. 357-360 ◽  
Author(s):  
Emiliano Mori ◽  
Claudia Allegrini ◽  
Sandro Bertolino
Keyword(s):  
Small Mammals ◽  
Linear Structures ◽  
Alpine Meadows ◽  
Capture Success ◽  
Live Trapping

AbstractLive-trapping of rodents is facilitated by their thigmotaxis (i.e. the tendency to walk along linear structures of the habitat). However, in open habitats, such as meadows and prairies, where linear structures (e.g. rocks and fallen branches) are generally absent and where densities are likely to be low, capturing rodents is often very demanding or ineffective. This applies especially to semifossorial small mammals. Therefore, we developed a technique to increase the capture success of these rodents in Alpine meadows. We applied a box in Tetrapak® with the perforated floor at the opening of Sherman traps. Semifossorial voles (Microtus spp.), leaving their burrows, would remain in a confined status, in the dark within the Tetrapak®, being forced to enter the trap or to go back in the tunnel. Sherman traps modified with Tetrapak® were positioned immediately upon active burrows, alternating with the same number of unmodified traps. Then, we compared the number of captures with and without this modification. Two trapping sessions were carried out, for 3 days/site each, in eight sites (totally 2784 trap-days). Overall, 55 semifossorial voles were trapped; 41 (74.6%) were caught in modified traps, showing that they increase the capture success of semifossorial voles in Alpine meadows.

A comparison of the effectiveness of camera trapping and live trapping for sampling terrestrial small-mammal communities

2010 ◽  
Vol 37 (6) ◽  
pp. 456 ◽  
Author(s):  
Natasha De Bondi ◽  
John G. White ◽  
Mike Stevens ◽  
Raylene Cooke
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
National Park ◽  
Cost Effective ◽  
Camera Trapping ◽  
Terrestrial Mammals ◽  
Live Trapping ◽  
Spatial Coverage ◽  
Presence Data ◽  
The Cost

Context. There is an increasing reliance on the use of camera-trap technologies for surveys of medium to large terrestrial mammals. Camera trapping may, however, also have significant applications for broad-scale surveys of small mammals. Aims. The present study aims to compare results from camera-trapping surveys to those of the more traditional live-trapping techniques. Specifically, it aims to test the effectiveness of the techniques for detecting species, and the cost effectiveness of both approaches. Methods. Surveys were conducted across 36 sites in the Grampians National Park, Victoria, Australia, between April and July 2009. At each site, independent surveys were conducted for small mammals by using a combination of Elliot and cage trapping, then camera trapping. Results for the two different approaches were compared for both their ability to generate small-mammal presence data and their cost effectiveness. Key results. Camera-trapping surveys of 36 sites in the Grampians National Park compared favourably with those of live-trapping surveys. Similar species were detected across the sites, and camera trapping was a considerably more cost effective than live trapping. Conclusions. Camera-trapping surveys of small terrestrial mammals may provide a new and cost-effective technique for surveying terrestrial small mammals. This is particularly the case when presence data are the main requirement of the survey, with no requirement to capture and tag animals. Implications. Given the cost-effective nature of camera trapping, there is potential to use this approach to increase the level of replication and spatial coverage of small-mammal surveys. Improving the replication and spatial coverage of studies has the potential to significantly increase the scope of research questions that can be asked, thus providing the potential to improve wildlife management.

scholarly journals Comparison of analgesic activities of aconitine in different mice pain models

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249276
Author(s):  
Jianhua Deng ◽  
Jiada Han ◽  
Jiahao Chen ◽  
Yanmin Zhang ◽  
Qiuju Huang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Visceral Pain ◽  
Thermal Stimulus ◽  
Diterpenoid Alkaloids ◽  
Hot Plate ◽  
Pain Model ◽  
Analgesic Effects ◽  
Pain Models ◽  
Nociceptive Responses ◽  
Analgesic Activities

Aconitine (AC) is the primary bioactive and secondary metabolite alkaloidin of Aconitum species which is accounted for more than 60% of the total diester-diterpenoid alkaloids in Aconite. To evaluate the analgesic effects of AC, 4 different pain models including hot plate assay, acetic acid writhing assay, formalin and CFA induced pain models were adopted in this study. In hot plate experiment, AC treatment at concentration of 0.3 mg/kg and 0.9 mg/kg improved the pain thresholds of mice similar to the positive drug aspirin at the concentration of 200 mg/kg (17.12% and 20.27% VS 19.21%). In acetic acid writhing experiment, AC significantly reduced the number of mice writhing events caused by acetic acid, and the inhibition rates were 68% and 76%. These results demonstrated that AC treatment revealed significant analgesic effects in both acute thermal stimulus pain model and chemically-induced visceral pain model. The biphasic nociceptive responses induced by formalin were significantly inhibited after AC treatment for 1h or 2h. The inhibition rates were 33.23% and 20.25% of AC treatment for 1h at 0.3 mg/kg and 0.9 mg/kg in phase I. In phase II, the inhibition rates of AC and aspirin were 36.08%, 32.48% and 48.82% respectively, which means AC showed similar analgesic effect to non-steroidal anti-inflammatory compounds. In the chronic CFA-induced nociception model, AC treatment also improved mice pain threshold to 131.33% at 0.3 mg/kg, which was similar to aspirin group (152.03%). Above all, our results verified that AC had obviously analgesic effects in different mice pain models.

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