Cage Traps Research Articles

Methods for live-trapping beaver (Castor spp.)

Effective live-trapping of beaver (Castor spp.) has been and will continue to be necessary for introductions, re-introductions, translocation for the preservation of populations, removal of nuisance beaver, and to obtain animals for fur breeding, zoological gardens and research. The aim of this study was therefore to review the existing knowledge about live-trapping through a literature study, contact with individuals involved in live-trapping, and personal experience. Before starting live-trapping, the area used by the beaver should be determined by careful reconnaissance. Beaver are usually captured either in unbaited traps placed at sites frequently visited by beaver, or in traps baited with castoreum or an aspen twig. Human scent on traps and around the trap site may be reduced by adding mud, water or scent. Usually Bailey or Hancock traps are used for live-trapping beaver. The Hancock trap is preferable because of its greater catch efficiency and versatility. Other traps reviewed are the Breathe Easy trap, Scheffer-Couch trap and different types of cage traps. Other methods used for live-trapping of beaver are snares (often considered highly effective), the Byelorussian trapping method, nets and seines, landing nets, pits and enclosures. Capture methods involving the destruction of lodges/dens and dams have often been employed in the past. Such methods require special permission in most countries and are usually not to be recommended. The Eurasian beaver (C. fiber Linnaeus, 1758) is reportedly more difficult to live-trap than its North American counterpart (C. canadensis Kuhl, 1820). New, effective methods for live-trapping of beaver also need to be developed.

Evaluation of the effects of multiple capture methods and immobilization drugs on mountain lion welfare

AbstractUsing a dataset of 591 capture events between 2001–2019 in California, USA, we examined the impact of capture methods and immobilization drugs on mountain lion (Puma concolor) welfare. The 3 methods used to capture mountain lions were cage traps, trained hounds, and cable restraints. The drugs used to immobilize mountain lions were either tiletamine/zolazepam (Telazol®), ketamine/medetomidine, or ketamine/xylazine. Mortality occurred in 1.4% of captures, with only one mortality out of 310 captures occurring since 2012. We used a logistic regression framework to compare morbidity and vital parameters of mountain lions among the different capture methods and immobilization drugs used. Vomiting (a risk factor for developing aspiration pneumonia) was the most common severe risk factor associated with cage trapping and was only seen with the use of ketamine/medetomidine or ketamine/xylazine. Morbidity scores were not well predicted by any of the variables we accounted for. Animals immobilized with Telazol® were more likely to experience abnormal heart and respiratory rates, as well as high body temperatures, than those immobilized with the other two combinations. Although there are risks associated with each of the capture methods and drug combinations commonly used in mountain lion captures in California, our analyses demonstrated they are all relatively safe when following appropriate animal welfare practices. Our analyses suggested that unaccounted for factors are equally or more important in explaining injury and physiological abnormality rates, and we urge that agencies train personnel in best practices and conservative decision‐making in order to assure that the welfare of the animal takes precedence over collaring. We suggest training on how to choose between several capture techniques, immobilization drugs and monitoring methods and how to reduce both detrimental effects to mountain lions and danger to humans.

Remotely triggered door and real‐time monitoring for bear cage traps

AbstractWe modified the bear cage trap with a low‐cost remotely triggered trap door and fitted the trap with a motion activated camera that relayed bear captures to researchers in real time. We built 4 modified bear cage traps and used them to capture free‐ranging American black bears (Ursus americanus) during summer 2020 on MPG Ranch in western Montana, USA. Lacking data on bear confinement time in traps from previous studies, we compared the amount of time that bears were confined in our modified traps with estimated confinement time had the same bears in our study been captured in traditional traps that were physically checked once daily at 0900, once daily at 1200, or twice daily at 0900 and 1600. We captured bears 30 times during 195 trap nights. The camera system relayed photos of all captures in real time and the remotely triggered door release was 100% successful. When we evaluated all bear captures and recaptures (n = 30), mean bear confinement time in our modified traps (4.92 hrs) was significantly lower than estimated mean confinement time had the same bears been captured in traditional traps that were checked once daily at 0900 (14.95 hrs), once daily at 1200 (10.73 hrs), or twice daily at 0900 and 1600 (7.01 hrs). For bears that were recaptured during regular trap monitoring hours (0700–1800) and remotely released without immobilization (n = 12), mean confinement time in our modified traps was <1 hr. By remotely monitoring traps, we saved an estimated US $6,580 or $13,624 in gas and staff hours during 3 months of trapping, had we physically checked traps once or twice daily, respectively. Our modified traps minimized animal confinement time, eliminated unnecessary animal immobilizations, and helped us maximize time and resource efficiencies. Our findings are relevant to bear research and management, and the technology we used can be adapted for trapping other wildlife species.

Live capture and handling of Taiwanese leopard cats Prionailurus bengalensis: an evaluation of trap designs and capture protocol

Behavioural and ecological studies often require capture and handling of animals for marking or collaring. Cage traps, in various designs, are commonly used for live‐capture of small mammals. Apart from costs and practicality, trap designs need to balance trap success and safety for the trapped animal. Inevitably, trapping and handling causes stress for the animals involved and can even result in injury or mortality. To optimise trap methods, it is important to share experiences. In this study, we describe our trapping and handling protocol for leopard cat, an elusive small felid which can be challenging to trap. We determine which factors influence trap success and compare three custom made cage trap designs: aviary‐, box‐ and side‐traps. We found that trap chance was affected by trap design, location and seasonality but, despite being causes of leopard cat mortality, not by human or domestic dog presence. The side‐trap provided the best tradeoff between trap success and safety, and was economic and easy to handle. Sacrificing live‐bait was unnecessary to successfully trap leopard cats. More male than female leopard cats visited the traps, resulting in a sex‐bias in trapped individuals. Due to a long response time, especially when continuous trap monitoring was absent, the time between leopard cat capture and release was > 10 h (mean ± SE = 16:18 ± 01:57 h). We therefore recommend to always use remote continuous monitoring devices when trapping animals. Although not related to drug dosage, recovery time was negatively related to the distance leopard cats moved after release, whereas total time between capture and release was not. To minimize exposure to human and domestic dog related threats, we released leopard cats after nightfall within their natural 18:00–06:00 h activity time, and only released individuals once fully responsive, which took > 4 h.

Assessing methods to live-capture wild boars (Sus scrofa) in urban and peri-urban environments

BackgroundWild boar (Sus scrofa) populations are increasing worldwide and invading urban areas. Live-capture can improve the management of this challenge, maximising efficiency, allowing scientific studies and potentially improving animal welfare....

The Efficiency of Live-Capture Traps for the Study of Red Fox (Vulpes vulpes) Cubs: A Three-Year Study in Poland.

Simple SummaryWild canids may be captured for a variety of purposes, including, for example, scientific research, conservation or relocation to new sites. The use of conventional live-capture traps (also referred to as cage traps), which involve safe trapping techniques, may be limited by the age of the target animal, landscape structure, proximity to areas intensively used by people and regulations at the national or regional level. Live-trapping with cage traps is the only legal method for capturing juvenile red foxes in Poland. However, little is known about the factors that can affect capture efficiency of these trapping devices. In this research, we developed standard operating procedures (SOPs) for the capture of fox cubs using cage traps and camera traps. We also identified factors that may facilitate or hamper the success of cage traps. The selectivity (total number of trapped red fox cubs per total number of trapped animals) of live-capture traps (91.4%) and the probability of capturing one cub per night (70.2%) were high. In the vicinity of human settlements, fewer cubs explored and entered cage traps. Capture efficiency was also affected by the weather, i.e., it increased in poor weather conditions (e.g., during rain, thunderstorms or ground frost). None of the trapped animals were injured. Live-trapping with cage traps can be an effective and safe alternative to other devices used to trap juvenile foxes. However, capture-efficiency is affected by trappers’ experience and a range of factors including weather conditions and distance to human settlements.Safe and efficient techniques for the live capture of carnivores are limited. In this study, we identified some of the factors that could affect the success of capturing red fox cubs with live capture traps (also known as cage traps). During a three-year period, we analysed 32 captures of 25 fox cubs (1.3 captures/fox). We assessed the impact of the following factors: sex of animals, month of trapping, weather conditions recorded for each trap-night, the willingness of cubs to explore and enter cage traps, the researchers’ activity around den complexes before trapping and distances to the nearest village or farm. The overall trap rate (32 captures, including recaptured cubs) and the trap rate for individual cubs (25 captures) was 11.2 cubs/100 trap-nights and 8.7/100 trap-nights, respectively. Animals other than foxes were captured only three times, thus the selectivity of the cage-trapping method was high (32/35 = 91.4%). The probability of capturing one cub per night was 70.2% (32 cubs/47 nights). Cubs inhabiting dens in the vicinity of human settlements were less likely to explore and enter traps. Vixens were more likely to relocate their litters if the activity of the staff setting the traps was intense at the trapping site. The success of trapping was higher during poor weather as, for example, during rain or thunderstorms. None of the trapped animals suffered any injuries. Whereas cage trapping can be an effective and safe capture method for juvenile foxes, capture efficiency is affected by the experience of the trappers and a range of other factors including weather and distance to human settlements.

APPLICATION OF TRAP BARRIER SYSTEM COMBINED WITH CAGE TRAP FOR CONTROLLING RATS IN RICE FIELD

Rice-field rat is a main pest of rice. Yield reduction caused by rat is quite high, because rats attack rice plant at all stages. One of the efforts applied to control rats is by using Trap Barrier System combined with cage trap. The objective of this research was to identify species of rat attacking rice plants and investigate the presence of rat by their footprints. The experiment was conducted in Jalur 6 Village Sumber Mulya, Sub-district Muara Telang, District Banyuasin, South Sumatra. One hectare of farmer’s rice field, divided into 3 sub-plot. Each sub-plot was planted with variety paddy of Inpari 22 (sub-plot A), Inpari 33 (sub-plot B), and Inpari 43 (sub-plot C). The number of cage traps was 6 traps per sub-plot. Observations were made 7 times, with an interval of 10 days. Results showed species of trapped rats in the research area was Rattus argentiventer, in which number of males was higher than females. Morphologically, the size of males were bigger than female. Number of footprints did not reperesentative the number of trapped rats. Inpari 43 variety was more preferred by rats because damage intensity was the highest than other two rice varieties.

Response of Wild Boars (Sus scrofa) to Two Attractants, and Use of Cage Traps to Capture Wild Boars in Korea

Response of Wild Boars (Sus scrofa) to Two Attractants, and Use of Cage Traps to Capture Wild Boars in Korea

Assessment of the role of small mammals in the transmission cycle of tegumentary leishmaniasis and first report of natural infection with Leishmania braziliensis in two sigmodontines in northeastern Argentina.

To contribute to the knowledge of the role of small mammals in the transmission cycle of tegumentary leishmaniasis caused by Leishmania braziliensis, we studied the small mammal community and its temporal and spatial association with phlebotominae, as well as small mammal infection by Leishmania spp. by PCR-RFLP analyses in an endemic area of northeastern Argentina. Ten small mammal samplings were conducted (2007-2009, 7506 Sherman trap nights and 422 cage trap nights). In two of these samplings, 16 capture stations each one consisting of a CDC light trap to capture phlebotominae, two to four Sherman traps and two cage traps were placed. We found co-occurrence of phlebotominae and small mammal captures in four stations, which were all the stations with small mammal captures and yielded 97% (2295 specimens, including 21 gravid females) of the total phlebotominae captures, suggesting that small mammals may provide a potential source of blood for phlebotominae females. One Didelphis albiventris and two Rattus rattus were associated with high captures of Nyssomyia whitmani, vector of L. braziliensis in the study area. The PCR-RFLP analyses confirm the presence of L. braziliensis in two sigmodontine small mammals (Akodon sp. and Euryoryzomys russatus) for the first time in Argentina, to our knowledge.

Entering and exiting behaviour of the phlebotomine sand fly Lutzomyia longiflocosa (Diptera: Psychodidae) in rural houses of the sub-Andean region of Colombia.

The present study identified the entering and exiting sites for Lutzomyia longiflocosa in rural houses of the sub-Andean region in Colombia. Entering sites were identified with sticky traps set up outside the bedrooms, around the eave openings, and with cage traps enclosing the slits in the doors and windows inside the bedrooms. Exiting sites were identified by releasing groups of females indoors. These females were blood fed and marked with fluorescent powders. Females were recaptured with the trap placement described above but set up on the opposite sides of the openings. In the entering experiment, a significantly higher number of females were captured in the sticky traps at the zone nearest the eave openings (n = 142) than those captured in the other zones of the trap (n = 52); similarly, a higher number of females were captured on the front side of the house (n = 105) than at the rear side (n = 37). Only two females were collected in the cage trap. In the exiting experiment, at the ceiling, the highest percentage (86.2%) of females was recaptured with sticky traps nearest the eave openings and on the front side of the house (70.0%). Seven females were collected in the cage trap. Lu. longiflocosa entered and exited houses primarily through the eave openings in a non-random pattern in relation to the sides of the house.

Hematologic and biochemical reference intervals for Wild Boar (Sus scrofa) captured by cage trap

Establishing reference intervals (RI) for hematologic and biochemical variables in wild animals presents great challenges because capture stress or anesthesia during sampling can affect blood variables. The aims of this study were to establish RI for hematologic and blood biochemistry variables for Wild Boar (Sus scrofa) caught using cage traps, and provide information on the studied variables for different age groups. Blood samples were obtained from 89 Wild Boars captured by cage trap between 2005 and 2013 in northeastern Spain. Piglets were handled without anesthesia, while juvenile and adult animals were anesthetized using a combination of tiletamine and zolazepam. Blood samples were collected from the anterior vena cava and were placed into plain and EDTA tubes. Thirteen hematologic and 21 biochemical variables were determined. Reference intervals for piglets and juvenile and adult groups were determined, and differences between these groups were statistically analyzed. Adults had higher HGB, PCV, MCH, MCHC, neutrophil count, and total protein, albumin, creatinine, and chloride concentrations than juveniles; in contrast, juveniles had higher values for lymphocyte count, cholesterol concentration, and ALP activity. Reference intervals determined in this study provide a baseline for interpreting hematologic and biochemical results in Wild Boar at different age stages, and contribute to optimization of the management of this species.

Short-term welfare implications of capture-mark-recapture trapping of medium-sized mammals: the brushtail possum (Trichosurus vulpecula) as a case study

AbstractCapture-mark-recapture (CMR) repeated at intervals is a commonly used method of population estimation of mammals. Most guidelines for the use of wild mammals recommend adequate measures to ensure a captured animal has food and water available, as needed, until it is released. Small mammals are often highlighted as needing special care, but recommendations are either less clear or absent for medium- and large-sized mammals. We therefore examined the short-term welfare implications of CMR trapping of medium-sized mammals, using the marsupial, brushtail possum (Trichosurus vulpecula) as a case study. Possums were caught in cage traps baited withcirca30 g of food and set for three consecutive days at monthly intervals. Timing devices on the traps measured when traps were sprung. Possums were confined in traps for, on average, 89% of each night they were trapped, plus a further 2-6 h between sunrise and the actual time of release from the traps. They lost 3-8% of their bodyweight on average, depending on the number of captures in a trapping session. A recently developed framework for humaneness assessment, based on five welfare domains, gave an overall welfare impact of mild-moderate for cage trapping of possums. The short-term solutions to these welfare impacts would be, at a minimum, to provide trapped possums with adequate additional food and water, and minimise their time spent in the traps. Guidelines for the use of wild animals in research and management could also be more prescriptive regarding the provision of food and water in studies of medium-sized mammals that involve repeated capture.

Effect of Trapping Method on Leukocyte Profiles of Black-Chested Spiny-Tailed Iguanas (Ctenosaura melanosterna): Implications for Zoologists in the Field

When wild animals are captured for zoological research, researchers must choose a method of capture, and often this can be some form of passive, baited cage trap, or a direct capture with nets or nooses. If information on basal levels of circulating leukocytes is a goal, these two methods may provide different information, since recent evidence indicates that animals that enter cage traps experience stress, and, elevated stress hormones are known to alter leukocyte numbers in circulation by lowering lymphocyte and raising heterophil numbers. We tested this idea using a study of Black-chested Spiny-tailed iguanas (Ctenosaura melanosterna), which were captured using cage traps () and noose (). Based on cell counts made from blood smears, iguanas caught with cage traps had significantly greater relative and absolute numbers of heterophils and higher heterophil-lymphocyte (H-L) ratios than those captured by noose. Cage-trapped animals also had a nonsignificant reduction in lymphocyte numbers. Similar trends were observed in animals captured with both methods. These patterns are consistent with the effects of stress hormones on white blood cell distributions and indicate that caution must be taken in interpreting leukocyte data from studies of wild animals captured with cage traps.

Haematological and biochemical responses of red foxes(Vulpes vulpes)to different capture methods and shooting

AbstractThis paper sought to determine whether common haematology and blood biochemistry values might assist in determining the relative welfare outcomes arising from the capture of red foxes(Vulpes vulpes)by treadle-snares, Victor Soft Catch® (VSC) #3 traps, cage traps, netting and sampling by shooting. Compared to all other capture methods and shooting, treadle-snared foxes had significantly higher mean albumin (ALB), creatine kinase (CK), red cell count (RCC), neutrophil to lymphocyte (N:L) ratio, sodium (Na), total protein (TP), white cell counts (WCC) and lower glucose (Gl). Treadle-snares were also associated with higher chloride (Cl), haemoglobin (Hb) and packed cell volume (PCV) than cage trapping and netting. Treadle-snares produced indicators of possible muscle damage, exertion and dehydration compared to cage and VSC traps. Cage trapping and netting produced lower indications of exertion, possible muscle damage and dehydration compared to both treadle-snares and VSC traps. These data do not support previous conclusions that due to similar injury scores, treadle-snares and VSC traps produced equivalent welfare outcomes. In restraining traps, injury and death sustained during capture are end-points of poor trapping welfare. Monitoring stress using physiological indicators allows the comparison of the relative potential for different capture techniques to cause pathological and pre-pathological states. As the response of physiological indicators to stress is not independent of time, accurate data on the duration of captivity and the relative intensity of struggling behaviour should be routinely collected when assessing the comparative humaneness of different trap devices.

Structure and Artificial Baits for Cage Traps to Capture Freshwater Palaemonid Shrimps

Structure and Artificial Baits for Cage Traps to Capture Freshwater Palaemonid Shrimps

Trapping small mammals for research and management: how many die and why?

Trapping programs are an essential part of mammal conservation and management, but trapping carries a risk of death for the study animals. Little information is available on mortality levels and its potential to influence studies. We examined the mortality levels recorded during 68 wildlife surveys within New South Wales, recording mortality rates associated with Elliott aluminium box and wire cage trapping for terrestrial mammals and harp traps for bats. We noted 232 deaths from 13623 small ground mammal captures in box traps, one death from 459 mammal captures in wire cage traps, and 44 deaths from 12,274 bat captures in harp traps. Mortality ranged from 0-13.3%, 0-0.6% and 0-9.1% of captures for box, cage and harp traps, respectively. No deaths were reported for 47% of surveys. Antechinus spp. comprised almost 95% of all trap deaths. Thirteen surveys provided detailed information for small ground mammal trapping, recording 111 deaths from 3651 small mammal captures. Box trap mortality in these surveys ranged from 0-7.5%, deaths being attributed to cold temperatures (generally winter) and multiple captures of individuals. Harp trap mortality stemmed from overheating, overcrowding and predation. Post-capture handling also contributed to mortality. No specific level of trap death can be ?expected? during a study as circumstances vary, but all efforts should be made to minimise the risk of deaths. This study found that mortality above 4% is unusual, resulting mainly from one-off ?extreme? mortality events. Minimising unnecessary recaptures and avoiding weather extremes should reduce mortality of small mammals during trapping studies, but will not prevent all deaths.

Temporal Distribution of Aster Leafhopper Sex Ratios and Spatial Pattern of Aster Yellows Phytoplasma Disease in Lettuce

The aster leafhopper, Macrosteles quadrilineatus Forbes, is an important pest of fresh market vegetable crops as the primary vector of the aster yellows (AY) phytoplasma. Two sampling methods, sticky trapping and inverted cage trapping, were used to monitor male and female leafhopper populations over three growing seasons in leaf lettuce fields in Ohio. Captures by one sampling method could not be used to estimate captures by the other method, because sticky traps captured significantly more male leafhoppers and cage traps captured significantly more females. The proportion of females collected in cage traps decreased significantly in individual plantings as lettuce matured and also over the course of the season in one of 2 yr of sampling by using both techniques. Subsamples of captured leafhoppers were tested for AY phytoplasma infection by using a polymerase chain reaction (PCR) assay. In one year of our study, more male than female leafhoppers were infected with AY phytoplasma. Because the field distribution of insect-vectored diseases can reveal information about vector movement, as well as vector identity, spatial analysis was performed. Analyses indicated the distribution of symptomatic AY phytoplasma-infected lettuce plants was significantly clustered and followed a beta-binomial distribution. Our data suggest that females may be responsible for at least the early season inoculation of clustered symptomatic lettuce plants.

Cage trap modifications that enhance the capture success of raccoons

Raccoons (Procyon lotor) often are considered a nuisance species in suburban and urban areas, and thus, must be removed. However, raccoons are capable of removing bait from cage traps without being captured and appear to avoid baits that are infested with fire ants (Solenopsis invicta). We modified Tomahawk® cage traps with an extended metal floor that acted as a trip device, hardware cloth wrapped around the back half of traps to reduce the potential of raccoons obtaining bait without entering the traps, and developed a hook upon which to place baits to minimize the probability of fire ants locating the bait. We then compared the proportion of raccoon captures, baits missing, and baits with fire ants between cage traps with and without the modified floor and bait hook. Twenty-five raccoons were caught, 80 baits were stolen, and 108 baits were infested with fire ants during 432 trap-nights. A greater proportion of raccoons were caught in (G=11.7, 3 df, P<0.01) and fewer baits were stolen from (G=11.0, 3 df, P<0.02) cage traps modified with the extended metal floor than without the modification. Traps equipped with hooks were minimally affected by fire ants present on the baits (i.e., 8 of 216 baits; 3.7%), which was much less (G=59.0, 1 df, P<0.0001) than traps without bait hooks (46.3%). Our modifications to cage traps enhanced the capture success of raccoons and should be considered if live-trapping of raccoons is required, especially in areas where fire ants are problematic.

Analysis of cage trapping for rabbit control on a Scottish hill farm

Rabbits were caught in wire mesh cage traps baited with carrot in a 10 ha field on a Scottish hill farm. The area used by the rabbits coming into the field was determined by the location of radio-collared individuals. In March the field was trapped out for 8 nights. The sample of rabbits obtained was analysed for sex, age, body and breeding condition to see if trapping was selecting part of the population. It was found that there was a bias towards males and non-pregnant females: of 185 rabbits caught in 32 traps, 62% were males. Assuming a 1:1 sex ratio in the population, the density of adult rabbits was estimated to be 15.9 ha −1. The results are discussed in relation to the potential effectiveness of cage trapping for rabbit control.