Trap Success Research Articles

Comparing Methods of Detecting an Elusive Dasyurid Marsupial, the Threatened Julia Creek Dunnart (Sminthopsis douglasi), in Central Western Queensland, Australia.

The Julia Creek dunnart, Sminthopsis douglasi, is a small, threatened carnivorous marsupial occurring in scattered populations in the grasslands of central and northwestern Queensland, Australia. The distribution of the species is largely unknown due to sporadic survey efforts and its historically low detection using traditional live trapping methods. There is an urgent need to determine the best methods of detection to optimise survey methodologies and more effectively manage species conservation efforts. In this study, we compared the effectiveness of live (Elliott) traps, baited white flash camera traps and thermal imagery binocular surveying for detecting S. douglasi. We deployed 40 white flash camera traps at two sites in Bladensburg National Park (south of Winton), where the species is known to occur, for three consecutive periods between June and November 2022. Four comparative sessions of live trapping were undertaken between April and August 2022 at the same locations. During the live trapping periods, a total of 12 nights of surveying were conducted with thermal imagery binoculars in a preliminary assessment of the technique. The total live trapping effort was 3600 trap nights (approximately 700 trap nights per site in each trapping event). Live trapping resulted in 12 detections of individual S. douglasi from 19 total captures. The highest trap success on a given trapping session was 1.71%, and overall trap success from both sites across all sessions was 0.53%. In comparison, baited camera traps (deployed facing the ground at 70 cm range) took 1,269,884 images over 5383 trap nights. There were 11 confirmed images of S. douglasi, on three individual occasions, which represented 2.10% of all small mammal captures and just 0.0009% of the total images. Four species of small mammals were detected using camera traps, whereas live trapping detected only two species. No small mammals were detected on any of the 12 thermal binocular surveys. Overall, our study highlights the comparative high utility of traditional live trapping for detecting S. douglasi. This research provides a framework for ongoing monitoring of the Bladensburg National Park population. It will be more broadly beneficial for informing the best detection techniques of S. douglasi in ongoing work investigating the overall distribution of the species. Similar studies assessing multiple detection methods for small terrestrial mammals have shown an advantage of white flash camera traps compared to other traditional detection techniques. Our contrasting results serve as a reminder that the utility of different techniques for detecting small mammals is best assessed on a species-by-species basis.

Relationship Factors of Prevention of Leptospirosis Disease Prevention of Rat Rate in Tandang Village, Semarang City

Based on data from the Semarang City Health Office, the highest rat population in Tembalang District in 2019 was in Tandang Village, with 164 rats caught. In addition, in 2018 there were 4 cases of Leptospirosis in Tandang Village and Leptospirosis was the highest infectious disease in Tandang Village, Tembalang District, Semarang City. This study aims to determine the relationship between the behavioral factors of leptospirosis disease prevention on rat density in Tandang Village, Semarang City. This study is a cross sectional study with a total sample of 64 respondents (RW 03 Tandang Village, Semarang City). The results of the analysis showed that the relative density of rats (trap success) in Tandang village was 28.1% and it was categorized as dense (> 7%) and showed that there was no relationship between knowledge of rat density (α = 0.05. P = 0.068), community attitudes. In the prevention of leptospirosis on rat density (α = 0.05. p = 0.07), there was a relationship between leptospirosis prevention behavior and rat density (α = p = 0.00). Conclusion: There is no relationship between knowledge and attitude in the prevention of leptospirosis on rat density. There is a relationship between leptospirosis prevention practices and rat density in Tandang Village, Semarang City.

Diversity, abundance and habitat association of small mammals in Maze National Park, Ethiopia

We investigated species composition, relative abundance, habitat association and density of small mammals in Maze National Park, Ethiopia. Data were collected using the capture-mark-recapture technique in three representative habitat types (grassland, bushland and riverine forest) from November 2021 to August 2022. Descriptive statistics and indices for diversity and evenness were used to analyse the data. A total of 679 rodents and insectivores were collected during a span of 2 646 trap nights. Of these, 534 (76.64%) individuals were newly captured, while 145 (23.36%) were recaptures. Overall trap success was 20.18%. Five species of rodents were captured: four from the family Muridae (Mastomys natalensis, Arvicanthis niloticus, Rattus rattus and Lemniscomys macculus) and one (Xerus rutilus) from the family Sciuridae; and one insectivore species (Elephantulus rufescens) from the family Macroscelididae. Mastomys natalensis (178; 33.3%) was the most abundant, while X. rutilus (1; 0.2%) and E. rufescens (1; 0.2%) were the least abundant. Small mammal species varied significantly with habitat types (χ2 = 6.101, df = 2, p ≤ 0.05), with the highest count in the bushland habitat (197; 36.89 %) and the lowest in riverine forest (152; 28.46%). The bushland and riverine forest habitats supported the highest (H’ = 1.04) and the lowest (H’ = 0.506) diversity of small mammal species, respectively. A relatively high number of small mammal species were caught during the wet season (n = 336) compared to the dry season (n = 198). Future studies using more trapping grids covering additional habitat types and genetic analyses for small mammal species confirmation are necessary for a better understanding of the Park’s small mammal fauna.

Evaluation of Rat Density and the Associated Factors in Leptospirosis Endemic Areas: The First Report on the Use of BI-Index

Introduction: Leptospirosis is a health problem in tropical countries where rats serve as the reservoir of Leptospira contamination. Previous investigations implementing the Bi-index to assess rat density in Leptospirosis endemic areas are highly limited. This study aimed to use the Bi-index in monitoring rat density and the associated factors in urban Leptospirosis endemic areas. Methods: Four endemic areas in Semarang City were selected as the study sites based on Leptospirosis data in Puskesmas Gayamsari. Live traps were positioned in one case house and 39-49 neighboring houses in a 100m radius, on three consecutive days. Trapped rats were collected for species identification, morphometrics evaluation, and calculation of Bi-index and rat indices, while environmental parameters were obtained through observation. Results and Discussion: 67.1% of participants were women, private employees, and aged 17-55, while trap success ranged from 2.5-26.5% with the Bi, diversity, dominance, and evenness indices of 0.02-0.32, 0.94-1.09, 0.36-0.44, and 0.79-0.96, respectively. Trapped species included Rattus norvegicus, Rattus tanezumi, and Mus musculus with proportions of 61.3%, 34.1%, and 4.7%, respectively. The presence of rats was associated with closeness to the river containing stagnant water, frequent flooding, water entering houses during floods, open trash bins, and rubbish bins around the houses. The high rat density, dominant species, and correlated environmental conditions are strategic targets in controlling Leptospirosis in Semarang City. Conclusion: The rat density (dominated by R. norvegicus) in Semarang City was correlated with water drainage and garbage management, hence further investigation was recommended to determine Leptospira bacterial infection in rodents.

Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa

ABSTRACT The Natal multimammate mouse (Mastomys natalensis) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10–30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74–92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.

Higher rat abundance in greener urban areas

Urban greening has become an increasingly popular strategy to improve urban life and human health. However, there are indications that the presence and extent of urban greenness may increase the abundance of wild rats. Therefore, we investigated which environmental and socio-economic factors are associated with rat abundance, with a focus on factors related to urban greenness. We systematically trapped rats (222 Rattus norvegicus and 5 Rattus rattus) in parks and residential areas in three cities in the Netherlands. We modelled the relative abundance of rats against various environmental and socio-economic variables. In addition, we compared municipality rat complaint data with our trapping data and analysed trap success over time. We observed positive relationships between the relative abundance of rats and both greenness (NDVI) and different proxies for food resources (restaurants and petting zoos). In addition, there were more municipality rat complaints in residential areas compared to parks, while there was a higher relative abundance of rats in parks. Our findings corroborate that greenness is associated with a higher abundance of wild rats, and that municipality rat complaints may underestimate the abundance of rats in greener urban areas. This study provides new insights on factors affecting relative rat abundance in cities and can guide policy makers and city planners how to minimize rat nuisance in the greener parts of cities. By taking these potential effects of urban greenness on rat abundance into account, measures can be taken that on the one hand maintain the beneficial effects of urban greening, but at the same time reduce the carrying capacity for rats.

Trapping Triatominae Bugs Using Mice-Baited Traps along the Peninsula of Baja California, Mexico.

During an exploratory fieldtrip along the peninsula of Baja California, Mexico, we used mice-baited traps in search of Triatominae, the vectors of Chagas disease. A total of 433 traps were set in five localities following a latitude gradient along the peninsula. Triatominae were caught in rocky ecotopes in two localities. The specimens were identified as Paratriatoma hirsuta in the first locality, and Dipetalogaster maxima in the second, in accordance with the reported distributions of these species. The overall trap success was 3.1%, with an average of 1.3 bugs per positive trap. In the site with most bugs collected, trap success was 26.8%. To the best of our knowledge, this is the first time that mice-baited traps have been used in this geographic area to collect Triatominae bugs. This short report confirms the usefulness of this trapping system when standardized protocols are needed.

Limitations of invasive snake control tools in the context of a new invasion on an island with abundant prey

In October 2020, a new population of invasive brown treesnakes (Boiga irregularis) was discovered on the 33-ha Cocos Island, 2.5 km off the south coast of Guam. Cocos Island is a unique conservation resource, providing refuge for many lizards and birds, including endangered species, which were extirpated from mainland Guam by invasive predators including brown treesnakes. We sought to evaluate the usefulness of toxic baiting with acetaminophen-treated carrion baits and cage trapping, common tools for the control of brown treesnakes on mainland Guam, as potential eradication tools on Cocos Island. We evaluated multiple bait types and bait presentations: on the ground, suspended in the canopy emulating aerial bait applications and in four plastic-tube bait station configurations intended to exclude non-target species. We monitored all baits with time-lapse cameras. Despite improved exclusion of non-targets by bait station design, most baits were quickly removed by non-target species, particularly coconut crabs (Birgus latro) and Mariana monitors (Varanus tsukamotoi). Monitoring of 1,250 baits available for 2,427 bait nights resulted in no observations of brown treesnakes taking any bait. Subsequently, we tested two trap types commonly used on Guam and compared trapping success with live versus dead mouse lures. In 10,553 trap nights using live and dead mouse lures, we only captured one brown treesnake, in a trap with a live mouse lure. These baiting and trapping rates are so low as to be ineffectual for all practical purposes. Concurrent visual searching and hand capture of brown treesnakes during initial rapid response efforts demonstrates that these low baiting and trapping success rates are not a result of low snake density. We make a case for our assumption that the ineffectiveness of these tools on Cocos Island is due to the context of extremely high abundance of preferred live prey, primarily large geckos and birds. Our results have profound conservation ramifications, because any future island invasions by brown treesnakes are likely to occur within similarly prey-rich environments where these baiting and trapping methods might be similarly ineffective.

Practical, effective and safer: Placing traps above ground is an improved capture method for the critically endangered ngwayir (western ringtail possum; Pseudocheirus occidentalis).

The capture of wild-living animals can provide valuable information that is critical in developing and implementing effective conservation actions. These capture procedures, however, often require direct handling of individuals by researchers, and conservationists should constantly seek to improve capture methods so that the impacts on animal welfare are minimised. The ngwayir (western ringtail possum; Pseudocheirus occidentalis) is a critically endangered arboreal marsupial in need of effective conservation. It is, however, not amenable to conventional trapping, leading to the use of methods such as nest robbing and tranquilisation using dart guns or pole syringes, which involve potentially serious animal welfare risks and longer exposure of animals to humans as compared to conventional trapping. In pursuit of an improved capture method, we investigated opportunistically whether placing traps above the ground would increase the capture success rate of the species, using wire cage traps baited with universal bait and fruit. Between 2010 and 2019, we deployed trapping grids in Locke Nature Reserve and adjacent campsites near Busselton, WA, Australia, with traps placed on the ground for 1,985 trap nights and traps placed on horizontal tree branches, fallen trees or fences, 1-2 m above ground for 694 trap nights. With the above ground traps we trapped 82 ngwayirs out of 694 trap nights, 27 in autumn and 55 in spring. We also captured eleven common brushtail possums (Trichosurus vulpecula; 1.6% trap success rate), 12 King's skinks (Egernia kingii; 1.7%) and five black rats (Rattus rattus; 0.7%). Trapping success rate was higher in elevated traps (up to 18.3%) compared to traps on the ground (0.5%) and using fruit as bait increased the trap success rate. These results suggest that using elevated traps baited with fruit is a practical, effective method to capture the ngwayir.

Forest carnivores living on the edge with invasive predators

AbstractThe proliferation of forest edges and invasive predators have been identified as two primary threats to carnivore populations globally. These threats often occur in unison, facilitated by anthropogenic activities (e.g., fragmentation), and together may pose a greater influence than when they occur separately. Targeted conservation actions for forest carnivores, including Madagascar carnivores, have been hindered by a failure to understand the relative contributions of these factors in driving species declines. To fill this gap, we conducted an extensive camera survey along the edge of intact, continuous protected rainforests in eastern Madagascar to evaluate the extent invasive predators and forest edge separately and in combination affect native carnivore space use. We hypothesized that structural vegetation changes at the forest edge interact with invasive predator trap success and occurrence to reduce native carnivore space use near the forest edge and separately have less influence than when combined. In contrast to findings in fragmented and degraded forests of Madagascar, we found hard forest edge and invasive predators alone do not indiscriminately reduce native carnivore space use in continuous intact forest. Instead, we found free‐roaming dogs and cats interact with their surrounding environment (i.e., forest edge) in unique ways that shape species response differently than within interior forest. At the forest edge, vegetational changes of increasing shrub cover and the occurrence of dogs reduce space use of three of four native carnivores. However, we found greater effects of proximity to villages, especially with high invasive predator activity (free‐roaming cats). Ultimately, native carnivores showed variable sensitivities to pressures we examined, providing support for species‐specific management actions to maximize conservation outcomes. We encourage future studies to consider evaluating the magnitude of separate and combined threats to carnivores. In doing so, conservationists can better identify when threats can be managed in isolation and when they require simultaneous mitigation.

Red fox trap success is correlated with piping plover chick survival

AbstractPredation management is an important component of managing species of conservation concern. The piping plover (Charadrius melodus; plover), a disturbance‐dependent and conservation‐reliant shorebird that nests on sandy beaches and barrier islands on the Atlantic Coast, was listed under the United States Endangered Species Act in 1986, with habitat loss and predation stated as key causes of its decline. We evaluated the relationship between a suite of predators and plover chick survival from 2015–2018. We used a camera grid to establish indices of the abundance of 3 known chick predators: red fox (Vulpes vulpes), raccoon (Procyon lotor), and domestic cat. We used camera detections in a survival model to assess potential relationships between predator species detection and plover chick survival. Plover chick survival was negatively related with red fox detection, but not with detection of the other 2 predators. In addition to the correlation with red fox detections, chick survival was negatively related to high plover nesting density. Our results suggest that red foxes were predators of piping plover chicks during our study, likely augmented by other density‐dependent sources of mortality. Targeted predator management could aid in conservation of piping plovers in this system as a short‐term solution, but long‐term recovery plans must also address habitat limitation.

PREVALENCE OF PATHOGENIC Leptospira spp. IN SMALL MAMMAL HOSTS FROM DUNGUN, TERENGGANU

Leptospirosis is a zoonotic disease caused by Leptospira, which is transmitted through infected mammalian species, including small mammals. However, the prevalence of pathogenic Leptospira spp. in small mammals, particularly between different site categories in the eastern part of Peninsular Malaysia, is still underexplored. Therefore, in this study, we aimed to determine the species composition of small mammals and the prevalence of pathogenic Leptospira spp. between different site categories from Dungun, Terengganu. We selected five case sites (leptospirosis cases were recorded) and five control sites (no leptospirosis cases were recorded) in Dungun, Terengganu, based on previous reports by the Ministry of Health (MOH) Malaysia (2016-2020). For three consecutive nights, 100 cage traps were used for each trapping session. In addition, kidney samples from captured individuals were extracted for the Polymerase Chain Reaction (PCR) detection of pathogenic Leptospira spp. Overall, 89 individuals from five species were captured (6.43% trapping success), consisting of Rattus norvegicus (n = 39), Rattus rattus (n = 27), Suncus murinus (n = 11), Rattus exulans (n = 10) and Tupaia glis (n = 2). Out of 89 individuals captured, 14 tested positive with a 15.7% (n = 14/89) prevalence rate. R. norvegicus was the most dominant captured species and had the highest number of infected individuals with pathogenic Leptospira (20.5%, n = 8/39). The statistical analysis revealed that there is a significant difference in pathogenic Leptospira spp. between case and control sites (P < 0.05), with control sites recording higher positive individuals (78.6%, n = 11/14) compared to case sites (21.4%, n = 3/14). However, no significant differences were observed between species and sex (P > 0.05). The results show that the monitoring of leptospirosis cases should not only focus on case areas but also control areas in order to prevent the outbreak of this disease in the future.

Why are antlion larvae rare under the leaf litter? Testing the hypothesis of improper trap maintenance

Abstract Understanding why animals avoid some locations is needed to improve the theory of habitat selection. This is key in semi‐sedentary organisms, such as antlion larvae, because once established they rarely move, and their performance largely depends on local environmental conditions. Antlion larvae are sit‐and‐wait predators that build conical pitfall traps in sandy soils to capture passing prey. They clean constantly their traps, expelling soil, prey carcasses and debris out of the pit to maintain their trapping success. Therefore, we propose that they avoid soils with leaf litter because leaves hinder the maintenance of their pits; a hypothesis that has not yet been tested. We first demonstrated that antlion larvae (Myrmeleon inmaculatus) are rare from soils with leaf litter in a tropical semi‐deciduous forest in Mexico. We then experimentally tested the effect of leaf litter on pit maintenance by adding debris in 90 antlion traps, 45 of which were covered with a leaf, and 45 remained uncovered. Two hours after adding the debris, we recorded its location and quantified the variation in depth and diameter of the pits. Larvae in uncovered traps were twice as effective at cleaning up the debris than larvae in covered traps. Furthermore, in just 2 h, covered traps were on average 21% shallower than control traps, probably because unsuccessful attempts to clean debris caused sand slides to fill the pit partially. Leaf litter seems to hinder the proper maintenance of antlion traps, explaining at least partially, why these animals are rare under leaf litter.

Evidence on the prevalence of emerging and re-emerging tick- and flea-borne rickettsial agents in acute encephalitis syndrome endemic areas of northeast Uttar Pradesh, India.

Outbreaks of acute encephalitis syndrome (AES) with unknown aetiology are reported every year in Gorakhpur district, Uttar Pradesh, India, and Orientia tsutsugamushi, the rickettsial pathogen, responsible for scrub typhus has been attributed as the primary cause of AES problem. However, information on the prevalence of other rickettsial infections is lacking. Hence, this study was carried out to assess any occurrence of tick- and flea-borne rickettsial agents in villages reporting AES cases in this district. In total, 825 peridomestic small mammals were trapped, by setting 9254 Sherman traps in four villages with a trap success rate of 8.9%. The Asian house shrew, Suncus murinus, constituted the predominant animal species (56.2%) and contributed to the maximum number (87.37%) of ectoparasites. In total, 1552 ectoparasites comprising two species of ticks and one species each of flea and louse were retrieved from the trapped rodents/shrews. Rhipicephalus sanguineus, the brown dog tick, was the predominant species retrieved from the trapped rodents/shrews, and the overall infestation rate was 1.75 per animal. In total, 4428 ectoparasites comprising five tick species, three louse species and one flea species were collected from 1798 domestic animals screened. Rhipicephalus microplus was the predominant tick species collected from the domestic animals. The cat flea, Ctenocephalides felis, constituted 1.5% of the total ectoparasites. Of all the ectoparasite samples (5980) from domestic animals and rodents, tested as 1211 pools through real-time PCR assays, 64 pools were positive for 23S rRNA gene of rickettsial agents. The PCR-positive samples were subjected to multi-locus sequence typing (MLST). In BLAST and phylogenetic analysis, the ectoparasites were found to harbour Rickettsia asembonensis (n = 9), Rickettsia conorii (n = 3), Rickettsia massiliae (n = 29) and Candidatus Rickettsia senegalensis (n = 1). A total of 22 pools were detected to have multiple rickettsial agents. The prevalence of fleas and high abundance of tick vectors with natural infections of rickettsial agents indicates the risk of transmission of tick- and flea-borne rickettsial diseases in rural villages of Gorakhpur. Further epidemiological studies are required to confirm the transmission of these agents to humans.

A microfluidic array enabling generation of identical biochemical stimulating signals to trapped biological cells for single-cell dynamics

Microfluidic-based analyses of single-cell dynamics in response to dynamic biochemical signals are emerging as pivotal approaches for investigating the effects of extracellular microenvironmental biochemical factors on cellular structure, function, and behavior. However, current devices often fail to consistently apply identical dynamic biochemical signals to trapped cells. In this study, we introduce a novel radially distributed single-cell trapping microfluidic array, designed to quantitatively and consistently apply identical biochemical stimulating signals to each trapped cell. Numerical simulations were employed to optimize microchannel geometry, enhancing trapping efficiency while minimizing signal distortion. Experimental validation demonstrated the trapping success rate and the single-cell trapping efficiency exceeding 99% and 85%, respectively. The microarray's capability to deliver identical dynamic biochemical stimulating signals, with various waveforms, to each unit was confirmed through fluorescein transport tests. Furthermore, we examined the intracellular calcium dynamics of U-2 OS human osteosarcoma cells in response to dynamic ATP signals, observing both single-peak calcium responses and calcium oscillations, which were modelled by a second-order system with a natural frequency of 1.6 mHz. Overall, our proposed microfluidic array offers a robust and valuable framework for advancing the understanding of single-cell dynamics.

Fluid hunter motivation in Central Africa: Effects on behaviour, bushmeat and income

Abstract Individual motivation for the rural use of common‐pool resources (CPRs) can be fluid, with the line between subsistence and commercial often unclear and in flux. Implications of fluid motivation are understudied yet important for social–ecological systems (SESs), such as bushmeat hunting throughout Central Africa that is essential to local protein/nutrition, income and culture. Making locally informative predictions of multiple SESs nested within a landscape‐scale SES has been historically difficult, but community‐driven participatory approaches provide new kinds and quantities of data, opening previously inaccessible doors for research and governance. We apply hierarchical Bayesian structural equation modelling to a novel dataset of 910 hunts from 111 gun and trap hunters across nine villages in Gabon, generated in a participatory process whereby hunters conducted GPS self‐follows in conjunction with paraecologist surveys of their motivation, behaviour and offtake. We (i) establish the human behaviour driving gun‐hunting and trapping success and predict its effect on offtake across villages and (ii) link fluid motivation of gun hunters to their behaviour, number of animals hunted, biomass yielded and income earned. Gun hunts across villages yielded more animals during the night than the day, and when hunters brought high amounts of ammunition and walked far distances from villages. Gun hunts were less successful when coupled with trapping while per‐hunt success of trapping itself was generally low and difficult to predict. Fluid gun hunters hunted fewer animals when motivated strictly by subsistence, despite no reduction in ammunition brought or distance walked, while offtake from strictly commercial versus mixed motivation was the same. Numbers of animals hunted, biomass and income were tightly linked. We discuss the implications of these results for the ecological sustainability of hunting and participatory forecasting in bushmeat research and policy. Read the free Plain Language Summary for this article on the Journal blog.

Space use by Callosciurus erythraeus in a fragmented landscape

Abstract Tree squirrel species that are successful invaders may modify their behaviour according to the characteristics of the invaded community. We studied the use of space by Callosciurus erythraeus in the main invasion focus established in Argentina, where suitable habitat is highly fragmented and immersed in a rural–urban landscape of the Pampas region. We evaluated habitat use in relation to the dominant arboreal vegetation (evergreen vs. deciduous) based on seasonal trapping data throughout two years and home range size and overlap based on seasonal radio-tracking data in two consecutive years. We captured 476 squirrels with a higher trapping success in areas dominated by evergreen vegetation. Effective home ranges were smaller for females (0.10–0.77 ha, n = 12) than for males (0.9–3.78 ha, n = 3). We observed home range overlap between and within both sexes, suggesting no or low territoriality. Our results support the two working hypotheses on the relatively higher use of areas dominated by evergreen vegetation and on the relatively small home range sizes and large overlapping areas associated to high squirrel density. The flexibility in the use of different type of arboreal patches would be another attribute linked to the invasion success of this species.

A LITERATURE REVIEW AND FIELD TEST ON THE ROLE OF BAIT TYPE ON CAPTURE SUCCESS OF ARBOREAL SMALL MAMMALS

Small mammals are widely studied in Brazil with well-established techniques. However, arboreal species are the least known. Yet, it is common to find studies only committed to capturing terrestrial species. Baits can influence the detection power of studies but, unlike traps, they are not usually assessed for efficiency. We compiled small mammal studies developed in Brazil from 1965 to 2011 (N=113), and we found 25 food items used as bait. Arboreal small mammals are mostly known from studies in the Atlantic Forest, and mostly use banana and peanut butter (ca. 75%) as bait. Only fifteen studies (13.2%) set traps in trees, and mostly used banana and peanut butter as baits. From April to June 2010, we investigated the efficiency of four food items (banana, fresh meat, mixed bait [pasta], and pineapple) to attract small arboreal mammals. We used Sherman traps in the understory and canopy, and Tomahawk traps in the canopy, on platforms suspended in tree branches, totaling 2,880 trap*nights. All traps and sampling stations received each bait for five consecutive nights of sampling, distributed into four campaigns, totaling 20 days of study. We recorded 10 small mammal species (5 arboreal and 5 scansorial), in 158 captures (capture success; CS=5.5%). Arboreal species were mostly attracted by banana bait, (CS=10.1%), it has captured more individuals (N=45; 77.6%), more times (N=73; 46%), ca. 30% more than the pasta, the second most efficient bait (N=49). Fresh meat bait was the least efficient (N=7), and pineapple bait obtained intermediate success (N=28). Sherman traps were 50% more efficient than Tomahawks. We recommend that every small mammal study perform a bait test structured by forest strata to maximize trapping success. If not possible, our results support that the best results for arboreal species can be achieved exclusively using Sherman traps baited with banana.

Distribution and Relative Abundance of Macrochelys (Alligator Snapping Turtles) in the Florida Panhandle

We trapped 4 large alluvial rivers (Ochlockonee, Apalachicola, Choctawhatchee, and Escambia), 10 of their tributaries, and 22 other streams during 2014–2018 to determine the distribution of Macrochelys (alligator snapping turtles) in the Florida panhandle. We trapped three 5-km sections of the 4 large rivers and 130–1347-m sections of 32 smaller streams. We captured 179 turtles in 855 trap nights (TN) for an overall catch per unit effort (CPUE) of 0.21, recording the first observations from Cypress, Bear, Dry, and Wetappo creeks. We failed to capture Macrochelys in 13 streams but suspect populations occur in most streams of all types between the Sopchoppy and Perdido rivers with adequate water depths and cover in the form of deep holes, undercut banks, or fallen trees. We had low trapping success (CPUE = 0.012) in 243 TN in the Choctawhatchee drainage despite apparently suitable habitat. The male:female ratio was 1.44:1, which was significantly different from 1:1. The 4 large rivers had proportionally larger females than smaller streams.

Diversity and Density of Small Mammal Species with Different Seasons and Habitats in Federal University Gashua, Yobe State, North-east Zone of Nigeria

The study examined diversity and density of small mammal species with different seasons and habitats in Federal University Gashua, Yobe State, North-East, Nigeria. The university environment was divided in to four (4) habitat types, namely; University residential area (URA), Acacia woodlot (AWL), Lake Area (LA) and Farm Land (LF) were used for the study. Small Mammal species survey was carried out for the period of six (6) months from August to October, 2022 (wet season) and January, to March, 2023 (dry season). Capture Mark–Recapture (CMR) and indirect observations methods were adopted; Survey was conducted using spring door traps of different sizes set at the habitat types during late evening hours 6:00 pm and checked in the morning hours from 6:00-8:30am for four (4) days per week with each habitat types being visited one day per week, making total of (96) man-days. Each habitat type was visited twice a day (morning and evening) which gave a total of (65;60) trapping night in both wet and dry seasons, the number decreased to 60 trapping night in the dry season was due to the wearing a way of vegetation cover. (32) Visits per habitat types and one (1) night survey per month. A total of ten (10) species of small mammals belonging to ten (10) families and seven (7) orders were recorded in the study. African Hedgehog Atelerix albiventris and White toothed shrew Crocidura flavescens were the most occurring species across The findings of the study shows that the overall diversity index was (1.692), where Four-toed hedgehog Atelerix albiventris had the highest species diversity90.363) and estimated population density of (64.44) followed by Giant pouched rat Cricetomys gambianus with (0.277; 0.018) respectively, Cape hare Lepus capensis and Mongoose Herpestes ichneumon who’s having the lowest diversity of (0.017) with (0. 564) density each in the study area. The month of February has higher number of captured percentage with (24%) in dry season, followed by October with (19%) in the wet season, the lowest capture percentage occurred with August (14%) in the wet season. University Residential Area had more number of individual species having (37.82 %), while Farm land had the least captured percentage of(16.85%).The trap success in both wet season and dry season’s period were (33.04%; 21.67%)respectively. Habitat alteration and destruction due to ongoing constructions project, mainly for university deployment might have accounted for small mammal species low diversity and density in Federal University Gashua.