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A survey for the Critically Endangered Durban Dwarf Burrowing Skink Scelotes inornatus (Smith 1849) was conducted in two protected areas in Durban, South Africa, in August and September 2021. Twelve sites, each encompassing a combination of vegetation type, elevation, slope and aspect, were sampled for S. inornatus using dug quadrats, pitfall-and funnel-trap arrays, and coverboard arrays. Seven S. inornatus were recorded, at least one by each sampling method. Individuals were captured at the forest edge and in the grassland part of the forest-grassland ecotone and none were captured in the interior of the forest. None of the sampling methods were suitable for the long-term monitoring of S. inornatus, although a modification of the coverboard array using terracotta tiles instead of corru-board tiles should be tested. Five S. inornatus captured were introduced to the Johannesburg Zoo's ex-situ insurance and captive-breeding population. Nine other sympatric species of herpetofauna were recorded during the survey, with the Bush Squeaker Arthroleptis wahlbergii Smith, 1849 the most caught and S. inornatus ranking fifth. This study provides information that is useful for addressing some of the conservation actions and research needed for S. inornatus, but more research on the biology of this skink (particularly on its life history and population size) and habitat management interventions (restoration and rehabilitation of its habitat) are required to assist with improving its conservation status. [ABSTRACT FROM AUTHOR]

Abstract The capture of neonate ungulates allows for the collection of valuable ecological data, including estimates of litter size. However, varied methods used to capture neonate ungulates can result in sampling biases. Our objective was to determine if opportunistic captures of neonate ungulates (i.e., locating neonates by visually scanning for adult females displaying postpartum behaviors) bias relative estimates of litter size and investigate potential causes if a bias does exist. We analyzed data from 161 litters of mule deer (Odocoileus hemionus) sampled using three different capture methods during 2019–2021 in Utah, USA. Estimates of litter size derived from opportunistic captures were smaller than estimates derived from movement-based captures or captures completed with the aid of vaginal implant transmitters (VITs). Age at capture was inversely related to estimates of litter size and likely influenced the detection bias associated with opportunistic captures. Neonates captured opportunistically were not older than neonates captured using movement-based methods, but were older than neonates captured with the aid of VITs. Distance between neonates from the same litter did not influence estimates of litter size. Researchers should be aware of the biases associated with different capture methods and use caution when interpreting data among multiple capture methods. Estimates of litter size derived from opportunistic captures should not be compared to estimates of litter size derived from alternative capture methods without accounting for the detection bias we observed.

The capture of neonate ungulates allows for the collection of valuable ecological data, including estimates of litter size. However, varied methods used to capture neonate ungulates can result in sampling biases. Our objective was to determine if opportunistic captures of neonate ungulates (i.e., locating neonates by visually scanning for adult females displaying postpartum behaviors) bias relative estimates of litter size and investigate potential causes if a bias does exist. We analyzed data from 161 litters of mule deer (Odocoileus hemionus) sampled using three different capture methods during 2019–2021 in Utah, USA. Estimates of litter size derived from opportunistic captures were smaller than estimates derived from movement-based captures or captures completed with the aid of vaginal implant transmitters (VITs). Age at capture was inversely related to estimates of litter size and likely influenced the detection bias associated with opportunistic captures. Neonates captured opportunistically were not older than neonates captured using movement-based methods, but were older than neonates captured with the aid of VITs. Distance between neonates from the same litter did not influence estimates of litter size. Researchers should be aware of the biases associated with different capture methods and use caution when interpreting data among multiple capture methods. Estimates of litter size derived from opportunistic captures should not be compared to estimates of litter size derived from alternative capture methods without accounting for the detection bias we observed. [ABSTRACT FROM AUTHOR]

Abstract Environmental DNA (eDNA) is increasingly used for biodiversity monitoring, particularly in aquatic systems. However, each step, from sample collection to bioinformatic analysis, can introduce biases and influence the reliability of results. While much effort has been put into the optimization of laboratory methods, less attention has been devoted to estimate the impacts of eDNA capture methods. To address this issue, water samples were collected at nine small ponds and puddles where up to 10 amphibian species occur, using precipitation, disc filters, and capsules. We focused on targeted detection of an amphibian species, Salamandra salamandra, and on the composition of the whole amphibian community. Species detection was performed using a novel qPCR assay for S. salamandra and high‐throughput sequencing, combined with stringent versus relaxed PCR replication thresholds. Filtration techniques (disc filters and capsules) outperformed precipitation, generating a higher number of detections of S. salamandra and higher amounts of captured eDNA, while species detection was identical between disc filters and capsules. There were no significant differences between capture methods regarding amphibian community composition. The variation in detection success associated with capture methods was far higher than that associated with PCR replication, regardless of the detection method used. Our results highlight the importance of choosing a suitable capture method for eDNA studies and suggest that the choice of capture method outweighs the choice of detection method used. To the best of our knowledge, this is the first study to compare high‐capacity capsules with common eDNA methods for water samples, such as precipitation and standard disc filters.

The capture of free-ranging individuals is often needed for research, population management and health assessment. Because of its iconic and threatened species status, methods to capture koalas (Phascolarctos cinereus) receive disproportionate scrutiny. We collated data on koala capture frequency, duration held by noose and incidents from six studies of koalas in Victoria and New South Wales that all used the 'noose and flag' method as the primary method of capture. Adverse events occurred in less than 1% of all captures (7 of 1236). Mean capture time in three of four locations recording duration held by noose was less than five minutes, minimising the duration of distress to the koala while allowing researchers to maintain control over the animal. The exception to this was a study in far south-west Victoria where trees were tall and koalas were relatively unresponsive to flagging, resulting in a longer mean duration held by noose (11.2 minutes). The reviewed capture data of the 'noose and flag' method suggest that this is an effective and safe capture method, allowing for capture of multiple individuals in a short period, and suitable for most habitat types and situations. The capture of wild koalas is necessary for research and population management. As an iconic species, methods to capture koalas receive disproportionate scrutiny. We reviewed the duration and outcome of 1236 koala captures utilising the 'noose and flag' method. Adverse events occurred in less than 1% of all captures. Our review suggests that this is an effective and safe capture method that minimises the duration of distress to koalas and allows for capture of multiple individuals in a short period and is suitable for most habitat types. Photograph by George Madani. [ABSTRACT FROM AUTHOR]

Population demography parameters of common small mammals have been obtained using two different census methods and intercompared. Resident population density and nonresident activity parameters were obtained on live-trap lines using the capture–mark–recapture method. Abundance parameters were obtained on break-back trap lines using the permanent removal (PR) method. Censuses performed using the PR method reflect the population dynamics of small mammals in general, but they may misrepresent the species ratio in the community. Multiple regression analysis shows that results obtained using the PR method are significantly affected both by the resident population density and nonresident activity of the species. Together, these factors explain 88.8% of the variance, while their individual contributions assessed on the basis of semipartial correlations in the multiple correlation model are as follows: r = 0.39 (resident population) and r = 0.46 (nonresident activities). [ABSTRACT FROM AUTHOR]

INTRODUCTION: The present study compares human landing catches of primary malaria vectors with two alternative methods of capture: the Shannon trap and the Mosquito magnet. METHODS: This study used regression models to adjust capture data to a negative binominal distribution. RESULTS: Capture numbers and relative percentages obtained from the three methods vary strongly between species. The highest overall captures were obtained for Anopheles triannulatus with captures for the Shannon trap and the Mosquito magnet measuring more than 330% higher than captures obtained by human landings. For Anopheles darlingi, captures by the Shannon trap and the Mosquito magnet were about 14% and 26% of human landing catches, respectively. Another species with malaria transmission potential that was not sampled by human landing captures weascaptured by the Shannon trap and the Mosquito magnet (Anopheles oswaldoi). Both alternative sampling techniques can predict the human landing of Anopheles triannulatus, but without proportionality. Models for Anopheles darlingi counts, after totaling daily captures, are significant and proportional, but prediction models are more reliable when using the Shannon trap compared with the Mosquito magnet captures. CONCLUSIONS: These alternative capture methods can be partially recommended for the substitution of human landing captures or, at least, as complementary forms of monitoring for malarial mosquitoes.INTRODUÇÃO: O presente estudo compara a captura através da isca humana dos principais vetores da malária, com dois métodos alternativos de captura, a armadilha luminosa de Shannon e a armadilha Mosquito magnet. MÉTODOS: O presente estudo utiliza modelos de regressão para ajustar os dados obtidos para uma distribuição binomial negativa. RESULTADOS: Os números e as proporções relativas obtidas nos três métodos variaram fortemente entre as espécies. A maior densidade capturada foi de Anopheles triannulatus, através das armadilhas de Shannon e do Mosquito magnet sendo mais de 330% superior que a obtida pela captura por isca humana. Para Anopheles darlingi, capturas com a armadilha de Shannon e com o Mosquito magnet representaram cerca de 14% e 26%, respectivamente, em comparação com a captura através da isca humana. Outras espécies com potencial de transmissão da malária não foram capturadas com a utilização da isca humana, mas foram coletadas na armadilha de Shannon e no Mosquito magnet (Anopheles oswaldoi). Ambas as técnicas alternativas de captura, podem predizer significativamente a captura através da isca humana de Anopheles triannulatus, porém sem proporcionalidade. Os números previstos para o Anopheles darlingi, após a contagem total da captura diária, são significativos e proporcionais, mas a previsão é mais confiável para a armadilha de Shannon que para o Mosquito magnet. CONCLUSÕES: A comparação de métodos alternativos de captura pode ser parcialmente recomendada para a substituição da captura através da isca humana ou, pelo menos, como uma forma complementar de coleta de mosquitos.

Animal research often relies on catching wild animals; however, individuals may have different trappability, and this can generate bias. We studied bias in mist netting, the main method for catching wild birds. The unusually high resighting rate in our study population-house sparrows ( Passer domesticus) on Lundy Island ( England)-allowed us to obtain accurate estimates of the population size. This unique situation enabled us to test for catching bias in mist netting using deviations from the expected Poisson distribution. There was no evidence that a fraction of the birds in the population consistently remained uncaught. However, we detected a different bias: More birds than expected were captured only once within a year. This bias probably resulted from a mixture of fieldworkers sometimes ignoring rapid recaptures and birds becoming net shy after their first capture. We had sufficient statistical power with the available data to detect a substantial uncaught fraction. Therefore, our data are probably unbiased toward catching specific individuals from our population. Our analyses demonstrate that intensively monitored natural insular populations, in which population size can be estimated precisely, provide the potential to address important unanswered questions without concerns about a fraction of the population remaining uncaught. Our approach can help researchers to test for catching bias in closely monitored wild populations for which reliable estimates of population size and dispersal are available. [ABSTRACT FROM AUTHOR]

Context. Determining the biodiversity of an area is essential for making targeted conservation decisions. Undertaking surveys to confirm species presence or to estimate population sizes can be difficult, particularly for elusive species. Bats are able to detect and avoid traps, making it difficult to quantify abundance. Although acoustic surveys using bat detectors are often used as a surrogate for relative abundance, the implicit assumption that there is a positive correlation between activity levels and abundance is rarely tested. Aims. We assessed the effectiveness of surveying techniques (i.e. trapping and acoustic monitoring) for detecting species presence and tested the strength of collinearity among methods. In addition, we tested whether the use of an acoustic lure (a bat-call synthesiser) increased bat-capture rate and therefore species detectability. Methods. Surveying was carried out over 3 years in central Scotland (UK), in 68 woodlands within predominantly agricultural or urban landscapes. Key results. There was a significant positive relationship between bat activity recorded on ultrasonic detectors and the relative abundance of Pipistrellus pygmaeus and P. pipistrellus, but not those in the genus Myotis. In general, acoustic monitoring was more effective than trapping at determining species presence; however, to ensure rarer or quiet species are recorded, a complementary approach is required. Broadcasting four different types of echolocation call resulted in a 2-12-fold increase in trapping success across four species of insectivorous bat found in the study region. Whereas lure effectiveness remained unchanged for female P. pygmaeus over time, there was a marked increase in the number of males captured using the lure throughout the summer (May to September). Conclusions. In the present study, we have demonstrated a variety of ways to increase surveying efficiency, which can maximise the knowledge of diversity in an area, minimise wildlife disturbance, and enhance surveying effectiveness. Implications. Increasing surveying efficiency can improve the accuracy of targeted conservation decisions. [ABSTRACT FROM AUTHOR]

lthough land snail communities could be a good indicator of soil quality and landscape structure impact, they are seldom analysed in an urban context, probably because of the lack of interest in this ecosystem and because no fast and reliable method of inter-site comparison seems to exist. The classical method of removing large quantities of soil leads to degradations unsuitable in urban gardens and involves time-consuming sorting. For the purpose of ecological comparisons, we analysed different methods to assess land snail communities in urban parks in order to set up a simplified strategy. Snail communities were sampled in three parks within the city of Paris (France) using (1) quadrat method (litter and soil removed over a given area, snails sorted later in the laboratory), (2) visual search in situ (hand-picking snails in the leaf litter), (3) wooden boards placed on the ground and regularly checked, and (4) pitfall traps, usually used for insect sampling. Our results suggest that the wooden board and pitfall trap did not yield enough data to determine community structure and that visual search was not sufficient to sample all dominant species, especially the smallest ones. In order to allow for replication of samples, we suggest a mixed strategy suitable for ecological comparisons, combining visual searches of five 0.5 m areas (15 min for each area) and litter and soil sampling on two 0.0625 m quadrats. [ABSTRACT FROM AUTHOR]

Abstract: As a contribution to the long-term emergence studies carried out as part of the “Breitenbach ecosystem project”, this paper presents the results obtained on emergence patterns and population dynamics of blackflies from 1984 to 1988. The Breitenbach is a small first order stream near Schlitz/Hesse, running into the Fulda river. Adult blackflies were caught in 4 greenhouse emergence traps, each spanning the whole width of the stream for a length of 6 m. A manual and then a partly automated method for collecting trapped insects was applied for three years and one year, respectively. Sixteen blackfly-species of different origin were found in the traps: a) autochthonous species: Prosimulium tomosvaryi, Simulium vernum s.l., S. cryophilum s.l., S. ornatum s.l. (common); S. costatum, S. trifasciatum, S. monticola, S. argyreatum (rare); b) species of doubtful origin: S. lundstromi, S. angustitarse, S. angustipes, S. aureum (very rare); c) allochthonous species: S. lineatum, S. equinum, S. erythrocephalum, S. noelleri. It was shown that the last 4 species had not emerged from the Breitenbach but had flown into the traps as adults. In addition, females of autochthonous species with blood or with mature eggs were trapped, which were also considered to have flown in. Besides revealing a limitation of the trap construction, they supported the detailed interpretation of some intricated patterns of appearance. Variations in emergence patterns and specimen numbers between years and traps were pronounced, but only in a few cases could they be attributed to changes in abiotic factors such as water temperature or discharge. P. tomosvaryi had the most simple and regular life cycle, with one well synchronised emergence peak annually from April to May (or even to June). No gradient of specimen numbers along the stream was evident. The two closely related species S. vernum and S. cryophilum had quite similar emergence patterns: There were two broad peaks per year, extending mainly from March to June and from July to October or November. In some cases the number and separation of consecutive generations was not clear. The abundance of both species clearly decreased downstream, more so for S. cryophilum than for S. vernum. In a trap closest to a tributary spring, S. cryophilum was the dominant species during three of the four years examined. The adults of S. ornatum displayed an intricate pattern of appearance, with very low specimen numbers in spring and medium to very high numbers in July/August and September/October. S. ornatum is the only blackfly species that inhabits both the Breitenbach and the adjacent section of the Fulda river. It was shown that females emerging from the Fulda river regularly invade the Breitenbach valley in greatly varying numbers and oviposit there. This leads to overlapping larval cohorts with corresponding emergence peaks. Although S. ornatum was the most abundant species in one year in the lower traps (60 to 80% of all individuals), it remains uncertain whether it is a long-term, permanent member of the autochthonous blackfly fauna of the Breitenbach. Estimates of total numbers of flown-in adults, actual emergence, dry weight biomass, the ecological separation of the species and their life cycle strategies are discussed. [Copyright &y& Elsevier]