Field-based evaluation of scat DNA methods to estimate population abundance of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial

2009 ◽  
Vol 36 (8) ◽  
pp. 721 ◽  
Author(s):  
Monica Ruibal ◽  
Rod Peakall ◽  
Andrew Claridge ◽  
Karen Firestone

Context. DNA extracted non-invasively from remotely collected scat samples has been used successfully to enumerate populations of a few endangered mammal species. However, scat DNA surveys relying on scent-marking behaviours need to identify if age- or sex-specific variations or seasonal changes in scat scent-marking patterns affect population estimates. Furthermore, owing to the low quantity and quality of scat DNA, a thorough assessment of the technique is needed when it is applied to different species to ensure that individual identification is reliable. Aims. In the current study, microsatellite genetic profiles derived from 208 remotely collected scats of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial carnivore, were compared with DNA profiles from tissue of 22 live-trapped individuals from the same study area to critically assess the reliability of the non-invasive method to estimate population abundance. Methods. Scat samples were collected at scent-marking sites over 4 consecutive months (April–July 2005), 7 weeks of which overlapped with the trapping program to allow direct comparisons of population estimates. Key results. Combining a multiple-tubes approach with error checking analyses provided reliable genetic tags and resulted in the detection of the majority of the live-trapped population (18 of 22 individuals). Ten additional individuals not known from trapping were also observed from scat DNA. A longer-term sampling regime was required for scats than for trapping to allow direct detection of a large proportion of the population and to provide a comparable population estimate. Critically, the 4-month scat collection period highlighted the importance of performing scat surveys during the mating season when scat scent marking is more frequent, and to avoid sex and age biases in scat marking patterns. Implications. Non-invasive scat DNA sampling methods that rely on scent-marking behaviours need to consider the duration of the sampling period and temporal differences in behaviours by the sexes and age groups to ensure that meaningful population estimates are achieved.


2018 ◽  
Vol 18 (4) ◽  
Author(s):  
Nuno M. Pedroso ◽  
Sofia V. Dias ◽  
Thais Rovere Diniz-Reis ◽  
Margarida Santos-Reis ◽  
Luciano Martins Verdade

Abstract: Sampling wild animal populations using non-invasive techniques is advised when dealing with threatened species. Hair samples provide ecological information like species and individual identification. However, hair trapping is scarcely used in otters, due to their aquatic habits. Most studies are with captive individuals, so there is the need to test non-invasive hair trapping methods in otters in the wild. The aim of this study was to develop a simple and cost-effective method to collect hair from otter species in a non-invasive way. The study was carried out in the Paranapanema River, São Paulo State, Brazil, with the Neotropical otter (Lontra longicaudis Olfers, 1818), a protected species. Hair traps (wooden sticks and tree roots with adhesive tape or wax bands) were set during six nights on river banks, otter trails and scent-marking sites. Traps were baited with otter fresh spraints from other river locations. From the 23 traps, 10 (43.7%) were successful in collecting otter hairs, mostly guard-hair. The sticks were much more efficient than the roots at capturing otter hair (70.6.% vs. 0%) as well as adhesive tape when compared to wax (71.4% vs. 0%). Method simplicity and efficiency suggest that it can be a cost-effective way for collecting otter hairs without the need for capturing individuals. This method can be used for: assessment of local otter distribution; collecting otter hair samples for sex and individual identification (by molecular analysis), trophic ecology (by isotopic analyses), ecotoxicology (by contamination analysis) or behaviour ecology (by hormonal and stress levels analysis). More trapping campaigns should be implemented to further test the method's efficiency.



2018 ◽  
Vol 10 (13) ◽  
pp. 12755-12768
Author(s):  
Uddalak Tathagato Bindhani ◽  
Abhijit Das

The dorsal surface of Duttaphrynus melanostictus is covered with keratinized warts of various sizes and shapes.  Using combinations and patterns of cranial and mid dorsal warts, we attempted to identify individual toads from a natural population as a non-invasive alternative to existing marking techniques based on toe clipping, pit tagging, and subcutaneous elastomer injections to facilitate population estimates.  An accuracy of 100% identification was achieved via this method, making it a potent tool for population studies in this species that is faster, cheaper and less disruptive than standard marking techniques.



2010 ◽  
Vol 37 (1) ◽  
pp. 27 ◽  
Author(s):  
Monica Ruibal ◽  
Rod Peakall ◽  
Andrew Claridge ◽  
Andrew Murray ◽  
Karen Firestone

Context. Enumeration of cryptic/rare or widely distributed mammal species is exceedingly difficult for wildlife managers using standard survey methods. Individual identification via non-invasive hair-DNA methods offers great promise in extending the information available from hairs collected to survey for presence/absence of a species. However, surprisingly few wildlife studies have attempted this because of potential limitations with the field method and genetic samples. Aim. The applicability of hair DNA to identify individuals and estimate numbers was assessed for a rare, medium-sized Australian marsupial carnivore, the spotted-tailed quoll (Dasyurus maculatus). Methods. Hair samples were obtained remotely in the field with baited hair-sampling devices (known as handi-glaze hair tubes) that permit multiple visitations by individuals and species. A hierarchical approach developed and applied to the DNA extraction and PCR protocol, based on single and four pooled hairs of each collected sample, was used to assess genotype reliability (cross-species DNA mixing, allelic dropout and false allele errors) and enumerate the local study population. These results were compared against a concurrent live-cage trapping survey that was equivalent in scale and trap density to enable a rigorous evaluation of the efficiency and reliability of the DNA-based hair-sampling technique. Key results. Of the 288 hair devices deployed, 52 (18%) captured spotted-tailed quoll hair and the majority (90%) of these samples provided adequate DNA to genetically profile individuals at 10 microsatellite loci and a sexing marker. The hierarchical approach provided a feasible way to verify whether cross-species DNA mixing had occurred in the pooled-hair DNA extracts by comparing the results against the independent single-hair DNA extract, and assess genotyping reliability of both DNA concentrations. Fewer individuals were detected using hair-sampling (n = 16) than live-trapping (n = 21), despite hair-sampling occurring over a longer period (40 cf. 26 nights). Conclusions. The population-level information gained by the DNA-based technologies adds considerable value to the remote hair-sampling method which up until the present study had been used to detect the presence of medium-sized mammals. Our study demonstrated the utility of the DNA-based hair-sampling method to identify spotted-tailed quoll individuals and for surveying local populations. However, improvements to the hair-sampling method, such as increasing the density of stations or the provision of a food reward, should be considered to enhance sampling efficiency to allow the enumeration of local populations. Implications. The use of remote hair-sampling devices that permit multiple visitations and do not require daily collection can be feasible and reliable to genetically identify individuals when coupled with appropriate strategies. By combining single- and pooled-hair DNA extracts, a good compromise between laboratory efficiency and data integrity is afforded.



2019 ◽  
Vol 12 (2) ◽  
pp. 94-99
Author(s):  
Rene D. Mileva-Popova ◽  
Nina Y. Belova

Summary Vascular-ventricular coupling is a major determinant of left ventricular load. The aim of our study was to assess non- invasively left ventricular load and its dependency on central hemodynamics. Sixty-five healthy and gender-matched individuals were divided in two groups according to their age: 20y/o and 50y/o. Applanation tonometry was performed using the Sphygmocor device. Central pressures and pulse wave analysis indices were computed. Central systolic (120±3 vs. 98±2 mm Hg) and pulse pressures (43±3 vs. 29±1 mm Hg) as well as the augmentation index (AIx75) (23±3 vs. 6±2%) were significantly higher in the 50y/o group (p<0.01). These parameters are relevant markers of arterial stiffness and evidenced the development of central arterial morphological and functional alterations in the older subjects. The time-tension index (TTI) computed from the systolic pressure area was significantly higher in the 50y/o subjects as compared to the 20y/o group (2378±66 vs. 1954±73 mmHg×s, p<0.01). Moreover, we have shown the presence of significant correlation between TTI and AIx75 (p<0.01) in both age groups. This finding confirmed the contribution of arterial stiffness for the impaired vascular-ventricular coupling. In conclusion, applanation tonometry might be utilized for non-invasive evaluation of the left ventricular load, which is an important parameter of cardiovascular risk.



Author(s):  
L. Yu. Orekhova ◽  
A. A. Petrov ◽  
E. S. Loboda ◽  
I. V. Berezkina ◽  
K. V. Shadrina

Relevance. The study of age-related features of microcirculation in periodontal tissues, using non-invasive functional research methods, allows us to develop the optimal range of therapeutic measures, as well as form a “personalized therapeutic case”.Purpose. Study of the functional state of the microvasculature in the tissues of the parodont in individuals of various age groups.Materials and methods. A standard dental examination of 80 patients was carried out, the sample of participants was ranked in 4 groups by age: 1 group – 12 years old, 2 group – 15 years old, 3 group – from 16 to 18 years old, 4 group – from 22 to 24 years old. Hygiene and periodontal indices were determined for all patients, such as papillarymarginal-alveolar (PMA) in the Parma modification, the Mulleman bleeding index in the Cowell modification (SBI), and the simplified Green Vermillion index of oral hygiene (OHI–s), caries intensity indicators for a permanent bite (CPI), as well as ultrasound dopplerography of periodontal tissues using the apparatus "Minimax-Doppler-K".Results. When studying microcirculation in periodontal tissues, distinctive characteristics of linear (Vas) and volumetric (Qas) blood flow rates, as well as indicators of pulsation indices (PI) and peripheral resistance (RI) in people of different age groups were recorded.Conclusions. This study confirms the presence of various hemodynamic indicators of periodontal tissues in the studied groups, which is due to structural features of the circulatory system in age periods.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Levente Kovács ◽  
Fruzsina Luca Kézér ◽  
Szilárd Bodó ◽  
Ferenc Ruff ◽  
Rupert Palme ◽  
...  

AbstractThe intensity and the magnitude of saliva cortisol responses were investigated during the first 48 h following birth in newborn dairy calves which underwent normal (eutocic, EUT, n = 88) and difficult (dystocic, DYS, n = 70) calvings. The effects of parity and body condition of the dam, the duration of parturition, the time spent licking the calf, the sex and birth weight of the calf were also analyzed. Neonatal salivary cortisol concentrations were influenced neither by factors related to the dam (parity, body condition) nor the calf (sex, birth weight). The duration of parturition and the time spent licking the calf also had no effect on salivary cortisol levels. Salivary cortisol concentrations increased rapidly after delivery in both groups to reach their peak levels at 45 and 60 min after delivery in EUT and DYS calves, respectively supporting that the birth process means considerable stress for calves and the immediate postnatal period also appears to be stressful for newborn calves. DYS calves exhibited higher salivary cortisol concentrations compared to EUT ones for 0 (P = 0.022), 15 (P = 0.016), 30 (P = 0.007), 45 (P = 0.003), 60 (P = 0.001) and 120 min (P = 0.001), and for 24 h (P = 0.040), respectively. Peak levels of salivary cortisol and the cortisol release into saliva calculated as AUC were higher in DYS than in EUT calves for the 48-h of the sampling period (P = 0.009 and P = 0.003, respectively). The greater magnitude of saliva cortisol levels in DYS calves compared to EUT ones suggest that difficult parturition means severe stress for bovine neonates and salivary cortisol could be an opportunity for non-invasive assessment of stress during the early neonatal period in cattle.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sougata Sadhukhan ◽  
Holly Root-Gutteridge ◽  
Bilal Habib

AbstractPrevious studies have posited the use of acoustics-based surveys to monitor population size and estimate their density. However, decreasing the bias in population estimations, such as by using Capture–Mark–Recapture, requires the identification of individuals using supervised classification methods, especially for sparsely populated species like the wolf which may otherwise be counted repeatedly. The cryptic behaviour of Indian wolf (Canis lupus pallipes) poses serious challenges to survey efforts, and thus, there is no reliable estimate of their population despite a prominent role in the ecosystem. Like other wolves, Indian wolves produce howls that can be detected over distances of more than 6 km, making them ideal candidates for acoustic surveys. Here, we explore the use of a supervised classifier to identify unknown individuals. We trained a supervised Agglomerative Nesting hierarchical clustering (AGNES) model using 49 howls from five Indian wolves and achieved 98% individual identification accuracy. We tested our model’s predictive power using 20 novel howls from a further four individuals (test dataset) and resulted in 75% accuracy in classifying howls to individuals. The model can reduce bias in population estimations using Capture-Mark-Recapture and track individual wolves non-invasively by their howls. This has potential for studies of wolves’ territory use, pack composition, and reproductive behaviour. Our method can potentially be adapted for other species with individually distinctive vocalisations, representing an advanced tool for individual-level monitoring.



PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e77541 ◽  
Author(s):  
Michael Walker ◽  
Carole Fureix ◽  
Rupert Palme ◽  
Georgia Mason


1984 ◽  
Vol 27 (3) ◽  
pp. 350-358 ◽  
Author(s):  
Bonnie Brinton ◽  
Martin Fujiki

This study investigated the manipulation of discourse topic in spontaneous conversation in three age groups. Subjects consisted of six dyads of peers at each of the following age levels (years:months): 5:0–5:11, 9:0–9:11, and adults. Fifteen min of discourse were taped, transcribed, and analyzed for each age level. Patterns of topic introduction, reintroduction, maintenance, and shading were considered at each age level. Although considerable variation within groups was evident, the results suggested several developmental trends. The number of topics introduced and reintroduced in the sampling period decreased with age, whereas the proportion of topics maintained increased with age. Additionally, subjects maintained topics for longer sequences of utterances with increasing age. Topic shading also increased with age. These results are discussed with regard to patterns of development, and clinical implications are considered.



Check List ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 2098 ◽  
Author(s):  
Camilo Sánchez-Giraldo ◽  
Juan M. Daza

The northern part of the Cordillera Central in Colombia has been recognized as a region of particular relevancy in vertebrates biodiversity. We provide a list of non-volant mammal species in Jaguas and San Carlos, two protected areas around hydroelectric projects on the eastern slope of the Cordillera Central in Antioquia. As part of an ongoing monitoring project, we obtained records from a standardized survey in 2011 and sporadic surveys in 2014–2015 (capture and non-invasive methods), and from the revision of voucher specimens. From 132 records we generated a list of 34 species, 22 species in Jaguas and 27 in San Carlos, belonging to 20 families and seven orders. We record the occurrence of four endemic and four threatened species, including the endemic and Endangered Tamarin, Saguinus leucopus, highlighting the importance of these protected areas for mammal conservation in this highly diverse region. 



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