scholarly journals Detection Rate of Bird Species and What It Depends on: Tips for Field Surveys

2022 ◽  
Vol 9 ◽  
Author(s):  
Federico Morelli ◽  
Vojtěch Brlík ◽  
Yanina Benedetti ◽  
Raphaël Bussière ◽  
Lucie Moudrá ◽  
...  
Keyword(s):  
Body Mass ◽  
Detection Rate ◽  
Bird Species ◽  
Imperfect Detection ◽  
Detection Rates ◽  
Field Surveys ◽  
Species Detection ◽  
Total Species Richness ◽  
Number Of Individuals ◽  
Total Species

Bird counting inevitably suffers from imperfect detection, which varies across species, habitats, period of the day, and seasons. Although various modeling techniques have recently been developed to account for this phenomenon, the biological basis of natural variation in detection remains insufficiently known. This study examined the bird species’ detection rate throughout the day, considering their body mass and diet type, concerning the environment and weather characteristics. Species detection rates were significantly affected by the number of individuals of that species but were unrelated to body mass. Overall, species with the highest detection rate were Corn bunting, Blackbird, European robin, House sparrow and Common chiffchaff. Granivores-insectivores and insectivores showed significant differences in detection rates throughout the day among habitats, with higher detection rates in grasslands during the afternoon. Insectivores showed higher detection rates in farmland during midday (warmest time of the day). Granivores, omnivores and scavengers did not show changes in detection rates in different day periods. Such patterns in daily detection rates were significant even when considering abundance and total species richness in each community. Finally, cloudiness was unrelated to the overall detection rate of birds, while temperature and wind affected detection rates in some guilds. Our findings provide some advice for choosing a suitable ornithological sampling method by considering the avian communities composition in combination with the type of environment, the diet of bird species, and the period of the day.

scholarly journals Fish species diversity in headwaters streams of Paraguay and Paraná Basins

2007 ◽  
Vol 50 (6) ◽  
pp. 1033-1042 ◽  
Author(s):  
Yzel Rondon Súarez ◽  
Sabrina Bigatão Valério ◽  
Karina Keyla Tondado ◽  
Alexandro Cezar Florentino ◽  
Thiago Rota Alves Felipe ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Environmental Factors ◽  
Fish Species ◽  
Total Species Richness ◽  
Paraná Basin ◽  
Parana Basin ◽  
Number Of Individuals ◽  
Total Species ◽  
Fish Species Diversity

The influence of spatial, temporal and environmental factors on fish species diversity in headwater streams in Paraguay and Paraná basins, Brazil was examined. A total of 4,605 individuals were sampled, distributed in 60 species. The sampled streams in Paraná basin presented a larger total species richness (42) than Paraguay streams (40). However the estimated richness was larger in Paraguay basin (53) than Paraná streams (50). The streams of Paraná basin had a greater mean species richness and evenness, while more individuals per sample were found in the Paraguay basin. Difference between the sub-basins were found in the Paraguay basin, while for the basin of Paraná, richness and evenness vary significantly between the sub-basins, but the number of individuals varied seasonally. The most important environmental factors to species diversity and abundance were altitude, water temperature, stream width and stream depth for both the basins.

scholarly journals Mistletoe as a keystone resource: an experimental test

2012 ◽  
Vol 279 (1743) ◽  
pp. 3853-3860 ◽  
Author(s):  
David M. Watson ◽  
Matthew Herring
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Small Scale ◽  
High Turnover ◽  
Total Species Richness ◽  
Before And After ◽  
The Status ◽  
Scale Experiment ◽  
Total Species ◽  
Keystone Resource

Various entities have been designated keystone resources, but few tests have been attempted and we are unaware of any experimental manipulations of purported keystone resources. Mistletoes (Loranthaceae) provide structural and nutritional resources within canopies, and their pervasive influence on diversity led to their designation as keystone resources. We quantified the effect of mistletoe on diversity with a woodland-scale experiment, comparing bird diversities before and after all mistletoe plants were removed from 17 treatment sites, with those of 11 control sites and 12 sites in which mistletoe was naturally absent. Three years after mistletoe removal, treatment woodlands lost, on average, 20.9 per cent of their total species richness, 26.5 per cent of woodland-dependent bird species and 34.8 per cent of their woodland-dependent residents, compared with moderate increases in control sites and no significant changes in mistletoe-free sites. Treatment sites lost greater proportions of birds recorded nesting in mistletoe, but changes in species recorded feeding on mistletoe did not differ from control sites. Having confirmed the status of mistletoe as a keystone resource, we suggest that nutrient enrichment via litter-fall is the main mechanism promoting species richness, driving small-scale heterogeneity in productivity and food availability for woodland animals. This explanation applies to other parasitic plants with high turnover of enriched leaves, and the community-scale influence of these plants is most apparent in low productivity systems.

scholarly journals Variation within the Bird Community of a Rehabilitated Urban Environment, Case of the Félix Houphouët-Boigny University Campus (Côte d'Ivoire)

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Ekoun Michael KONAN ◽  
Valérie Florence GUETONDE ◽  
Coffi Jean Magloire NIAMIEN ◽  
Kouassi Hilaire YAOKOKORE-BEIBRO
Keyword(s):  
Species Richness ◽  
Ecological Impact ◽  
Bird Species ◽  
Bird Community ◽  
University Campus ◽  
Significant Drop ◽  
Bubulcus Ibis ◽  
Total Species Richness ◽  
Ploceus Cucullatus ◽  
Total Species

In order to understand the ecological impact of the rehabilitation of the Félix Houphouët-Boigny University Campus on the bird community, a study was carried out over two months (October-November 2016). The ornithological inventory carried out by the IPA method in five different habitats identified on the campus gave a total species richness of 51 bird species of 41 genera, 27 families and 13 orders for 1374 birds, with H' = 2.93 and J = 0.74. Five species dominate the population (819 individuals, Fr = 59, 61%). These are Bubulcus ibis (9.32 %), Apus affinis (8.95 %), Corvus albus (19.94 %), Ploceus cucullatus (10.48 %), Lonchura cucullata (10.92 %). The most diversified habitat is the Habitations (26 bird species), while the most abundant is the Brush (416 individuals). Only seven species are common to all sampled habitats. Thus, 12 species observed on campus formerly could not be observed during the present study. Similarly, 18 species observed in this study were not observed in the previous study. The profound transformation of the environment following the rehabilitation has led to a slight increase in diversity but a significant drop in numbers. It is therefore important to better understand the different interactions between the components of the habitat and the various species involved. Such data would be crucial in urban planning policies.

scholarly journals Comparing detectability patterns of bird species in small ponds using multi-method hierarchical modelling

2019 ◽  
Author(s):  
José M. Zamora-Marín ◽  
Antonio Zamora-López ◽  
José F. Calvo ◽  
Francisco J. Oliva-Paterna
Keyword(s):  
Sampling Methods ◽  
Bird Species ◽  
Breeding Period ◽  
Large Species ◽  
Imperfect Detection ◽  
Detection Rates ◽  
Hierarchical Modelling ◽  
Occupancy Detection ◽  
Animal Diversity ◽  
Conservation Actions

AbstractRobust knowledge of biodiversity distribution is essential for designing and developing effective conservation actions. However, monitoring programmes have historically assumed all species are detected equally with no spatial or temporal differences in their detection rates. However, recently, interest in accounting for imperfect detection has greatly increased in studies on animal diversity. In this respect, birds are the most widely used group for hierarchical occupancy-detection modelling, mainly due to the relative ease of sampling and the large number of bird datasets that are available. Nevertheless, there are no studies that have tried to evaluate the effectiveness of different bird sampling methods based on a hierarchical modelling approach. In an attempt to remedy this situation, we conducted point transects (PT), point transects plus video monitoring (PV) and mist netting (MN) in 19 small ponds located in the province of Murcia, southeastern Spain, one of the most arid regions of Europe. Multi-method hierarchical models were fitted to the detection histories of 36 common bird species with three main objectives: to compare the effectiveness of the three sampling methods for detecting the bird species using ponds, to assess the effect of sampling date on species detectability, and to establish the influence of body size and diet on species detectability. The results showed PV to be the most effective sampling method for detecting species occupancy, although detection rates ranged widely among bird groups, and some large species were weakly detected by all the methods. Average detectability increased during the breeding period, a pattern shown similarly by all sampling methods. Our approach is particularly applicable to both single- and multi-species bird monitoring programmes. We recommend evaluating the cost-effectiveness of available methods for sampling design in order to reduce costs and improve effectiveness.

scholarly journals Temporal and Spatial Use of Even-Aged Reproduction Stands by Bird Communities in Central Pennsylvania

2003 ◽  
Vol 20 (3) ◽  
pp. 117-123 ◽  
Author(s):  
Susan C. Talbott ◽  
Richard H. Yahner
Keyword(s):  
Species Richness ◽  
Breeding Season ◽  
Tree Species ◽  
Management Practice ◽  
Bird Species ◽  
Basal Area ◽  
Total Species Richness ◽  
Species Richness And Abundance ◽  
Overstory Trees ◽  
Total Species

Abstract In 1992, the Pennsylvania Bureau of Forestry adopted a new forest management practice known as even-aged reproduction with reservation (EAR), which replaces clearcutting on state forestlands. The EAR guidelines mandate the retention of at least 12 trees/ha and 24–36 m2/ha of basal area, representing a diversity of overstory and understory species. During summer 1998, we compared the temporal (breeding season vs. mid-summer) and spatial (edge versus interior) use of EAR stands by birds. In addition, we compared observed vs. expected use of overstory trees in EAR stands. In each of ten representative EAR stands, we sampled birds twice per season along two-edge and two-interior transects. Total species richness and abundance (all species combined), species richness and abundance of ground-shrub foragers, and species richness of canopy-sallier foragers were significantly (P < 0.05) higher in the breeding season than in mid-summer. Eight of 20 common bird species analyzed also were significantly (P < 0.05) more abundant during the breeding season (e.g., black-and-white warbler and chestnut-sided warbler), and one species was significantly (P < 0.05) more abundant during mid-summer. Total species richness, total abundance, and abundance of ground-shrub foragers were significantly higher (P < 0.05) in interiors compared to edges of EAR stands. Five species also were significantly (P < 0.05) more abundant in interiors of EAR stands, whereas no species was more common in edges. All species combined and three foraging guilds showed differential use (P < 0.05) of overstory tree species; eight species also differed significantly in their use of abundant tree species. Based on our findings, we believe that EAR stands are excellent substitutes for clearcuts on state forestlands, although we caution that our findings were based only on one yr of data. We recommend the continued retention of a diversity of overstory trees, especially snags and rough-barked trees, in both edges and interiors of EAR stands for use by a variety of bird species during both the breeding season and mid-summer. North. J. Appl. For. 20(3):117–123.

Estimating tadpole-detection rates using visual field surveys: effects of survey time, tadpole species and tadpole density

2017 ◽  
Vol 44 (2) ◽  
pp. 147 ◽  
Author(s):  
N. Iwai
Keyword(s):  
Visual Field ◽  
Detection Probability ◽  
Detection Rate ◽  
Negative Relationship ◽  
Visual Observation ◽  
Target Species ◽  
Detection Rates ◽  
Field Surveys ◽  
Detection Probabilities ◽  
Species Occupancy

Context When understanding species occupancy, estimation of detection probability for the target species is often required, provided by repeated surveys. However, if the actual detection probability of the species is determined experimentally, such estimates are not required, and the reliability of the occupancy data obtained by a particular survey effort can be determined. Aims The aim of this study was to determine the detection rate of tadpoles using visual field surveys, as well as to explore the effects of survey time, species and tadpole density on the tadpole-detection rate. The suitability of visual surveys for detecting tadpole occupancy was also assessed. Methods Batch-identified tadpoles were released into several pools and repeatedly counted over successive days to calculate detection rates using visual observation. In Experiment 1, the effects of tag colour, survey time (morning vs night) and species on the detection rates of two species of tadpoles (Babina subaspera and Odorrana splendida) were examined. In Experiment 2, the effects of tadpole density on O. splendida were examined. Key results Detection rates varied by survey time, species and tadpole density; mean rates ranged from 0.2 to 0.6 for B. subaspera and 0.4 to 0.8 for O. splendida, with higher rates at night. There was a negative relationship between detection rate and tadpole density. Based on these detection rates, it was calculated that single visual surveys of O. splendida tadpoles can achieve detection probabilities near 1.0 when more than four individuals occur in a patch. Conclusions Variations in detection probability should be considered in field surveys. If the factors that cause variations in detection rates are controlled, visual surveys of tadpoles should, at least in some species, provide detection probabilities near 1.0. Implications When repeated surveys to estimate species occupancy are not practicable, determination of the actual detection probability of the target species using real detection rates provides a robust alternative approach.

scholarly journals Training: improving antenatal detection and outcomes of congenital heart disease

2018 ◽  
Vol 7 (4) ◽  
pp. e000276 ◽  
Author(s):  
Orhan Uzun ◽  
Julia Kennedy ◽  
Colin Davies ◽  
Anthony Goodwin ◽  
Nerys Thomas ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Detection Rate ◽  
Congenital Heart ◽  
Training Programme ◽  
Referral Rate ◽  
Cardiac Anomaly ◽  
Cardiac Ultrasound ◽  
Detection Rates ◽  
Antenatal Detection ◽  
The Uk

ObjectivesThis study describes the design, delivery and efficacy of a regional fetal cardiac ultrasound training programme. This programme aimed to improve the antenatal detection of congenital heart disease (CHD) and its effect on fetal and postnatal outcomes.Design setting and participantsThis was a prospective study that compared antenatal CHD detection rates by professionals from 13 hospitals in Wales before and after engaging in our ‘skills development programme’. Existing fetal cardiac practice and perinatal outcomes were continuously audited and progressive targets were set. The work was undertaken by the Welsh Fetal Cardiovascular Network, Antenatal Screening Wales (ASW), a superintendent sonographer and a fetal cardiologist.InterventionsA core professional network was established, engaging all stakeholders (including patients, health boards, specialist commissioners, ASW, ultrasonographers, radiologists, obstetricians, midwives and paediatricians). A cardiac educational lead (midwife, superintendent sonographer, radiologist, obstetrician, or a fetal medicine specialist) was established in each hospital. A new cardiac anomaly screening protocol (‘outflow tract view’) was created and training on the new protocol was systematically delivered at each centre. Data were prospectively collected and outcomes were continuously audited: locally by the lead fetal cardiologist; regionally by the Congenital Anomaly Register and Information Service in Wales; and nationally by the National Institute for Cardiac Outcomes and Research (NICOR) in the UK.Main outcome measuresPatient satisfaction; improvements in individual sonographer skills, confidence and competency; true positive referral rate; local hospital detection rate; national detection rate of CHD; clinical outcomes of selected cardiac abnormalities; reduction of geographical health inequality; cost efficacy.ResultsHigh levels of patient satisfaction were demonstrated and the professional skill mix in each centre was improved. The confidence and competency of sonographers was enhanced. Each centre demonstrated a reduction in the false-positive referral rate and a significant increase in cardiac anomaly detection rate. According to the latest NICOR data, since implementing the new training programme Wales has sustained its status as UK lead for CHD detection. Health outcomes of children with CHD have improved, especially in cases of transposition of the great arteries (for which no perinatal mortality has been reported since 2008). Standardised care led to reduction of geographical health inequalities with substantial cost saving to the National Health Service due to reduced false-positive referral rates. Our successful model has been adopted by other fetal anomaly screening programmes in the UK.ConclusionsAntenatal cardiac ultrasound mass training programmes can be delivered effectively with minimal impact on finite healthcare resources. Sustainably high CHD detection rates can only be achieved by empowering the regional screening workforce through continuous investment in lifelong learning activities. These should be underpinned by high quality service standards, effective care pathways, and robust clinical governance and audit practices.

scholarly journals Mortality due to primary brain tumours in China and detection rate in people with suspected symptoms: a nationally representative cross-sectional survey

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Bin Jiang ◽  
Hongmei Liu ◽  
Dongling Sun ◽  
Haixin Sun ◽  
Xiaojuan Ru ◽  
...  
Keyword(s):  
Brain Tumour ◽  
Brain Tumours ◽  
Detection Rate ◽  
Epidemiological Data ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Detection Rates ◽  
Primary Brain Tumours ◽  
Symptom Screening ◽  
Nationally Representative

Abstract Background and purpose Epidemiological data on primary brain tumours (PBTs) are lacking due to the difficulty in case ascertainment among the population. Thus, we aimed to estimate mortality due to PBTs in China nationwide and the detection rate in people with suspected symptoms. Methods A multistage, complex sampling survey regarding mortality due to PBTs in Chinese individuals was carried out by reviewing all causes of death within a year. The detection rates in people with suspected symptoms were estimated based on PBT symptom screening and neurologist reviews and compared between groups by logistic regression analysis. Results Weighted mortality due to PBT was 1.6 (0.8–3.3) per 100,000 population in Chinese individuals, 1.8 (0.7–4.6) per 100,000 population in men, and 1.5 (0.5–4.5) per 100,000 population in women. Among 14,990 people with suspected symptoms, the PBT detection rate was 306.9 (95% CI 224.7–409.3) per 100,000 population in the total population, 233.0 (95% CI 135.7–373.1) per 100,000 population in men, and 376.9 (95% CI 252.4–546.3) per 100,000 population in women. People with an unsteady gait (OR 2.46; 95% CI 1.09–5.51; P=0.029), visual anomalies (3.84; 1.88–7.85; P<0.001), and headache (2.06; 1.10–3.86; P=0.023) were more likely to have a brain tumour than those without corresponding symptoms, while people with dizziness/vertigo were less likely to have a brain tumour than those without corresponding symptoms (0.45; 0.23–0.87; P=0.017). Conclusions Mortality due to PBT in China was low, with a nationwide estimate of 21,215 (10,427–43,165) deaths attributable to PBTs annually. However, the detection rate of PBTs can be greatly improved based on symptom screening in the population.

scholarly journals The Effects of Social Distancing Policies on non-SARS-CoV-2 Respiratory Pathogens

2021 ◽  
Author(s):  
Jeff Nawrocki ◽  
Katherine Olin ◽  
Martin C Holdrege ◽  
Joel Hartsell ◽  
Lindsay Meyers ◽  
...  
Keyword(s):  
Public Health ◽  
Influenza A ◽  
Detection Rate ◽  
Respiratory Illness ◽  
Respiratory Pathogens ◽  
Public Health Response ◽  
Mixed Effect ◽  
Detection Rates ◽  
Social Distancing ◽  
The Impact

Abstract Background The initial focus of the US public health response to COVID-19 was the implementation of numerous social distancing policies. While COVID-19 was the impetus for imposing these policies, it is not the only respiratory disease affected by their implementation. This study aimed to assess the impact of social distancing policies on non-SARS-CoV-2 respiratory pathogens typically circulating across multiple US states. Methods Linear mixed-effect models were implemented to explore the effects of five social distancing policies on non-SARS-CoV-2 respiratory pathogens across nine states from January 1 through May 1, 2020. The observed 2020 pathogen detection rates were compared week-by-week to historical rates to determine when the detection rates were different. Results Model results indicate that several social distancing policies were associated with a reduction in total detection rate, by nearly 15%. Policies were associated with decreases in pathogen circulation of human rhinovirus/enterovirus and human metapneumovirus, as well as influenza A, which typically decrease after winter. Parainfluenza viruses failed to circulate at historical levels during the spring. Total detection rate in April 2020 was 35% less than historical average. Many of the pathogens driving this difference fell below historical detection rate ranges within two weeks of initial policy implementation. Conclusion This analysis investigated the effect of multiple social distancing policies implemented to reduce transmission of SARS-CoV-2 on non-SARS-CoV-2 respiratory pathogens. These findings suggest that social distancing policies may be used as an impactful public health tool to reduce communicable respiratory illness.

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