Sound recording of bird vocalisations in forests. I. Relationships between bird vocalisations and point interval counts of bird numbers - a case study in statistical modeling

2004 ◽  
Vol 31 (2) ◽  
pp. 195 ◽  
Author(s):  
R. B. Cunningham ◽  
D. B. Lindenmayer ◽  
B. D. Lindenmayer

Morning vocal activity data for birds were collected using automatic sound recorders at 165 sites in fragmented forests at Tumut in south-eastern Australia. A model was developed to describe the statistical properties of the vocal activity data and study the relationship between the number of 'elements' (or notes) broadcast by birds and the number of birds recorded by human observers. We discuss the practical issues of finding a model where variance heterogeneity and skewness is a feature of the data, while the context of the problem required that multiplicative relationships be preserved. A satisfactory fit to our vocal activity data was obtained by using a Gamma distribution.For most groups of birds, the observed relationships between vocal activity and the number of birds recorded by human point counts were weak but statistically significant.Our analysis suggests that these data provide limited useful information about vocal activity per bird. Automatic sound-recording data may be informative for drawing inferences about temporal patterns in vocal activity but do not seem useful as a method for estimating the abundance of birds. A significant relationship was identified between the number of species vocalising, as measured by sound recorders, and the number of species observed by point count method. However, the relationship was far from isometric and there were many more species detected by the sound recorders than by human observers.Results from analyses of vocal activity data gathered at Tumut were confirmed by additional data obtained in a subsequent, small calibration study in the Namadgi National Park in the Australian Capital Territory.

2004 ◽  
Vol 31 (2) ◽  
pp. 209 ◽  
Author(s):  
D. B. Lindenmayer ◽  
R. B. Cunningham ◽  
B. D. Lindenmayer

As early morning bird vocalisation is a major feature of many bird communities, longitudinal profiles of vocal activity data, collected using sound recorders, were compared for a range of habitat types in the Tumut area of south-eastern Australia. There was a significant, and roughly linear, decline in vocal activity across the morning after an initial early peak of activity. Vocal activity persisted longer at sites located within large areas of continuous eucalypt forest than in the strip- and patch-shaped eucalypt remnants surrounded by extensive stands of radiata pine or at sites dominated by stands of radiata pine. There was evidence that the pattern of persistence of vocal activity differed among the different bird groups.


2012 ◽  
Vol 52 (28) ◽  
pp. 333-340 ◽  
Author(s):  
Vagner Cavarzere ◽  
Thiago Vernaschi Vieira da Costa ◽  
Luís Fábio Silveira

Due to rapid and continuous deforestation, recent bird surveys in the Atlantic Forest are following rapid assessment programs to accumulate significant amounts of data during short periods of time. During this study, two surveying methods were used to evaluate which technique rapidly accumulated most species (> 90% of the estimated empirical value) at lowland Atlantic Forests in the state of São Paulo, southeastern Brazil. Birds were counted during the 2008-2010 breeding seasons using 10-minute point counts and 10-species lists. Overall, point counting detected as many species as lists (79 vs. 83, respectively), and 88 points (14.7 h) detected 90% of the estimated species richness. Forty-one lists were insufficient to detect 90% of all species. However, lists accumulated species faster in a shorter time period, probably due to the nature of the point count method in which species detected while moving between points are not considered. Rapid assessment programs in these forests will rapidly detect more species using 10-species lists. Both methods shared 63% of all forest species, but this may be due to spatial and temporal mismatch between samplings of each method.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Thomas Francis Lado ◽  
David Gwolo Phanuel Mogga ◽  
Richard Angelo Lado Benjamin

The study was carried out to determine patterns of birds’ species richness, alpha and beta diversities; and abundance in Badingilo national park using a 10 m fixed-radius point count method. A total of 2670 individuals were recorded from 182 points in the park. The highest expected number of species (Jack1 estimator) was observed in the Riverine habitat and least was in the Agriculture and Human settlement habitat type. The total number of species observed in the park was 63; however Jack1 estimator indicated that there were 68 species in the park. The majority of the birds observed during the study were resident species, few migratory and Palaearctic bird species. Few birds observed in the park were abundant. The most abundant species was the village weaver (381 individuals), and the rarest species were black-bellied bustard, barn owl, black scimitar bill and tree pipit (one individual each).


Birds ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 351-361
Author(s):  
Michał Budka ◽  
Kinga Kułaga ◽  
Tomasz Osiejuk

The point-count method is one of the most popular techniques for surveying birds. However, the accuracy and precision of this method may vary across various environments and geographical regions. We conducted sound-recorder-based point-counts to examine the accuracy and precision of the method for bird biodiversity estimation as a function of geographical region, habitat type and the time of day at which the survey began. In temperate (Poland) and tropical (Cameroon) regions, we recorded soundscapes on two successive mornings at 36 recording sites (18 in each location). At each site, we analyzed three 5-min surveys per day. We found no differences in the accuracy and precision of the method between regions and habitats. The accuracy was significantly greater at sunrise than during later surveys. The similarity of the bird assemblages detected by different surveys did not differ between regions or habitats. However, the bird communities described at the same time of day were significantly more similar to each other than those detected by surveys conducted at different times. The point-count method provided statistically indistinguishable estimates of bird biodiversity in different geographical regions and habitats. However, our results highlight two weaknesses of the method: low accuracy (41–54%), which limits the usefulness of a single survey in understanding bird–environment relationships, and changes in accuracy throughout the day, which may result in the misinterpretation of the status of bird populations.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259805
Author(s):  
Govind Tiwari ◽  
Puneet Pandey ◽  
Rahul Kaul ◽  
Hang Lee ◽  
Randeep Singh

Diurnal raptors show a wider distribution compared to other groups of birds including passerines, woodpeckers, and seriemas, but occur at lower-than-expected densities. Estimating the precise abundance is essential to achieve conservation goals but the methods used to estimate the populations of birds need to be appropriate to arrive at meaningful conclusions. We compared the two survey methods: roadside point count and strip transects, for estimating species richness and abundance of raptors in the arid landscape of Rajasthan. Roadside point counts and roadside strip transects were done on 50 transects between December 2019- February 2020 (with an average length of 20 km and a total distance of 3000 km) to assess the species richness and abundance of raptors. A total of 2954 observations of raptors belonging to 35 species were recorded using both methods. Mann Whitney U test result showed no significant difference in species richness and abundance estimates between both methods (p = 0.206). The point count method yielded a higher relative abundance of 2.79 individuals [10 km2]-1h-1 than the 1.90 individuals [10 km2]-1h-1 obtained during the strip transect. Also, the number of unidentified species were less for point counts. Extrapolation values indicated that both the methods do not differ much for the detection of unsampled species. The choice of survey method depends on the objectives of the study, but our results favor the use of point counts rather than strip transects to survey raptors in open habitats. The information generated from this study is expected to provide the most efficient method to study the abundance and distribution of raptors in similar landscapes.


2018 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Faizal Mahdi Syamal ◽  
Sugeng Prayitno Harianto

Kibang Pacing Village with an area of 83.55 km2 had converted that lead to a change of the vegetation structure from multistrata into monostrata that could threaten the wildlife such as the milky stork bird (Mycteria cinerea) that classified as a threatened species. The objectives of this study were to determine the number of individual and distribution patterns of milky stork in Rawa Pacing at Kibang Pacing Village, Menggala Timur Sub-District, Tulang Bawang Regency. Data collection was conducted through direct observation using point count method at 3 (three) point counts. The results observed 513 encounters of the milky stork, showing the most encounter at Point Count 3. The higher encounter occurred in the morning than in the afternoon which because diurnal bird species generally started their daily activities to find foods in the morning. The abundance of milky stork population in Kibang Pacing Village was 126 individuals, showing the highest number at Point Count 3. Illegal hunting and other human activities in Rawa Pacing could potentially cause disruption on natural habitat that may threaten the existence and sustainability of the milky stork bird.  Keywords: milky stork, Mycteria cinerea, pacing swamp, population.


2017 ◽  
Vol 19 (1) ◽  
pp. 69
Author(s):  
Frendi Irawan ◽  
Mochamad Hadi ◽  
Udi Tarwotjo

Dragonflies role as a predator in an ecosystem and become a healthy aquatic bio-indicators related to the life cycle. The diversity of habitat, food and predators affect community structure dragonfly. This study aims to determine the composition and community structure dragonfly morning and afternoon as well as the relationship with the physical environmental factors on four habitat in Semirang waterfall. Research using transect Point Count method. Statistically, the biodiversity of odonata in each habitat is significantly different. The results shows there are 15 species from 10 Family in morning observations and 12 species of 6 Family in afternoon observations, with a total of 17 species of 10 family of odonata. Biodiversity in each station is low to moderately with high evenness. The highest abundance found in river habitat without the canopy during the afternoon that Vestalis luctuosa (61.29%), while the lowest abundance found in the the canopied river habitat when afternoon that is Drepanosticta spatulifera (1.33%). Common species at area of Semirang waterfall are Euphaea variegata, Orthetrum sabina and Vestalis luctuosa. Endemic species at area of Semirang waterfall are Heliocypha fenestrata, Drepanosticta spatulifera and D. sundana. Key words : Community structure, Odonata, Semirang waterfall


2005 ◽  
Vol 119 (3) ◽  
pp. 377 ◽  
Author(s):  
J. Ryan Zimmerling

During spring and summer 1997, non-passerines were surveyed in three woodlots near Arnprior, Ontario, using standard point counts, and standard point counts combined with “pishing” (pishing involves the observer saying the words “pish pish pish pish” in a continuous series of short bursts). Of the 27 non-passerine species detected, 22 were recorded on more days using pishing as opposed to the standard point count method. However, only three of these species were recorded on significantly more days using pishing. Several woodpecker species approached more closely during point counts with pishing, which facilitated identification. In contrast, raptors and some other non-passerines that may have otherwise gone unnoticed were identified as they fled from the pishing sound. Hence, when the overall goal of research is to detect species richness or to gather presence and absence data in woodlands, point counts combined with pishing may increase detectability of some non-passerines.


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