Subtropical Broad-Leaved Urban Forests as the Foremost Dynamic and Complex Habitats for a Wide Range of Bird Species

Broad-leaved subtropical forests are the most productive, diversified, and complex ecosystems on the planet. Unfortunately, they are currently under severe threat from anthropogenic activities, such as. deforestation, housing settlements, and agricultural expansion. In response to these severe effects, the present study was conducted to explore the current conservation status and population structure of a wide range of bird species inhabiting different subtropical broad-leaved urban forests of Pakistan. In total, 2879 individuals comprising 53 species and 28 families were detected between December 2017 and November 2018 as revealed through the distance sampling line transect method. The habitat selection among bird species varied according to vegetation structure and composition, food resources, adjoining habitats, and human settlements. According to IUCN Red List data, one species was deemed vulnerable out of 53 bird species, while the remaining 52 species were ranked as ofleast concern. The findings of the density analysis revealed that bird density varied between six subtropical broad-leaved forests. Palamar (3.954 ± 0.221 birds/ha) and Kityari (3.138 ± 0.162 birds/ha) were densely populated, whereas Kamal Khan (1.102 ± 0.178 birds/ha) was of the least concern. Likewise, the diversity analysis showed that Kamal Khan was a more diverse habitat (Shannon–Wiener Index; H’ = 3.581 ± 0.021). Shahabad was richer (Margalef Richness Index; R1 = 8.007 ± 0.053) and Dob Ghar was evenly distributed (Pielou J Evenness Index; E = 0.940 ± 0.005) compared to other urban habitats studied. Eight foraging guilds were identified among the bird species. Insectivores were the most abundant bird species utilizing the urban dwelling habitats. carnivores/piscivores/insectivores utilized Dob Ghar forest, while more frugivores utilized Kamal Khan and Dob Ghar. Based on the data, it was concluded that subtropical broad-leaved urban forests are dynamic, complex, and of vital significance for a diverse range of bird species.

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State of Conservation and Population Structure of Bird Species Inhabiting in Various Subtropical Urban Forests

10.21203/rs.3.rs-193142/v1 ◽

2021 ◽

Author(s):

M. N. Rajpar ◽

M. Zakaria

Keyword(s):

Population Structure ◽

Conservation Status ◽

Distance Sampling ◽

Bird Species ◽

Urban Forests ◽

Avian Species ◽

Bird Diversity ◽

Line Transect ◽

Distance Analysis ◽

Wide Range

Abstract To determine the conservation status and population structure of avian species living in various subtropical broadleaved urban forests, namely Dob Ghar, Kamal Khan, Kityari, Palamar, Seya Sar and Shahabad of Pakistan, we aimed to use the distance sampling line transect process. To avoid double counting of the same bird individual, a total of 180 counting points were set at 250 m from each other. In all, between December 2017 and November 2018, 2,879 individuals representing 53 species, 28 families and 9 orders were detected. One species was vulnerable (VU) out of 53 bird species, while the remaining 52 species were the least concerned (LC). In particular, the results of the distance analysis indicate that, in six subtropical broad-leaved forests, the bird population can vary. For eg, Palamar (0.954 ± 0.221 birds/ha) and Kityari (0.938 ± 0.162 birds/ha) were densely populated by bird species, while Kamal Khan (0.102 ± 0.178 birds/ha) was less concerm. Similarly, the CAP findings showed that bird species in Dob Ghar were more diverse (H’ = 33.92 ± 1.368) and equally distributed (E = 0.9657 ± 0.004) and that the Shahabad ecosystem was rich in bird species (R1 = 8.007 ± 0.053) compared to other habitats. In addition, the length of the twigs and topological changes in the dendrogram have shown that bird diversity may vary from habitat to habitat. The bird species were classified into eight foraging guilds. Insectivores were the most abundant bird species using all habitats in abundance. By cons, Carnivore/Piscivore/Insectivore averted to use the forest habitats Dob Ghar and Frugivore Kamal Khan and Dob Ghar. The findings of this study revealed that broad-leaved subtropical urban forests are home to a wide range of avian species. However, habitat selection among bird species varied across habitats according to vegetation structure and composition, food resources, adjoining habitats, and human settlements.

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Conservation Value, Management and Restoration of Europe’S Semi‑Natural Open Landscapes

Hacquetia ◽

10.1515/hacq-2015-0017 ◽

2015 ◽

Vol 14 (1) ◽

pp. 5-17 ◽

Cited By ~ 17

Author(s):

Marta Carboni ◽

Jürgen Dengler ◽

Jasmin Mantilla-Contreras ◽

Stephen Venn ◽

Péter Török

Keyword(s):

Management Practices ◽

Anthropogenic Activities ◽

Abiotic Factors ◽

Conservation Status ◽

Ecosystem Functions ◽

Woody Vegetation ◽

Special Issue ◽

Current Conservation ◽

Dry Grassland ◽

Wide Range

Abstract Most semi-natural open habitats in Europe have been traditionally maintained by anthropogenic activities, such as grazing or mowing, preventing the establishment of woody vegetation. These habitats harbour a remarkably rich biodiversity in terms of both plant and animal species, but are also highly threatened, mainly by agricultural intensification and land abandonment. With this Editorial we introduce a Special Issue initiated by the European Dry Grassland Group (EDGG) at the Open Landscapes Conference (Hildesheim, 2013) and the 11th European Dry Grassland Meeting (Kulikovo Pole, 2014). We aim to give a short introduction to the current conservation status, significance and research of semi-natural open habitats in Europe and present the collected articles of the Special Issue. These papers cover a wide range of different semi-natural open habitats, including wood-pastures, heathlands, steppes, semi-dry and dry grasslands across the Palearctic region and address issues related to the assessment methods, threats, management and restoration of these habitats. We conclude that, in order to ensure their conservation and to monitor the changes in open habitats, integrative approaches are needed that take into account not only vegetation records, but also multiple animal taxa, abiotic factors, management practices, ecosystem services and modelling simulations for anticipating possible future scenarios. We also recommend that decision-makers should support actions to conserve open habitats in Europe by addressing such major challenges as the encroachment of woody vegetation. We are convinced that the present Special Issue will contribute to a better understanding of ecosystem functions and support the biodiversity conservation and management of semi-natural open habitats.

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Assessing the Population Status of a Tree Species Using Distance Sampling:Aquilaria crassna(Thymelaeaceae) in Northern Laos

International Journal of Forestry Research ◽

10.1155/2012/265831 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 5

Author(s):

Anders Jensen ◽

Henrik Meilby

Keyword(s):

Tree Species ◽

Conservation Status ◽

Distance Sampling ◽

Average Density ◽

Survey Method ◽

Line Transect ◽

Population Status ◽

Wide Range ◽

Nontimber Forest Product ◽

Present Case Study

Lack of reliable and accurate field data affect assessments of population status of tree species, especially tropical taxa with broad distributions. Use of distance sampling techniques may help to overcome the problem. This paper describes a method for estimation of absolute density of a rare tree species with scattered and clumped distribution, using line transect distance sampling. The method was applied to previously harvested populations ofAquilaria crassnaPierre ex H. Lec. (Thymelaeaceae) at four sites in Northern Laos. This species is destructively harvested to yield agarwood, probably the world’s most valuable nontimber forest product and categorised as ”critically endangered“. The average density of felledA. crassnatrees at the four sites was 2.2 ha−1, indicating that harvesting has been extensive. However, the estimated densities of living saplings, 10.9 ha−1, small trees (DBH < 10 cm), 10.6 ha−1, and larger trees (DBH ≥ 10 cm), 1.7 ha−1, suggest that populations are not wiped flat. The survey method should stand a good chance of wider use as a tool in management and conservation of a wide range of tree species. Results of the present case study could suggest that the conservation status ofA. crassnashould be re-categorised.

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Birds species composition and abundance of a relativelly undisturbed vegetation at Mount Pati, Lokoja, Kogi State

Brazilian Journal of Biological Sciences ◽

10.21472/bjbs.061225 ◽

2019 ◽

Vol 6 (12) ◽

pp. 271-282

Author(s):

Dauda Tanko ◽

Rita Chinweuba

Keyword(s):

State Government ◽

Diversity Index ◽

Anthropogenic Activities ◽

Bird Species ◽

Activity Level ◽

Line Transect ◽

Biological Factors ◽

Wet Season ◽

Fuel Wood ◽

Wiener Diversity Index

Avifauna of a relatively undisturbed vegetation at Mount Patti of Lokoja was surveyed from January to June, 2018. Line transect and point count techniques were used for data collection. This was done by weekly visits to the site between 6:00 h and 10:00 h of the day. Bird identification was done with the aid of a pair of binoculars, Field Guide of birds of western Africa and recorded bird calls. Monthly variation and season variation in bird composition and abundance were compared using Shannon-Wiener diversity index and equitability index. There were 39 species in 21 families encountered during the survey. The Family Nectarinidae had the highest number of 5 species, followed by Columbidae and Estrildidae with 4 species each. A total of 1,148 individuals were encountered during the six months survey with village weaver having the highest encountered rate of 107 while yellow-throated Long-claw had the least encountered rate of 4 individuals. Fluctuation was observed in the monthly encountered rate of the birds. Diversity and equitability indices had their highest values of 5.24 and 1.51 in January. More birds (696) were encountered in the wet season than the dry season (452). Four species were seen only in the wet season. Species effort curve showed that there are more species to be discover. The number of species encountered in this study revealed that the mountain is rich composition of bird species, even though the site seems to favour species that show preference to disturbed areas. The on-going anthropogenic activities probably paved way to these species to move in. Monthly and seasonal fluctuation of bird species diversity and abundance may be due to a combination of physical and biological factors. The physical and biological factors observed at the site which we speculate could be reasons for the observed fluctuations include slash and burnt system of farming, fuel-wood harvesting, intensive sporting activities creation of foot paths etc. High encountered rate indicate abundance and high activity level of the species. The village weaver was the most encountered species probably because they are known to be lousy, move in flocks and breed in colonies. In view of the rich composition and abundance of bird species on Mount Patti and the site being a suitable breeding site for the weavers. We recommend further study of the place as there are yet more species to be discovered as indicated by the species effort curve. There is need for conservation procedures to be initiated at the place and this study should serve as a baseline to initiate such programme by the state government.

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Conservation status of mammals and birds in southwestern Australian forests. I. Is there evidence of direct links between forestry practices and species decline and extinction?

Pacific Conservation Biology ◽

10.1071/pc980296 ◽

1998 ◽

Vol 4 (4) ◽

pp. 296 ◽

Cited By ~ 9

Author(s):

M. C. Calver ◽

J. Dell

Keyword(s):

Negative Impact ◽

Conservation Status ◽

Bird Species ◽

Fire Regimes ◽

Personal Identification ◽

Base Line ◽

Mammal Species ◽

Current Conservation ◽

Forestry Practices ◽

European Settlement

Sixteen mammal species and 22 bird species whose distributions extended into southwestern Australian forests before European settlement have been listed as threatened at some time in Commonwealth legislation, State legislation, or action plans of Environment Australia or its predecessors. Confident assessment of the causes of conservation status is hampered by poor base-line data, few studies of putative impacts and a preponderance of circumstantial or anecdotal rather than experimental evidence. However, introduced foxes were Implicated In the current conservation status of 62% of the mammal species recognized, while 44% of them were negatively impacted by feral cats, 44% by agricultural clearing and 44% by changed fire regimes. Forestry practices were impllcated in the conservation status of only one mammal species. For the bird species recognized, changed fire regimes had the greatest negative impact (45% affected), agricultural clearing affected 41%, draining of wetlands affected 32% and grazing by livestock affected 22%. Forestry practices were not directly implicated in the conservation status of any bird species. While these results suggest that forestry has had minimal direct impact on the mammals and birds of the forests, the conclusion should be treated cautiously because of the poor data. While awaiting a rigorous evaluation, we argue for a strong precautionary approach to forestry in the region. With proper forest management and sound sylvicultural [sic] treatment there is no reason why there should not be built up on the wreckage of the once splendid forests of Western Australia tended forests which will yield for all time 100 cubic feet of timber per acre per year. Lane-Poole (1920). There are many reasons why Australian environmentalists would like to end logging in native forests. The preservation of wilderness, aesthetics, an almost religious identification with old growth forests and the conservation of forest wildlife figure importantly in environmental efforts to restrict logging. Wilderness and a personal identification with trees and undisturbed forests are fundamentally incompatible with logging. Recher (1996).

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Out of the darkness: the first comprehensive survey of the Critically Endangered Anjouan Scops Owl Otus capnodes

Bird Conservation International ◽

10.1017/s0959270914000185 ◽

2014 ◽

Vol 25 (3) ◽

pp. 322-334 ◽

Cited By ~ 1

Author(s):

KATHLEEN E. GREEN ◽

BRONWEN M. DANIEL ◽

SAMUEL P. LLOYD ◽

ISHAKA SAID ◽

AMELAID HOUMADI ◽

...

Keyword(s):

Population Size ◽

Conservation Status ◽

Distance Sampling ◽

Bird Species ◽

Iucn Red List ◽

Critically Endangered ◽

Encounter Rate ◽

Wet Season ◽

Point Counts ◽

Comprehensive Survey

SummaryAlthough birds are among the best studied taxa, many of the globally threatened species lack the information required to fully assess their conservation status and needs. One such species is the Anjouan Scops Owl Otus capnodes which was presumed extinct until its rediscovery to science in 1992. Based on the limited extent and decline of the moist forests in the highlands of Anjouan in the Comoro Islands, a population size of only 100–200 pairs was estimated and the species was classified as ‘Critically Endangered’. The current study is the first comprehensive survey ever conducted on this species, and aimed to establish the current distribution and population size. Point counts with distance sampling were conducted across the agroforestry and forest zones of Anjouan in both a dry and wet season. A niche suitability model predicted the species distribution to be wider than expected with owls observed as low as 300 m altitude and in highly modified agroforestry habitats. However, the encounter rate in natural relatively undisturbed forest was significantly greater than in other habitats. The wider than expected geographic range of O. capnodes supports a possible downlisting of this species on the IUCN Red List to ‘Endangered’. Population size was found to be far greater than previously thought, at approximately 3,450 individual owls in the dry season and 5,450 in the wet season. These results show the importance of investing in robust surveys of poorly known and cryptic bird species, and provide up to date and important information for landscape scale conservation planning in the Comoros Islands.

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Avifauna in three vegetation types on Mundanthurai Plateau, South India

Journal of Tropical Ecology ◽

10.1017/s0266467400007999 ◽

1994 ◽

Vol 10 (3) ◽

pp. 323-335 ◽

Cited By ~ 10

Author(s):

A. J. T. Johnsingh ◽

Justus Joshua

Keyword(s):

Species Diversity ◽

South India ◽

Deciduous Forest ◽

Conservation Status ◽

Bird Species ◽

Line Transect ◽

Vegetation Types ◽

Secondary Vegetation ◽

Dry Deciduous Forest ◽

Bird Species Diversity

ABSTRACTPatterns of bird species diversity within three vegetation types were investigated by the line transect method on Mundanthurai Plateau, South India. Minimum numbers of species and individuals were seen in the study area during July and August. Such seasonal variation was more pronounced in riverine and dry deciduous forest than in the secondary vegetation which was avoided by most of the winter migrants. There was a greater species overlap between riverine and dry deciduous forest than between riverine and secondary vegetation.No relationship could be established between bird species diversity and tree species/foliage height diversity. The secondary vegetation had fewer specialized forest species and more generalists. Larger birds (>200 g) were rare but smaller ones (<50 g) were more common. The paper emphasizes that the conservation status of avifauna in managed forests in India needs to be assessed and monitored.

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Tendencias poblacionales recientes de la avutarda hubara en las Islas Canarias: análisis metodológico y estado de conservación

Animal Biodiversity and Conservation ◽

10.32800/abc.2012.35.0125 ◽

2012 ◽

Vol 35 (1) ◽

pp. 125-139

Author(s):

C. Schuster ◽

◽

J. J. Iglesias-Lebrija ◽

L. M. Carrascal ◽

◽

...

Keyword(s):

Canary Islands ◽

Conservation Status ◽

Distance Sampling ◽

Small Variation ◽

Population Trends ◽

Line Transect ◽

Sampling Area ◽

Average Value ◽

Houbara Bustard ◽

Population Sizes

Recent population trends of the houbara bustard in the Canary Islands. Methods and conservation status Determining conservation status requires rigorous and reliable data about population sizes and trends, especially if they have to be applied to islands where the species have small populations. The Canary bustard houbara (Chlamydotis undulata fuertaventurae) is catalogued as ‘in danger’ by the Red Book of the Birds of Spain. This work analyzes the value of previously published information on the species using the method of adjacent linear transects separated by 200 m, as a baseline for establishing robust population trends in 30 important areas (ranging from 1.3 to 12.8 km2) for the houbara in the islands of Lanzarote and Fuerteventura (Canary Islands). Censuses were repeated on the same dates (from November to December) and localities as those carried out in 1994, 2004 and 2006. The detection probability of the houbara was estimated by means of distance sampling, being 0.42 up to 250 m from the observer, and 0.82 in the main census belt of 100 m on either side of the line transect. The method of adjacent linear transects —counting the maximum number of hubaras detected— provides accurate figures of population densities (detection of 95.2% of the birds). The previous estimations of houbara densities can therefore be considered highly trustworthy, with a probable average underestimation of only 5 %. Nevertheless, the confidence intervals of density estimations using only one census were very large. Therefore, with only one census per sampling area and year it is not possible to obtain precise estimates of houbara densities with small variation around the average value. This raises concern when trying to obtain solid evidence about the increases–decreases of houbara populations comparing different dates or study areas. The density of the Canary Island hubara bustard decreased significantly from 2004/2006 to 2011 in eight areas of Fuerteventura (Vega Vieja, Los Alares–Pocetas, Matas Blancas, Lorenzo– Diviso, Corralejo, Lajares and Fimapaire) and in two areas of Lanzarote (Argana and La Santa). Conversely, the density of the houbara significantly increased in three areas of Lanzarote (Zonzamas, Guatiza and Llano de las Maretas). As a whole, average population density did not differ significantly between 2004/2006 and 2011 in Fuerteventura (slight decrease of 29% in 2011), but there was a significant increase in Lanzarote (increase of 60% from 2004/2006 to 2011). The change in density from 2004/2006 to 2011 tended to be an increase in areas further from paved roads, and a decrease in locations predominantly covered by loose sandy soils.

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Estimating the population size of a threatened arboreal marsupial: use of distance sampling to dispense with ad hoc survey techniques

Wildlife Research ◽

10.1071/wr10090 ◽

2010 ◽

Vol 37 (6) ◽

pp. 512 ◽

Cited By ~ 5

Author(s):

Paul J. de Tores ◽

Sue Elscot

Keyword(s):

Land Use ◽

Population Size ◽

Ad Hoc ◽

Conservation Status ◽

Distance Sampling ◽

Potential Effect ◽

Decision Makers ◽

Biological Information ◽

Line Transect ◽

Land Use Decisions

Context. Long-term land-use decisions potentially affecting the conservation status of rare fauna are often based on a dearth of relevant biological information and population estimates are regularly derived from ad hoc methodologies. This can significantly affect the outcomes from development assessment and approval processes. Aim. Our aims were to apply distance-sampling techniques to derive robust, quantitative estimates of the population size of a threatened arboreal marsupial, the western ringtail possum (Pseudocheirus occidentalis Thomas, 1888), demonstrate the advantages of this approach and, in doing so, provide conservation managers, decision makers and consultants with a reliable framework for surveying the species. Methods. We used line-transect sampling to derive estimates of density and abundance for P. occidentalis at two sites in south-western Western Australia where estimates were previously derived through ad hoc techniques. Key results. Our findings support the assertion that previous surveys of P. occidentalis populations have underestimated the population size to a varying extent at both of our survey sites. Land-use and development-application decisions have previously been based on similar surveys. Conclusions. Distance sampling, if applied routinely when surveying P. occidentalis, will reduce the uncertainty associated with derived estimates of abundance. Implications. Appropriate use of distance-sampling methods will enable managers and decision makers to assess more quantitatively the potential effect from, and place appropriate approval conditions on, proposals that modify or destroy P. occidentalis habitat. The use of the program Distance will enable such decisions to be based on robust, repeatable estimates of population size, with quantified confidence limits and variance estimates.

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Evaluation of the analysis of distance sampling data: a simulation study

Ornis Svecica ◽

10.34080/os.v20.22642 ◽

2010 ◽

Vol 20 (1) ◽

Author(s):

Robert Ekblom

Keyword(s):

Distance Sampling ◽

Bird Species ◽

Simulated Data ◽

Probability Of Detection ◽

Parameter Estimates ◽

Area Of Interest ◽

Field Situation ◽

Wide Range ◽

Density Values ◽

Distance Data

Distance sampling is used to estimate number of individuals in an area of interest. The idea is that with known distances to the observed individuals, one can model the probability of detection in relation to distance and thereby account for individuals that were not detected. Distances can be recorded either exactly or in discrete categories. In this study I validated the method using simulated distance sampling data for two hypothetical bird species and compared the estimated density values to the known true densities. Generally the true densities and numbers of individuals were very similar to (and always within the 95% confidence interval of) the parameter estimates from the analysis of the simulated data. The analyses were also robust to modifications of the data such as truncation and grouping of the distances into discrete categories. The confidence intervals increased, however, when using only two distance groups. Given that critical assumptions of the model can be met in the field situation, distance data can thus be used in a wide range of bird studies to calculate reliable density estimates.

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