scholarly journals Multi-annual and seasonal patterns of waterbird assemblages in a Mediterranean coastal lagoon (El Mellah lagoon) of Northeastern Algeria

2017 ◽  
Vol 36 (2) ◽  
pp. 146-157
Author(s):  
Salah Telailia ◽  
Lamia Boutabia ◽  
Mohamed Dhaya El-Hak Khemis ◽  
Ali Elafri ◽  
Nawel Djebbari
Keyword(s):  
Relative Abundance ◽  
Coastal Lagoons ◽  
Bird Species ◽  
Diversity Indices ◽  
Species Number ◽  
Marked Decline ◽  
Breeding Seasons ◽  
Waterbird Assemblages ◽  
Northeastern Algeria

Abstrat Recently, Mediterranean coastal lagoons have raised considerable environmental concerns. Long-term studies of seasonal changes in waterbird assemblages are therefore extremely important in terms of ecological relevance and conservation of these sensitive ecosystems. An ornithological survey of four years was carried out in a typical costal wetland (El Mellah lagoon) of Northeastern Algeria. Intra-seasonal comparison of waterbird assemblages (diversity indices) demonstrates clear changes between the wintering and the breeding periods. It seems that the first one was rich in term of species number than the second season (43 against 24). In contrast, the breeding seasons were more equilibrate (high values of Simpson, Shannon and evenness index). Additionally, curves in the diversity/dominance diagram revealed that both wintering and breeding assemblages share the same characteristics of community structure, few dominant species (with intermediate relative abundance) and many rare species with the relative abundance lower than 0.1. Invertebrates (25 species) and piscivorous (11 species) are the most abundant guilds over the four years of study (no significant differences among years have been calculated). The marked decline in bird species diversity recorded in this study (in comparison with previous studies) is mainly due to salinity oscillations (due to aquaculture activities) and may be of concern to wetland managers and it might be useful to provide some guidelines about the characteristics that coastal lagoons have to follow in the construction process to enhance the biodiversity.

scholarly journals The effect of climate change on the duration of avian breeding seasons: a meta-analysis

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171710 ◽  
Author(s):  
Lucyna Halupka ◽  
Konrad Halupka
Keyword(s):  
Migratory Birds ◽  
Meta Analysis ◽  
Bird Species ◽  
Egg Laying ◽  
Long Distance ◽  
Local Climate ◽  
Ecological Flexibility ◽  
Breeding Grounds ◽  
Breeding Seasons

Many bird species are advancing the timing of their egg-laying in response to a warming climate. Little is known, however, of whether this advancement affects the respective length of the breeding seasons. A meta-analysis of 65 long-term studies of 54 species from the Northern Hemisphere has revealed that within the last 45 years an average population has lengthened the season by 1.4 days per decade, which was independent from changes in mean laying dates. Multi-brooded birds have prolonged their seasons by 4 days per decade, while single-brooded have shortened by 2 days. Changes in season lengths covaried with local climate changes: warming was correlated with prolonged seasons in multi-brooded species, but not in single-brooders. This might be a result of higher ecological flexibility of multi-brooded birds, whereas single brooders may have problems with synchronizing their reproduction with the peak of food resources. Sedentary species and short-distance migrants prolonged their breeding seasons more than long-distance migrants, which probably cannot track conditions at their breeding grounds. We conclude that as long as climate warming continues without major changes in ecological conditions, multi-brooded or sedentary species will probably increase their reproductive output, while the opposite effect may occur in single-brooded or migratory birds.

scholarly journals The Mid-Winter Assemblage And Diversity Of Bird Populations At Patlakhawa Protected Forest, Coochbehar, West Bengal, India

Ring ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 31-53 ◽  
Author(s):  
Asitava Chatterjee ◽  
Shuvadip Adhikari ◽  
Anandamay Barik ◽  
Subhra Kumar Mukhopadhyay
Keyword(s):  
West Bengal ◽  
Bird Species ◽  
Diversity Indices ◽  
Point Of View ◽  
Species Number ◽  
Habitat Types ◽  
Swamp Forest ◽  
Bird Populations ◽  
Niche Diversity ◽  
Habitat Fidelity

ABSTRACT We compared avian community structure of six contrasting habitat types at Patlakhawa Protected Forest of Dooars of West Bengal. During three weeks of the mid-winter studies 154 bird species representing 41 families were recorded. Of the 154 recorded species, 22 were observed in grasslands, 22 in swamp forest, 46 in riverine forest, 52 at miscellaneous plantation areas, 43 at forest edges and 51 at wetlands. The Shannon-Wiener general diversity indices varied among the habitats and ranged from 2.323 to 3.458. Richness (5.813-11.410), evenness (0.406-0.641) and dominance (0.042-0.128) indices also varied considerably among the study locations. The highest diversity, the lowest dominance and a very high evenness were characteristics of miscellaneous plantations. Grasslands showed highest evenness and considerably high species diversity. The lowest avian evenness and diversity were recorded in wetlands and swamp forests. Insectivorous birds were most numerous (53), followed by carnivorous (40), omnivorous (29) and frugivorous (15) birds. Winter appeared to be the best time for niche occupancy at the Himalayan foothills for assemblages of either winter migrants and visitors or altitudinal and passage migrants, as about 30% of all encountered species were migrants. 96 bird species were observed to occur at any one of these habitat types showing high habitat fidelity. Mixed avian foraging assemblages that varied in species number and compositions were observed and they contain 11 to 17 species. Avifaunal niche diversity and richness in different habitats of Patlakhawa Protected Forest during mid-winter envisaged its importance from conservation point of view.

scholarly journals Effects of research disturbance on nest survival in a mixed colony of waterbirds

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7844
Author(s):  
Jocelyn Champagnon ◽  
Hugo Carré ◽  
Lisa Gili
Keyword(s):  
Survival Rate ◽  
Reproductive Success ◽  
Bird Species ◽  
Daily Survival Rate ◽  
Negative Effects ◽  
Control Zone ◽  
Daily Survival ◽  
Disturbed Zone ◽  
Breeding Seasons

Background Long-term research is crucial for the conservation and development of knowledge in ecology; however, it is essential to quantify and minimize any negative effects associated with research to gather reliable and representative long-term monitoring data. In colonial bird species, chicks are often marked with coded bands in order to assess demographic parameters of the population. Banding chicks in multi-species colonies is challenging because it involves disturbances to species that are at different stages of progress in their reproduction. Methods We took advantage of a long term banding program launched on Glossy Ibis (Plegadis falcinellus) breeding in a major mixed colony of herons in Camargue, southern France, to assess the effect of banding operation disturbance on the reproductive success of the three most numerous waterbirds species in the colony. Over two breeding seasons (2015 and 2016), 336 nests of Glossy Ibis, Little Egrets (Egretta garzetta) and Cattle Egrets (Bubulcus ibis) were monitored from a floating blind in two zones of the colony: one zone disturbed twice a year by the banding activities and another not disturbed (control zone). We applied a logistic-exposure analysis method to estimate the daily survival rate (DSR) of nests and chicks aged up to three weeks. Results Daily survival rate of Glossy Ibis was reduced in the disturbed zone while DSR increased for Little and Cattle Egrets in the disturbed zone. Nevertheless, DSR was not reduced on the week following the banding, thus discarding a direct effect of handling on breeding success of Glossy Ibis. The protocol and statistical analysis presented here are robust and can be applied to any bird species to test for the effect of a research disturbance or other short and repeated temporal events that may affect reproductive success over one or more breeding seasons.

scholarly journals AVIAN SPECIES COMPOSITION PROFILE AND FEEDING GUILDS UNDER THE AEROBIC RICE FIELD

2021 ◽  
Vol 21 (1) ◽  
pp. 63-71
Author(s):  
Badrulhadza Amzah ◽  
Razali Baki ◽  
Mohd Hafizi Yahya
Keyword(s):  
Bird Species ◽  
Wiener Index ◽  
Diversity Indices ◽  
Current Status ◽  
Species Number ◽  
Feeding Guilds ◽  
Aerobic Rice ◽  
Feeding Guild ◽  
Set Up ◽  
Water Scarce

In Malaysia, the aerobic rice production system is an alternative approach to growing rice in a water-scarce environment. Like irrigated rice, aerobic rice also can sustain a diversity of avian fauna. The current status of birds in the rice fields of Malaysia especially under aerobic rice condition has not been widely researched. Therefore, this study aims to document the richness, diversity and feeding guilds of bird species in aerobic rice cultivation area. Birds were sampled and recorded using four randomly set up mist net at an upscaling aerobic rice plot in Serdang, Selangor during a period of the one month starting from the milky stage of the plant (75 days after emergence) until two weeks after harvest. 139 birds representing 11 species belonging to 7 families were recorded in the aerobic rice plot. The most abundant bird family observed was Estrildidae (80.58%), followed by Hirundinidae (6.47%), and Meropidae and Motacillidae (both recorded 5.04%). Scaly-breasted munia (50.36%) and white-headed munia (28.06%) are the most abundant birds, while other types of munia such as chestnut munia and white-rumped munia are present in small numbers. Munias were the most observed bird species number (36.36%) and therefore can be considered as the main avian pest of aerobic rice. The diversity indices, The Shannon-Wiener Index was 1.43 while The Reciprocal Simpson Index was 2.93. The richness index (The Margalef Index) was 2.03. The Equitability Index was 0.59. In term of feeding guild, most species belong to insectivore (45.45%) and granivore (36.36%) while the rest were piscivore/insectivore and granivore/insectivore. However, the granivore recorded the highest number of individuals (112 or 80.58%) compared to other guilds. Presence of a relatively high diversity of bird species with varieties of feeding guilds indicated that aerobic rice does provide an attractive habitat or foraging site for avian fauna.

scholarly journals Diversity of bird communities of the forest in the Boyarska experimental station at the gradient of anthropic load

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
V.A. Gaychenko ◽  
◽  
T.V. Shupova ◽  
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Conservation Status ◽  
Bird Species ◽  
Parus Major ◽  
Diversity Indices ◽  
Bird Communities ◽  
Experimental Station ◽  
Α Diversity ◽  
Synanthropization Index

Bird communities was researched according to the transect method in the nesting period of 2013 and 2015. 4 model forest plots in the Boyarskaya Experimental Station were selected. All of them are culturelphytocenoses based onPinus sylvestris L., Quercus robur L., Q. rubra L. The species composition of birds, their abundance, α-diversity indices, synanthropization index of bird communities (to Jedryctkowski) were analyzed. The similarity of bird communities was determined using cluster analysis in "Origin Pro 9.0". 65 bird species of 11 orders were recorded. 35 species of them live in the species reserve. On model plots that not have conservation status, the number of species in bird communities is 20–27. In plots with a dominance of Q. robur, 42 species were recorded, with a dominance of P. sylvestris - 35 species of the birds. Dominants in bird communities Parus major L. and Fringilla coelebs L. The presence in the list of subdominants Anthus trivialis L. and Phylloscopus sibilatrix Bechstein is a positive characteristic of the forest. The synanthropic of bird communities increases according to the increase in anthropic load: the synanthropization index from 0.4 to 0.65, the relative abundance of synanthropic birds in communities from 0.66 to 0.81. There are no alien birds. The species diversity and the number of bird species in the communities decreases along the gradient of increasing anthropic load. The similarity of bird communities and their α-diversity depends by the anthropic load, and not by the ratio of the species composition of the forest trees. The distribution of relative abundance of species in bird communities, on the contrary, is associated with the ratio of the species composition of trees. In forest plots dominated by P. sylvestris, bird communities are balanced, in plots with a predominance of Q. robur, disturbances in the development of bird communities are noticeable.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

scholarly journals Domain randomization-enhanced deep learning models for bird detection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Mao ◽  
Jun Kang Chow ◽  
Pin Siang Tan ◽  
Kuan-fu Liu ◽  
Jimmy Wu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Continuous Monitoring ◽  
Bird Species ◽  
Training Data ◽  
Learning Models ◽  
Fine Grained ◽  
Bird Detection ◽  
Relationship Of ◽  
The Relationship

AbstractAutomatic bird detection in ornithological analyses is limited by the accuracy of existing models, due to the lack of training data and the difficulties in extracting the fine-grained features required to distinguish bird species. Here we apply the domain randomization strategy to enhance the accuracy of the deep learning models in bird detection. Trained with virtual birds of sufficient variations in different environments, the model tends to focus on the fine-grained features of birds and achieves higher accuracies. Based on the 100 terabytes of 2-month continuous monitoring data of egrets, our results cover the findings using conventional manual observations, e.g., vertical stratification of egrets according to body size, and also open up opportunities of long-term bird surveys requiring intensive monitoring that is impractical using conventional methods, e.g., the weather influences on egrets, and the relationship of the migration schedules between the great egrets and little egrets.

Nest cameras do not affect nest survival in a meadow-nesting shorebird

2020 ◽  
pp. 1-10
Author(s):  
VOLKER SALEWSKI ◽  
LUIS SCHMIDT
Keyword(s):  
Nest Survival ◽  
Bird Species ◽  
Conservation Strategies ◽  
Survival Models ◽  
Northern Germany ◽  
Term Study ◽  
Long Term Study ◽  
Limosa Limosa ◽  
Study Sites

Summary Identifying the fate of birds’ nests and the causes of breeding failure is often crucial for the development of conservation strategies for threatened species. However, collecting these data by repeatedly visiting nests might itself contribute to nest failure or bias. To solve this dilemma, automatic cameras have increasingly been used as a time-efficient means for nest monitoring. Here, we consider whether the use of cameras itself may influence hatching success of nests of the Black-tailed Godwit Limosa limosa at two long-term study sites in northern Germany. Annually between 2013 and 2019, cameras were used to monitor godwit nests. In 2014 and 2019, nests were randomly equipped with cameras or not, and nest survival checked independently of the cameras. Nest-survival models indicated that survival probabilities varied between years, sites and with time of the season, but were unaffected by the presence of cameras. Even though predation is the main cause of hatching failure in our study system, we conclude that predators did not learn to associate cameras with food either when the cameras were initially installed or after they had been used for several years. Cameras were thus an effective and non-deleterious tool to collect data for conservation in this case. As other bird species may react differently to cameras at their nests, and as other sets of predators may differ in their ability to associate cameras with food, the effect of cameras on breeding success should be carefully monitored when they are used in a new study system.

scholarly journals Long-Term Changes in Floristic Diversity as an Effect of Transforming the Lake into a Retention Reservoir

2021 ◽  
Vol 13 (14) ◽  
pp. 7642
Author(s):  
Joanna Sender ◽  
Danuta Urban ◽  
Monika Różańska-Boczula ◽  
Antoni Grzywna
Keyword(s):  
Drainage System ◽  
High Water ◽  
Diversity Indices ◽  
Habitat Diversity ◽  
Peat Bogs ◽  
Ecological Index ◽  
Natural Lakes ◽  
Lighting Conditions ◽  
Low Reaction Temperature

The Łęczna-Włodawa Lake District is one of the most valuable natural regions in Europe. It is an area of numerous lakes, peat bogs, swamps and forests, which has been undergoing intensive transformation for decades. Among the largest projects were the creation of the Wieprz Krzna Canal system along with the drainage system and the transformation of natural lakes into retention reservoirs. Among the transformed lakes is Lake Wytyckie. The land was used for analyses near the lake, and floristic and habitat analyses were carried out within the boundaries of the contemporary embankment. The studies were carried out from the 1950s, when the lake functioned as a natural reservoir, through to the 1980s (the transformation of the lake), to the 2020s. Lake Wytyckie was transformed into a retention reservoir by increasing its size and flooding the areas inhabited mainly by peat bog, meadow and forest vegetation, which contributed to the impoverishment of both species and habitat diversity of the area, while it increased the nutrient richness of the water. This was reflected both in the decline in the value of individual diversity indices as well as in the ecological index numbers. In the first period of the research, the area was dominated by wetlands, not drained, with a large variety of species that preferred good lighting conditions. Additionally, the habitat was characterized by low reaction, temperature and trophic values. In the following period, there was an increase in the depth of the water of the reservoir, characterized by high water visibility values, which contributed to the presence of protected species, as did the low moisture content of the areas within the embankment and a neutral pH. The factors currently influencing the formation of the vegetation structure are the high humidity of the entire embankment area, the increase in pH, and the significant increase in the share of built-up areas in the immediate vicinity.

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