scholarly journals STUDY OF THE FACTORS AND DEGREE OF ASSOCIATION BETWEEN VARYING POPULATION OF BIRD SPECIES AND THEIR MICROHABITAT

2019 ◽  
Vol 07 (02) ◽  
Author(s):  
Sombuddha Roy Bhowmick
Keyword(s):  
Bird Species ◽  
Degree Of Association ◽  
Varying Population

scholarly journals Birds associated with treefall gaps in a lowland forest in southwestern Brazilian Amazonia

2021 ◽  
Vol 51 (1) ◽  
pp. 42-51
Author(s):  
Jônatas LIMA ◽  
Edson GUILHERME
Keyword(s):  
Forest Canopy ◽  
Bird Species ◽  
Fragmented Landscape ◽  
Amazon Forest ◽  
Lowland Forest ◽  
Brazilian Amazonia ◽  
Vegetation Height ◽  
Treefall Gaps ◽  
Survival And Reproduction ◽  
Degree Of Association

ABSTRACT Natural communities are dynamic systems in time and space. The spatial distribution of plants and animals tends to coincide with the availability of resources needed for the survival and reproduction of each species. Natural treefall gaps offer a number of resources that influence the distribution of birds within the forest. We compared the understory bird assemblages of natural treefall gaps (15 sampling points) with those found in the adjacent forest (15 points) in the Humaitá Forest Reserve in southwestern Brazilian Amazonia. We used mist-nets to sample birds and obtained 700 captures of 105 species. Species richness, number of individuals, and species composition were all similar between gaps and forest, although six species presented some degree of association with the gaps, and nine with the forest. Nectarivores preferred gaps significantly over forest, whereas insectivores and frugivores were distributed equally between gaps and forest. Vegetation height and density differed between gaps and forest, and influenced the distribution of bird species in the two environments. Fruit availability was positively correlated with frugivore abundance in gaps. Overall, 33.3% of the birds associated with the treefall gaps are from lower forest canopy, while the others are understory species. We showed that the use of natural gaps by birds in a fragmented landscape of the Amazon forest contributes to the environmental heterogeneity and succession dynamics following natural events of habitat disturbance.

Items’ Cross-Category Associations as a Confounding Factor in the Implicit Association Test

2001 ◽  
Vol 48 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Melanie C. Steffens ◽  
Inga Plewe
Keyword(s):  
Implicit Association Test ◽  
Confounding Factor ◽  
Reaction Times ◽  
Association Test ◽  
The Other ◽  
Reaction Time Difference ◽  
Implicit Association ◽  
Male And Female ◽  
Research Activities ◽  
Degree Of Association

Abstract. The introduction of the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998 ) has stimulated numerous research activities. The IAT is supposed to measure the degree of association between concepts. Instances have to be assigned to these concepts by pressing appropriate keys as quickly as possible. The reaction time difference between certain conditions, termed the IAT effect, is used as an indicator of the degree of the concepts’ association. We tested the hypothesis that the degree of association between one concept (or category) and the instances of the other presented concept also influences reaction times. In our experiment, the instances in the target categories, male and female names, were kept constant. The adjectives in the evaluative categories were manipulated: Either the pleasant adjectives were female-associated and the unpleasant adjectives were male-associated, or vice versa. These stereotypic associations were indeed found to exert a substantial influence on the size of the IAT effect. This finding casts doubt on the assumption that the IAT effect may be interpreted as a pure measure of the degree of association between concepts.

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

Experimentally increased costs of parental care are shunted to offspring in species with extended care

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Life History ◽  
Parental Care ◽  
Total Duration ◽  
Bird Species ◽  
Life History Strategy ◽  
Experimental Treatment ◽  
Cost Of Care ◽  
Adult Survival ◽  
Supporting Evidence ◽  
Trade Offs

Biparental care systems are a valuable model to examine conflict, cooperation, and coordination between unrelated individuals, as the product of the interactions between the parents influences the fitness of both individuals. A common experimental technique for testing coordinated responses to changes in the costs of parental care is to temporarily handicap one parent, inducing a higher cost of providing care. However, dissimilarity in experimental designs of these studies has hindered interspecific comparisons of the patterns of cost distribution between parents and offspring. Here we apply a comparative experimental approach by handicapping a parent at nests of five bird species using the same experimental treatment. In some species, a decrease in care by a handicapped parent was compensated by its partner, while in others the increased costs of care were shunted to the offspring. Parental responses to an increased cost of care primarily depended on the total duration of care that offspring require. However, life history pace (i.e., adult survival and fecundity) did not influence parental decisions when faced with a higher cost of caring. Our study highlights that a greater attention to intergenerational trade-offs is warranted, particularly in species with a large burden of parental care. Moreover, we demonstrate that parental care decisions may be weighed more against physiological workload constraints than against future prospects of reproduction, supporting evidence that avian species may devote comparable amounts of energy into survival, regardless of life history strategy.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

Three hundred years of House Sparrow (Passer domesticus) persecution in Germany

2007 ◽  
Vol 34 (2) ◽  
pp. 307-317 ◽  
Author(s):  
J. SEITZ
Keyword(s):  
Rural Areas ◽  
House Sparrow ◽  
Bird Species ◽  
Passer Domesticus ◽  
Second World War ◽  
Population Increase ◽  
World War ◽  
Large Numbers ◽  
Urban And Rural Areas ◽  
Second World

Modernization of agriculture, economic development and population increase after the end of the Thirty Years' War caused authorities in many parts of Germany to decree the eradication of so-called pest animals, including the House Sparrow. Farmers were given targets, and had to deliver the heads of sparrows in proportion to the size of their farms or pay fines. At the end of the eighteenth century German ornithologists argued against the eradication of the sparrows. During the mid-nineteenth century, C. L. Gloger, the pioneer of bird protection in Germany, emphasized the value of the House Sparrow in controlling insect plagues. Many decrees were abolished because either they had not been obeyed, or had resulted in people protecting sparrows so that they always had enough for their “deliveries”. Surprisingly, various ornithologists, including Ernst Hartert and the most famous German bird conservationist Freiherr Berlepsch, joined in the war against sparrows at the beginning of the twentieth century, because sparrows were regarded as competitors of more useful bird species. After the Second World War, sparrows were poisoned in large numbers. Persecution of sparrows ended in Germany in the 1970s. The long period of persecution had a significant but not long-lasting impact on House Sparrow populations, and therefore cannot be regarded as a factor in the recent decline of this species in urban and rural areas of western and central Europe.

JENIS BURUNG DI KAMPUS UNIVERSITAS TANJUNGPURA

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Sutarto Kusuma Indra ◽  
Kustiati Kustiati ◽  
Rafdinal Rafdinal
Keyword(s):  
Habitat Loss ◽  
Human Life ◽  
Natural Habitat ◽  
Bird Species ◽  
Residential Land ◽  
Encounter Rates ◽  
Passer Montanus ◽  
Quality Degradation

Quality degradation, modification, and habitat loss are significant threats to bird species. The natural habitat of birds has been modified into residential land and facilities to meet the needs of human life as happened at Tanjungpura University. This study aims to determine of birds species at Tanjungpura University. Observations were carried out from January to March 2019. The method used in collecting the data from bird was “Encounter rates” which was conducted in the morning starting at 6 – 9 am and at 3 - 6 pm. The data obtained were analyzed with the formula of simple abundance scale and frequency of attendance. The birds found at Universitas Tanjungpura are 28 species classified into 23 genera, 17 families, and seven orders. Birds found to have an abundance order scale are classified into abundant, general, frequent and, unusual categories. Birds included in the abundant category are Collocalia fuciphaga and Passer montanus. The types of bird foods at Tanjungpura University consist of frugivore, insectivore, granivore, herbivore, carnivore, piscivore, omnivore, molluscivore, and nectarivore. The value of attendance frequency have range between 10-100%. The bird species with highest frequency of attendance’s value is Passer montanus, Pycnonotus aurigaster, Pycnonotus goiavier, Collocalia fuciphaga, and Anthreptes malacensis.

Steigende Bestandszahlen bei Spechten und anderen Vogelarten dank Zunahme von Totholz? | An increase in the population of woodpeckers and other bird species thanks to an increase in the quantities of deadwood?

2009 ◽  
Vol 160 (11) ◽  
pp. 334-340 ◽  
Author(s):  
Pierre Mollet ◽  
Niklaus Zbinden ◽  
Hans Schmid
Keyword(s):  
Forest Inventory ◽  
Bird Species ◽  
National Forest Inventory ◽  
Population Increase ◽  
National Forest ◽  
Forest Species ◽  
Breeding Populations ◽  
Willow Tit ◽  
Middle Spotted Woodpecker ◽  
Important Habitat

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.

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