scholarly journals PREDATION OF PALE-BREASTED THRUSH EGGS BY THE ARIEL TOUCAN IN BRAZIL: FAILURE OF THE ANTI-PREDATORY STRATEGY

2021 ◽  
Vol 26 (2) ◽  
pp. 278-282
Author(s):  
Yair Guillermo Molina Martínez
Keyword(s):  
Bird Species ◽  
Predatory Behavior ◽  
Egg Predation ◽  
Predatory Strategy

The Channel-billed Toucan (Ramphastos vitellinus ariel) is an omnivorous bird that eventually is nest-robbers. Several birdsongs display anti-predatory strategies such as attacks and mobbing calls to face this kind of predators. This note reports a predatory event of one Channel-billed Toucan upon eggs of Pale-breasted Thrush (Turdus leucomelas), and describe the anti-predatory behavior, principally alert and mobbing calls of the thrush. Even though the Pale-breasted Thrush displayed the anti-predatory behaviors to harass the toucan, the egg predation was not avoided. Although the predation upon eggs by Ramphastos vitellinus has been reported several times, the majority of reports lacks of identity of the bird species affected, this being the first confirmed record in Turdus leucomelas.

scholarly journals Hunting Behavior and Diet of Cooper's Hawks: An Urban View of the Small-Bird-In-Winter Paradigm

The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 474-483 ◽  
Author(s):  
Timothy C. Roth ◽  
Steven L. Lima
Keyword(s):  
Bird Species ◽  
Passer Domesticus ◽  
Columba Livia ◽  
Sturnus Vulgaris ◽  
Predatory Behavior ◽  
Hunting Behavior ◽  
Zenaida Macroura ◽  
Accipiter Cooperii ◽  
Risk Of Predation ◽  
Cooper's Hawks

Abstract We examined the predatory behavior of wintering urban Cooper's Hawks (Accipiter cooperii). Eight Cooper's Hawks (7 female, 1 male) were radio-tracked intensively during two winter periods from 1999–2001. We observed 179 attacks, 35 of which were successful, for an overall attack success rate of 20%. We recorded an additional 44 kills resulting from unobserved attacks. European Starlings (Sturnus vulgaris), Mourning Doves (Zenaida macroura), and Rock Doves (Columba livia) made up 95% of the prey attacked and 91% of the diet. Smaller birds (<70 g), such as House Sparrows (Passer domesticus), were numerous in the study area but were rarely attacked. Mammals were not included in the diet. Surprise attacks (initiated at close range, often from behind an obstruction), were more successful than “open” attacks, although the latter were more frequent. In addition, attacks on single individuals were significantly more successful than those on flocks. Nonetheless, many attacks were attempted on large flocks. Our results suggest that the smaller bird species (<70 g) in our urban study area were at low risk of predation from Cooper's Hawks. Comportamiento de Caza y Dieta de Accipiter cooperii: Una Visión Urbana del Paradigma de Aves Pequeñas durante el Invierno Resumen. Examinamos el comportamiento de depredación de individuos urbanos de la especie Accipiter cooperii durante el período de invernada. Ocho individuos (siete hembras y un macho) fueron seguidos intensamente mediante radio telemetría durante dos períodos invernales desde 1999 hasta 2001. Observamos 179 ataques, de los cuales 35 fueron exitosos, con una tasa general de éxito de ataque del 20%. Adicionalmente, registramos 44 muertes que resultaron de ataques no observados. Sturnus vulgaris, Zenaida macroura y Columba livia compusieron el 95% de las presas atacadas y el 91% de la dieta. Aves pequeñas (<70 g), como Passer domesticus, fueron muy abundantes en el área de estudio pero fueron raramente atacadas. La dieta no incluyó mamíferos. Los ataques sorpresivos (iniciados a una corta distancia, generalmente desde detrás de algún objeto) fueron más exitosos que ataques “abiertos,” aunque estos últimos fueron más frecuentes. Además, los ataques sobre individuos que se encontraban solos fueron significativamente más exitosos que aquellos sobre bandadas. Sin embargo, muchos ataques fueron intentados sobre bandadas grandes. Nuestros resultados sugieren que en nuestra área de estudio urbana las especies de aves más pequeñas (<70 g) tenían un menor riesgo de ser depredadas por A. cooperii.

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.

Die Brutvogelfauna eines Nadelwaldes der nördlichen Voralpen nach dem Sturm Lothar

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer
Keyword(s):  
Forest Succession ◽  
Coniferous Forest ◽  
Bird Species ◽  
Individual Species ◽  
Mountain Forest ◽  
Breeding Bird ◽  
Point Counts ◽  
Federal Institute ◽  
Central Switzerland ◽  
Bird Fauna

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

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