Insectivorous Birds

Determinadas espécies de aves insetívoras generalistas, como as do
gênero Hypocnemis (Aves: Thamnophilidae), parecem ser pouco afetadas
por perturbações ambientais. Desta forma, é possível que a dieta destas
aves represente um bom indicador da diversidade de artrópodes, uma vez
que estes animais forrageiam em um amplo espectro de ambientes. Nesse
sentido, o objetivo deste estudo foi avaliar como o estágio de perturbação
ambiental afeta a composição e riqueza de artrópodes e verificar como
essa variação se reflete na dieta de Hypocnemis peruviana. De novembro
de 2007 a outubro de 2008, foram estudadas três áreas, preservada,
intermediária e antropizada no município de Cruzeiro do Sul, Acre, Brasil.
Artrópodes foram coletados com guarda-chuva entomológico e armadilhas
de solo. As aves foram amostradas com rede de neblina utilizando a
técnica de “playback” e sua dieta foi estudada através da análise das fezes.
Artrópodes de 14 ordens foram amostrados sendo que a riqueza de
ordens e abundância de indivíduos seguiu um gradiente crescente de
acordo com o nível de perturbação das áreas, estas diferenças foram
significantes estatisticamente (p < 0.05). Foram encontradas oito ordens
de artrópodes nas fezes de H. peruviana, não havendo diferença
significativa na riqueza de ordens na dieta entre as áreas estudadas.
Hymenoptera foi a ordem mais consumida, seguida por Arachnida e
Coleoptera. As proporções de consumo das ordens como itens
alimentares diferiram significativamente daquelas que ocorreram em cada
área (p < 0.05) e variaram entre estas. Nossos resultados mostraram que
apesar desta ave ser considerada generalista ela apresenta alguma
seletividade com relação à seleção dos itens alimentares.

Abstrak: Kajian burung telah dijalankan di kawasan batu kapur Bukit Kepala Gajah di Lenggong, Perak, dari Julai 2010 hingga Januari 2011. Kawasan kajian telah dibahagikan kepada tiga zon: pinggir hutan, perantaraan hutan dan pedalaman hutan. Kaedah persampelan jarak point count telah digunakan dalam kajian ini. Sejumlah 7789 pemerhatian telah direkodkan, mewakili 100 spesies-spesies burung daripada 28 famili. Pycnonotidae, Timaliidae dan Nectariniidae adalah famili dominan dan menunjukkan bilangan pemerhatian yang tertinggi dalam kawasan kajian, manakala Motacillidae menunjukkan bilangan pemerhatian yang paling sedikit. Spesies-spesies burung telah dikelaskan kepada tiga kumpulan pemakanan: pemakan serangga, pemakan buah dan lain-lain (pemakan segala, pemakan daging, pemakan madu dan pemakan bijirin). Kekayaan spesies burung-burung pemakan serangga adalah berbeza secara signifikan antara zon-zon hutan yang dikaji (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), dengan burung-burung pemakan serangga lebih banyak dijumpai di pedalaman hutan. Tiada perbezaan yang signifikan dijumpai antara kekayaan spesies di zon-zon hutan sama ada kumpulan pemakan buah atau gabungan kumpulan pemakanan yang lain-lain.

Species present in the fossil record may continue to exist at an archaeological site, allowing study that fine-tunes our picture of the ecological past. A large wintering population of Eurasian Crag Martins Ptyonoprogne rupestris (ECM) roosts at the 'Gorham's Cave Complex' UNESCO World Heritage site in Gibraltar, which is best known for its occupation by Neanderthals at times when ECMs were also present. Its complex geomorphology allows the study of use of different micro-sites (caves) within the roost. We used mark-recapture to test whether birds showed fidelity to micro-sites for roosting, and for differences in condition of birds across micro-sites. ECM showed very high fidelity towards microsites, within and between years, with > 90% chance of recapture at caves where they were first caught. Condition of birds differed between micro-sites, suggesting differences in roost quality between caves; birds were more likely to be recaptured at the micro-site where birds were in best condition, indicating higher survivorship. Our results demonstrate extremely fine-scale fidelity at the largest roosting site documented for ECM globally. Implications for conservation are discussed. The study provides current knowledge of a bird that has been using these caves since the Pleistocene and more generally on these caves as refuges.

This study has been carried out between 2009-2011 in order to figure out insectivorous bird spieces in Bartın. During the study, over 100 bird observations have been done in 27 different locations. In consequence of observations, 50 insectivorous bird spieces from 16 families belonging to 6 orders have been observed. The insectivorous bird spieces that have been observed are species belong families. It has been observed that among these insectivorous bird spieces found in Bartın, 27 of them are summer migrant, 10 of them are winter migrant and 13 of them are resident indigenous birds. Among all, 5 species (Motacilla alba L., Hirundo rustica L., Parus major L., Erithacus rubecula (L.), Turdus merula L.) are observed in all locations.

1. The proportion of aphids in the cereal arthropod fauna has increased since the introduction of herbicides in the 1950s. In order to examine whether this increase has negative consequences for partridge chicks, a controlled experiment was carried out. Four groups of partridge chicks were fed dierent diets of ®xed mixtures of grasshoppers and aphids, with aphid contents ranging from 0% to 45% wet weight. One additional group was allowed to select how much to eat of aphids and grasshoppers (self-selection). 2. Over the run of the 5-day experiment the self-selecting chicks ate 7% wet weight of aphids and showed a higher growth rate than all groups on ®xed diets. 3. Increasing the proportion of aphids in the chick diet above the self-selected level had negative consequences for chick growth and¯ight feather development. 4. Food consumption and growth eciency were markedly lower when chicks were fed a diet with a high proportion of aphids. 5. It is concluded that high densities of aphids cannot substitute for a diverse insect fauna as food for partridge chicks. Changes in the composition of the cereal arthropod fauna towards aphids constituting a greater proportion of available chick food may be detrimental to chick survival.

Preferences for foraging in particular tree species have been well documented in a variety of bird species, but underlying reasons remain little investigated. Understanding the causal bases for such patterns of habitat use can help to elucidate mechanisms of habitat selection and, therefore, community organization and structure. I experimentally tested the hypothesis that fine-scale foliage structure of two deciduous tree species influences the foraging behavior of three small, insectivorous bird species. On sugar maple (Acer saccharum), with its orbicular leaves elevated above the branch, Black-throated Blue Warblers (Dendroica caerulescens) and American Redstarts (Setophaga ruticilla) captured prey predominantly from lower leaf surfaces, whereas Black-throated Green Warblers (Dendroica virens) captured prey predominantly from upper leaf surfaces. In contrast, on yellow birch (Betula alleghaniensis), with its oblong-ovate leaves held within the plane of the supporting branch, all three bird species captured prey disproportionately from upper leaf surfaces. Overall, aerial maneuvers were used more frequently to capture prey from upper than from lower leaf surfaces on sugar maple, but the opposite occurred on yellow birch, where nonaerial maneuvers were used more frequently to capture prey from upper than from lower leaf surfaces. Those results indicate that the leaf surface from which prey are more easily captured (with less energetically costly non-aerial maneuvers) differs between those tree species. Experimental manipulation of leaf dispersion and distance to prey demonstrated that leaf dispersion is the chief determinant of prey capture location (upper vs. lower leaf surfaces), and that distance to prey is the chief determinant of prey capture maneuver (aerial vs. non-aerial). When foraging on artificial branches in which vertical distance between branches was systematically increased experimentally, Black-throated Green Warblers captured a significantly smaller proportion of prey from lower surfaces of leaves on the upper branch than did Black-throated Blue Warblers. Taken together, these results indicate that different tree species, as well as different locations within tree species, present insectivorous birds with distinct foraging environments and, therefore, constitute distinct foraging microhabitats. Furthermore, even closely related bird species that are generally similar morphologically respond in behaviorally unique ways to differences in foliage structure. For those reasons, forest management practices that enhance tree species diversity could concomitantly enhance foraging opportunities (niche diversity) for forest insectivores and may thus help to promote high bird species diversity and maintain abundant populations.

Species present in the fossil record may continue to exist at an archaeological site, allowing study that fine-tunes our picture of the ecological past. A large wintering population of Eurasian Crag Martins Ptyonoprogne rupestris (ECM) roosts at the &#39;Gorham&#39;s Cave Complex&#39; UNESCO World Heritage site in Gibraltar, which is best known for its occupation by Neanderthals at times when ECMs were also present. Its complex geomorphology allows the study of use of different micro-sites (caves) within the roost. We used mark-recapture to test whether birds showed fidelity to micro-sites for roosting, and for differences in condition of birds across micro-sites. ECM showed very high fidelity towards microsites, within and between years, with &gt; 90% chance of recapture at caves where they were first caught. Condition of birds differed between micro-sites, suggesting differences in roost quality between caves; birds were more likely to be recaptured at the micro-site where birds w...

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.

RESUMO-Aprescllta-se ullla analise cOlllparativa da dicta de 16 aves i/lsetlvoras de sub-hosque da illia Cm'ialla e oito da illia Mexialla. IdclIlIficou-sc 2.044 presas, elll 121 eS{()lIIagos, para a illta Ca vialla, e 9-/.8 presas, elll 79 esroJ/Jagos, para a illw M exi[///{{. 0 lIIill/em de presas reg ist raclas fo i maior 110 illw Co vial/a do qlle 1I{l ill/{{ Mexialla (Xl :::: 120.6: P < 0.001). De:.o ilo catego rfas de presasforalll identifieadas lias eSlolllagos das (Il'es eoleraclas /la illw Cal'ialla ellquwlfO de:.essei s foralll idelll/fieadas para a illia Mexialla. Qllill:.e entegorias de presas foralll COfl/llIIS cis dlla s ilhas, tres ocorreralll sOli/elite I/{I f/ll([ Cavialla e /1111([ categ oria foi reg istrada sOll/ellfe 1/(/ ;lho Mexiafla. As alllostras da illla COl' i{///{/ apresell!({J"{//J/ Ifill IIwior /IIill/em d e Coleoptera, Fonllicidae. ill/arums de Forlllicida e e larvas de Coleoptera, ellqllalllo as {l/J/ostm s da illw Mexiafla apres el/{aralll IIIIIII/aio r !/IlII/era d e larvas d e Lepidop-{era e de a/gulls arrr6podes Iloodores (IlYlllenoptera. Lepidoptera e Hellliplera). As prapor(•oes das cntegorias d e presas I'ariaralll ellffe as especies. COl/siderando a I)/"ese ll~,•a \'S. (l1I5 e IlC;(I das categorias [{{xo llvlI/icas, ell COlllimiIOS diferclI(•as signijicalil'as 110 diela d e Cranioleuca mue ll eri e Thamnophilus nig roc inercus. A dil 'CI"sidade d e p resos

In this paper we are studing the diet composition of the short-toed treecreeper's Certhia brachydactyla (Brehm, 1820) nestling in the suburban area of El Harrach (Algeria). The diet analysis is based on examining fecal sacs which were carried out by parents and placed on the bark of Washingtonia robusta and Jacaranda mimosifolia near the nest during the breeding season 2014/2015. Fecal sacs were collected and treated separately in 70% alcohol to identify prey-species. In total, 277 items, representing 66 prey-species were identified from the collected fecal sacs of short-toed treecreeper nestling. The relative abundance index revealed that the insects were dominants with 67.15%, followed by arachnids 27.44%, Gastrapoda 3.61% and the other classes were poorly represented. Regarding the order of the different class-preys, the diet consisted predominantly of Araneae with (27.44%), followed by Coleoptera (24.91%) and Hymenoptera (18.05%). For the prey size, it varied from 1 mm to 15 mm with an average of 4.33±0.13 mm. And the most represented prey measuring was between [2,55-4,11 mm].

Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female's diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations.

We examined diets of six insectivorous bird species (n = 202 individuals) from two vegetation zones along the Colorado River in Grand Canyon National Park, Arizona, 1994. All bird species consumed similar quantities of caterpillars and beetles, but use of other prey taxa varied. Non-native leafhoppers (Opsius stactagolus) specific to non-native tamarisk (Tamarix chinensis) substantially augmented Lucy's Warbler (Vermivora luciae) diets (49%), while ants comprised 82% of Yellow-breasted Chat (Icteria virens) diets. Yellow Warbler (Dendroica petechia) diets were composed of 45% aquatic midges. All bird species consumed the non-native leafhopper specific to tamarisk. Comparison of bird diets with availability of arthropod prey from aquatic and terrestrial origins showed terrestrial insects comprised 91% of all avian diets compared to 9% of prey from aquatic origin. Seasonal shifts in arthropod prey occurred in diets of three bird species, although no seasonal shifts were detected in arthropods sampled in vegetation indicating that at least three bird species were not selecting prey in proportion to its abundance. All bird species had higher prey overlap with arthropods collected in the native, mesquite-acacia vegetation zone which contained higher arthropod diversity and better prey items (i.e., Lepidoptera). Lucy's Warbler and Yellow Warbler consumed high proportions of prey items found in greatest abundance in the tamarisk-dominated vegetation zone that has been established since the construction of Glen Canyon Dam. These species appeared to exhibit ecological plasticity in response to an anthropogenic increase in prey resources.

The authors measured plasma carotenoid levels in three insectivorous bird species, the pied flycatcher (Ficedula hypoleuca), the blue tit (Cyanistes caeruleus), and the great tit (Parus major) in metal-polluted and unpolluted sites around a copper smelter. Their aim was to determine whether there was interspecific, age-related, or yearly variation in carotenoid levels and their responses to the ambient pollution level. The three bird species showed qualitatively and quantitatively similar carotenoid profiles, with lutein being always the predominant plasma carotenoid. Ficedula hypoleuca nestlings showed higher plasma carotenoid levels in the unpolluted than in the polluted area, whereas no significant differences were found in F. hypoleuca females or in nestlings or females of the Parids. Yearly comparison of plasma concentrations (only for P. major nestlings) showed, however, that levels varied nonsynchronously between polluted and unpolluted sites among the breeding seasons, with the yearly variation being higher in the polluted area. The survival of nestlings did not depend on their plasma carotenoid concentrations. The two Parid species showed lower nestling survival at sites with high metal exposure levels. The authors conclude that plasma carotenoid levels showed a marked spatial, temporal, and age-related variation, but were not directly related to heavy metal exposure or the reproductive success of birds. Environ. Toxicol. Chem.