Ornithological Studies Research Articles

Measurement Error Revisited: Its Importance for the Analysis of Size and Shape of Birds

Abstract. Measurement error in morphological characters is an important issue for many ornithological studies (e.g. ecomorphology, quantitative studies of heritability, studies of systematic and geographic variation). The variation in external morphological characters, such as wing and tarsus length, is usually evaluated using multivariate statistical methods such as principal component analysis (PCA). These are often considered better than univariate statistical methods for explaining size and shape variation in bird populations because they reduce the ‘dimensionality’ of the data — the size of individual measures (wing etc.) are assumed to contain a component reflecting a general character ‘size’. However, the effect of measurement error on principal components has not been formally assessed with respect to such data. Here we report three examples in order to assess the importance of measurement error for analyses within and between bird populations. The effect of measurement error on PCA is also discus...

Avian studies and research opportunities in the Luquillo Experimental Forest: A tropical rain forest in Puerto Rico

The Luquillo Experimental Forest (LEF) located on the Caribbean island of Puerto Rico has a rich history of ecological research, including a variety of avian studies, and is one of the most active ecological research sites in the Neotropics. The LEF spans an elevational range from 100 to 1075 m over which five life zones and four forest types are found in a warm, humid subtropical climate. A total of 23 bird species breeds here and another 76 species, mostly migrants, are known to occur. The food web of the forest in the lower elevations is especially well studied, which allows an assessment of the role of birds in the food web. The LEF is noted for its high densities of Eleutherodactylus frogs and Anolis lizards, which may depress insect densities thereby contributing to the low species richness and densities of most insectivorous birds. The signature species of the forest is the endangered Puerto Rican Parrot ( Amazona vittata) that has been the focus of intensive long-term research and recovery efforts, which have spawned research on associated species, including long-term studies on the Pearly-eyed Thrasher ( Margarops fuscatus) and botfly ( Philornis spp.) ectoparasitism. Given the frequency of hurricane disturbance to the LEF and studies providing baseline for comparisons, research has made major contributions to an understanding of the effects of hurricanes on forest ecosystems including bird populations and their resources. We summarize these and other studies from the LEF to characterize the avifauna and its environment while noting studies with management implications and identify opportunities for future ornithological studies.

PRELIMINARY BASELINE SURVEY OF AVIFAUNAL DIVERSITY IN JIMMA ZONE, SOUTH-WESTERN ETHIOPIA

AbstractMultidimensional poverty, which is deeply-rooted within least-developed African countries like Ethiopia, is forcing local people to heavily rely on natural resources for their subsistent livelihoods. As a result, remaining wilderness areas in tropical Africa which support huge but little known biological diversity, are subject to extensive habitat loss, fragmentation and degradation in turn causing loss of plant and animal species and ecosystem services provided by them. Coffee forest fragment within the Jimma Zone of Ethiopia cannot be expected to be an exception to such scenario. Taking this persistent problem into consideration, we carried out a preliminary survey of bird biodiversity in selected areas of Jimma Zone during a short term bird ringing training held from Sept. 30 to Oct. 20, 2008. The main objective of the survey was to identify and document bird species of Jimma Zone, Southwestern Ethiopia, for further in-debth ornithological studies. Survey data were collected through exhaustive observations in and around 10 coffee forest fragments in Garuke, one fragment in Eladale, one urban area site in Jimma town and in scrubland vegetation around Gilgel Ghibe hydropower reservoir, Jimma Zone, Southwestern Ethiopia. In addition, five mist-nets were employed to capture understory forest birds in two purposively selected coffee forest fragments. Mist nets were opened at 5:50 A.M. and checked every 30 minutes until they were closed at 12:00 A.M. Over 196 bird species were identified during this survey and of these, 41 individuals belonging to 20 species were captured in Garuke and 23 individuals of 9 bird species in Eladale. Montane white-eye (Zosterops poliogastrus) followed by Olive sunbird (Nectarinia olivacea), Abyssinian slaty-flycatcher (Melaenornis chocolatinus) and Rupell’s robinchat (Cossypha semirufa) were the most frequently captured bird species. Of the sites surveyed, Gilgel Ghibe hydropower reservoir had strikingly highest bird species diversity. We approached the reservoir almost in a constant site near Bulbul Kebele (the smallest administrative unit in Ethiopia) and recorded over 115 bird species within about 300 meters distance! We learnt that this area was an important and most appropriate site to see a number of migrant and resident species as well as to undertake future bird ringing activities. We believe that the result of this survey will contribute much for the preparation of a comprehensive bird species checklist for Jimma Zone that could serve as important baseline information for more focused future ornithological investigations in the area so as to promote bird conservation through ecotourism activities and improve the livelihood of local people.

Dinámica temporal de la avifauna en un parque urbano de la ciudad de Puebla, México

Presentamos información sobre la dinámica temporal de las aves de la Laguna de San Baltazar, un espacio urbano ubicado en el sur de la ciudad de Puebla. De febrero a diciembre de 2008 realizamos censos en trayectos para el registro visual y auditivo de las especies. Registramos un total de 46 especies y 1,308 individuos. La riqueza, abundancia y diversidad varió estacionalmente (ANOVA, P < 0.05). El período otoño-invierno presentó la mayor riqueza y abundancia, revelando la importancia del componente migratorio. El aumento de estudios avifaunísticos en áreas urbanas y suburbanas puede ser especialmente útil para los gestores urbanos a la hora de diseñar parques en los que se potencien, no sólo sus servicios sociales de esparcimiento, sino también sus valores naturales.

Are bird populations in tropical and subtropical forests of South America affected by climate change?

The tropical and subtropical moist forests of South America have been seen as remarkable for their great wealth of animals and plants and as the world leader in bird diversity. However, a problem is apparently affecting bird populations in these habitats, to the extent that most of the sites that I have studied in the last few years were practically “ornithological deserts”. Censuses conducted in the Amazon rainforest in Ecuador and Bolivia have revealed no more than 15 species and 18 individuals in 1 day. It is evident that this is not a problem of the kind usually induced by humans at a local level, such as deforestation, hunting or pesticide use. The low diversity and activity were observed not only in disturbed habitats, but also in well-preserved national parks and reserves. If it is related to human activities, then this must be more widespread. One such possibility is global warming. For ornithological studies, this is a very severe problem that must be closely examined to see whether it is also a threat to bird survival and if it is related to climate change.

Role of Avian Community in Reduction of <i>Spodoptera</i> Pest Population in Sugar Beet at Pune

Experiments were conducted at Vasantdada Sugar Institute, Pune in a RBD with three replications during 2005 to 2007 in sugar beet (var. posada) for control of Spodoptera litura Fab. The ornithological studies had shown the major avian community, Acridotheres tristis (Linnaeus), Passer domesticus (Linnaeus), Vanellus indicus (Boddaert), Corvus splendens (Vieillot), Centropus sinensis (Stephens), Pycnonotus cafer (Linnaeus), Eudynamys scolopacea (Linnaeus), with a relative abundance of 14.33, 13.26, 11.46, 5.73, 3.87, 3.54, and 2.79%, respectively.The reduction in mean S. litura population due to the pick up of the larvae by birds during three crop seasons ranged from 33.90 to 69.47%. Installation of minimum 15 bird perches/ha in 60 days after sugar beet sowing noticed effective considering the number of birds sittings (130.66/day), reduction in larval population of S. litura (39.99%), and root yield (71.36 ton/ha).Keywords: Sugar beet, Spodoptera, avian community, yield.doi: 10.3126/on.v6i1.1650Our Nature (2008)6:19-25

Strigiformes e Caprimulgiformes em Santa Catarina, sul do Brasil: Registros relevantes e novas localidades

http://dx.doi.org/10.5007/2175-7925.2009v22n4p125Com as crescentes pesquisas ornitológicas em Santa Catarina, muitas localidades já possuem satisfatório conhecimento sobre sua avifauna, porém, alguns táxons ainda são subamostrados na maioria desses estudos avifaunísticos. Tal subamostragem de certos grupos de aves, como as noturnas (Strigiformes e Caprimulgiformes), pode prejudicar a avaliação do status de ocorrência e situação populacional dessas espécies. Neste sentido, apresentamos registros de sete espécies de Strigiformes (Megascops sanctaecatarinae, Pulsatrix koeniswaldiana, Strix hylophila, S. virgata, Glaucidium minutissimum, G. brasilianum e Asio stygius) e seis de Caprimulgiformes (Nyctibius griseus, Podager nacunda, Nyctidromus albicollis, Caprimulgus sericocaudatus, C. longirostris e Macropsalis forcipata) observados recentemente em nossos estudos, sendo que todas as espécies aqui apresentadas foram registradas em ao menos uma localidade inédita para Santa Catarina.

Predicting Annual Fecundity from Nest Success

Nest success, the probability that a nest will fledge offspring, is a widely measured parameter in ornithological studies, and is usually estimated by monitoring the fates of nests throughout a breeding season. Because nest success es- timates are commonly reported in the avian literature, a key question in population studies is how to derive annual fecun- dity rates, F (a vital parameter in population biology), from nest success data when breeding individuals are not marked. In this manuscript, we describe a simple, recursive model that generates an estimate of the frequency distribution of an- nual fecundity rates that can be achieved for a species, given precise and unbiased estimates of nest success, the average number of young that fledge per successful nest, and three life history parameters: the maximum number of possible suc- cessful broods per breeding season (J), the maximum number of possible nesting attempts per breeding season (K), and the maximum brood size (B). We illustrate the model for 3 hypothetical species in which the average young that fledge per successful nest is 2 offspring: (1) a single-brooded species in which J =1, K = 3, B = 3; (2) a double-brooded species in which J = 2, K = 3, B = 3, and (3) a triple-brooded species in which J =3, K = 3, B = 3. In general, the frequency distributions of acceptable fecundity solutions for single-, double-, and triple-brooded species are all approximately symmetric, and are defined by Fave (the average acceptable solution), Fmin (the minimum acceptable solution), and Fmax (the maximum acceptable solution). The breadth of these distributions, or the difference between Fmin and Fmax, appears to be controlled largely by solutions where an unequal number of young fledge across attempts. However, when examining relationships between annual fecundity and nest success across the full spectrum of nest suc- cess values, we find that, more often than not, non-linear relationships characterized the association between nest success, Fmax, Fmin, and Fave. The only case where nest success predicts annual fecundity in a linear fashion occurred when J = K. Thus, the assumption that nest success is an adequate indicator of annual fecundity should be viewed with caution.

Bird nest predation in a southern Tunisian oasis habitat: No evidence of “edge effect”

Numerous ornithological studies conducted in patchy habitats have linked high intensity of nest predation with habitat edges. This “edge effect” hypothesis was primarily investigated in temperate, boreal and tropical fragmented forests, and there is a need for investigations from different habitat systems. Here we provide the results of one study on bird nest predation in relation to edge context in one oasis in southern Tunisia. Our aim was to assess the importance of nest predation as a source of nest failure in the studied oasis and to test if the edge effect hypothesis applies in this habitat system. We found that although predation represents an important source of nest failure in all studied species, the edge effect hypothesis does not seem to apply in the studied oasis. Indeed, daily nest predation rate did not vary with edge context for all studied species, which could be explained by the fact that nest predator guild is mainly composed of small species that use oasis interior and edges in similar ways. The effects of predators coming from the surrounding areas do not seem to significantly increase nest predation rates in oasis edges compared to oasis interior. We also found that nest predation rates were similar for all bird species, suggesting that among-species differences in nest concealment and nesting behaviour did not seem to account for nest survival in the studied oasis. However, further more detailed species-level studies are needed to test this hypothesis and to identify more accurately the determinants of nest predation in the oasis habitat.

Ernst Mayr (1904-2005) and the birds of Oceania and adjacent areas

In 1928–1930, Ernst Mayr (1904–2005) went on ornithological expeditions to New Guinea and the Solomon Islands. The results obtained formed the foundation of his later systematic studies as a research ornithologist at the American Museum of Natural History (New York City) where he analyzed the variation, distribution, and speciation of the birds of Oceania, especially New Guinea, Melanesia and Polynesia, and of some adjacent regions. These studies are here summarized and several examples of avian distribution patterns and of regional character analyses of birds are illustrated. The results of Mayr's ornithological studies formed the intellectual database for his later work in the fields of zoogeography and evolutionary biology. Modern molecular analyses of certain groups of monarch flycatchers indicated a history of diversification in the tropical Pacific which accords well with the results of Mayr's morphological analyses of these species. A letter by E. Stresemann to E. Mayr reviewing the book on Birds of the Philippines (1946) by J. Delacour & E. Mayr is included. Lists of 26 new biological species of birds and 445 new subspecies which Mayr described are presented as well as a list of animals and plants named in his honor and the taxa of birds described by Hartert (1930) from the material Mayr had collected in northwestern New Guinea in 1928. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Applications of stable isotope analyses to avian ecology

In the past 20 years the use of stable isotope analysis has become increasingly common in ecological studies. In fact, in some instances these techniques have yielded remarkable insights into the foraging preferences and migrations of birds. Despite these advances and the potential of the approach, it is possibly still not as widely used as might be expected. In this paper we aim to illustrate the potential of the approach in the hope of encouraging more avian ecologists to think again about how these techniques might provide insights in the systems on which they work. We discuss some of the principles behind the approach, and review some of the more recent ornithological studies that have used stable isotope techniques to trace trophic pathways or infer migratory origins. We follow this by discussing some of the latest ideas on how stable isotopes may be used to generate community metrics and close by detailing the important assumptions and caveats that should be considered before undertaking any studies using this technique.

A importância da Serra das Torres para a conservação de aves no estado do ES

The fauna composition of many ecosystems in the state of Espírito Santo is still insufficiently known, what makes hard to take decisions on the regional biodiversity conservation. The present paper presents the preliminary results on the ornithological studies developed at Serra das Torres, a region that contains one of the most expressive native forest remains of the southern Espírito Santo. A total of 120 species of birds, distributed among 37 families, were registered in the studied area, including endangered species (Penelope obscura,Strix huhula, Ramphodon naevius and Melanerpes flavifrons) as well as many endemic species of the Atlantic Forest. However, it is suggested that the local bird richness might be much higher. These data corroborate the premises that Serra das Torres is a major importance area for biological conservation and therefore its inclusion in some category of the National System of Conservation Units (SNUC) is recommended.

Noteworthy bird records at Lagoa Santa, southeastern Brazil

Lagoa Santa, a small town in southeastern Brazil where naturalist Peter Lund lived, is regarded nowadays as an important historical site for the biological sciences. From 1847 to 1855, J.T. Reinhardt, hosted by Lund, collected 343 bird species. This material is an outstanding reference for many modern ornithological studies. The present paper reports the occurrence of some rare and threatened birds for the region of Lagoa Santa between 1998 and 2005. In this account I list the Rusty-margined Guan Penelope superciliaris Temminck, 1815; the Roseate Spoonbill Platalea ajaja Linnaeus, 1758; the Maguari Stork Ciconia maguari (Gmelin, 1789); the Wood Stork Mycteria americana Linnaeus, 1758; the Black Hawk-eagle Spizaetus tyrannus (Wied, 1820) and the Turquoise-fronted Parrot Amazona aestiva (Linnaeus, 1758). It is also reported the southernmost record for the Blue-and-yellow Macaw Ara ararauna (Linnaeus, 1758) and the range extension of the Crowned Slaty flycatcher Griseotyrannus aurantioatrocristatus (d'Orbigny and Lafresnaye, 1837). These data can be used as a baseline for studies of colonization and extinction.

A importância do ensino de pós-graduação na formação de recursos humanos para o estudo da biodiversidade no Brasil: um estudo de caso na ornitologia

Entre 1970 e 2005 foram produzidas 397 dissertações de mestrado e 108 teses de doutorado com temas ornitológicos em 43 instituições brasileiras. A maioria dos estudos foi produzida em instituições localizadas na região sudeste. Instituições do norte e nordeste contribuíram com um número relativamente baixo de estudos ornitológicos. As avifaunas dos biomas Costeiro e Marinho, a Mata Atlântica e o Cerrado foram as mais bem estudadas, enquanto um baixo número de pesquisas foi realizado na Caatinga e na Amazônia. Desde 1990 foi observado um expressivo aumento na produção científica de estudos ornitológicos nos cursos de pós-graduação do Brasil. A diversidade temática dos estudos também se ampliou ao longo dos anos, mas ainda é dominada por estudos de comunidade, comportamento e sinecologia. Temas emergentes como sistemática molecular, macroecologia e ecologia de paisagens já começam a ser explorados nos cursos de pós-graduação. A ampliação dos programas de pós-graduação e a contínua diversificação temática dos estudos ornitológicos são os desafios para os cursos destes programas no Brasil nos próximos anos.

Strong effects of various incidence and observation angles on spectrometric assessment of plumage colouration in birds

The assessment of plumage colouration has become a common procedure in many ornithological studies, especially after the discovery of differences between avian and human visual systems, namely the avian ability to perceive ultraviolet wavelengths. There are many techniques available for plumage colour assessment. Nevertheless, unidirectional reflectance spectrometry seems actually to be the method of choice and is used in most studies. The active avian visual communication skills, the physical characteristics of the plumage surface and the birds’ body shape prompted us to study plumage colouration with different angles of incidence and observation by bidirectional reflectance spectrometry. In this study, we explore the effect of different angles of incidence and observation, on a single plane of incidence, on the reflectance spectrometric assessment of five differently coloured body regions of the blue fronted Amazon parrot (Amazona aestiva). Measurements were made using a AVS-USB2000 spectrometer with a DH-2000 light source and two different reflection probes (bifurcated fibre optic probe and a specially designed fibre holder). The results of this study illustrate clear angle dependence of colour parameters in differently coloured non-iridescent plumage regions of the blue fronted Amazon parrot. Our results may have direct implications on the observed transmitted information of display and its associated predation risk (trade-off) in birds, but also in other animals. Moreover, the results show that unidirectional reflectance spectrometry alone may be a rather limited procedure to quantify and compare true colour of a complex surface such as birds’ plumage. Therefore, slight but behavioural important characteristics of plumage pattern may remain undiscovered with this method.

Using time-lapse digital video recording for a nesting study of birds of prey

Remote photography using various photo, movie or video devices has been employed in numerous studies in wildlife research during the last 50 years. Given the rapid advances in digital technologies, digital video and photo techniques are becoming more common in use, and publications that introduce a new method or equipment for video surveillance in wildlife research (and in ornithological studies particularly) are appearing almost every year. However, still no special guide to the great variety of equipment and methods is available, and the choice and use of suitable gear for scientific purposes may be difficult for non-specialists. In this paper, we review the most common surveillance techniques used in today’s nest studies, as well as the most essential properties of image recording equipment. We also describe the digital video recording technique, which we used for observations of raptor nests, and summarise our experience of its operation. As an example of the obtained data, we present the timing of prey deliveries of goshawks and common buzzards.

Demography, Genetics, and the Value of Mixed Messages

AbstractIverson et al. (2004) used estimates of the homing rate for molting adult Harlequin Ducks (Histrionicus histrionicus) in Alaska to draw inferences about population structure. Homing rates, defined as one minus the ratio of birds recaptured elsewhere to those recaptured at the original banding site, were high (0.95–1.00) for males and females. Iverson et al. (2004) concluded that these high rates of homing are indicative of demographic independence among molting groups separated by small distances (tens to hundreds of kilometers) and that conservation efforts should recognize this fine-scale population structure. We re-examined their use of the homing rate, because their assumption of equal detection probability across a wide sampling area could have led to an upward bias in their estimates of site fidelity. As a result, we are hesitant to agree with their conclusion of high adult homing to molting areas and that molt-site fidelity is evidence for demographic independence. Our hesitancy stems from the fact that little is known about juvenile and adult movements within and among years, breeding area origins, and the variation of demographic parameters (e.g., survival and productivity) among molting groups. Furthermore, population genetic data of these molting groups suggest gene flow at both nuclear and mitochondrial loci. Such mixed messages between demographic (i.e., banding) and genetic data are increasingly common in ornithological studies and offer unique opportunities to reassess predictions and make more robust inferences about population structure across broad temporal and spatial scales. Thus, we stress that it is this broader scale perspective, which combines both demography and genetics, that biologists should seek to quantify and conservation efforts should seek to recognize.

Occurrence of the whistling heron, Syrigma sibilatrix (Temminck, 1824) (Aves: Ciconiiformes), in Goiás state, central Brazil

Between 1999 and 2004 we recorded the whistling heron, Syrigma sibilatrix, in Goiás state, central Brazil.One specimen was collected and deposited in the Fundação Museu de Ornitologia de Goiânia (FMOG12855). Observations were conducted in some municipalities of the Goiânia metropolitan region and in thewest-central, northeastern and southern regions of Goiás. Probably, the range expansion of this species is dueto the increase of pastures, artificial ponds and other anthropic areas in the region. However, it may onlyreflect the paucity of ornithological studies in central Brazil.

Flight Calls and Their Value for Future Ornithological Studies and Conservation Research

Flight Calls and Their Value for Future Ornithological Studies and Conservation Research

Colonial Nesting Birds of Chikhacheva Bay (Tatarskii Strait, Sea of Japan)

This paper presents new data on species composition, density, and migration patterns of marine colonial birds obtained during ornithological studies in Chikhacheva Bay (northern part of Tatarskii Strait) in 2001–2002.