32 resultados para Ornithologists


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Published also as no. 15 of the Reports of the expedition.

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Vol. 1-67 also called no. 1-474.

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Vol. 1-67 also called no. 1-474.

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The impact of urban development and climate change has created the impetus to monitor changes in the environment, particularly, the behaviour, habitat and movement of fauna species. The aim of this chapter is to present the design and development of a sensor network based on smart phones to automatically collect and analyse acoustic and visual data for environmental monitoring purposes. Due to the communication and sophisticated programming facilities offered by smart phones, software tools can be developed to allow data to be collected, partially processed and sent to a remote server over the network for storage and further processing. This sensor network which employs a client-server architecture has been deployed in three applications: monitoring a rare bird species near Brisbane Airport, study of koalas behaviour at St Bees Island, and detection of fruit flies. The users of this system include scientists (e.g. ecologists, ornithologists, computer scientists) and community groups participating in data collection or reporting on the environment (e.g. students, bird watchers). The chapter focuses on the following aspects of our research: issues involved in using smart phones as sensors; the overall framework for data acquisition, data quality control, data management and analysis; current and future applications of the smart phone-based sensor network, and our future research directions.

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Few studies have investigated the vocal communication of ratites, and none has investigated the spectral and temporal structure of vocalizations of Apteryx, the only extant ratite genus in New Zealand. We describe the long-range vocalization (whistle call) and vocal behavior of male and female North Island Brown Kiwi (Apteryx mantelli). Spontaneous calling by seven pairs was recorded in the field over a one-year period. Call notes produced by males were tonal in nature; the fundamental frequency was ~1.5 kHz, with overtones reaching up to ~13.0 kHz. Call notes produced by females contained a series of tightly packed, poorly defined harmonics and consisted of a fundamental frequency of ~0.1 kHz, with overtones reaching ~7.0 kHz. The amplitude within notes of females was concentrated into two prominent formants. Some individuals of pairs exhibited duetting behavior that resulted in alteration of the inter-note interval after the onset of the call of their mate. Our findings draw attention to the uniqueness of the North Island Brown Kiwi's vocalizations, and we uncovered some unexpected structural features that call for further investigation.

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Ornithologists have been exploring the possibilities and the methodology of recording and archiving animal sounds for many decades. Primatologists, however, have only relatively recently become aware that recordings of primate sound may be just as valuable as traditional scientific specimens such as skins or skeletons, and should be preserved for posterity (Fig. 16.1). Audio recordings should be fully documented, archived and curated to ensure proper care and accessibility. As natural populations disappear, sound archives will become increasingly important (Bradbury et al., 1999). Studying animal vocal communication is also relevant from the perspective of behavioural ecology. Vocal communication plays a central role in animal societies. Calls are believed to provide various types and amounts of information. These may include, among other things: (1) information about the sender's identity (e.g. species, sex, age class, group membership or individual identity); (2) information about the sender's status andmood (e.g. dominance, fear or aggressive motivation, fitness); and (3) information about relevant events or discoveries in the sender's environment (e.g. predators, food location). When studying acoustic communication, sound recordings are usually required to analyse the spectral and temporal structure of vocalizations or to perform playback experiments (Chapter 11)...

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Approximately 90% of the original woodlands of the Mount Lofty Ranges of South Australia has been cleared, modified or fragmented, most severely in the last 60 years, and affecting the avifauna dependent on native vegetation. This study identifies which woodland-dependent species are still declining in two different habitats, Pink GumBlue Gum woodland and Stringybark woodland. We analyse the Mount Lofty Ranges Woodland Bird Long-Term Monitoring Dataset for 1999-2007, to look for changes in abundance of 59 species. We use logistic regression of prevalence on lists in a Bayesian framework, and List Length Analysis to control for variation in detectability. Compared with Reporting Rate Analysis, a more traditional approach, List Length Analysis provides tighter confidence intervals by accounting for changing detectability. Several common species were declining significantly. Increasers were generally large-bodied generalists. Many birds have already disappeared from this modified and naturally isolated woodland island, and our results suggest that more specialist insectivores are likely to follow. The Mount Lofty Ranges can be regarded as a 'canary landscape' for temperate woodlands elsewhere in Australia without immediate action their bird communities are likely to follow the trajectory of the Mount Lofty Ranges avifauna. Alternatively, with extensive habitat restoration and management, we could avoid paying the extinction debt. © Royal Australasian Ornithologists Union 2011.

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This unique book is the first of its kind to explore the diversity of interactions between insects and birds. A group of international experts enthusiastically agreed to contribute to the four sections of the book following the success of an Entomological Club Conference on Insect and Bird Interactions. The first section covers population management issues, discussing effects on birds highly relevant to the planting of large areas of GM crops, new opportunities for increasing biodiversity in farming landscapes, and the novel aspect of managing insects by exploiting birds as biological control agents. This is followed by a section discussing the effects of insecticides on bird populations, and includes a contribution from the RSPB, as well as a re-appraisal of the effects of DDT on raptors. Next, the foraging behaviour of birds on insects is discussed, with chapters also on 'warning' coloration in insects and learning by birds. The first chapter in this section is unusual in having been written by an ophthalmologist and covers colour vision in birds, more specifically ultraviolet vision in relation to insect coloration. Finally, the authors look at insects that are parasites of birds or feed on the detritus in nests, and review the ecology and evolution of the co-adaptation of insect ectoparasites with birds. Insect and Bird Interactions is unparalleled in scope and coverage and will be of interest to entomologists, ornithologists, and ecologists alike.

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The general statement that birds are recorded more often on morning than on afternoon counts is quite common and widespread among ornithologists. Although many investigators have reported temporal variations in bird detections using Point Counts in temperate regions, few researches regarding the same objectives have been conducted in Neotropical habitats or used transect counts as field method. We used transect counts to test the hypothesis that birds are evenly recorded between times of day in a predominantly open Cerrado landscape in southeastern Brazil. Although not always significantly, the number of species and individuals were consistently greater during the morning counts, which corroborates the fact that birds can be more detectable during this time of day. However, a few families as well as a small percentage of species were more likely to be recorded during either one of the two periods we analyzed. Our results suggest that morning counts should detect higher number of both species and individuals in our study area, but specific taxa show distinct patterns of detection which should be acknowledged prior to sampling.

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I examined the size of small mammal prey taken by White-tailed Kites (Elanus leucurus) in the Americas from data obtained in the literature and unpublished material from southern Brazil. Mean weight of adult small mammal prey in the kite's diet ranged between 19.5 and 64.2 g. Mammalian prey taken weighed between 2 and 53% of the kite's body weight. Although the White-tailed Kite is a small mammal specialist, in relation to the size of prey taken, this raptor can be considered a generalist hunter.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)