Topography as a determinant of bird distribution in secondary Atlantic Forest fragments

SummaryIn this study I compare bird communities along an elevational gradient in an Atlantic forest remnant (Pico do Corcovado in Ubatuba) in coastal Sao Paulo state, Brazil. Forests at low elevations are structurally more complex and more diverse in plant species than those along the slopes and at higher elevations in this remnant. Consequently it is hypothesized that low elevation forests contain a greater diversity of bird species. Results from the study in the Corcovado area show clear differences in the distribution of forest birds along the elevational gradient from both qualitative and quantitative aspects. The structurally more complex forest at low elevations contains the most diverse avifauna, including several of the rarest and most threatened species. The importance of this remnant as a whole is apparent due to the high diversity observed (254 species), the high proportion of endemic species, and the extent to which the avifauna is endangered. Protection of forests at all elevations along the Serra do Mar is required to maintain diversity of bird species, particularly the many endemic and endangered species restricted to specific elevations.

The effects of habitat heterogeneity, as measured by satellite image texture, on tropical forest bird distributions

Bird communities in lowland Neotropical forests exhibit temporal and spatial variation in species composition and abundance at multiple scales. Detecting and explaining such variation requires adequate methods for sampling those bird communities but counting birds in highly diverse lowland forests of the Neotropics can be particularly challenging. Point counts are one of the most frequently used methods for counting birds in tropical forests but inter- and intra-observer variability in detecting and identifying sounds may cause problems. Acoustic monitors (passive acoustic monitors; autonomous recording units) provide an alternative and potentially effective method to sample bird communities by acting, in effect, as “point counts”, recording vocalizations at a given point for a set time. I used acoustic monitors to examine patterns of species richness, spatial distribution, and community composition of birds in a lowland forest in eastern Ecuador, one of the most diverse regions on earth. I deployed monitors at 25 locations, each separated by at least 200 m, on each of two 100-ha plots (Harpia, Puma) at Tiputini Biodiversity Station during January–February, 2013–2017. Monitors were set to record for 10 min followed by a 5-min break, from 0545 h to 0810 h (10 recording periods/morning). Recordings were later reviewed to identify species; no attempt was made to distinguish individuals or to estimate distance. Results were compared with contemporaneous direct observations along transects on the same plots. A total of 214 species were identified from recordings on both plots, combined, with slightly more on Harpia (208) than on Puma (188). Number per year ranged from 142 on Harpia in 2016 to 161 on Puma in 2015. Number per point was ~45 with an overall range of 29–68. Number of species detected in recordings was similar to but somewhat less than the number recorded during direct observations. Number of species recorded increased rapidly from the first period (0545–0555 h) to the third (0615–0625 h) but showed little subsequent change. Most species were recorded at relatively few points; the four most widely distributed species were the same on both plots (Patagioenas plumbea, Xiphorhynchus guttatus, Capito aurita, Ramphastos tucanus), all of which are relatively loud canopy or subcanopy species. Ordinations based on species composition illustrated differences between plots based on both recordings and direct observations; similarly, patterns of species composition differed between methods. Acoustic monitors can be an effective tool for sampling bird communities and may be particularly effective and efficient for sampling loud species with distinctive songs. Nonetheless, results from monitors may provide different perspectives on species composition when compared to direct observations. Which method is preferred likely will depend on the specific objectives of individual studies.

The bird species distribution along a dry forest-oak woodland vegetation gradient was studied in autumn and spring in two consecutive years. Intra-seasonal comparisons showed that bird species had similar distributions in each of the two years. Inter-seasonal changes were mainly due to compositional differences even though resident species generally used similar habitats in both seasons. Ordination analyses, based on the first year bird species abundances, showed a clearly segregated distribution between forest and woodland birds. Within these two vegetation types, the distribution tended to be more individualistic. Nevertheless further habitats could be identified according to groups of birds having similar distributions. These habitats did not correspond to the plant associations which resulted from a previous classification of the vegetation. Observations of the plant use by the birds during the study period showed that, in most cases, the plant variables associated with ordination analyses are unlikely to be very important for the bird species life cycles.

Rivers as barriers to dispersal and past forest refugia are two of the hypotheses proposed to explain the patterns of biodiversity in the Atlantic Forest. It has recently been shown that possible past refugia correspond to bioclimatically different regions, so we tested whether patterns of shared distribution of bird taxa in the Atlantic Forest are 1) limited by the Doce and São Francisco rivers or 2) associated with the bioclimatically different southern and northeastern regions. We catalogued lists of forest birds from 45 locations, 36 in the Atlantic forest and nine in Amazon, and used parsimony analysis of endemicity to identify groups of shared taxa. We also compared differences between these groups by permutational multivariate analysis of variance and identified the species that best supported the resulting groups. The results showed that the distribution of forest birds is divided into two main regions in the Atlantic Forest, the first with more southern localities and the second with northeastern localities. This distributional pattern is not delimited by riverbanks, but it may be associated with bioclimatic units, surrogated by altitude, that maintain current environmental differences between two main regions on Atlantic Forest and may be related to phylogenetic histories of taxa supporting the two groups.

In order to examine the bird species changes within different vegetation structures, the variations were compared between Commiphora-dominated vegetations with those of Vachellia tortilis and Vachellia robusta-dominated vegetations, and also compared the birds of grassland with those of Vachellia drepanolobium and Vachellia seyal-dominated vegetations. This study was conducted between February 2010 and April 2012. A total of 40 plots of 100 m × 100 m were established. Nonparametric Mann-Whitney U-test was used to examine differences in bird species between vegetations. Species richness estimates were obtained using the Species Diversity and Richness. A total of 171 bird species representing 103 genera, 12 orders, and 54 families were recorded. We found differences in bird species distribution whereby V. tortilis has higher bird species richness (102 species), abundance, and diversity when compared with Commiphora with 66 species and V. robusta with 59 species. These results suggest that variations in bird species abundance, diversity, and distribution could be attributed to differences in the structural diversity of vegetation. Therefore it is important to maintain different types of vegetation by keeping the frequency of fire to a minimum and prescribed fire should be employed and encouraged to control wildfire and so maintain a diversity of vegetation and birds community.

The distribution of birds in Africa south of the Sahara is now comparatively well documented, both specifically and subspecifically. The most significant features of avian geography in Africa concern the distribution of birds of the evergreen forest. Montane evergreen forest above about 1300 m. usually differs from its lowland counterpart in floristic composition, in the abundance of epiphytic bryophytes, and in the smaller height of the trees. In tropical Africa typical montane forest exists, at least vestigially, on most mountains that rise much above 5000 feet (at much lower altitudes near the sea). The lowland forest of West Africa is divided into two blocks, west (Upper Guinea) and east (Lower Guinea) of the Dahomey gap which runs approximately between Accra and Lagos and is almost entirely savanna. Hence the climatic change that would permit west-to-east communication of these lowland East African animals could not coincide with the change required for the montane birds.

The distributions of bird species have changed over the past 50 years in China. To evaluate whether the changes can be attributed to the changing climate, we analyzed the distributions of 20 subspecies of resident birds in relation to climate change. Long-term records of bird distributions, gray relational analysis, fuzzy-set classification techniques, and attribution methods were used. Among the 20 subspecies of resident birds, the northern limits of over half of the subspecies have shifted northward since the 1960s, and most changes have been related to the thermal index. Driven by climate change over the past 50 years, the suitable range and latitude or longitude of the distribution centers of certain birds have exhibited increased fluctuations. The northern boundaries of over half of the subspecies have shifted northward compared with those in the 1960s. The consistency between the observed and predicted changes in the range limits was quite high for some subspecies. The changes in the northern boundaries or the latitudes of the centers of distribution of nearly half of the subspecies can be attributed to climate change. The results suggest that climate change has affected the distributions of particular birds. The method used to attribute changes in bird distributions to climate change may also be effective for other animals.

Land use changes operate at different scales. They trigger a cascade of effects that simultaneously modify the composition or structure of the landscape and of the local vegetation. Mobil animals, and birds in particular, can respond quickly to such multi-scalar changes. We took advantage of a long term study on the response of songbirds to land-use changes on four Mediterranean islands in Corsica and Sardinia to explore the benefits of a multi-scale analysis of the relationships between songbird distribution, vegetation structure and landscape dynamics. Field data and aerial photographs were used to describe the vegetation at three different scales. Birds were censused by point counts. We used statistical variance decomposition to study how bird distribution and vegetation at various scales were linked. We analysed multi-scale vegetation changes (floristic composition, plot vegetation type, and landscape structure) and their consequences on bird distribution with multivariate and non-parametrical tests. The distribution of most species was linked to at least two spatial scales. The weight of a given scale was consistent with life-history traits for species whose biology was well-known. In the examples studied, vegetation composition, vegetation type and landscape changes that resulted from land abandonment negatively affected birds depending on open or heterogeneous areas. Our results emphasize that multi-scale analyses can greatly enhance our understanding of bird distribution and of their changes. Management of these populations should take into account measures at various spatial scales depending on the sensitivity of the species.

The main objective of this paper is to present and discuss the best methods to estimate live above ground biomass in the Atlantic Forest. The methods presented and conclusions are the products of a workshop entitled "Estimation of Biomass and Carbon Stocks: the Case of Atlantic Rain Forest". Aboveground biomass (AGB) in tropical forests is mainly contained in trees. Tree biomass is a function of wood volume, obtained from the diameter and height, architecture and wood density (dry weight per unit volume of fresh wood). It can be quantified by the direct (destructive) or indirect method where the biomass quantification is estimated using mathematical models. The allometric model can be site specific when elaborated to a particular ecosystem or general that can be used in different sites. For the Atlantic Forest, despite the importance of it, there are only two direct measurements of tree biomass, resulting in allometric models specific for this ecosystem. To select one or other of the available models in the literature to estimate AGB it is necessary take into account what is the main question to be answered and the ease with which it is possible to measure the independent variables in the model. Models that present more accurate estimates should be preferred. However, more simple models (those with one independent variable, usually DBH) can be used when the focus is monitoring the variation in carbon storage through the time. Our observations in the Atlantic Forest suggest that pan-tropical relations proposed by Chave et al. (2005) can be confidently used to estimated tree biomass across biomes as long as tree diameter (DBH), height, and wood density are accounted for in the model. In Atlantic Forest, we recommend the quantification of biomass of lianas, bamboo, palms, tree ferns and epiphytes, which are an important component in this ecosystem. This paper is an outcome of the workshop entitled "Estimation of Biomass and Carbon Stocks: the Case of Atlantic Rain Forest", that was conducted at Ubatuba, São Paulo, Brazil, between 4 and 8 December 2006 as part of the Brazilian project "Ombrophylus Dense Forest floristic composition, structure and function at the Núcleos Picinguaba and Santa Virginia of the Serra do Mar State Park", BIOTA Gradiente.

Distribution of birds on the globe’s surface is a subject to the division on land and zoogeographical regions which are characterized by specific features that display owing to presence of so-called demonstrative species. The paper presents an analysis of the avifauna Notogea and Neogea, significant differences and the uniqueness of species richness of the zoogeographic lands and gives a representation of the current state of distribution of demonstrative bird species on the planet. It is proposed to change the name of the Papuan zoogeographical subregion on Papua to agree it with the origin of the country, as it was done else where. It is also proposed to include the Antarctic in Notogea zoogeographical land which is a specific territory with the original and endemic fauna. It also has a number of bird species that are common for New Zealand, Australian and Polynesian regions of the same land. Keywords: Zoogeography, land and zoogeographical region, Notogea, Neogea, demonstrative species, distribution of birds are endemic.

Background1. Colombia with 1941 known recorded bird species is one of the most species rich countries in the world. Efforts are necessary to conserve, study and promote sustainable use of this important taxonomic group throughout Colombia’s vast territory.2. In an ideal world, informed decisions that are based on sound scientific information should be likelier to have successful outcomes. Nevertheless, there are barriers that make it difficult to access and use information in a timely fashion. Those same barriers impede the study, conservation and sustainable use of bird species in Colombia. On the other hand, given that there is good documentation about the ecology of a large number of species, information about the distribution of birds can be easily incorporated into decision-making processes, once this information becomes readily available in a consumable format using Geographic Information Sciences tools.3. In this context, the main objective of this paper is to present the first compilation of the current distribution of 1889 (97%) species of birds in Colombia, using expert criteria. The shapefiles were used to show the distribution and diversity of bird species in Colombia under both geopolitical and conservation geographic units.4. The information provided in this paper can be used as a baseline for a huge number of initiatives that aim to strengthen conservation efforts and improve knowledge about one the most unique taxonomic groups in the country. These range from land use planning strategies at the municipal or department scale to sustainable use of bird species - such as those initiatives related to bird watching - in Colombia.New informationThis study has considered three key aspects: 1) the importance of birds for Colombia’s ecosystems, 2) the privileged place of Colombia in bird species richness and 3) the importance of data mobilisation in formats easily consumable by Geographic Information Systems (GIS) to facilitate the processes of informed decision-making. We present the first compilation - in shapefile format - for 1889 of the 1941 bird species recorded from Colombia. Using this novel collection, we showed the species richness of birds in Colombia’s 33 Departments plus its Captial District (DPs), 1122 Municipalities (MNs), 58 protected areas (PAs), 39 Regional Autonomous Corporations (the authorities responsible within their respective jurisdictions for regulating the environment and renewable natural resources in Colombia; CARs) and 916 Collectively Titled Territories (including both indigenous reservations and afro-descendant communities; CTTs). In addition, we provide a list of known bird species richness for the above geographic units found in the available literature. The information provided here can be used as a baseline for a huge number of initiatives concerning the study, conservation and sustainable use of bird species present in Colombia, providing access to key features of bird distribution that should facilitate decision-making.

This research aims to determine (1) the types of bird species on Nusa Manu and Nusa Leun Islands, Sawai Village (2) The distribution of bird species on Nusa Manu and Nusa Leun Islands, Sawai Village. This research uses the census method to collect data on bird species. The research results show that there are 13 species of birds on Nusa Manu Island and 12 species of birds on Niusa Leun Island. The highest distribution of bird species on the island of Nusa Manu is black honey (Nectariana aspasia), sriganti honey (Nectariana jugularis), Seram honey (Lichmera monticola) and garden fan (Rhipidura leucophrys) with a frequency of 11.43%, while the lowest distribution of bird species is , sea croak (Butorides striatus) and coral egret (Egretta sacra) with a frequency of 2.86%. The highest bird distribution on Nusa Leun Island is black honey (Nectariana aspasia) and garden fan (Rhipidura leucophrys) with a frequency of 14.29%, while the lowest bird distribution is sea cockerel (Butorides striatus), great egret (Egretta alba). and eastern elephant (Numenius madagascariensis) with a frequency of 3.5-7%.

Buried Seeds, Newly Dispersed Seeds, and the Dynamics of a Lowland Forest in Malaysia

This study investigates the species composition and distribution of gallinaceous birds (Galliformes) in the south of eastern Europe, specifically within the territory of present‐day Ukraine, during the Late Pleistocene and Holocene. The research is based on the comprehensive revision of skeletal remains found at archaeological sites. The findings reveal that seven galliform species were present in the region during these periods: hazel grouse, willow ptarmigan, rock ptarmigan, capercaillie, black grouse, grey partridge and common quail. The study highlights the crucial role of the Crimean Mountains as a refugium during the last glaciation, where the greatest diversity of gallinaceous birds was observed. The research also addresses the changes in the distribution and abundance of these birds over time, noting the loss of some species and the appearance of others. The findings underscore the importance of understanding past environmental changes and their impact on bird populations, which can inform current conservation efforts. The study concludes that while some species have shown high ecological plasticity and adaptability, others have experienced significant range contractions requiring targeted conservation measures.