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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Variação sazonal e a influência da estrutura da paisagem na ocorrência de Charadriidae e Scolopacidae no litoral do Rio Grande do Sul

Scherer, Angelo Luís 25 February 2010 (has links)
Made available in DSpace on 2015-03-05T16:20:41Z (GMT). No. of bitstreams: 0 Previous issue date: 25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O Brasil é visitado anualmente por milhares de aves costeiras que realizam movimentos sazonais da América do Norte para a América do Sul e vice-versa. Destacam-se as que vêm no norte com a aproximação do inverno boreal que chegam à procura de locais de parada e invernada, onde encontram alimentação farta, propiciando-lhes a continuidade do seu ciclo de vida. O presente trabalho tem por objetivo contribuir com o conhecimento a respeito da variação sazonal e influência da paisagem na ocorrência de aves costeiras ao longo do litoral médio na planície costeira do Rio Grande do Sul, Brasil. O trabalho é apresentado através de dois artigos que tratam dos temas propostos, estando formatado em uma versão preliminar de acordo com as normas de submissão da revista científica Journal of Ornithology. O primeiro artigo apresenta dados referentes à ocorrência e a variação sazonal de aves costeiras das famílias Charadriidae e Scolopacidae ao longo de 120 Km de praia durante um período de dois anos evidenciando a importância / The coast of Rio Grande do Sul State, Brazil, includes a remarkable number of habitats used by many Nearctic shorebirds species during the non-breeding season in the austral summer months. During two years we evaluated the abundance of shorebird monthly, along 120 km of the beach in Rio Grande do Sul, southern Brazil. Of the 17 species recorded, the most abundant were the Sanderlings (Calidris alba), White-rumped Sandpiper (Calidris fuscicollis) and Red Knot (Calidris canutus). The highest abundance occurred between October and April, and the lowest abundance occurred between May and September. Of the total species, 14 were migrant shorebirds from north hemisphere, one is a migrant shorebird from south hemisphere and two were resident. Some species were present throughout the year. Nine species were constantly registered, two were sporadic and six were incidental recorded. This study confirms that the beaches of Rio Grande do Sul State, are an important migration stopover and winter site for many shorebir
12

Linking shorebird and marsh bird habitat use to water management in anthropogenic and natural wetlands in the Colorado River Delta

Gómez Sapiens, Martha Marina January 2014 (has links)
I estimated patterns of shorebird abundance and species diversity in the Colorado River Delta and Upper Gulf of California wetlands in order to determine the relative contribution of intertidal wetlands and non-tidal anthropogenic wetlands to support shorebird habitat use. Species richness varied from 15 to 26 species among sites and 29 species were detected across sites. Density during the peak migration month was higher at the anthropogenic wetland Cienega de Santa Clara (mean = 168 ind/ha, 95% C.I. 29-367), and the intertidal Golfo de Santa Clara (mean = 153 ind/ha, 95% C.I. 17-323). Anthropogenic wetlands (playa and lagoons) supported high abundance of shorebirds along with intertidal wetlands in the Colorado River Delta (mudflats). In contrast, intertidal wetlands farther south on the Sonoran Coast presented lower abundance but higher diversity of shorebird, likely as a result of the higher diversity of habitats (rocky shore, sandy beach, estuary). I modeled water management scenarios for the Cienega in order to determine the response of the dominant vegetation (southern cattail, Typha domingensis Pers.) and the area of the outflow pool below the marsh to different scenarios of water management. The model indicates that if the inflow rate is reduced below the current 4-5 m³s⁻¹ the vegetated area of the Cienega that supports habitat for marsh birds would decrease in proportion, as would the area of the outflow pool in the Santa Clara Slough identified previously as shorebird habitat. Increases in salinity will also reduce the vegetated area due to the low salt tolerance of T. domingensis. In winter about 90% of inflow water exits the Cienega into the Santa Clara Slough due to low evapotranspiration contributing to inundate areas that are used by wintering and migrating shorebirds. Lastly, I explored the feasibility of using Vegetation Indices (NDVI and EVI) to model Yuma Clapper Rail detections in the Cienega de Santa Clara as well as the effects of adding other habitat variables and the presence of fire events in the performance of linear models based on NDVI. Both NDVI and EVI were positively related to the Yuma Clapper Rail detections. The relationship was weak to moderate, but significant (P<0.001), which suggests other factors besides the vegetation condition play an important role in the bird distribution pattern. A model including all the variability among years was a better predictor of the rails detected per transect, than models for fire and non-fire years. We did not find a significant effect from adding habitat features (water % or vegetation %), and we recommend to include variables at both microhabitat level and landscape level, relevant before and during the breeding season in order to increase the explanatory power of models.
13

Distribuição espacial e temporal de aves limícolas (Charadriiformes) na Ilha dos Caranguejos, Golfão Maranhense, Brasil / Spatial and temporal distribution of shorebirds (Charadriiformes) in Crab Island,Gulf of Maranhao, Brazil

Carvalho, Dorinny Lisboa de 12 December 2008 (has links)
Made available in DSpace on 2016-08-17T15:00:42Z (GMT). No. of bitstreams: 1 Dorinny Lisboa de Carvalho.pdf: 1040265 bytes, checksum: 222b9982d76512080d90402414be0760 (MD5) Previous issue date: 2008-12-12 / PETRÓLEO BRASILEIRO S.A. / We studied spatial and seasonal distribution of shorebirds (Charadriiformes) in Island of Caranguejos, Gulf of Maranhão. Censuses were conducted seasonally (considering arrival of migrants in South America, wintering, departure and breeding in North America) from September/2007 to July/2008, in two sectors of Island, North and South. We used the methods of point count, transect and estimate. The North Sector showed greater richness, the South, most abundance. The North Sector did not show differences in number of individuals or significantly different (Kruskal-Wallis, H = 1.0163, df = 3, P = 0.7973) between the periods. The Southern Sector showed greater abundance in the arrival (35,046) winter (35,708), decline in departure (20,046) and increasing of abundance in reproductive period (92), showed no significantly different (Kruskal-Wallis , H = 4.1596, df = 3, P = 0.2447). Considering the total number of shorebirds, the following pattern was observed: high abundance during the period of arrival (46,698), and winter (41,263), followed by declines in the individuals numbers in departure (24,169) and reproductive (6071), not significantly different (Kruskal-Wallis, H = 28,892, df = 3, P = 0.4090). There was no significantly different considering the abundance of time of arrival (Mann-Whitney U = 44.00; Z = 0.7107, P = 0.4773), winter (Mann-Whitney U = 48.50; Z = 0.3909 P = 0.6959), departure (Mann-Whitney U = 38.00; Z = 11,371, P = 0.2555) and reproductive (Mann-Whitney U = 45.00; Z = 0.6396, P = 0 , 5224) between North and South. Temporal distribution showed a high abundance in the months September to November (autumn migration) and from December to February (winter) reducing the number of individuals in the months of March to May and low values were recorded from June to August, when the birds are breeding in Arctic. Calidris pusilla was the most abundant species in all periods. Spatial distribution was related to the change of tide. Island of Caranguejos is a important wintering site for migratory shorebirds, its conservation is important for maintenance of birds group in wild life. / Objetivou-se descrever a distribuição espacial e temporal de aves limícolas (Charadriiformes) na Ilha dos Caranguejos, Golfão maranhense. Os censos foram realizados sazonalmente (considerando a chegada dos migrantes na América do Sul, invernada, partida e reprodução na América do Norte) de setembro/2007 a julho/2008 em dois setores da Ilha, denominados Norte e Sul. Utilizou-se os métodos de ponto fixo, transecto e estimativa. O Setor Norte apresentou maior riqueza, o Sul, maior abundância. O Setor Norte não mostrou diferenças nítidas no número de indivíduos nem diferença significativa (Kruskal-Wallis, H= 1,0163; gl= 3; P= 0,7973) entre os períodos. O Setor Sul apresentou maior abundância no período de chegada (35.046) e invernada (35.708), com declínio no período de partida (20.046) e elevando o número de indivíduos no período reprodutivo (92), não mostrando diferença significativa (Kruskal- Wallis, H= 4,1596; gl= 3; P= 0,2447). Considerando o número total de aves limícolas, se deu o seguinte padrão: alta abundância no período de chegada (46.698) e invernada (41263), seguida por declínios nos números de indivíduos nos períodos de partida (24.169) e reprodutivo (6.071), não houve diferença significativa (Kruskal-Wallis, H= 28,892; gl= 3; P= 0.4090). Não houve diferença significativa da abundância considerando os períodos de chegada (Mann-Whitney U= 44,00; Z= 0,7107; P= 0,4773), invernada (Mann-Whitney U= 48,50; Z= 0,3909; P= 0,6959), partida (Mann-Whitney U= 38,00; Z= 11,371; P= 0,2555) e reprodutivo (Mann-Whitney U= 45,00; Z= 0,6396; P= 0,5224) entre os setores Norte e Sul. A distribuição temporal mostrou alta abundância nos meses setembro a novembro (migração de outono) e dezembro a fevereiro (invernada) diminuindo o número de indivíduos nos meses de março a maio e baixos valores nos meses de junho a agosto quando as aves estão se reproduzindo no Ártico. Calidris pusilla foi a espécie mais abundante em todos os períodos. A distribuição espacial se deu de acordo com a variação de maré. A Ilha dos Caranguejos se mostrou como um importante sítio de invernada de aves limícolas migratórias, sendo fundamental a conservação dessa área para a manutenção desse grupo de aves na vida silvestre.
14

Flutuação temporal e a relação da amplitude de maré com as aves aquáticas da Laguna da Ilha Comprida, SP, Brasil / Temporal fluctuation and the relation of tidal amplitude with aquatic birds at laguna da Ilha Comprida, SP, Brazil

Roberta Tonolli Chiavone Delchiaro 02 July 2012 (has links)
O objetivo deste trabalho foi estudar a composição da avifauna aquática, a diversidade, suas abundâncias, a variação mensal e sazonal das populações e entender a relação desses fatores com a variação de maré na Laguna da Ilha Comprida. Ocorreram 6193 indivíduos referentes a 54 espécies, a diversidade de acordo com o Índice de Shannon foi 2,7036. Não houve diferença estatística no número total de indivíduos entre os meses e estações. Já a riqueza variou, sendo o maior valor na primavera, explicada pela ocorrência de espécies visitantes do hemisfério norte durante a migração para o sul. Houve correlação negativa entre a riqueza de espécies, número de indivíduos e diversidade, com a oscilação da maré, pois conforme a maré diminuía, aumentava a área disponível para descanso e forrageio. A Família Ardeidae apresentou correlação negativa mais forte em relação à amplitude de maré ao ser comparada as Famílias Scolopacidae e Charadriidae. Este fato ocorreu pela presença de Egreta caerulea que depende da maré baixa para forragear. A Laguna é uma importante área para avifauna aquática utilizada para alimentação e descanso, principalmente na maré baixa, além de ponto de parada para aves costeiras na migração para o sul durante a primavera. / The objectives of this work was to study the composition of aquatic bird, its diversity, abundance, monthly and seasonal variation of the bird populations and understand the relation of these factors with tidal variation at Laguna da Ilha Comprida Island. We registered 6193 individuals of bird referring to 54 species, being that the Shannon diversity index was 2,7036. There were not statistics difference between total number of individuals, the months and seasons. However there was variation of the species richness, being the biggest valor in the spring, explained for the occurrence of visiting species of north hemisphere during the migration for the south. There were negative correlation enters the species richness, individual number and diversity with the tidal oscillation. Because when the tide was low, increase the area available for rest and foraging. The Ardeidae family presented stronger negative correlation in relation of tidal variation when comparative being the Families Scolopacidae and Charadriidae. This fact occurred for the presence of Egreta caerulea that depends on the low tide to foraging. The Laguna is an important aquatic area for bird, used for feeding and rest, during the low tide and stopover for coastal birds in the migration for the south during the spring
15

Development and dynamics of gut microbial communities of migratory shorebirds in the Western Hemisphere

Grond, Kirsten January 1900 (has links)
Doctor of Philosophy / Division of Biology / Brett K. Sandercock / Gastrointestinal microbiota play a vital role in maintaining organismal health, through facilitating nutrient uptake, detoxification and interactions with the immune system. Shorebirds vary widely in life-history characteristics, such as habitat, migration and breeding system, but the dynamics of their gut microbial communities are unknown. In my dissertation, I investigated composition and dynamics of gut microbiota in migratory shorebirds from embryos to 10 day old chicks, and determined environment and host-related factors affecting gut microbial communities of adults. First, I tested whether precocial chicks from three species of arctic-breeding shorebirds acquire gut microbiota before or after hatching using next-generation sequencing. In addition, I documented the dynamics of gut microbial establishment. I showed that gut microbiota were absent in shorebird embryos before hatching, but that stable gut communities established within the first three days after hatching. In addition, gut microbiota of young shorebird chicks were more similar to the environmental microbiome than later in life, suggesting that the environment is a likely source for microbial recruitment. After reaching adulthood, shorebirds migrate long distances, potentially exposing them to a wide range of microorganisms. Host phylogeny and environmental factors have both been identified as drivers of gut microbiota composition in birds in previous studies. The second part of my project aimed to compare the relative importance of host and environmental factors that underlie variation in gut microbiota composition in eight species of migratory shorebirds sampled across the North American Arctic. I found that sampling site was the main driver of variation in gut microbiota of Arctic-breeding shorebirds, and that site-related variation in gut microbiota of shorebirds was a result of differences in core bacterial taxa that occurred in more than half of the analyzed samples. A relatively large influence of local environment on gut microbiota composition of chicks and adults lead to the question: how does site affect pathogen prevalence in shorebirds? Migratory behavior has been hypothesized to have evolved as a response to variation in climatic conditions and food availability, to avoid predation, and to reduce risk of exposure to pathogens. The migratory escape hypothesis predicts avoidance of high disease prevalence areas through migration, and has been proposed as one of the main reasons that many bird species migrate to the Arctic for breeding. To test the migratory escape hypothesis in shorebirds, I screened for prevalence of seven known avian pathogens in shorebirds at different stages of migration. I did not detect the majority of pathogens we tested for, with the exception of Campylobacter jejuni and C. coli. Prevalence of C. jejuni in shorebirds was linked to sampling sites but not shorebird species. My dissertation is the first comprehensive study to broadly characterize the gut microbiota in shorebirds. Overall, local environment emerged as an important factor in shaping microbiota composition in Arctic-breeding shorebirds throughout my dissertation research. The role of local environment in shaping gut microbiota invites future investigations of the interactions among shorebirds and the microorganisms present in their environment, as well as the functions gut microbiota perform within their shorebird hosts.
16

Nutritional Value and Management of Waterfowl and Shorebird Foods in Atlantic Coastal Moist-Soil Impoundments

Sherfy, Mark Huffman 23 April 1999 (has links)
The mid-Atlantic coast region, an area of continental significance to migratory and wintering waterfowl and shorebirds, contains numerous moist-soil impoundments that are managed for waterbirds. Positive relationships between nonbreeding body condition and subsequent survival and reproduction have been documented for waterfowl, yet few evaluations of habitat management consider nutritional value of foods. I assessed 2 types of impoundment manipulation, using nutritional data as a basis for evaluation.Invertebrate and plant seed production were measured in disced and control plots in impoundments at Back Bay National Wildlife Refuge. Seed production was higher (P = 0.0614) in disced (1052 ± 468 kg / ha) than in control (529 ± 226 kg / ha) plots. Discing produced higher Chironomid larva abundance during spring, and higher abundance of Amphipods and non-Chironomid Diptera during fall. Waterbird predation reduced abundance of Chironomid larvae, non-Chironomid Diptera, and Amphipods. The predation effect on Total Invertebrate dry mass was 2x higher in disced than in control areas.Invertebrate production also was measured in habitats denuded by foraging greater snow geese (Anser caerulescens atlantica) at Prime Hook National Wildlife Refuge. Chironomid larvae were 2 -6x more abundant in vegetated habitats than in areas where geese had foraged intensively, but exclosure data showed little effect of shorebird predation on invertebrate abundance. These results suggest that high goose populations can reduce waterbird food availability, and that shorebird use of invertebrates in denuded habitats is low.Mean true metabolizable energy (TME) of moist-soil seeds and invertebrates in blue-winged teal (Anas discors) ranged from -0.18 - 3.47 kcal / g. Correction of means for fiber concentration eliminated negative values, thereby enhancing their practical value.Potential duck use-days predicted using TME and seed production data were about 2x higher for disced than for control areas at Back Bay. Magnitude of the discing effect on duck use-days was largely insensitive to different estimates of seed nutritional value, although substantial variation in absolute measures of potential carrying capacity occurred. Discing positively influenced invertebrate abundance, and quantity and quality of moist-soil seeds produced, and should be considered a viable habitat management approach for both shorebirds and waterfowl. / Ph. D.
17

Interactions between shorebirds and benthic macrofauna : making small things bigger / Interactions spatio-temporelles entre oiseaux limicoles et macrofaune benthique : une approche multi-échelles

Philippe, Anne 17 November 2016 (has links)
Les vasières intertidales sont des environnements complexes et changeants, qui abritent des invertébrés enfouis dans le sédiment (la macrofaune benthique) et sont visités de manière saisonnière par de grands migrateurs : les oiseaux limicoles. Ce travail de recherche s’intéresse aux relations proie-prédateur entre les oiseaux limicoles et leur ressource alimentaire : la macrofaune benthique. La thèse est articulée en 8 chapitres qui présentent des études à différentes échelles spatio-temporelles : des saisons à la décennie, et de la baie à la route migratoire. Ces études sont basées sur un échantillonnage régulier des vasières intertidales du Golfe de Gascogne (France) ainsi que d’échantillonnages en mer des Wadden (Pays-Bas) et au Banc d’Arguin (Mauritanie). Les données de macrofaune (qualité, taille, densité, biomasse) sont couplées aux données de comptages de leurs prédateurs ainsi qu’à leur comportement alimentaire (reconstruction du régime alimentaire d’après les isotopes, les fécès, la modélisation ou l’observation de vidéos). Ces huit études apportent un éclairage sur l’écologie de leurs interactions (en intégrant des variables environnementales telles que le temps d’inondation, la granulométrie, la température, la production primaire, ou encore la latitude). Une attention particulière est portée à la variabilité des proies et du comportement alimentaire de leurs prédateurs, dans l’espace et le temps. Des encarts viennent illustrer pour l’un les techniques de reconstruction du régime alimentaire, pour l’autre les défenses développées par les mollusques marins, ou encore la relation entre énergie à disposition et sélection du site pour les limicoles. / Intertidal mudflats are complex ecosystems undergoing constant changes, home to infaunal invertebrates (benthic macrofauna), and migratory sites for particular birds : shorebirds. This research focuses on predator-prey interactions between shorebirds and their macrobenthic prey. The present thesis is composed of 8 chapters which illustrate different spatio-temporal scales : from seasons to the decade, and from the bay to the migratory flyway. These studies are based on regular benthic sampling of intertidal flats along the Bay of Biscay (France), as well as sampling data from the Dutch Wadden Sea and the Mauritanian Banc d’Arguin. Macrobenthic data (quality, sizes, densities, biomass) are linked with shorebird counts and data about their feeding behaviour (diet reconstruction from isotopes, faeces, modeling and video observations). These eight studies shed light on particular relationships between some prey and their predators, and the ecology of these interactions (including environmental variables such as inundation time, grain size, temperature, primary production, or even latitude). Particular attention is given to the variability of prey and predator behaviour in time and space. Inserts are included in between chapters to illustrate for instance different diet reconstruction techniques, anti-predation traits in marine molluscs, or relation between energy available and site selection in shorebirds.
18

COI Barcoding of the Shorebirds: Rates of Evolution and the Identification of Species

Elbourne, Rebecca 07 December 2011 (has links)
This study assembles COI barcodes from 1814 specimens from the shorebird order, Charadriiformes and examines variation relative to time, rate of evolution and taxonomic level. In the suborder Scolopaci, 95% of sampled species were identified correctly. COI barcode variation within monotypic species was low (0-1% maximum distance) but showed a wide range within polytypic species (0-5%). Preliminary Charadrii results suggest similar trends but success is reduced in the third suborder, Lari. Rates of COI evolution are found to be lowest in the Lari and this leads to reduced species identification in recently radiated families: just 49% of the Laridae and 57% of the Stercoraridae are identified but 100% of the older Alcidae. In the faster Scolopaci, subspecies are at the limit of resolution with some well differentiated subspecies not distinguished by barcodes. The interplay of evolutionary rates, divergence dates and gene flow appears to determine COI barcode differentiation between taxa.
19

COI Barcoding of the Shorebirds: Rates of Evolution and the Identification of Species

Elbourne, Rebecca 07 December 2011 (has links)
This study assembles COI barcodes from 1814 specimens from the shorebird order, Charadriiformes and examines variation relative to time, rate of evolution and taxonomic level. In the suborder Scolopaci, 95% of sampled species were identified correctly. COI barcode variation within monotypic species was low (0-1% maximum distance) but showed a wide range within polytypic species (0-5%). Preliminary Charadrii results suggest similar trends but success is reduced in the third suborder, Lari. Rates of COI evolution are found to be lowest in the Lari and this leads to reduced species identification in recently radiated families: just 49% of the Laridae and 57% of the Stercoraridae are identified but 100% of the older Alcidae. In the faster Scolopaci, subspecies are at the limit of resolution with some well differentiated subspecies not distinguished by barcodes. The interplay of evolutionary rates, divergence dates and gene flow appears to determine COI barcode differentiation between taxa.
20

Uso de habitats e sazonalidade de aves limícolas no Canal da Raposa, Ilha de São Luís, Maranhão, Brasil. / Use of habitats and seasonal occurrence of shorebirds on Channel Fox's, Island of Sao Luis, Maranhao, Brazil.

Silva, Laís de Morais Rego 15 February 2007 (has links)
Made available in DSpace on 2016-08-17T15:00:42Z (GMT). No. of bitstreams: 1 LAIS_ DE_ MORAIS_ REGO _SILVA.pdf: 832865 bytes, checksum: c498c083ec0f78b354b2e99bdf847b57 (MD5) Previous issue date: 2007-02-15 / PETRÓLEO BRASILEIRO S.A. / The objective of this work was to characterize use of habitat and seasonality of shorebirds in Raposa s Channel, North of São Luís Island, Gulf of Maranhão. The censuses of shorebirds occurred during two consecutive weeks of each month between February and November 2006. Three areas (each one with 3ha) were selected for censuses, considering the type of flat (mud, sand-mud, sand). The censuses were taken during one spring tide and during one neap tide of each month. In foraging, 17407 shorebirds were observed during the study. The highest density of shorebirds feeding was in the mudflat (180.95 ind/ha), then sand-mudflat (100.25 ind/ha) and sandflat (27.10 ind/ha). Calidris pusilla was the most abundant species in Raposa s Channel (n = 8922) and in the mudflat (n = 7578). In sand-mudflat, Tringa semipalmata was the most abundant species (n = 1270) and in the sandflat it was Pluvialis squatarola (n = 130). Tringa semipalmata was the most abundant species in the roost area (n = 788). The highest density of shorebirds feeding was observed during neap tides. The high density of shorebirds observed probably might be due to the study area to form a mosaic of habitats still conserved. Pluvialis squatarola, Numenius phaeopus, Tringa semipalmata, Calidris canutus, A. interpres and Charadrius semipalmatus presented this seasonal pattern: high density between February and April, decreases between May and July and increase in density between August and November. Calidris pusilla and differed for presenting increases in density in July; Limnodromus griseus had presented high density only since August and Charadrius collaris had increases in density between February and July, and decreases between August and November. The seasonal patterns demonstrated the importance of Raposa s Channel as stopover area for some species and winter area for others shorebirds species. Thus, the identification and characterization of Raposa s Channel as important wintering area for migratory shorebirds is fundamental to create conservation plans for north brazilian coast, in order to maintaining the shorebirds populations at long term in nature. / Este trabalho teve como objetivo caracterizar o uso de habitats e a sazonalidade de aves limícolas no Canal da Raposa, norte da Ilha de São Luís, Golfão Maranhense. Os censos de aves limícolas ocorreram durante duas semanas consecutivas de cada mês entre fevereiro e novembro de 2006. Foram selecionadas três áreas (cada uma com 3ha) para a realização dos censos, considerando o tipo de substrato (lamoso, areno-lamoso e arenoso). Os censos foram realizados durante uma maré de sizígia e durante uma maré de quadratura de cada mês. Foram observadas 17407 aves limícolas forrageando durante o período de estudo. A maior densidade de aves limícolas em forrageio foi verificada no substrato lamoso (180,95 ind/ha), seguido pelo areno-lamoso (100,25 ind/ha) e pelo arenoso (27,10 ind/ha). Calidris pusilla foi a espécie mais abundante (n = 8922) no Canal da Raposa, sendo também mais abundante no susbtrato lamoso (n = 7578). No Areno-lamoso, Tringa semipalmata foi mais abundante (n = 1270) e no arenoso foi Pluvialis squatarola (n = 130). Tringa semipalmata também foi a espécie mais abundante (n = 788) na área de descanso. Houve maior densidade de aves limícolas forrageando durante as marés de quadratura. A alta densidade de aves limícolas observada provavelmente se deve ao fato da área estudada se tratar de um mosaico de habitats ainda conservados. Pluvilais squatarola, Numenius phaeopus, Tringa semipalmata, Calidris canutus, Arenaria interpres e Charadrius semipalmatus apresentaram o seguinte padrão sazonal: alta densidade entre fevereiro e abril, decréscimos entre maio e julho e acréscimos de agosto a novembro. Calidris pusilla diferiu por apresentar acréscimos no mês de julho; Limnodromus griseus apresentou altas densidades somente a partir de agosto e Charadrius collaris obteve maior densidade de fevereiro a julho e decréscimos de agosto a novembro. Os padrões sazonais mostraram a importância do Canal da Raposa como área de parada para algumas espécies de limícolas e como área de invernada para outras. Portanto, a identificação e caracterização do Canal da Raposa como uma importante área de invernada para aves limícolas migratórias é fundamental para traçar planos de conservação para a costa norte brasileira, a fim de manter as populações de aves limícolas em longo prazo na natureza.

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