(for four years) and late-summer burning (one or three years before the study) on both songbirds 29 and non-passerines in a previously homogeneous reedbed. We surveyed birds by a combination 30 of line transects and point counts in a quasi-experimental design consisting of six treatment 31 levels. Management led to a higher diversity of marsh habitats and increased bird diversity. The 32 species richness and abundance of non-passerines (ducks and geese, wading birds, gulls and 33 terns, rails, coots and grebes) was higher in recently burned than in unburned or old-burned 34 patches. The species richness of farmland songbirds was higher in grazed patches than in non-35 grazed patches, and reed songbirds had higher richness and abundance in unburned, old-burned 36 or grazed patches than in recently burned patches. Total Shannon diversity and evenness of birds
In this study we explored the linkage between wing size of Great Reed Warbler males (Acrocephalus arundinaceus) and their habitat selection and relate these linkages to differences in reed habitat quality. We measured the wing sizes of males nesting in 6 different reed habitats. To explain reed habitat selection, we modeled male wing size as a function of 7 predictor variables describing reedbeds: proportion of managed reed; densities of mixed, old, and fresh reed; reed stem diameter; water depth; and fluctuation of water level. Mean wing size was greatest for males at large canals, intermediate at mining ponds and smaller canals, and lowest at marshes and very small canals. The proportion of managed reed and fluctuation of water level were negatively related to wing size, and water depth was positively related to wing size, which suggests that males with larger wings preferred reed habitats with little management in deep water with little fluctuation in water level. We concluded that the availability of stable, deep water and lack of management are primarily important in attracting larger-winged (presumably dominant) males. Keywords: wing size, reed management, water depth, fluctuation of water level, male, habitat selection, Acrocephalus arundinaceus Selección de há bitat de carrizo con relación al tamaño del ala de machos de Acrocephalus arundinaceus RESUMENEn este estudio exploramos el vínculo entre el tamaño del ala de los machos de Acrocephalus arundinaceus y su selección de hábitat, y relacionamos estos vínculos con diferencias en la calidad del hábitat de carrizo. Medimos el tamaño del ala de machos anidando en seis hábitat diferentes de carrizo. Para explicar la selección del hábitat de carrizo, modelamos el tamaño del ala de los machos como una función de siete variables predictivas de los carrizales: proporción de carrizales con manejo, densidad de carrizo mixto, viejo o nuevo, diámetro del tallo del carrizo, profundidad del agua y fluctuación del nivel del agua. El tamaño medio del ala de los machos fue mayor en los canales grandes, intermedio en los estanques cavados y en los canales más pequeños, y menor en los pantanos y en los canales muy chicos. La proporción de los carrizales con manejo y la fluctuación del nivel del agua estuvieron negativamente relacionadas al tamaño del ala, y la profundidad del agua estuvo positivamente relacionada al tamaño del ala, lo que sugiere que los machos con alas más grandes prefirieron hábitats de carrizo con poco manejo en aguas profundas y con poca fluctuación del nivel del agua. Concluimos que la disponibilidad de agua estable y profunda y la falta de manejo son principalmente importantes para atraer a los machos (presumiblemente dominantes) con alas más grandes. Palabras clave: Acrocephalus arundinaceus, fluctuación del nivel del agua, macho, manejo del carrizo, profundidad del agua, selección de hábitat, tamaño del ala INTRODUCTION
Báldi (2001) studied how inundation affected the local breeding passerines at the Kis-Balaton wetland. He collected observations in 3 groups (before, immediately after, and years after inundation) and quantified the changes in community structure parameters, community composition, differences between areas and periods, and species and abundances. Savi's Warbler, Locustella luscinioides, declined immediately after inundation, while Reed Bunting, Emberiza schoeniclus, and Sedge Warbler, Acrocephalus schoenobaenus, declined in the long term. However, the Great Reed Warbler (GRW), Acrocephalus arundinaceus, was the only species with a continuous increasing trend. Vadász et al. (2008) reported that the cutting of reed negatively influenced species richness and the abundance of reed passerines on Lake Kolon in Central Hungary. Savi's Warbler, Moustached Warbler Acrocephalus melanopogon, Sedge Warbler, and Reed Warbler Acrocephalus scirpaceus especially avoided cut areas, while GRW did not (Vadász et al., 2008). Báldi and Moskát (1995) and Moga et al. (2010) recorded the presence of GRW in unmanaged, burned, and mowed reed stands. Despite these sporadic observations, our knowledge about the effects of reed management and environmental factors on the breeding success of GRW is weak.Nests of small open-nesting birds are often difficult to detect in the early stages of the breeding season (Mayfield, 1975). Due to the lack of information for the period before nests are found, estimates of mortality, survival, and breeding success can be severely biased. Mayfield (1975) developed a method for estimating breeding success that reduced potential sources of error. The proposed Mayfield estimator has been further recognized as a maximum likelihood estimator (MLE). The asymptotic distribution of the MLE has been calculated, which provides a measure of asymptotic variance (Hensler and Nichols, 1981). MLE and variance can be used to test the significance of daily survival (Hensler and Nichols, 1981). Lloyd and
ABSTRACT.---We surveyed five reed habitats (mining pond, sand pit, large canal, small 1 canal and lowland river) in north-western Vojvodina (Serbia) between 2009-2011 to study 2 habitat use and to estimate nest success in an understudied region of the breeding range of the 3 Great Reed Warbler (Acrocephalus arundinaceus). Data from 174 nests showed that habitat 4 use differed considerably between the habitat types, but was not related to the area of the 5 study site or the reed bed. Higher-than-expected numbers of nests along the small canal and 6 the river suggested that Great Reed Warblers preferred these to other habitats for nesting. 7Habitat use was closely linked to the availability of reed edges and the quality of the reed 8 stand. Overall Mayfield nest success was 43%, slightly lower than in northern and western 9 Europe. Nest success was low along the small and large canal, where brood parasitism by 10Common Cuckoos (Cuculus canorus) and nest predation were high due to nearby tree lines 11 providing perching sites to cuckoos and predators. Nest success was intermediate at the 12 mining pond due to very high predation pressure and adverse weather, and nest success was 13 highest in the sand pit (despite high Cuckoo parasitism) and the river (despite relatively high 14 predation). In conclusion, our results suggest that canals can function as ecological traps, 15 which attract edge-preferring Great Reed Warblers but are highly accessible to predators and 16 brood parasites. In contrast, sand pits can be perceptual traps because they provide good 17 resources for nesting but were less attractive to Great Reed Warblers than other habitats. 18Habitat use in relation to habitat availability thus depends primarily on the availability of reed 19 edges and the quality of the reed stand, whereas nest success also depends on the 20 characteristics of the surroundings and weather conditions.
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