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Mester B.,Hungarian Academy of Sciences | Szalai M.,Koros Maros National Park Directorate | Mero T.O.,Nature Protection and Study Society NATURA | Puky M.,HAS CER DRI | Lengyel S.,Hungarian Academy of Sciences
Biological Conservation | Year: 2015

Ecosystem management often aims to maintain a diversity of habitats to benefit a large number of specieswithin a landscape. We studied the effects of wetland management by low-intensity cattle-grazing and late-summer burning on marsh vegetation and globally declining anuran amphibians (frogs and toads) in a previously homogeneous reedbed. Burning effectively removed old reed and increased the variability of reed cover and marsh vegetation by the next spring. However, reed grew back strong in areas burned 2 or 3 years before the study, indicating that fire rejuvenates reedbeds. In contrast, cattle-grazing kept reed cover homogeneously lowand created open water surfaces. The number of amphibian species and individuals decreased with mean reed cover and old reed density, and increased with variability in reed cover. Correspondingly, amphibian richness and counts were greatest in newly burned areas the next spring. In contrast, a year later, richness and counts were greatest in grazed-only areas,with large decreases in newly burned and control areas. Our results suggest that combined management with grazing and burning can create different habitat patches, some of which will be optimal for amphibians in one year, whereas other patches may become suitable in a subsequent year when successional changes alter previously optimal patches. To maximise optimal habitats, mosaic management should repeat burning once every 2 or 3 years in a rotational manner, and also maintain low-intensity cattle-grazing, which controls reeds and benefits amphibians more sustainably. Our study supports spatiotemporally varied management to facilitate habitat heterogeneity and complexity in dynamic landscapes. © 2015 Elsevier B.V.


Mero T.O.,Debrecen University | Zuljevic A.,Nature Protection and Study Society NATURA | Varga K.,Debrecen University | Bocz R.,Hortobagy National Park Directorate | Lengyel S.,Hungarian Academy of Sciences
Turkish Journal of Zoology | Year: 2014

In this study, we present the effects of reed burning and precipitation on the breeding success of Great Reed Warblers on a mining pond (2008-2011). Breeding success, i.e. the probability that an egg would produce a fedgling, was 0.43. Clutch survival was lowest in 2010, due to the precipitation and high water level during the season. Breeding success was higher in the second half of the breeding season, although in 2008 and 2011 precipitation was also higher in the second half than in the first half of the breeding season. During the first half of the breeding season, daily egg and nestling survival did not differ. However, in the second half of the breeding season, daily egg survival was higher than daily chick survival. In years when reed was burned, breeding density varied between 7.7 and 12.3 pairs ha-1, which was not significantly lower than in years when reed was not managed (average: 13.2 pairs ha-1). Despite the availability of fresh reed in large areas, birds placed their nests mainly in mixed reed stands. Breeding success in fresh and mixed reed did not differ. Generally, breeding success and density were not affected by reed burning, but water level affected breeding success and density. © TÜBİTAK.


Mero T.O.,Nature Protection and Study Society NATURA | Zuljevic A.,Nature Protection and Study Society NATURA
Acta Zoologica Bulgarica | Year: 2015

Previous attempts to determine the age of the great reed warbler, Acrocephalus arundinaceus, after the complete moult have exposed a number of uncertainties. The present study provides evidence that the age of adult birds of this species cannot be determined precisely by using the colours of the iris and the tarsus as well as by the presence or absence of tongue spots. Between 2008 and 2014, we ringed a total of 2783 individuals (1445 adults and 1338 nestlings) and 76.5% of the captured adult birds had olive-green irises. Recaptures revealed that the colour of the iris changed from olive-green to reddish-brown in 19.7% of the individuals and the change in the opposite direction was similarly frequent (21.3%). In 57.4% of the cases, the iris colour remained constant throughout the years. As the nesting season progressed, the colour of the tarsus changed from bluish-grey to flesh-pink, while the presence or absence of tongue spots did not display any trend. The most frequent combinations were an olive-green iris, a bluish-grey or flesh-pink tarsus and the presence of tongue spots. In birds of exactly known age (ringed as nestlings; n = 25), the combinations of the three variables varied strongly. Furthermore, the changes in the three variables did not demonstrate any relationship with the increasing age of the individuals. Our results suggest that these criteria may not be suitable for age determination, and a more reliable method is needed. At the same time, we advise that aging criteria should be verified in advance for birds of exactly known age before applying them to unknown individuals.


Mero T.O.,Debrecen University | Zuljevic A.,Nature Protection and Study Society NATURA | Varga K.,Debrecen University | Lengyel S.,Debrecen University
Natura Croatica | Year: 2013

We monitored the breeding success of the Common Cuckoo (Cuculus canorus) in four reed habitats (e. g. clay pits, marsh and fishponds, small canals and large canals) in northwestern Vojvodina (Serbia) between 2009 and 2011 (three breeding seasons). A total of 596 Great Reed Warbler (Acrocephalus arun- dinaceus) nests were found and monitored. The overall parasitism rate for the study area was 0.127, which was calculated from the number of parasitized nests (76) divided by the total number of Great Reed Warbler nests (596). The parasitism rate did not vary with the total number of Great Reed Warbler nests at a study site. The number of parasitized and successful parasitized nests showed significant negative relationship, which means more parasitized nests resulted with more brood lost. The parasitism rate varied significantly among habitats but not among years while the number of successfully parasitized nests differed among both habitats and years. Parasitized nests found in small and large canals showed the highest reproductive success of Cuckoos. Loss of parasitized nests through predation and bad weather circumstances was relatively high in this study compared to other areas.


Mero T.O.,Nature Protection and Study Society NATURA | Zuljevic A.,Nature Protection and Study Society NATURA
Ethology Ecology and Evolution | Year: 2015

Knowledge of the effects of nest position with regards to distance from shore and vegetation structure on the nest defence behaviour of Great Reed Warblers is lacking. Nest defence behaviour was investigated in the case of 110 monogamous breeding pairs during the breeding season of 2011. We found that nest distance from shoreline and from the reed edge adjacent to water, and reed density, influenced nest defence behaviour positively. However, time elapsed since hatching did not affect parental behaviour. Similar to what was found in previous studies, females defended nests more intensively. Previous papers reported higher predation pressure near both reed edge types (near shoreline and water) than in interior parts of the reed bed, and considering these and our results we suggest that the nest defence pattern of monogamous Great Reed Warblers may vary similarly near both edge types, while in the case of interior parts of reed beds further studies are required for proper conclusions. © 2015 Dipartimento di Biologia, Università di Firenze, Italia


Mer T.O.,Nature Protection and Study Society NATURA | Zuljevic A.,Nature Protection and Study Society NATURA | Lengyel S.,Hungarian Academy of Sciences
Bird Study | Year: 2015

Capsule Clutch initiation date decreased with longitude, clutch size increased with latitude and decreased with maximum temperature, whereas the number of fledglings increased both with latitude and longitude, and decreased with maximum temperature in 19 European studies of the Great Reed Warbler. Our study confirmed previous findings about the increasing trend in clutch size with latitude, but also found earlier clutch initiation dates and higher number of fledglings longitudinally from west to east, with precipitation closely associated with clutch initiation date and maximum temperature closely associated with the number of fledglings. © 2015 British Trust for Ornithology.


Mero T.O.,Nature Protection and Study Society NATURA | Mero T.O.,Hungarian Academy of Sciences | Zuljevic A.,Nature Protection and Study Society NATURA
Acta Zoologica Bulgarica | Year: 2016

We studied the effects of roosting starlings, Sturnus vulgaris, on the nest defence behaviour of great reed warbler, Acrocephalus arundinaceus, monogamous parents from 54 nests. A generalised linear mixed model was constructed to investigate the effects where the nest defence behaviour was the dependent variable and the independent variables were year (2011, 2014 and 2015), patch (roosting vs. non-roosting reed patches), sex and nest ID (as random effect). We found that the nest defence behaviour of great reed warblers was more intensive in years when starlings roosted. The significant interaction between year and patch indicated that the nest defence behaviour was more intensive in roosting reed patches. Similarly to previous studies, the females defended the nest more aggressively than the males. In conclusion, we suggest that nest defence behaviour of the great reed warbler in roosting areas might be influenced by various factors, e.g. the excessive noise of roosting starlings or the motion and density of birds in the vicinity of the nests. © 2016 Institute of Biodiversity and Ecosystem Research - BAS.


Mero T.O.,Debrecen University | Zuljevic A.,Nature Protection and Study Society NATURA
Acta Zoologica Bulgarica | Year: 2014

The migration of tits has been the subject of a number of studies, whereas very little is known as concerns their movements in their wintering areas in urban habitats. This study presents the effects of weather variables (the air temperature, the number of days with a snow cover and the amount of precipitation) on the distances moved by the Great Tit Parus major and the Blue Tit Cyanistes caeruleus in an urban habitat during autumn and winter. Ringing data from 32 successive years (1981-2013) in Sombor, Serbia, were used. The Great Tits proved to move larger distances, searching the entire town, while the Blue Tits rather moved only within particular areas of the town. The female Great Tits moved significantly larger distances than the males, while such a difference between the sexes was not observed in the Blue Tits. Neither the number of days with a snow cover nor the air temperature affected the distances moved in either species, whereas a higher amount of precipitation led to shorter distances moved in the Great Tits but not in the Blue Tits. The movement activities of the Great Tits were lower in periods when precipitation was frequent.


Mero T.O.,Debrecen University | Zuljevic A.,Nature Protection and Study Society NATURA
Acta Zoologica Bulgarica | Year: 2014

The effects of physical variables of the reed (e.g. the diameter and density of the reed stems) on the breeding success of the Great Reed Warbler were studied in the cases of the nest-supporting reed stems and the stems in the surroundings of 124 nests in three different reed habitats (mining ponds, small canals and large canals). The mean diameter of the nest-supporting stems correlated positively with the mean diameter of the stems in the surroundings. The diameters of both the nest-supporting reed stems and the stems in the surroundings varied significantly between the three reed habitats, whereas the density of the stems in the surroundings did not. We subdivided the reed densities into three categories: "sparse" (50-160 stems/m2), "intermediate" (160-270 stems/m2) and "dense" (270-380 stems/m2). The Great Reed Warbler significantly preferred the intermediate reed density for breeding, while the highest breeding success was recorded in the dense reed. However, the clutch survival did not differ between the three reed density categories. Whereas the intermediate reed density was mostly used by the Great Reed Warbler for nesting, this was not the subgroup with the highest breeding success, probably because of the different predation types.


In the spring of 2011,an individual of the rotan, Perccottus glenii Dybowski 1877, was found in the stomach of a European perch, Perca fluviatilis L., captured in a drainage-irrigation channel in eastern Hungary. This is the first recording of the rotan found in the diet of the European Perch in Central Europe. © 2016, Croatian Natural History Museum. All rights reserved.

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