scholarly journals Causes of the dieback of littoral stands in an overpopulated water-bird reserve: Role of eutrophication, fish and geese

2021 ◽  
Vol 11 (2) ◽  
pp. 79-90
Author(s):  
Richard Svidenský ◽  
Andrea Kučerová ◽  
Hana Čížková
Keyword(s):  
Ecological Factors ◽  
Shoot Density ◽  
Mineral Nutrient ◽  
Ecological Stability ◽  
Anser Anser ◽  
Water Bird ◽  
Nesting Sites ◽  
Negative Effect ◽  
Water Birds ◽  
Greylag Geese

European fishponds can serve as refuges for water birds if the fish stocks are limited, but the effects of other ecological factors on their ecological stability are rarely considered. The aim of this study is to determine the causes of marked dieback of littoral stands dominated by Typha angustifolia L. in a hypertrophic fishpond that is also a valuable water bird reserve. A field study and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox conditions, fish and water birds. The physico-chemical characteristics of the water and sediments confirmed hypertrophic conditions in the fishpond, but a mesocosm experiment did not indicate it had a negative effect on plant growth. On the other hand, a field enclosure experiment showed that in sparse stands, unfenced parts had a significantly smaller shoot density than fenced parts. This was attributed to grazing by greylag geese (Anser anser L.). In addition, damage to belowground parts of plants were ascribed to large individuals of albeit a few large common carp (Cyprinus carpio L.). This study highlights a conservation dilemma as large numbers of geese destroy littoral stands in fishpond nature reserves, which then become unsuitable nesting sites for other species of water birds.

scholarly journals Disentangling causes of the dieback of littoral stands in an overloaded water-bird reserve: roles of eutrophication, fish and geese

2021 ◽  
Author(s):  
Richard Svidenský ◽  
Andrea Kučerová ◽  
Hana Čížková
Keyword(s):  
Sediment Quality ◽  
Bird Species ◽  
Ecological Factors ◽  
Shoot Density ◽  
Field Investigation ◽  
Mineral Nutrient ◽  
Fish Stocks ◽  
Water Bird ◽  
Physico Chemical ◽  
Negative Effect

Abstract European fishponds used for semi-intensive fish production can serve for refuges of water birds if the fish stocks are limited but the effects of other ecological factors on the ecosystem stability are seldom considered. The aim of this study is to elucidate causes of a marked decline of littoral stands dominated with Typha angustifolia in a hypertrophic fishpond forming a part of a valuable water-bird reserve. Field investigation and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox condition, fish and geese. The physico-chemical characteristics of water and sediments confirmed hypertrophic conditions in the fishpond but a follow-up mesocosm experiment did not prove a negative effect of the sediment quality on the plant growth. On the other hand, a field enclosure experiment showed a significant negative effect on shoot density, which was attributed to grazing by geese. An additional damage to plant belowground parts was ascribed to large carp individuals, albeit in small numbers. The study points to a conservation dilemma caused by large numbers of geese destroying littoral stands in a fishpond nature reserve, which then looses its nesting function for other water-bird species.

scholarly journals From individual to population level: Temperature and snow cover modulate fledging success through breeding phenology in greylag geese (Anser anser)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Didone Frigerio ◽  
Petra Sumasgutner ◽  
Kurt Kotrschal ◽  
Sonia Kleindorfer ◽  
Josef Hemetsberger
Keyword(s):  
Ambient Temperature ◽  
Reproductive Output ◽  
Population Level ◽  
Egg Laying ◽  
Future Research ◽  
Breeding Phenology ◽  
Anser Anser ◽  
Fledging Success ◽  
Average Annual Temperature ◽  
Greylag Geese

AbstractLocal weather conditions may be used as environmental cues by animals to optimize their breeding behaviour, and could be affected by climate change. We measured associations between climate, breeding phenology, and reproductive output in greylag geese (Anser anser) across 29 years (1990–2018). The birds are individually marked, which allows accurate long-term monitoring of life-history parameters for all pairs within the flock. We had three aims: (1) identify climate patterns at a local scale in Upper Austria, (2) measure the association between climate and greylag goose breeding phenology, and (3) measure the relationship between climate and both clutch size and fledging success. Ambient temperature increased 2 °C across the 29-years study period, and higher winter temperature was associated with earlier onset of egg-laying. Using the hatch-fledge ratio, average annual temperature was the strongest predictor for the proportion of fledged goslings per season. There is evidence for an optimum time window for egg-laying (the earliest and latest eggs laid had the lowest fledging success). These findings broaden our understanding of environmental effects and population-level shifts which could be associated with increased ambient temperature and can thus inform future research about the ecological consequences of climate changes and reproductive output in avian systems.

Behavioural and physiological correlates of personality in greylag geese (Anser anser)

2009 ◽  
Vol 28 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Simona Kralj-Fišer ◽  
Brigitte M. Weiß ◽  
Kurt Kotrschal
Keyword(s):  
Anser Anser ◽  
Greylag Geese

scholarly journals Social context modulates digestive efficiency in greylag geese (Anser anser)

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Didone Frigerio ◽  
Kurt Kotrschal ◽  
Carla Fabro ◽  
Verena Puehringer-Sturmayr ◽  
Lara Iaiza ◽  
...  
Keyword(s):  
Social Context ◽  
Digestive Efficiency ◽  
Anser Anser ◽  
Greylag Geese

scholarly journals Water Birds as Indicators of Ecological Conditions in a Ramsar Wetland (Sebkhet Bazer, East of Algeria)

2021 ◽  
Author(s):  
Sabrina Djerboua ◽  
Sofia Djerdali ◽  
José Guerrero-Casado ◽  
Abdelkrim Si Bachir ◽  
Ali Guendouz
Keyword(s):  
Water Body ◽  
Linear Models ◽  
Abiotic Factors ◽  
Bird Community ◽  
Ecological Indicator ◽  
Bird Abundance ◽  
Seasonal Differences ◽  
Water Bird ◽  
Physico Chemical ◽  
Water Birds

Background: Wetlands are the highly complex ecosystems due to various interactions between the components, where, the most iconic of ecological changes are the water birds. The current study was aimed to examine the interactions between the water birds diversity, abundance and the abiotic factors in Sebkhet Bazer. Methods: The investigation was conducted between March 2013 and December 2014 in Sebkhet Bazer (Sétif, Algeria, 36°05'N and 5°45'E), by monitoring water birds abundance (grouped into 4: Anatidae, Rallidae, Phoenicopteridae and Shorebirds) and measuring the physico-chemical water parameters (depth, temperature, pH, salinity and vegetation cover). All statistical analysis was performed using the InfoStat software (2017), it was carried out in two steps, by testing of fixed linear models; first of the seasonal differences in water body variables and second of the seasonal differences in bird abundance for the 4 water bird groups. Result: The results showed that the physico-chemical parameters of water varied considerably from season to season. The four groups of birds reached their lowest abundance in summer, with Rallidae and Phonicopteridae being more abundant in spring, Anatidae in winter and Shorebirds in autumn, suggesting that this variation is attributed to changes in water body characteristics between the four seasons. Therefore, the abundance of the different water bird group could be used as an ecological indicator of this wetland’s characteristics. If these features are altered by climate change, the water bird community would be also affected.

scholarly journals Latitudinal-Related Variation in Wintering Population Trends of Greylag Geese (Anser Anser) along the Atlantic Flyway: A Response to Climate Change?

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0140181 ◽  
Author(s):  
Cristina Ramo ◽  
Juan A. Amat ◽  
Leif Nilsson ◽  
Vincent Schricke ◽  
Mariano Rodríguez-Alonso ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Trends ◽  
Anser Anser ◽  
Related Variation ◽  
Atlantic Flyway ◽  
Greylag Geese ◽  
Wintering Population

scholarly journals Social and life-history correlates of hormonal partner compatibility in greylag geese (Anser anser)

2009 ◽  
Vol 21 (1) ◽  
pp. 138-143 ◽  
Author(s):  
Brigitte M. Weiß ◽  
Kurt Kotrschal ◽  
Erich Möstl ◽  
Katharina Hirschenhauser
Keyword(s):  
Life History ◽  
Anser Anser ◽  
Greylag Geese

scholarly journals Physiological implications of pair-bond status in greylag geese

2011 ◽  
Vol 8 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Claudia A. F. Wascher ◽  
Brigitte M. Weiß ◽  
Walter Arnold ◽  
Kurt Kotrschal
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Group Living ◽  
Decisive Role ◽  
Pair Bond ◽  
Dependent Manner ◽  
Anser Anser ◽  
The Social ◽  
Greylag Geese ◽  
Free Ranging

In group-living vertebrates, reliable social allies play a decisive role in dealing with stressors. For example, support by social allies is known to dampen glucocorticoid responses. It remains unknown, however, how social embedding affects the sympatho-adrenergic axis as indicated by heart rate (HR) in non-human animals. We studied the relationships between HR, pair-bond status and distance from the pair-partner in twenty-five free-ranging greylag geese ( Anser anser ) in a natural social environment. In three individuals, we investigated HR responses following partner loss. Overall, we found a context- and sex-dependent difference in HR between paired and unpaired individuals, paired males having a lower HR during agonistic encounters, and unpaired females having a lower HR during resting. Also, in paired females HR increased with increasing distance from the partner. Our data suggest that HR is modulated by pair-bond status in greylag geese in a context- and sex-dependent manner, which may be representative for social vertebrates in general. Despite the low sample size, the present study indicates that proper social embedding may optimize an individual's physiological investment in the social domain. This reduces individual energy expenditure and may benefit health and reproductive success.

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