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1

The influence of climate conditions on breeding phenology of the Grey Heron Ardea cinerea L. in Northern Poland

100%
Jakubas D.
Polish Journal of Ecology
|
2011
|
tom 59
|
nr 1
The breeding phenology of the Grey Heron Ardea cinerea L. was investigated in three colonies situated on the Baltic Sea coast in Poland in 1999–2002. The heronries differ in localization (inland vs coastal) and local climate conditions. In inland location, air temperatures in spring were lower by 1.1–1.5°C and ice cover was present on foraging grounds longer by 19–29 days comparing to coastal ones. Herons occupied all colonies in similar dates (multi-year median date for all colonies: 5 March). However, birds from one coastal heronry tended to start breeding 9–10 days earlier (multi-year median date: 28 February) than birds from other colonies, what might be possible due to early presence of herons in the vicinity. Accessibility of foraging grounds (lack of ice cover) in spring was an important factor affecting the onset of breeding as dates of colony occupation, egg laying and hatching were positively correlated with the dates of last ice cover occurrence on the foraging grounds (r> 0.75, P <0.05). Intercolony differences in hatching dynamics might result from various frequencies of replacement clutches, and nests of late breeding subadults. In one season (2002), the number of medium-aged chicks per nest and fledging success were negatively correlated with the hatching date. Since chick mortality rate during last three weeks before fledging was not correlated with hatching date (suggesting similar food conditions in the course of the season), worse breeding parameters late in the season could be reflected in the lower clutch size or/and hatching success/chick survival rate during the first three weeks in nests of late breeders (i.e. subadults and replacement breeders).
2

Grey Heron Ardea cinerea productivity in relation to habitat features and different spatial scales

100%
Manikowska-Slepowronska B., Slepowronski K., Jakubas D.
Polish Journal of Ecology
|
2016
|
tom 64
|
nr 3
Life history traits of birds like survival or reproduction are strongly related to habitat features which affect food and nest-site availability. However, impact of habitat variables on life-history traits, which may be scale-dependent is barely studied. We investigated the relationships between landscape features and productivity (expressed as the number of 21–38 day old chicks per nest) of a colonial waterbird, the Grey Heron Ardea cinerea in northern Poland. In 2014 we analysed the landscape features (hydrographic features, habitat area, habitat patchiness and distances to the nearest water bodies, coastline, rivers/canals, buildings and roads) around the six colonies. We analysed all those features in four spatial scales around the colony: close proximity of the colony (0–1 km), closer foraging grounds (0–10 km), far foraging grounds (0–20 km) and far foraging grounds excluding close foraging areas and proximity of the colony (10–20 km). The differences in productivity among the colonies was not significant in the studied year (mean number of chicks ± SD: 3.57 ± 0.52). At each spatial scale excluding 10–20 km radius, Grey Heron productivity increased with increasing habitat heterogeneity and decreased with increasing length of rivers/canals and area of pastures. The results of this study indicate that the spatial scale of 0–10 km was the best to indicate relationships between landscape features and productivity in herons. Distance to the nearest river/canal banks, buildings and roads were related positively to productivity. Our study revealed the importance of landscape complexity of aquatic and terrestrial habitats for the Grey Heron productivity.
3

Distribution and population dynamics of Grey Heron [Ardea cinerea] in Belorussia

100%
Samusenko I. E.
The Ring
|
1993
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tom 15
|
nr 1-2
4

Seasonal diet of the Grey Heron Ardea cinerea on an oceanic island [Tenerife, Canary Islands]: indirect interaction with wild seed plants

80%
Rodriguez A., Rodriguez B., Rumeu B., Nogales M.
Acta Ornithologica
|
2007
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tom 42
|
nr 1
77-87
5

The effect of Grey Heron [Ardea cinerea L.] colony on the surrounding vegetation and the biometrical features of three undergrowth species

80%
Zolkos K., Meissner W.
Polish Journal of Ecology
|
2008
|
tom 56
|
nr 1
Bird breeding colonies are known to influence the habitats and phytocoenoses they occupy in different ways. Most papers concern long-lasting colonies, in which floristic composition of phytocoenoses have been already altered largely. This research was aimed to estimate the changes in the floristic composition of the forest phytocoenosis after three years of the existence of the Grey Heron (Ardea cinerea L.) breeding colony as well as to examine the influence of nutrient enrichment on the size and shape of leaves and inflorescences of three plant species Rumex acetosella L., Anthoxanthum odoratum L. and Moehringia trinervia (L.) Clairv., which have different habitat requirements. The number of vascular plant species within the colony area (0.4 ha) increased almost double and appearance of new, mostly nitrophilous, taxa like Sambucus racemosa L., Galeopsis pubescens Besser and Stellaria media (L.) Vill. were observed. The vertical structure of phytocoenosis has also changed. The undergrowth appeared and dense moss layer was mostly eliminated. In case of all investigated species, the enlargement of leaf surface was found. The greatest relative increase concerned leaf width of Moehringia trinervia and Rumex acetosella – 67 and 73%, respectively. The leaf blade of Anthoxanthum odoratum increased largely in length (99%). The enlargement of the surface of assimilative apparatus was not only due to the increase of linear dimensions, but also to rounding of the leaf blade. This was not observed in case of Rumex acetosella which is characterized by elongated, lanceolate leaf blade. Differences observed among the species are probably due to differentiated leaf blade structure. Only Moehringia trinervia can be found in well-established Grey Heron colonies, while Rumex acetosella and Anthoxanthum odoratum are known to be suppressed by heavy input of nitrogen fertilizer. Thus, it seems that after few years of benefits at least Rumex acetosella and Anthoxanthum odoratum withdraw from the area altered by Grey Heron colony, because the change in root absorption and capacity in highly fertile habitat leads to toxic accumulation of nutrients.
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