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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

Analiza jakosciowa i ilosciowa awifauny projektowanego rezerwatu "Dolina Michalowskiej Strugi"

100%
Jakubas D.
Parki Narodowe i Rezerwaty Przyrody
|
1999
|
tom 18
|
nr 1
29-35
3

Analiza jakosciowa i ilosciowa awifauny rezerwatu Kacze Legi

100%
Jakubas D.
Przegląd Przyrodniczy
|
2003
|
tom 14
|
nr 1-2
113-119
4

Awifauna Trojmiejskiego Parku Krajobrazowego

63%
Jakubas D., Ozarowski D.
Przegląd Przyrodniczy
|
1997
|
tom 08
|
nr 3
117-121
5

Avifauna of Hornsund area, SW Spitsbergen: present state and recent changes

51%
Wojczulanis-Jakubas K., Jakubas D., Stempniewicz L.
Polish Polar Research
|
2008
|
tom 29
|
nr 2
187-197
The purpose of this study was to present the current state of avifauna in the vicinity of Polish Polar Station, at Hornsund (SW Spitsbergen). During four seasons (2003-2006) ten bird species were recorded as breeding there. Among them colonial little auk and Arctic tern were most abundant. Six additional species were noted during the breeding season but none of them bred there and their visits in the study plots were a consequence of their nesting nearby study area. Remaining 11 species were recorded during migration. The most pronounced changes over the last 35 years has been a considerable increase in number of barnacle geese exploiting the tundra as their foraging and resting area.
6

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

51%
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.
7

Body size variation of European Storm Petrels Hydrobates pelagicus in relation to environmental variables

51%
Jakubas D., Wojczulanis-Jakubas K., Jensen J.-K.
Acta Ornithologica
|
2014
|
tom 49
|
nr 1
Body size differentiation may have developed in response to environmental gradients. A pattern of large individuals prevailing in colder areas is often observed and is explained by the heat conservation hypothesis (Bergmann's rule). To understand patterns driving body size variation in a pelagic seabird, the European Storm Petrel Hydrobates pelagicus, we examined the relationship between wing length, body mass and environmental variables in breeding areas (sea surface temperature, air temperature and wind speed). As this species has been divided into two subspecies: Mediterranean H. p. melitensis and Atlantic H. p. pelagicus, we performed the analyses at different scales (species, Atlantic subspecies and regional North Atlantic). At the species and subspecies scales, there was a longitudinal increase in wing length from west to east. At the subspecies and regional scale, we found a latitudinal increase in this variable from south to north. This result and the significant increase of wing length with decreasing sea surface and air temperatures are concordant with Bergmann's rule. In addition, body mass at the species and subspecies scales decreased with increasing wind speed, what may have a functional implication (small body mass may increase manoeuvrability over waves in conditions of stronger wind). Both genetic (two subspecies differing in body size) and environmental factors seem to be important forces driving intercolony variation in body size. Our study on sexual size dimorphism (SSD) revealed that in 156 molecularly sexed adults from the Faeroes, wing and tail length, and body mass exhibited female-biased SSD, while head-bill length showed male-biased SSD. The best discriminant function for sexing based on body measurements correctly classified 75% of individuals. Considering low correctness of proposed functions and geographical variation of body size, use of alternative methods (e.g. molecular tools) is recommended for sex discrimination in the European Storm Petrel.
8

Report on passerines ringed in the Lake Druzno reserve in 1999-2001

51%
Jakubas D., Michno B., Nitecki C., Ulatowska J.
The Ring
|
2002
|
tom 24
|
nr 2
9

Faeces deposition and numbers of vertebrate herbivores in the vicinity of planktivorous seabird colonies in Hornsund, Spitsbergen

51%
Jakubas D., Zmudczynska K., Wojczulanis-Jakubas K., Stempniewicz L.
Polish Polar Research
|
2008
|
tom 29
|
nr 1
45-58
Ornithogenic tundra developing near large seabird colonies with its dense vegetation creates sites for foraging, hiding and breeding of herbivores. Grazing, trampling and faeces deposition are considered as the most important ways that vertebrate herbivores influence the plants. Excrement deposition level informs us on the intensity of grazing i.e. foraging ground attractiveness. We have compared vertebrate herbivores' faeces deposition (biomass) in the vicinity of big colonies of piscivorous (kittiwake Rissa tridactyla and Brunnich's guillemot Uria lomvia) and planktivorous (little auk Alle alle) seabirds and the control area was in Hornsund, SW Spitsbergen. Much higher level of faeces deposition was recorded nearby seabird colonies as compared to the control area. These finding points out that vertebrate herbivores concentrate and feed more intensively on rich ornithogenic pastures. Number of herbivores and their faeces deposition level recorded nearby planktivorous seabird colony were greater as compared to those found nearby the colony of piscivores. The highest number of geese (Branta bernicla and Anser brachyrhynchus) and of their faeces biomass were found near the colony of planktivorous little auk, where distinct gradient in faeces deposition level along the colony-seashore axis was recorded. Reindeers Rangifer tarandus were observed in considerable numbers near the little auk colony, and were not recorded at all near cliff-nesting sites of kittiwakes and guillemots. Total deposition of excrements produced by geese was generally higher if compared to reindeers.
10

Alczyk - sztandarowy gatunek Arktyki

51%
Wojczulanis-Jakubas K., Jakubas D., Stempniewicz L.
Kosmos
|
2013
|
tom 62
|
nr 3
11
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Dr Czesław Nitecki (1939-2018)

50%
Jakubas D.
Ornis Polonica
|
2018
|
tom 59
|
nr 2
12

Ringing of Passerines in the Druzno Lake Reserve in 1990-1999

45%
Jakubas D., Michno B., Nitecki C., Strawinski S., Ulatowska J.
The Ring
|
1999
|
tom 21
|
nr 2
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