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1

Seasonal Changes in the Diversity and Numbers of Waterbirds in a Tropical River in Southern Africa

Kopij G., Paxton M.

Polish Journal of Ecology

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2018

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Vol. 66, nr 3

257--269

EN

Although freshwater habitats play a crucial role in most ecosystems in the world, little is known on their functioning in tropical regions even in regard to the most often studied avian communities. In this study, counts on waterbirds were conducted in dry and wet season (in years 2001-2008) in a riverine habitat in southern Africa (Shamvura stretch of the Okavango River). In total, 84 waterfowl species were recorded. The birds were assigned to different guilds according to their migration activity, diet and nesting site selection. In overall, the species number was almost the same (74 vs. 73) in the wet and dry season. The abundance of all resident species recorded was lower in wet (N = 5992) than in dry seasons (N = 6965)(χ2 = 73.1, P < 0.01). In both seasons Palearctic migrants were represented by seven species, which comprised 1-2% of all waterbirds. Six species were classified as dominants: African reed cormorant Phalacrocorax africanus, African openbill stork Anastomus lamelligerus, cattle egret Bubulcus ibis, wattled lapwing Vanellus senegallus, African darter Anhinga rufa and white-faced duck Dendrocygna viduata. In the wet season the dominant species comprised 68%, while in dry season – 52.5% of all birds recorded. Significant seasonal differences in the numbers of individuals were shown for the following species: African reed cormorant, great egret, squacco heron, wattled lapwing and pied kingfisher. Insectivorous and omnivorous birds were more abundant in wet season, while piscivorous, carnivorous and plant eating birds in dry season. These differences can be related mainly to seasonal variation in the availability of food as well as to the timing of breeding.

2

Effect of Winter Temperature and Maize Food Abundance on Long-Term Population Dynamics of the Wild Boar Sus scrofa

Kopij G., Panek M.

Polish Journal of Ecology

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2016

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Vol. 64, nr 3

436--441

EN

In a few recent decades, population increase of the wild boar has been evidenced in various European countries. As the result of this increase, the wild boar has expanded into farmlands, especially in some regions, where the cultivated maize constitutes the main source of its diet through the larger part of the year. The effect of winter weather and land use changes on the expansion of wild boar was analysed in a farmland in southern Poland. Over 21 years (1985–2005) in the study area of about 681 km2 a rapid increase in the number of harvested wild boars was recorded. While in the middle 1980′s, there were only about 40 animals harvested per hunting season, in 2005 the number increased to 180. The rapid increase was, in general, correlated positively to the increasing surface area of the maize crops — from 205 ha (0.9%) in 1985 to 3212 ha (14.9% of arable lands) in 2004. However the correlation between the increase of the average late winter (February/March) temperature and the number of wild boars seems to be negative and contrary to our expectations, the numbers of wild boars were found to be higher under the lower temperatures in that period of the year.

3

Dietary overlap of co-occurring Barn owl, Tyto alba Scopoli and Spoted eagle owl, Bubo africanus Temnick in urban and rural environments

Kopij G., Symes C. T., Bruyns R.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

801--805

EN

Diet of co-occurring Barn Owl and Spotted Eagle Owl has been studied by means of pellet contents analysis in urban and rural environments in the Highveld of South Africa. In urban environment, diet of both owl species was dominated by murid rodents (mainly Otomys, Mastomys and Rhabdomys). In rural environment, Barn Owl diet was also dominated by murid rodents, but in the diet of the Spotted Eagle Owl higher proportion of birds and non-murid rodents was recorded. Although in the rural environment the breadth of diet niche was wider in Spotted Eagle Owl (DB = 35.41) than in Barn Owl (DB = 12.67), there was almost total dietary overlap (DO = 0.98) between these two co-occurring owl species. For contrast, there was only slight food niche overlap (DO = 0.12) between these owl species co-occurring in the urban environment, but the diet breadth here was also wider in Spotted Eagle Owl (DB = 29.02) than in Barn Owl (DB = 17.90). In the urban environment diet breadth of the Spotted Eagle Owl is, therefore, slightly wider than in rural environment, while in the case of the Barn Owl the reverse is true. Probably there is lower abundance of available prey in urban and rural areas in the Highveld, in comparison with more natural habitats. This may force both species to resort to a more diverse diet to meet their energy requirements. Both species show, therefore, high plasticity of foraging.

4

Food niche overlap in co-existing Barn Owl Tyto alba (Scopoli 1769) and Great Horned Owl Bubo virginianus Gmelin 1788 in intensively used farmland

Kopij G.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

179--181

EN

The study was conducted at a site where the Great Horned Owl and the Barn Owl nested in a close proximity to each other in an intesivelly managed farmland in north-eastern Oregon. By the means of pellet content analysis it has been shown that food niches of both species almost totally overlapped. Their main diet was composed of Microtus voles (numerically: 79% in Great Horned Owl and 86% in Barn Owl) which were probably superabundant in this site.

5

Diet of the Przewalski's horse Equus przewalskii in the Chernobyl exclusion zone

Slivinska K., Kopij G.

Polish Journal of Ecology

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2011

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Vol. 59, nr 4

841-847

EN

In 1998, 21 Przewalski's horses Equus przewalskii have been introduced in the Chernobyl exclusion zone. During the years 1999.2000, studies on food preference were carried out in a special enclosure (70 ha) constructed for theses horses. A total of 52 plant species, belonging to 25 families were grazed by the horses. This comprised 43 % of all plant species recorded in this area. The most common families were Poaceae (17 species), Fabaceae (7 species) and asteraceae (7 species). In general, Elytrigia repens, Trifolium pratense, Vicia cracca, Poa trivialis, Dactylis glomerata and Bromus inermis were the most preferred plant species. This preference has, however, varied from month to month. The most preferred plant species in May were Elytrigia repens, Corynephorus canescens, Festuca valesiaca and Chenopodium albuy; in June - Fabaceae , in July - Dactylis glomerata and Trifolium and in August - Elytrygia repens and Vicia cracca. A total of 27 anti-helminthic plant species were recorded in the study area, 18 of them were grazed by Przewalski's horse.

6

Effect of the colony edge on the clutch size and fledging success in the Little Egret Egretta garzetta (L.)

Uzun A., Kopij G.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

393-396

EN

The term "edge effect' can be defined as an abrupt and local change in the abundance, diversity, composition etc. at the edge of any distinct, spatial patches (structure(s). It usually refers to forest/field, meadow/shrub and other ecotone environments. This effect in relation to breeding densities and success in birds has been the focus of considerable debate (Manolis et al. 2002). The edge of bird colony is expected to affect similarly on avian population (Krebs 1974). Although such studies can be very useful for management and conservation strategies, they are scarce in the Mediterranean.

7

Segregation in sympatrically nesting red-winged starling Onychognathus Morio (L.) and European Starling Sturnus Vulgaris L.

Kopij G.

Polish Journal of Ecology

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2009

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Vol. 57, nr 3

589-595

EN

If two related species come into contact, it could be expected that, in order to coexist, they will either shift their niches apart from each other or one species will replace the other in the course of ever growing competition. Recently, two starling species, the indigenous Red-winged Starling and the exotic European Starling, came into contact in some places in Lesotho (southern Africa). In this paper, some breeding parameters of these species have been compared in an area of their co-occurrence. Studies were carried out in an urbanised habitat in Lesotho, in four consecutive breeding seasons (August-March) during the years 1998-2001. The average density of the Redwinged Starling was 13.8 pairs 100 ha[^-1], while that of the European Starling was 9.3 pairs 100 ha[^-1]. The proportion of the Red-winged Starling to European Starling breeding pairs (1.0:0.7) was strikingly constant over the four consecutive breeding seasons. Most Red-winged Starling breeding territories (78%, N = 56) were located within builtup areas, while most European Starling territories were located either within built-up areas (25%) or on the border of built-up areas and open areas (59%, N =41). Most Red-winged Starling nests (96%) were situated in buildings (N = 46), while European Starling nests were located both in tree holes (43%) and in buildings (57%, N = 28). Both starling species show high nest site tenacity. The Red-winged Starling daily activity pattern during the nestling phase differed considerably from that of the European Starling. Although both starling species do not overlap their feeding niches and daily and seasonal activities, their sympatric occurrence in urbanised habitats may be limited, if suitable nesting sites are lacking.

8

Effect of change in land use on breeding bird communities in a Silesian farmland (SW Poland)

Kopij G.

Polish Journal of Ecology

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2008

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Vol. 56, nr 3

511-519

EN

Two study areas, 210 ha (A) and 120 ha (B), have been selected. Arable grounds dominated (92%) in the study area A, while meadows (63% in 1989 and 47% in 2003) - in the study area B. The changes in land use in both study areas have occurred in 2003 comparatively with 1989. In the study area A, an increase of the area with maize (from 1.1 ha to 38.4 ha) and oat (from 5.6 to 28.4 ha), and decrease in area of the rape (from 41.3 to 0.3 ha) and root plants (from 16.7 to 6.4 ha) have been recorded, while the clover and broad bean have totally disappeared as cultivated plants. In the study area B, a conversion of some dry meadows into arable grounds and an abandonment of more than half of the remaining area of meadows has been carried out. The landscape in the study area A was more fragmented in 1989 than in 2003, while in the study area B the reverse was true. On average, cereal areas increased - especially wheat (from 1.5 to 2.4 ha), maize (from 0.6 to 3.8 ha) and oat (from 0.6 to 1.9 ha), while rape areas decreased (from 2.0 to 0.3 ha). The mapping method has been employed to show the effect of these changes on breeding bird community in both years (1989 vs. 2003). In the study area A, density (pairs x 100[^-1] ha) of the Skylark Alauda arvensis (28.1 vs. 17.1) and Marsh Warbler Acrocephalus palustris (12.9 vs. 2.4) has significantly decreased; while that of Corn Bunting Miliaria calandra (1.4 vs. 8.1) and gallinaceous birds (2.9 vs. 8.1) has significantly increased over the last 14 years. The most numerous species in the group of gallinaceous birds, the Common Quail Coturnix coturnix, probably benefits from the enlargement of oat and barley cultivations. The Skylark was negatively affected by the enlargement of study areas with cultivated plants, especially with the wheat and maize. The Corn Bunting has been, probably, positively affected by the enlargement of maize and barley cultivations, as well as from the warming effect. The decline of the Marsh Warbler could have been caused by the decrease of the area with rape cultivations but it may also reflect short-term fluctuations. In the study area B, only densities of the Chaffinch Fringilla coelebs and Blackbird Turdus merula have significantly increased, and no statistically significant declines were recorded. These increases can be linked to changes in the age structure of tree and shrub stands in the existing small forests, clumps and hedgerows, but these species show probably a general increase in numbers over large areas of farmlands in Poland and possibly in some other European countries.