Ignacy Kitowski

Social learning of hunting skills in juvenile marsh harriers Circus aeruginosus

The impact of social factors on the improvement of hunting skills of juvenile marsh harriers during their first autumnal migration were studied in SE Poland. While foraging with adult birds, juveniles performed more dives on prey both in terms of number of trials and rates. Hunting sessions of juveniles were more efficient in the presence of adults than in the absence of adults. Juveniles hunting with adults and other juveniles could select adequate habitat patches in which access to prey is easier. The role of vertical and horizontal transmission of information in the development of hunting skills in juvenile marsh harrier were confirmed because faster development of hunting ability was achieved in the social hunting after the end of their postfledging dependency period.

Age-related differences in foraging behavior of Montagu's harrier Circus pygargus males in south-east Poland

The hunting behaviour and habitat use of second-calendar-year males (subadult) and grey (adult) males of Montagus harrier Circus pygargus were compared in south-east Poland. Subadult males performed cruising flights less frequently than did adult males. In contrast, subadult males more frequently soared thermals and were harassed more often by other birds. Overall, adult males were more frequently engaged in hunting activities than subadult males. Additionally, adult males were more successful in trapping prey than were subadult males. Only 7% (n=92) of trapping attempts by subadult males were successful, compared with 17% (n=126) by grey males. Both adult and subadult males tried to catch prey flushed by foxes Vulpes vulpes. Subadult males were seen begging and pirating from prey-carrying raptors.

Play behaviour and active training of Montagu’s harrier (Circus pygargus) offspring in the post-fledging period

Play bouts and active training of juveniles by Montagu’s harrier (Circus pygargus) adults in the post-fledging period were observed. Fledglings often played with prey and with a variety of inanimate objects such as bits of moss, regurgitated pellets, sticks and a wad of hay. Inanimate objects selected for play were, in length, very similar to the common vole (Microtus arvalis), which is the most common prey of the species during their breeding period. Some recently fledged individuals were trained to capture invertebrate prey by adults demonstrating techniques for the fledglings and thus develop their hunting skills. Training sessions took place only in the foraging areas of the adult birds.

Trends in the Arrival Dates of Spring Migrants in Lublin (E Poland)

Abstract. Long-term trends in the first arrival dates of 15 common breeding bird species to the city of Lublin (eastern Poland) were studied for the period 1982–2006. Only two species tested, Whitethroat Sylvia communis and Blackcap Sylvia atricapilla, demonstrated a statistically significant trend toward earlier arrival. No significant correlation between the first arrival date and spring (March to May) temperature was found for any of the species studied although some correlations were significant with temperatures of individual months. A significant correlation with winter temperature was found for only 2 species, Lesser Whitethroat Sylvia curruca and Blackcap. Short distance migrants arrived significantly earlier (median date: April 13) than the long distance migrants examined (median: May 7). The mean first arrival date of short distance migrants was more temperature related than that of long distance migrants. The results support the hypothesis that climate related changes in the first arrival dates of birds are manifested less in birds in the interior of the European continent than on its periphery.

INTER-SEXUAL DIFFERENCES IN HUNTING BEHAVIOUR OF MARSH HARRIERS (CIRCUS AERUGINOSUS) IN SOUTHEASTERN POLAND

Inter-sexual differences in foraging tactics of Marsh Harriers (Circus aeruginosus) were studied in southeastern Poland. Observed individuals preferred foraging in regularly mowed meadows and fields and avoided feeding over burned meadows. The basic technique of foraging was cruising flights (90.2%, N = 724). However, the use of hovering flights was also observed, especially during attacks on large prey in tall vegetation (above 1.5 m). This foraging technique appeared to be the most efficient of all the methods used in prey capturing. Overall hunting success was 10.7% (six of 56 observed attacks). At the moment of the first sighting, females were less cruising in comparison with males, but were frequently soaring. The fist seen males were more often engaged in hunting activities than females. Cases of ‘sky dancing’ performed by males above the foraging area far from breeding territories were unexpected. The study proved high foraging plasticity of Marsh Harriers, which used some habitat patches completel...

Coexistence of Owl Species in the Farmland of Southeastern Poland

Abstract. n The study relates to the Little Owl Athene noctua, Barn Owl Tyto alba, Tawny Owl Strix aluco, and Longeared Owl Asio otus. By coexistence is meant the simultaneous nesting, or territorial occupation in the breeding period, of more than one owl species within the area of one farm. Altogether, 48 territories of owls in 16 farm building complexes were found. Distances between nearest-neighbour nest sites were 16-203 m. In the Little Owl the average distance was 43 m ± 28, in the Tawny Owl 159 m ± 61. The number of young in broods of Little Owls nesting in coexistence was significantly lower compared to those nesting with other owls. The considerable incidence of coexistence found was related to the specific conditions of the study area: “islands” of farm building complexes offered favourable nesting sites, while the surrounding monoculture fields provided hunting territories with only limited opportunities for nesting. The productivity of the Little Owl and Barn Owl in the study area was low, probably because of interactions brought about by nesting in close proximity.