First record of the spiny-cheek crayfish (

The spiny-cheek crayfish Orconectes limosus (Rafinesque, 1817) is one of the most problematic invasive crayfish species in Europe. Here we report the first occurrence of spiny-cheek crayfish in Slovenia, 300 km upstream from the previously known records in the mouth of Drava River in Croatia. The species was not expected to colonize this area for at least two decades. This new isolated population will significantly alter our predictions of the ongoing colonization of the Drava River basin in Austria, Slovenia and Croatia

A contribution to the knowledge of the European pond turtle (Emys orbicularis (Linnaeus, 1758)) distribution along the Drava river in Slovenia

Predstavljene so nove in že objavljene najdbe močvirske sklednice v Podravju. Prvič v Sloveniji je bila potrjena podvrsta Emys orbicularis orbicularisNew discoveries together with published data on European pond turtle along the Drava river in Slovenia are presented. Subspecies Emys orbicularis orbicularis was confirmed for the first time in Sloveni

The diet of great cormorants Phalacrocorax carbo on the Drava river in the winter of 1995/96 (Slovenia)

Diet of the Great Cormorant Phalacrocorax carbo was studied by means of regurgitated pellets collected in March 1996 at night roost along the Drava river near Miklavž na Dravskem polju. Altogether, remains of 741 fish were found. Total weight of these fish was estimated at 115 kg. The diet consisted of 14 fish species (Chub Leuciscus cephalus, Nase Chondrostoma nasus, Barbel Barbus barbus, Grass Carp Ctenopharyngodon idella, Gold Fish or Prussian Carp Carassius auratus, Bream Abramis brama, Common Carp Cyprinus carpio, Danube Roach Rutilus pigus virgo, Roach Rutilus rutilus, Perch Perca fluviatilis, Ruffe Gymnocephalus cernuus, Striped Ruffe Gymnocephalus schraetzer, Zingel Zingel zingel and Pike Esox lucius). The diet was dominated by Perch (52.5% by number, 53.1% by mass) and Nase (14.0% by number, 22.3% by mass). Most of the fishes consumed by Cormorants belonged to the 18-22 cm (32.1%) size class. Average length of consumed Perch was 21.9 cm (median 21.5 cm, Q1-Q3: 18.9-25.2 cm) and 26.7 cm of Nase (median 25.3 cm, Q1-Q3: 22.3-31.9 cm). Average length of all prey in the diet of Great Cormorant was 21.3 cm (median 20.9 cm, Q1-Q3: 18.1-25.2 cm, min-max: 6.1-46.3 cm). Specimens of the first quartile constituted 6.4% mass of all prey, of the second and third quartiles 42.2%, and of the last quartile 51.3% mass of all prey. Length frequency distribution of the Perch, especially low proportion of small Perch in the Cormorants\u27 diet, depended on standing waters\u27 ice cover. Small Perches are abundant in standing waters, as they feed on plankton, which is most abundant there. In the winter of 1995/96 all standing waters in the Drava region were covered with ice and fishes in these waters were inaccessible to Cormorants. But as Ruffe and bigger Perches are not restricted to plankton diet, they also frequented flowing nonfrozen waters and were thus accessible to Cormorants\u27 diet was probably higher than in feeding habitat, while the proportion of Nase, Barbel and Chub was probably lower than in feeding habita

The diet of great cormorants Phalacrocorax carbo on the Sava river between Ljubljana and Zagorje (Slovenia)

Diet of Great Cormorants Phalacrocorax carbo occurring on the Sava river between Ljubljana and Zagorje was studied in the winter 1998/99 by means of regurgitated pellets, collected at the Cormorants\u27 night roost at Hotič. Among 473 collected pellets, 69.8 % contained remains of fish. The pellets also contained worms Nematoda and tapeworms Cestoda, remains of caddis flies trichoptera, snails Gastropoda and a frog Rana sp. In separate pellets, remains of 1 to 69 fish (median 2, average 3.9) were found: in 41.8 % pellets remains of 1 fish, in 93.6 % remains of up to 10 fish. Altogether, remains of 1,288 fish were found. Length and weight were determined for 1,279 of them. Total weight of these fish was estimated at 57 kg. The diet consisted of 12 fish species (trout Salmo trutta, grayling Thymallus thymallus, chub Leuciscuscephalus, nase Chrondrostoma nasus, danube roach Rutilus pigus virgo,roach Rutilus rutilus, barbel Barbus barbus, bream Abramis brama, bleak Alburnus alburnus, pike Esox lucius, perch Perca fluviatilis and ruffe Gymnocephalus cernuus). The diet was dominated by Cyprinidae (85.8 % by number, 90.5 % by biomass). Gravling and trout were represented with 6.5 % by number and 3.6 % by mass and pike, perch and ruffe in 7.3 % by number and 3.6 % by mass. Inside Cyprinidae chub with 16.4 % by number and 38.6 by biomass and nase with 3.9 % by number and 16.5 % by biomass were most frequent. The proportion of undetermined Cyprinidae was 57.1 % by number and 28.5 % by mass. Prey size ranged from 23 to 345 mm. Most frequent length class was 70-170 mm (50 % by number and 19 % by mass), but large individuals (170 mm) were most important (25.0 % by number and 80.1 % by mass) in the diet of Great Cormorants. The numbers of specimens of Cyprinidae, Percidae and Salmonidae between months were significant, while the numbers of specimens of determined Cyprinids were not. We concluded that the differences in the investigated area depended more on random detection of fish. Chub and nase arespecies with shoaling habits, and were assumed that they were easier detectable by Great Cormorants than the non-shoaling specie

Črešnja pri Bistri, a newly discovered pile-dwelling settlement in the Ljubljansko barje

The results are presented of interdisciplinary research at the newly discovered pile-dwelling settlement of Črešnja pri Bistri in the Ljubljansko barje (the Ljubljana Moor), dated approximately to the 36th century BC. The article discusses the stratigraphy, archaeological finds, dendrochronological investigations, and the analyses of macroscopic remains of plants, and macro-faunal remains of mammals, birds, and fish

Distribution and population size of the European pond turtle Emys orbicularis in Ljubljansko barje, Slovenia

The exact understanding of distribution and natural history is the necessary prerequisite for conservation of the endangered European pond turtle. In this study we examined the distribution and population size of pond turtles in Ljubljansko barje, a bog of European importance (Natura 2000 site, intended to be included into the Convention on Wetlands, the ‘Ramsar list’). For doing so, we used different capture and observation methods. Four hundred kilometres of drainage ditches were investigated by foot, fish traps were set at 507 localities, and 171 pond turtles were captured and measured. We conclude that pond turtles are distributed all over Ljubljansko barje, but concentrated in just 18 km2 (areas of Gmajnice and Draga pri Igu) out of the 170 km2 total size of Ljubljansko barje. In these two areas reproduction was confirmed. The relative density for Gmajnice was calculated to 16 turtles per square kilometre, which is lower than in Draga pri Igu, with a minimum of 57 turtles per square kilometre. The main threats for the survival of pond turtles are habitat loss, nest destruction by agriculture, an increase of floods during the past 100 years, inappropriate cleaning out of drainage ditches, and the presence of invasive non-native turtles. To make conservation efforts for the European pond turtle more effective in Ljubljansko barje, we recommend using wire meshes for protecting nests and shifting the cleaning out of ditches to the active period of pond turtles

Distribution modelling as an approach to the conservation of a threatened alpine endemic butterfly (Lepidoptera: Satyridae)

Mountain butterfly species are often restricted in their distribution and under threat from habitat destruction and climate change. Due to the inaccessibility of their habitats the distributions of many such species are unknown. We have investigated whether information on the habitat requirements of the Alpine endemic species Erebia calcaria could be used for modelling its potential distribution. We surveyed part of its range using transects and recorded habitat and environmental parameters. The most important parameters determining the presence of the species were average height of the vegetation,maximum height of the vegetation, percentage area of bare ground, number of food plants and slope. Furthermore, the abundance of E. calcaria is strongly affected by site exposure and grazing intensity. Using these results we modelled the potential distribution of the species in its known historical range in Slovenia. In the region covered by the model 70% of the records of E.calcaria were within the predicted distribution. It is reasonable to proposethat such a high detection rate justifies the use of distribution models for predicting a species range and providing important additional information for their conservation. In the case of E. calcaria, we have shown that endemic mountain butterflies can be strongly threatened by fragmentation of their habitat, overgrazing and succession, which could be further amplifiedby changes in climate

Črešnja pri Bistri, novoodkrito kolišče na Ljubljanskem barju

The results are presented of interdisciplinary research at thenewly discovered pile-dwelling settlement of Črešnja pri Bistri inthe Ljubljansko barje (the Ljubljana Moor), dated approximate-ly to the 36th century BC. The article discusses the stratigraphy,archaeological finds, dendrochronological investigations, and theanalyses  of  macroscopic  remains  of  plants,  and  macro-faunalremains  of  mammals,  birds,  and  fish. Predstavljamo  rezultate  interdisciplinarnih  raziskav  nanovoodkriti koliščarski naselbini Črešnja pri Bistri na Ljubljanskembarju, ki jo okvirno datiramo v 36. stoletje pr. Kr. V prispevkuobravnavamo stratigrafijo, arheološke najdbe, dendrokronološkeraziskave,  raziskave  makroskopskih  rastlinskih  ostankov,  os-tanke  sesalske  makrofavne,  ptičev  in  rib