Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation

Razvoj kolonije navadnih čiger Sterna hirundo in rezultati naravovarstvenega upravljanja v bazenih za odpadne vode pri Ormožu v obdobju 1992-2002 (SV Slovenija)

A colony of Common Terns Sterna hirundo and Black-headed Gulls Larus ridibundus formed in 1981 in the wastewater basins of the sugar factory in Ormož. From than on, the colony has been monitored regularly by direct counting. The site was flooded in 1994 and, in 1995 and 1996, Common Terns andBlack-headed Gulls did not breed. In 1997> the first artificial breeding raft (surface area 12.5 m2) was placed, followed in 1998 and 2001 by additional rafts (14 m2 and 96 m2, respectively). All rafts were placed with the intention of preserving the Common Tern, since this species is highly endangded in Slovenia. As a result, the biggest mixed Common Tern and Black-headed Gull colony in Slovenia has been established on the artificial brecding rafts. In 2002, 64 pairs of Common Tern and 113 pairs of Blackheaded Gull bred on rafts, amounting to 45% and 50% respectively of the Slovene breeding population. Black-headed Gulls started to breed in higher numbers on the largest rafts, placed in 2001, and, for that reason, the percentage of Terns breeding on the rafts decreased. In 2000 all the Terns, but in 2001 only80% of those in the basins were breeding on rafts. It is most probable that the bigger rafts, with special breeding structures for Common Terns, weremore attractive for Black-headed Gulls. Obviously they liked thc heterogeneous raft surface, because they built their nests on the breeding structures planned to increase the breeding success of Common Terns.Leta 1981 so navadne čigre Sterna hirundo in rečni galebi Larus ridibundus oblikovali novo kolonijo v bazenih za odpadne vode Tovarne sladkorja v Ormožu.Število gnezdečih rečnih galebov in navadnih čiger redno spremljamo z metodo večkratnega štetja s teleskopom. Leta 1994 je zaradi dviga vodne gladine v bazenih kolonijo preplavilo. V letih 1995 in 1996 navadne čigre in rečni galebi v bazenih niso gnezdili. Leta 1997 je bil v bazenih postavljen prvi gnezditveni splav površine 12,5 m-\u27, leta 1998 drugi s površino 14 m` in leta 2001 trije med seboj povezani enaki splavi s skupno površino 96 mz. Postavili smo j ih z namenom, da bi se oblikovala nova kolonija navadne čigre in da bi se ta ptica ohranila kot gnezdilka na tem območj u. Na gnezditvenih splavih je tako nastala največja mešana kolonija navadnih čiger in rečnih galebov v Sloveniji. Leta 2002 je na splavih gnezdilo 64 parov navadnih čiger in 113 parov rečnih galebov. To je 45% slovenske populacije navadnih čiger in 50% rečnih galebov. Rečni galebi so začeli množično gnezditi na splavih šele leta 2001, ko smo namestili tri največje splave. Odstotek gnezdečih čiger na splavih se je zmanjšal: leta 2002 jih je 20% gnezdilo na naplavinah in blatnihpolojih, leta 2000 pa so vse gnezdile na splavih. Menim, da so rečni galebi množično zasedli nove splave zaradi njihove velikosti in heterogene površine. Na splave smo namestili večje število gnezditvenih struktur (strešnike, veje, štore - za kritje mladičem pred dežjem, vročino in plenilci)za navadno čigro. Na teh strukturah so gnezdili rečni galebi

Population decline and land-use changes in hunting habitat of the Red-backed shrike Lanius collurio at Šturmovci (NE Slovenia)

In 1997 and 2003, pairs of Red-backed Shrike Lanius collurio were censused in the Šturmovci area, primarily alluvial floodplain forest that was eventually transformed into pastures and meadows with numerous trees, solitary shrubs andhedges. It is located 7 km SE of Ptuj (UTM WM73, NE Slovenia) . The area count method, a simplified mapping method, was applied. The mapped area covered 4.4 km2. In both years, data on Red-backed Shrike\u27s hunting habitats were gathered, while in 2003 data on perching site types and their heights were also collected. In 1997, 89 pairs were counted (density 20.5 pairs/km2), while in 2003, 53 pairs were recorded (density 12.2 pairs/km\u27). Between 1992, when the first census was carried out by STUMBERGER et al. (I993), and 2003 the breeding pair population declined by 69%. In 2003, the highest breeding density in 1 km2 square was 23.3 pairs. Most Red-backed Shrikes hunted in meadows, 88% in 1997 and 60% in 2003. Most of those that hunted in meadows, did so in mown meadows: 72% in 1997 and 57% in 2003. The highest perching sitewas 10 m, the lowest 0.5 m from the ground. Average height of perching sites was 2.6 +- 1.8 m. The highest perching sites were found in overgrowing habitat. Disappearance of meadows due to intensive farming and cessation of mowing are the main causes for the Redv backed Shrike\u27s population decline at Sturmovci

Aviafaunal conservation assessment of the Sava river b etween Krško and Jesenice na Dolenjskem and a proposal for a new important bird area (IBA) in Slovenia

Inventory of avifauna was carried out in 2008 within a 32 km2 area of the SavaRiver between Krçko and Jesenice na Dolenjskem with the aim to evaluate the conservation importance of the area. Birds were counted twice on 25.3 km of line transects placed in three landscape types - woods, agricultural landscape, and mosaic. Breeding birds along the Sava River, with emphasis on common kingfisher Alcedo atthis and common sandpiper Actitis hypoleucos, and of water bodies of the area were surveyed, too. In total, 132 species were recorded, 88 of which were breeders. Fifteen breeders are listed in Annex 1 ofthe Council Directive 79/409/EEC on the conservation of wild birds. Three ofthem meet the criteria for IBA/SPA designation - night heron Nycticorax nycticorax, black kite Milvusmigransand common kingfisher Alcedo atthis. The criteria used were: (1) more than 1% of the national breeding population of the species in the area, (2) more than two breeding pairs of the species in the area and more than five breeding pairs comprising the total national population, (3) for the qualifying species, five most important areas for the species in the region (Slovenia) can be proposed at the most. The proposed newIBA/SPA Sava river between Krško and Jesenice na Dolenjskem is the only area for the night heron and black kite and the fourth most important area forthe common kingfisher in Slovenia

Koconogi čuk Argolius funereus najden v goli kraški krajini otoka Pag (S Dalmacija, Hrvaška)

On 28 Apr 2005, a dead young (2Y) male Tengmalms Owl Aegolius funereus was found on the island of Pag (N Dalmatia, Croatia) in bare karst area of the rocky Ravna plateau (app. 200 m a.s.l.) of Mt. Dolac. So far, only four published data of Tengmalms Owl occurrence in the coastal part of Croatia exist, and all of them are older than 70 years. The bird most probably migrated to the island from its nearest breeding area-Mt. Velebit. According to the literature, part of the population, especially young birds and females,are nomadic during the non-breeding period. But the question on the habitat used on the island of Pag remains open. It is known that during the non-breeding period. But the question on the habitat used on the island of Pagremains open. It is known that during the non-breeding period, Tengmalms Owls usually move within their potential breeding range and habitat, which is probably not the case as far as this find is concerned. The carcass was found under the turbine of the wind farm, and collision with the turbine was clearlythe cause of the birds death. To our knowledge, no monitoring to evaluate the impact of the discussed wind farm on bird mortality exists, but should certainly be started in view of the references and data presented herewith.Dne 28.4.2005 je bil na Pagu na goli kraški planoti "Ravna" (cca. 200 m n.v.) gore Dolac najden mrtev koconogi čuk Aegolius funereus, mlad (2Y) samec. Najdba je zanimiva, ker gre za enega redkih podatkov o pojavljanju koconogega čuka na obalnem predelu Hrvaške. Doslej so bili za to območje potrjeni le štirje podatki, tri iz okolice Senja in en iz okolice Dubrovnika (Zagospom), in vsi starejši od 70 let. Konconogi čuk je na Pag najverjetneje migriral s svojih najbližjih gnezdišč na Velebitu. Znano je namreč, da je del populacije koconogega čuka, posebej mlade ptice in samice, zunaj gnezditvenega obdobja nomadski. Odpira se vprašanje habitata, v katerem je ptica bivala na Pagu, sajnaj bi koconogi čuk tudi zunaj gnezditve izbiral potencialni gnezditveni habitat, to pa so v Evropi mešani in iglasti gozdovi višjih leg. Kadaver z zdrobljeno lobanjo je bil najden pod peto vetrnico v vetrni elektrarni Ravna 1. Vzrok smrti je bil trk z vetrnico. Po naših podatkih v tej vetrni elektrarni ne opravljajo študije vpliva elektrarne na smrtnost ptic, kar bi bilo po tujih priporočilih in upoštevajoč omenjeno najdbo nujno potrebno

Population dynamics and habitat use by Northern Lapwing Vanellus vanellus in agricultural landscape of Dravsko and Ptujsko polje (NE Slovenia)

The Northern Lapwing numbers across Europe are declining owing to its insufficient breeding success. To determine the size, dynamics and habitat use of the lapwing population at Dravsko and Ptujsko polje, a survey was carried out between 2016 and 2018. In 2016, 2017 and 2018, we recorded 148, 130, and 117 pairs, respectively. The population declined during the study and the population trend is uncertain. Approximately 12 to 21% of the national lapwing population was recorded at Dravsko and Ptujsko polje, making them one of the most important breeding areas in Slovenia. The majority of lapwings were found in bare tilled fields and fields with young spring crops that enable unbroken all-round views. Crop data analysis showed a significant preference for maize fields which are mostly bare tillage at the start of the incubation period and therefore act as an ecological trap for lapwings due to the time coincidence of the nesting period and farming operations. For the protection of the lapwing in Slovenia, we recommend a time limit of farming operations or avoiding individual nests while working in the field. Both measures are recommended to be implemented in combination with the provision of suitable foraging habitat for chicks. For greater effectiveness, we propose priority implementation of conser vation measures on traditiona l breeding sites