1683 KB156 KB198020212020Bordjan, Dejanštevilka:186/187letnik:41str. 69-118ISSN:0351-2851DOI:10.2478/acro-2020-0006COBISSID:169805827URN:URN:NBN:SI:doc-57CTL8LUenDruštvo za opazovanje in proučevanje ptic SlovenijeAcrocephalusbirdsbreeding biologygnezditvena biologijaMallard Anas platyrhynchosmlakarica Anas platyrhynchosornitologijaornitologypopulacijapopulationpticeSloveniaSlovenijaThe Mallard Anas platyrhynchos in Slovenia| pregled z oceno trenutne populacije| a review with an estimation of its current population| Mlakarica Anas platyrhynhos v Sloveniji|Although the Mallard is one of the most numerous and best-studied waterbirds in the world, it received almost no attention in Slovenia. It is one of the most frequently observed waterbirds in our country, with frequency often reaching 100%. Sites with lower frequency either freeze in winter or have a low number of individuals to start with. The Mallard is also the most dominant species (17.5% and 89.0%) with higher dominance at sites less suitable for waterbirds due to the lack of available shoals. Mallards reach their maximum numbers during fall migration and winter. Spring migration has no discernible peak and has been significant only for Lake Cerknica. On shallow waters, the maximum is reached in August and September, a month before fall migration begins, indicating local movement to food-rich sites. Females make up only 36.7% of the observed Mallards and reach the maximum proportion (41.5%) in winter and the lowest in April and May (14.7%), when they nest. The breeding season in Slovenia lasts from mid-January to early December, with the majority of females rearing broods from April to July. Average brood size is 6.2 ± 2.66 and declines with season, age of young and altitude. It varies between habitat types and is highest on Treatment and Coastal Wetlands (7.3) and lowest on deep waters such as Reservoirs (5.7) and Lakes (5.6). No really high breeding densities were found in Slovenia and were similar to those in other countries. Breeding densities are higher on smaller Ponds (< 8 ha), on sites with isolated islands and breeding colonies of gulls and terns (e.g. Lake Ptuj). Breeding density also decreases with elevation. Slovenian breeding population is estimated at 1,473–3,763 bp and wintering population averages 22,237 (10,376–32,010) individuals. Data suggest a decline in the wintering population most likely due to warmer winters. The majority of Mallards winter in NE Slovenia, where eight of eleven sites have a maximum of more than 1,000 Mallards. Most Mallards winter on the Drava river with Ptuj and Ormož lakes, where the highest numbers of Mallards were also recorded (Lake Ptuj: 8,330 ind., Lake Ormož: 5,400 ind.). The highest number of individuals during spring migration was recorded on Lake Cerknica (4,581) and during autumn migration on Medvedce reservoir (3,379). Apart from standing waters, the highest density of wintering Mallards is found in urban sections of slow-flowing rivers, probably due to higher safety and food availability. 72,731 Mallards were hunted between 2001 and 2018, mainly in NE Slovenia (28% in the Pomursko hunting management district). The number of Mallards hunted is declining in all hunting areas and has declined by 64% since 2001 and even more since the 1990s. According to hunt data, hunting is by far the most important cause of the Mallard mortality in Slovenia (97.4%), followed by predation (1.1%). The Mallard mortality in Slovenia is largely unstudied and natural mortality is most likely underestimated, not only because it does not include mortality in the pre-fledging period, a period with the lowest survival, but also because the detectability of natural mortality is considerably lower. In contrast to the hunted numbers, there have been only nine recoveries of ringed individuals from abroad in the last 100 years, suggesting that hunters may not be reporting recoveries to the ringing centre. Apart from the 1972–1975 period, when 87% of Mallards were ringed, the intensity of ringing of Mallards in Slovenia is low, resulting in only seven Mallards recovered abroad. The longest distance of a Mallard ringed in Slovenia comes from Ukraine (1,290 km), while the longest distance between ringing and recovery sites is 2,075 km from an individual ringed in Finland. The only colour morphs documented in Slovenia are Mallards with paler feathers, attributed to one of the colour aberrations resulting from lower melanin productivity. Only few hybrids and mixed pairings with other wild duck species were observedNamen prispevka je zapolniti vrzel v znanju te sicer zelo razširjene in številčne vrste v Sloveniji. Mlakarica je ena najpogosteje opazovanih vrst vodnih ptic pri nas, ki na območju rednih monitoringov pogosto doseže frekvenco pojavljanja 100 %. Mlakarica je tudi najbolj dominantna vrsta vodne ptice pri nas z razponom dominance 17,5–89,0 %. Samice dosegajo samo 36,7 % vseh opazovanih mlakaric z najvišjim deležem (41,5 %) pozimi in najnižjim v začetku gnezdenja (14,7 %), ko so samice na gnezdih. Mlakarica je najštevilčnejša med jesensko selitvijo in pozimi. V Sloveniji zabeležena gnezditvena sezona traja večji del leta, od sredine januarja pa vse do začetka decembra. Glavnina samic spelje svoje v povprečju 6,2 ± 2,66 veliko leglo med aprilom in julijem. Velikost legla upada s časom, starostjo mladičev in nadmorsko D. Bordjan: The Mallard Anas platyrhynchos in Slovenia: a review with an estimation of its current population 101 višino in je najvišja na bazenih za odpadne vode ter na obalnih mokriščih (7,3), najnižja pa na globokih zadrževalnikih (5,7) in jezerih (5,6). Zares visokih gostot gnezdečih parov v Sloveniji nismo zabeležili in gostote so bile podobne povprečnim gostotam mlakarice po svetu. V Sloveniji ocenjeno gnezdi 1473–3763 parov in prezimuje v povprečju 22.237 (10.376–32.010) osebkov mlakaric. Velika večina mlakaric prezimuje v SV Sloveniji, največ na reki Dravi na Ptujskem (do 8330 os.) in Ormoškem jezeru (do 5400 os.). Največ mlakaric prezimuje na stoječih vodnih telesih, na rekah pa na urbanih odsekih, kjer se zadržujejo v večjem številu zaradi krmljenja in varnosti. Slovenska zimska populacija mlakarice je v upadu, verjetno zaradi vse toplejših zim. Najvišje število mlakaric na selitvi je bilo zabeleženo spomladi na Cerkniškem jezeru (4581) in jeseni na zadrževalniku Medvedce (3379). V obdobju med 2001 in 2018 je bilo ustreljenih 72.731 mlakaric, večina v SV Sloveniji (28 % v Pomurskem lovsko-upravljavskem območju). Število letno ustreljenih mlakaric upada v vseh lovsko-upravljavskih območjih in je upadlo za 64 % od leta 2001. V lovskih evidencah je najpomembnejši vzrok smrtnosti mlakaric lov, ki dosega 97,4 % vse zabeležene smrtnosti. Med drugo zabeleženo smrtnostjo je najpomembnejše plenjenje, ki dosega 1,1 % smrtnosti. Ker je pri mlakarici največja zabeležena smrtnost pri mladičih, ki niso zajeti v uradne lovske statistike, ter ker je zaznavnost naravne smrtnosti občutno nižja od lova, je zelo verjetno naravna smrtnost vrste pri nas močno podcenjena. Kljub dolgi tradiciji obročkanja in velikemu številu ulovljenih mlakaric imamo zelo malo ponovnih najdb obročkanih mlakaric, v zadnjih 100 letih le devet tujih najdb. Slednje nakazuje na možnost, da lovci ne poročajo o najdbah Slovenskemu centru za obročkanje ptic. Z izjemo obdobja 1972–1975, ko je bilo obročkanih 87 % vseh mlakaric, je intenzivnost obročkanja mlakarice pri nas zelo nizka. Rezultat je samo sedem najdb naših mlakaric na tujem. Največja razdalja na tujem najdene mlakarice je iz Ukrajine (1290 km), medtem ko je izvor najdaljše tuje najdbe pri nas je iz Finske (2075 km). V Sloveniji so bile zabeležene samo barvne oblike s svetlejšim perjem, ki so posledica tvorbe premalo melanina. Prav tako redki pri nas so križanci in mešani pari z drugimi vrstami racTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaDruštvo za opazovanje in proučevanje ptic Slovenije