Odziv prostoživečih ptic na hranjenje rjavega medveda, volka in rožnatega pelikana v Živalskem vrtu Ljubljana

Benedičič, Iva (author), Vrezec, Al (mentor), Glavan, Gordana (comentor)

Živali v ZOO Ljubljana hranijo po določenem urniku s specifično hrano glede na posamezno vrsto živali. Gre za stalen in relativno dostopen vir hrane, ki ga izkoriščajo nekatere prostoživeče ptice. To predstavlja tudi izgubo hrane za oskrbovane živali. V raziskavi smo popisali prostoživeče vrste ptic na območju živalskega vrta ter ugotavljali, katere od njih se hranijo s hrano namenjeno rjavemu medvedu (Ursus arctos), volku (Canis lupus) in rožnatemu pelikanu (Pelecanus onocrotalus). Med aprilom 2015 in januarjem 2016 smo na območju izvedi tri popise ptic. Hranjenje medvedov in volkov smo snemali s kamero in analizirali prisotnost prostoživečih ptic in njihovo vedenje. S poskusom smo ocenili, koliko mesa lahko vrana med hranjenjem poje. Med hranjenjem pelikanov smo popisali število prisotnih sivih čapelj in njihovo vedenje. Z opazovanjem smo določili število osebkov na krmišču in njihov odziv na hrano (kaj in koliko so jedli). Poskušali smo ovrednotiti škodo, ki jo ptice povzročijo živalskemu vrtu. Pri hranjenju opazovanih živali so se pojavljale v glavnem siva vrana, sraka in siva čaplja. Med hranjenjem medvedov so se vrane hranile z briketi, ribjimi glavami in ribami. Med vranami je bilo malo kompeticij, medvedu pa so se izogibale. Med hranjenjem volkov so vrane s kljuvanjem pojedle približno 1,9 % govejega mesa namenjenega volku v poletnem in 3,2 % v zimskem obdobju. V to oceno ni zajeta količina kunčjega mesa, ki so jo odnesle, ki pa je verjetno višja. Domnevamo, da so vrane tudi koristne, saj med brskanjem po tleh pojedo tudi ostanke, ki bi sicer verjetno gnili. Med hranjenjem pelikanov je bila prisotna samo siva čaplja, ki je pojedla 1,7 % rib namenjenih pelikanom.

• Language: Slovenian
• Keywords: živalski vrt, komenzalizem, kleptoparazitizem, siva vrana, vedenjske strategije, medvrstni odnosi
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2018
• PID: 20.500.12556/RUL-105390
• COBISS.SI-ID: 4933199
• Publication date in RUL: 24.11.2018

BENEDIČIČ, Iva, 2018, Odziv prostoživečih ptic na hranjenje rjavega medveda, volka in rožnatega pelikana v Živalskem vrtu Ljubljana [online]. Master’s thesis. [Accessed 17 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=105390

Secondary language

• Language: English
• Title: Response of wild birds to feeding of brown bear, wolf and white pelican in ZOO Ljubljana

Abstract

Animals in Ljubljana ZOO are fed with a specific diet to a set schedule. This represents a consistent and relatively accessible food source for some species of wild birds. Consequently there is a loss of food for kept animals. This thesis intends to survey wild birds foraging on feeding grounds of brown bear (Ursus arctos), wolf (Canis lupus) and white pelican (Pelecanus onocrotalus) and survey the size of populations living in ZOO area. Between April 2015 and January 2016 we carried out three surveys of bird populations. Feeding of bear and wolf had been filmed and presence of wild birds, along with their behavior, was monitored. We conducted an experiment to determine the average amount of meat that hooded crow can consume when feeding. During feeding of pelican we documented the number of grey herons and their behavior. By observation, we determined number of specimens in the feeding area and response to food (the type and quantity of consumed food). An attempt was made to evaluate the loss to the ZOO caused by birds. During feeding of observed animals, mainly hooded crow, magpie and grey heron were spotted. During feeding of bear, hooded crows consumed a kibble, fish and fish heads. There was little conflict among crows, but they avoided the bear. During feeding of wolf, hooded crows consumed approximately 1,9 % of meat by pecking in summer observation period and 3,2 % in winter observation period. However, they managed to carry away a significant amount of rabbit carrion that was not included in this estimate. We suspect the presence of crows has also some benefits, since they feed on leftover pieces of food that would otherwise be left to rot. During feeding of pelican, only grey heron was observed. It consumed only 1,7 % of fish dedicated to pelicans.

• Keywords: zoo, commensalism, kleptoparasitism, hooded crow, behavioral strategies, interspecies interactions