European Hamster at the edge: declining in nature and rare in owl pellets

Abstract

Over the last decades, the European Hamster (Cricetus cricetus) has been declining in many parts of its European range. Due to the lack of recent information on the occurrence and status of the European Hamster in the south-western Carpathian Basin west of the Danube, we used information gathered from prey remains in Common Barn-owl (Tyto alba) pellets. In spite of considerable sampling effort, we retrieved only few hamster remnants. Two skulls were found in Podolje (Croatia) in 2007 and 2016, respectively. Further five hamsters were retrieved from pellets collected in 2017, 11 km to the northwest in Udvar (Hungary). In Sátorhely, 5 km north from Udvar, one roadkill male was found on 27.07.2019. Testimonies from local inhabitants confirmed the current presence of the European Hamster in the area. Our results suggest the presence of a small isolated population in the border area of Croatia (UTM 10 km grid square CR27) and Hungary (CR18, CR19). This small isolated population is on the south-western limit of the range of the species. We presume that the population requires conservation attention because of its isolated position at the edge of the species’ range, its small size and low abundance. We call for a transboundary action by nature conservation authorities in Croatia and Hungary.

Full text

Ornis Hungarica 2020. 28(2): 66–73.
DOI: 10.2478/orhu-2020-0017
European Hamster at the edge: declining in
nature and rare in owl pellets×
Jenő j. Purger1,2*, Kornélia kuRuCz1, Dávid SzéP1, Dragica
Purger2,3, Boris KryštuFeK4, Danijel ivajnšič5, Tina KlenovšeK5
& Franc janŽeKovič5
Purger, J. J., Kurucz, K., Szép, D., Purger, D., Kryštufek, B., Ivajnšič, D., Klenovšek, T. &
Janžekovič, F. 2020. European Hamster at the edge: declining in nature and rare in owl pellets.
– Ornis Hungarica 28(2): 66–73. DOI: 10.2478/orhu-2020-0017
Abstract Over the last decades, the European Hamster (Cricetus cricetus) has been declining in many parts of
its European range. Due to the lack of recent information on the occurrence and status of the European Hamster
in the south-western Carpathian Basin west of the Danube, we used information gathered from prey remains
in Common Barn-owl (Tyto alba) pellets. In spite of considerable sampling effort, we retrieved only few ham-
ster remnants. Two skulls were found in Podolje (Croatia) in 2007 and 2016, respectively. Further ve ham-
sters were retrieved from pellets collected in 2017, 11 km to the northwest in Udvar (Hungary). In Sátorhely,
5 km north from Udvar, one roadkill male was found on 27.07.2019. Testimonies from local inhabitants con-
rmed the current presence of the European Hamster in the area. Our results suggest the presence of a small
isolated population in the border area of Croatia (UTM 10 km grid square CR27) and Hungary (CR18, CR19).
This small isolated population is on the south-western limit of the range of the species. We presume that the
population requires conservation attention because of its isolated position at the edge of the species’ range, its
small size and low abundance. We call for a transboundary action by nature conservation authorities in Croa-
tia and Hungary.
Keywords: Baranja, Cricetus cricetus, Croatia, Hungary, Tyto alba
Összefoglalás A mezei hörcsög (Cricetus cricetus) az utóbbi néhány évtizedben európai elterjedési területének
egy jelentős részéről visszaszorult. Aktuális előfordulási adatok hiányában a Dunától nyugatra, a Kárpát-meden-
ce délnyugati részén gyöngybagoly (Tyto alba) köpetekből előkerülő zsákmánymaradványok alapján nyert infor-
mációkat használtuk a mezei hörcsög elterjedésének és státuszának megállapítására. A mintavételezésbe fektetett
jelentős erőfeszítések ellenére csak kevés hörcsög maradványa került elő. A horvátországi Podolje terepülésről
2007-ben és 2016-ban összesen két koponyát, majd 11 km-re északnyugatra a magyarországi Udvar települé-
sen 2017-ben gyűjtött köpetekből 5 mezei hörcsög maradványait mutattuk ki. Udvartól mindössze 5 km-re észa-
ki irányban, Sátorhelynél az úton 2019.07.27-én egy elgázolt hím példányt találtunk. A mezei hörcsög aktuális
jelenlétét a területen a helyi lakosság meggyelései is alátámasztották. Az összegyűlt adatok arra utalnak, hogy
Horvátország (CR27 a 10 km-es UTM háló alapján) és Magyarország (CR18, CR19) határmenti területén él egy
kis elszigetelt populáció, mely a faj elterjedési területének délnyugati határán van. Megítélésünk szerint ez a po-
puláció megérdemli a természetvédelem gyelmét, mivel a faj elterjedési területének peremén található, helyze-
te elszigetelt, mérete kicsi, és a hörcsögök előfordulási gyakorisága alacsony. Horvátország és Magyarország ter-
mészetvédelmi hatóságait határon átnyúló fellépésre hívjuk fel.
Kulcsszavak: Baranya, Cricetus cricetus, Horvátország, Magyarország, Tyto alba
1
Department of Ecology, Institute of Biology, University of Pécs, 7624 Pécs, Ifjúság útja 6., Hungary
2
BioRes Limited Partnership, 7624 Pécs, Barackvirág utca 27., Hungary
3
Department of Pharmacognosy, Faculty of Pharmacy, University of Pécs, 7624 Pécs, Rókus utca 2., Hungary
Received: October 31, 2020 – November 06, 2020 – November 09, 2020
×
Presented at 2
nd
Hungarian Owl Research Conference held in Pécs on 11
th
September 2020.

67
J. J. Purger, K. Kurucz, D. Szép, D. Purger, B. Kryštufek,
D. Ivajnšič, T. Klenovšek & F. Janžekovič
Introduction
The European Hamster (Cricetus cricetus) has been a common inhabitant of agricultural
landscape in many parts of Europe and Asia. During population outbreaks, hamsters were
serious pests to crops (Nechay 2000). Since the 1950s, populations in western and central
parts of Europe experienced gradual decline, which was observed also in the western Car-
pathian Basin (Surov et al. 2016, Banaszek et al. 2020, Kryštufek et al. 2020). Chain of
events like habitat fragmentation and degradation, including a decline in food supplies, al-
so damped down its population cycles (Nechay 2008). An increase in winter precipitation
and widespread monocultures further contributed to population decline (Tissier et al. 2016).
Small, fragmented and isolated populations are vulnerable to various threats, which accel-
erate their further decline and nally lead to extinction (Weinhold 2008). Improvements in
land management are a crucial step to avoid further decline (Tissier et al. 2016). The IUCN
status of the species is Critically Endangered which was justied by a decline in reproduc-
tive rate, population size and distributional range.
Recent surveys retrieved local hamster extinctions in certain parts of Hungary, includ-
ing Southern Transdanubia (e.g. Bihari 2004, 2007, Cserkész 2017, Kondor & Cserkész
2017). In this communication, we address the situation in the Baranya region. Baranya (al-
so Baranja) is a at plain between the Drava and Danube Rivers and is administratively di-
vided between Hungary and Croatia. European Hamsters used to be widespread and com-
mon throughout the Croatian part of the region (Petrov 1992) but are now restricted to the
southern part of the Hungarian Baranya (Nechay 2000). The hamster population in Bara-
nya is of particular conservation interest for at least two reasons. Because of recent decline
(Bihari 2007, Cserkész 2017, Kondor & Cserkész 2017), it requires conservation manage-
ment on its own. Equally important, Baranya anchors the entire hamster population along
the Drava in Croatia and Slovenia. This population is in a shape of a long (c. 200 km) and
very narrow stripe (up to 20 km) which stretches – presumably continuously – on the right
bank of the river. Gene ow in this narrow corridor can become disrupted at any point and
at any time, making the right bank of the Drava a deadly effective population trap for ham-
sters. The area is densely populated and heavily used for agriculture. The majority of infor-
mation on hamsters is from the early 1970s (Ružić 1978, Petrov 1992) and is therefore pri-
marily of historical interest. There are no hamsters on the left bank of the Drava River in
Hungary (Bihari 2007, Cserkész 2017), however, during an outbreak in the 1980s, the ham-
ster population spread toward the Drava Plain till the western edge of Baranya County, Hun-
gary (Nechay 2000).
The presence of European Hamsters at the far end of the Drava in Slovenia was conrmed
for the rst time in May 1980. Two specimens were found in the vicinity of the village
Obrež, situated alongside the road Ormož – Središče ob Dravi (Kryštufek 1987). This tiny
population is very marginal and restricted to a narrow strip of agricultural habitat between
4
Slovenian Museum of Natural History, 1000 Ljubljana, Prešernova 20., Slovenia
5
Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Koroška cesta 160., Slovenia
*corresponding author, e-mail: purgerjj@gmail.com

ORNIS HUNGARICA 2020. 28(2)
68
the hilly area to the north and the river to the south. The last individual was recorded in late
1990s and recent observations yielded no positive evidence on the animal. The conservation
status in Croatia was reviewed by Tvrtković (2006), but this account includes hardly any
new evidence. Tvrtković mainly stressed the lack of recent scientic information. While the
current situation in Croatia is enigmatic, the European Hamster presumably still has consid-
erable populations in the lowland to the east of the Danube in Hungary and Voivodina (the
northern part of Serbia) (Banaszek et al. 2020).
In the Hungarian Baranya, the European Hamster is very rare (Bihari 2007, Cserkész
2017, Kondor & Cserkész 2017), hence its detection is a difcult task. In such cases,
mammalogists frequently collect information from remnants found in pellets of avian
predators, particularly owls. Owl pellet analysis is an important supplementary meth-
od in small mammal surveys (Mikuska et al. 1979, Horváth et al. 2007). In contrast to
trapping, it can be particularly effective in monitoring difcult-to-detect small mammals
(Torre et al. 2004, Heisler et al. 2016). The method has its limitations, e.g. the exact lo-
cation of a small mammal prey can only be assumed. Despite this, the information gath-
ered from the owl pellets can facilitate and direct further research, which can utilize dif-
ferent eld techniques.
Research in Hungary retrieved the European Hamster as an important and frequent prey
of the large-bodied Eurasian Eagle-owl (Bubo bubo), while the smaller Common Barn-owl
(Tyto alba) and the Northern Long-eared Owl (Asio otus) preyed on hamsters only rare-
ly or extremely rarely (Bihari et al. 2008). The Common Barn-owl prefers open areas dur-
ing hunting (Taylor 1994) and, as an opportunistic feeder, consumes prey in proportion to
its abundance in the hunting habitat (Tores et al. 2005). Although the European Hamster is
not an easy prey due to its comparatively large and robust body and aggressive behaviour
(Kryštufek et al. 2020), we still presumed that the Common Barn-owl should be able to cap-
ture juvenile European Hamsters, e.g. at the time they start feeding above ground.
Our goal in this study was twofold. Firstly, we aimed to re-evaluate the current distribu-
tion of the European Hamster in Southern Transdanubia, relying primarily on the results of
owl pellet analyses. In order to complete the distributional picture, we also used unpublished
observations and literature data. Another goal was to re-draw attention to the importance of
owl pellet collections and analyses in the detection of elusive small mammals and in per-
forming a non-invasive monitoring.
Material and methods
Our database on prey composition of Common Barn-owl pellets contains information
gained between the years 2007–2017 (Croatian part of Baranya, and Udvar in Hungary) and
is based on remnants of 11,792 small mammal individuals. The database is stored at the De-
partment of Ecology, University of Pécs. We extracted the information on the occurrence of
hamster present in the study area, as well as on their relative abundance (Yom-Tov & Wool
1997). We completed the list of hamster records by interviews carried out among local or-
nithologists and upon sporadical inspection of roadkills (one skeleton is preserved in the

69
J. J. Purger, K. Kurucz, D. Szép, D. Purger, B. Kryštufek,
D. Ivajnšič, T. Klenovšek & F. Janžekovič
Natural History Museum of Slovenia). The four persons were included in searching for ty-
pi cal hamster holes (burrows) in agricultural habitats. Walking in transects about 5 meters
apart, we examined the agricultural plots suggested by the hamster observers and also those
areas, which we considered as potential habitats based on our own experience. In the period
between 2018 and 2020, searching was performed two times in spring and three times in au-
tumn in the areas north of the Croatian settlement of Podolje, and ve times in Hungary in
the area enclosed by the Udvar, Sátorhely, Nagynyárád and Majs settlements.
Results and discussion
Positive records of European Hamsters in Baranya are summarized in Table 1. All sites are
located close to the international border between Croatia and Hungary (Figure 1). Three re-
cords are from Common Barn-owl pellets, one observation was a road casualty, and two
were reliable verbal reports (Table 1). One of the records is historic (1988) but we still list it
to document more thoroughly the status of the hamster in this part of Baranya.
For the hamster from Podolje, we were not certain if it had been preyed by the Common
Barn-owl near its resting site (Table 1). In 2007, we carefully sampled owl pellets in Cro-
atia between the Drava and Danube rivers and the Hungarian border but found no further
hamsters (Szép et al. 2018). Earlier detailed surveys in this part of Croatia (e.g. Mikuska
et al. 1978, Mikuska & Vuković 1980, Tórizs 2010, 2011) similarly did not detect a single
European Hamster. The species, however, was reported for the area prior to the mid-1970s
(Ružić 1978, Petrov 1992). Despite this, we concluded that a single skull does not provide
Map
Id
Locality,
Country Latitude Longitude Date Mode Material Source
1Podolje,
Croatia 45.815394 18.728147 28.09.2007 Owl pellets
1, juv,
skull and
mandible
Szép et al.
2018
1Podolje,
Croatia 45.815394 18.728147 29.10.2016 Owl pellets
1, juv,
skull and
mandible
own data
2Udvar,
Hungary 45.900367 18.659647 16.03.2017 Owl pellets
5, juv,
skull and
mandible
own data
3Sátorhely,
Hungary 45.942702 18.643589 27.07.2019 Roadkill 1, male,
carcass own data
4Majs,
Hungary 45.917971 18.632420 2015–2020 Observation
in nature
Csaba László,
pers. comm.
5Babarc,
Hungary 46.002709 18.551715 1988 Observation
in nature
Tamás Treitz,
pers. comm.
Table 1. Occurrences of European Hamster (Cricetus cricetus) in the border region of Croatia and
Hungary
1. táblázat Mezei hörcsög (Cricetus cricetus) előfordulások Horvátország és Magyarország határmenti
régiójában

ORNIS HUNGARICA 2020. 28(2)
70
indisputable evidence on the presence of the hamster but instead left open the possibility that
the owls might prey the hamster to the east of the Danube in the nearby Serbia.
A subsequent survey, repeated in 2016, revealed a young hamster skull from the same lo-
cation (Table 1, Figure 1). A year later a large pellet sample was collected from the attic of a
family house in Udvar (the Hungarian side of Baranya), which contained skeletal remnants
of ve hamsters (Table 1, Figure 1). The site was so close to the Hungarian-Croatian border
that hamsters could be preyed upon on either side.
Intensive owl pellet surveys have been continuously undertaken in Baranya (the southern
county of Hungary) since 1985. European Hamster remains were not found either in the rst
ten years (Horváth 1999) or in subsequent surveys (e.g. Horváth 1998). Such a lack of evi-
dence is surprising, as hamsters were present in Southern Transdanubia during the last deca-
des of the 20
th
century (Nechay 2000, Bihari 2004). Near the current nding site (Figure 1), it
was observed in Babarc (CR19) in spring 1988 (Tamás Treitz, pers. comm.). We accepted the
presence of the European Hamsters in Hungary as proven after a road casualty was found at
Sátorhely (Table 1, Figure 1). Mr. Csaba László drew our attention to the carcass of the ham-
ster that he collected. He recollected another observation of European Hamster nearby a few
years earlier. In his testimony, hunters also observed hamsters on nearby elds (in the area of
settlement Majs) several times during the last ve years (Csaba László, pers. comm.). In 2019,
we surveyed the vicinity of the site of the road casualty, as well as potentially suitable habitats
in Croatia, but found no sign on the presence of the European Hamster.
Our survey covered only a small surface area in the border between Croatia and Hunga-
ry. The question remains whether there are still hamster habitats in the southern section of
Figure 1. Occurrences of European Hamster (Cricetus cricetus) in the border region of Croatia and
Hungary (1–5), on the south-western limit of its distribution range
1. ábra A mezei hörcsög (Cricetus cricetus) előfordulási helyszínei Horvátország és Magyarország
határmenti régiójában (1–5), elterjedési területének délnyugati határán

71
J. J. Purger, K. Kurucz, D. Szép, D. Purger, B. Kryštufek,
D. Ivajnšič, T. Klenovšek & F. Janžekovič
Drava in Slavonia and further west. In Hungary, no hamsters were found in Common Barn-
owl pellets collected along the Drava and Mura (e.g. Horváth 1998, Purger 1998, Szép et
al. 2017), but similar surveys have never been conducted on the Croatian side (Tvrtković
2006). It would therefore be important to urgently perform this task.
Conclusion
Results of the Common Barn-owl pellet analyses and further data from eld observations
proved that a small isolated population of the European Hamster is still present in the
Croatian-Hungarian border area. The habitat patch, which is estimated to cover an area of
20 × 10 km is on the south-western limit of the hamster’s distribution range. Without prop-
er attention and timely conservation measures, and in the absence of further population
monitoring, hamsters can easily vanish from this area in the near future, just like they did
in many parts of their European range. To counterbalance the negative population trend, a
joint coordinated action by the relevant nature conservation authorities and cross-border
cooperation is urgently needed, here and now.
Acknowledgements
We are grateful to Csaba László, Tamás Treitz and Béla Simonkovics for their information
and help during the work and Ákos Halmai for his help in preparing the map. The project
“Bilateral Scientic and Technological (TéT) Cooperation Hungarian-Slovenian Relation
(2018-2.1.11-TÉT-SI-2018-00015)” was implemented with the support of the National Re-
search, Development and Innovation Ofce from the NKFIH Fund and Slovenian Research
Agency project nb. BI-HU/19-20-009.
Banaszek, A., Bogomolov, P., Feoktistova, N., La Haye, M., Monecke, S., Reiners, T. E., Rusin, M., Surov, A.,
Weinhold, U. & Ziomek, J. 2020. Cricetus cricetus. – The IUCN Red List of Threatened Species 2020: e.
T5529A111875852. DOI: 10.2305/IUCN.UK.2020-2.RLTS.T5529A111875852.en (Downloaded on 04 Oc-
tober 2020.)
Bihari, Z. 2004. A hörcsög (Cricetus cricetus) magyarországi elterjedésének változása az elmúlt 50 év alatt
[Changes in the distribution of Hamster (Cricetus cricetus) in Hungary during the past fty years]. – Termé-
szetvédelmi Közlemények 11: 559−566. (in Hungarian with English Summary)
Bihari, Z. 2007. Mezei hörcsög Cricetus cricetus (Linnaeus, 1758) [European Hamster]. – In: Bihari, Z., Csorba,
G. & Heltai, M. (eds.) Magyarország emlőseinek atlasza [Atlas of mammals in Hungary]. – Kossuth Kiadó,
Budapest, pp. 176−178. (in Hungarian with English Summary)
Bihari, Z., Horváth, M., Lanszki, J. & Heltai, M. 2008. Role of the Common Hamster (Cricetus cricetus) in the di-
et of natural predators in Hungary. – In: Millesi, E., Winkler, H. & Hengsberger, R. (eds.) The Common Ham-
ster (Cricetus cricetus): Perspectives on an endangered species. Austrian Academy of Sciences, Wien. – Bio-
systematics and Ecology Series 25: 61–68.
Cserkész, T. 2017. A mezei hörcsög aktuális helyzete [The current distribution of the European Hamster]. – In:
Holes, A. (ed.) Magyarország környezeti állapota 2016 [The state of the environment in Hungary in 2016]. –
Herman Ottó Intézet, Budapest, pp. 76–81. (in Hungarian)
References

ORNIS HUNGARICA 2020. 28(2)
72
Heisler, L. M., Somers, C. M. & Poulin, R. G. 2016. Owl pellets: a more effective alternative to conventional trap-
ping for broad-scale studies of small mammal communities. – Methods in Ecology and Evolution 7(1): 96–
103. DOI: 10.1111/2041-210X.12454
Horváth, G., Jurčević Agić, I., Merdić, E., Tórizs, I. & Purger, J. J. 2007. Small mammal monitoring based on the
analysis of owl pellets. – In: Purger, J. J. (ed.) Manual for the investigation of biodiversity along the Drava
River. – University of Pécs, pp. 203–217. (in Croatian)
Horváth, Gy. 1998. Kisemlős (Mammalia) faunisztikai vizsgálatok a gyöngybagoly (Tyto alba) köpetanalízise
alapján a Dráva mentén (1995–1997) [The investigation of the small mammal fauna of the River Dráva plain
region, based on the analysis of Barn Owl (Tyto alba) pellets between 1995–1997]. – Dunántúli Dolgozatok
(Publicationes Transdanubiensis) Természettudományi Sorozat (Studia Pannonica) 9: 475–488. (in Hunga ri-
an with English Summary)
Horváth, Gy. 1999. A gyöngybagoly (Tyto alba Scop., 1769) köpetvizsgálatának tíz éve Baranya megyében
(1985–1994) [Ten years of Barn Owl (Tyto alba Scop., 1769) pellet analysis in county Baranya]. – Állattani
Közlemények 84: 63–77. (in Hungarian with English Summary)
Kondor, T. & Cserkész, T. 2017. A mezei hörcsög (Cricetus cricetus) populációs trendjének és elterjedésének vál-
tozása Magyarországon [Changes in the population trend and distribution of the European Hamster (Cricetus
cricetus) in Hungary]. – Bükki Emlőstani Kutatócsoport Egyesület, Eger, pp. 18. (in Hungarian)
Kryštufek, B. 1987. Hrček (Cricetus cricetus Linnaeus, 1758; Rodentia, Mammalia) edini stepski sesalec v slo-
venski favni [Hamster (Cricetus cricetus Linneaeus, 1785; Rodentia, Mammalia) the only steppe mammal in
the Slovene fauna]. – Varstvo Narave 13: 93–98. (in Slovenian with English Summary)
Kryštufek, B., Hoffmann, I. E., Nedyalkov, N., Pozdnyakov, A. & Vohralík, V. 2020. Cricetus cricetus (Rodentia:
Cricetidae). – Mammalian Species 52(988): 10–26. DOI: 10.1093/mspecies/seaa001
Mikuska, J. & Vuković, S. 1980. Kvalitativna i kvantitativna analiza ishrane kukuvije drijemavice, Tyto al-
ba Scop. 1769, na području Baranje, sa posebnim osvrtom na rasprostranjenost sitnih sisavaca [Qualita-
tive and quantitative analysis of the diet of Common Barn-owl, Tyto alba Scop. 1769, in Baranja region,
with a focus on the distribution of small mammals]. – Larus (31–32): 269–288. (in Croatian with German
Summary)
Mikuska, J., Pivar, G. & Pančić, S. 1978. Analiza ishrane kukuvije drijemavice, Tyto alba Scop. 1769, na po-
dručju Specijalnog zoološkog rezervata „Kopački rit” i okoline s posebnim osvrtom na faunu sitnih sisava-
ca [Diet analysis of Common Barn-owl, Tyto alba Scop. 1769, in the area of the Special Zoological Reserve
“Kopački rit” and the surrounding area, with a focus on the fauna of small mammals]. – Priroda Vojvodine
4: 45–46. (in Serbo-Croatian).
Mikuska, J., Tvrtković, N. & Džukić, G. 1979. Collecting and analysis of bird pellets as one more important meth-
ods for studying the fauna of Mammals in Yugoslavia. – Archives of Biological Sciences 29(3–4): 157–160.
Nechay, G. 2000. Status of Hamsters: Cricetus cricetus, Cricetus migratorius, Mesocricetus newtoni and other
hamster species in Europe. – Council of Europe Publishing, Strasbourg, France, Nature and Environment
Series 106.
Nechay, G. 2008. Peak numbers of Cricetus cricetus (L.): do they appear simultaneously? – In: Millesi, E., Win-
kler, H. & Hengsberger, R. (eds.) The Common Hamster (Cricetus cricetus): Perspectives on an endangered
species. – Austrian Academy of Sciences, Wien. – Biosystematics and Ecology Series 25: 69–77.
Petrov, B. M. 1992. Mammals of Yugoslavia: Insectivores and Rodents. – Natural History Museum in Belgrade,
Special issues 37: 1–186.
Purger, J. J. 1998. A Dráva mente Somogy megyei szakaszának kisemlős (Mammalia) faunája, gyöngybagoly,
Tyto alba (Scopoli, 1769) köpetek vizsgálata alapján [Small mammal fauna of the region of Drava river in
county Somogy (Hungary), obtained by Barn Owl, Tyto alba (Scopoli, 1769) pellet analysis]. – Dunántúli
Dolgozatok (Publicationes Transdanubiensis) Természettudományi Sorozat (Studia Pannonica) 9: 489–500.
(in Hungarian with English Summary)
Ružić, A. 1978. Distribution and abundance of the Common Hamster (Cricetus cricetus Linnaeus, 1758; Roden-
tia, Mammalia) in Yugoslavia. – Biosistematika 4(1): 203–208. (in Serbo-Croatian with English Summary)
Surov, A., Banaszek, A., Bogomolov, P., Feoktistova, N. & Monecke, S. 2016. Dramatic global decrease in the
range and reproduction rate of the European Hamster Cricetus cricetus. – Endangered Species Research 31:
119–145. DOI: 10.3354/esr00749
Szép, D., Horváth, G. F., Krčmar, S. & Purger, J. J. 2018. Connection between prey composition and the land-
scape structure in the hunting area of Barn Owls (Tyto alba) in Baranja (Croatia). – Periodicum Biologorum
120(2–3): 125–233. DOI: 10.18054/pb.v120i2-3.6650

73
J. J. Purger, K. Kurucz, D. Szép, D. Purger, B. Kryštufek,
D. Ivajnšič, T. Klenovšek & F. Janžekovič
Szép, D., Klein, Á. & Purger, J. J. 2017. The prey composition of the Barn Owl (Tyto alba) with respect to land-
scape structure of its hunting area (Zala County, Hungary). – Ornis Hungarica 25(2): 51–64. DOI: 10.1515/
orhu-2017-0015
Taylor, I. R. 1994. Barn Owls: Predator – Prey Relationships and Conservation. – Cambridge University Press,
Cambridge, 304 p.
Tissier, M. L., Handrich, Y., Robin, J-P., Weitten, M., Pevet, P., Kourkgy, C. & Habold, C. 2016. How maize mon-
oculture and increasing winter rainfall have brought the hibernating European Hamster to the verge of extinc-
tion. – Scientic Reports 6: 25531. DOI: 10.1038/srep25531
Tores, M., Motro, Y., Motro, U. & Yom-Tov, Y. 2005. The Barn Owl – a selective opportunist predator. – Israel
Journal of Zoology 51(4): 349–360. DOI: 10.1560/7862-9E5G-RQJJ-15BE
Tórizs, I. 2010. A gyöngybagoly [Tyto alba (Scop.) 1769] monitorozása a Drávaszögben, különös tekintettel a
táplálkozásbiológiára [Monitoring of the Common Barn-owl (Tyto alba (Scop.) 1769) in Baranja, with spe-
cial regard to feeding biology]. – MS Thesis, University of West Hungary, Sopron, 67 p. (in Hungarian)
Tórizs, I. 2011. Gyöngybagolyvédelem a Drávaszögben [The conservation of Common Barn-owl in Baranja]. –
Rovátkák 3: 34–54. (in Hungarian)
Torre, I., Arrizabalaga, A. & Flaquer, C. 2004. Three methods for assessing richness and composition of small
mammal communities. – Journal of Mammalogy 85(3): 524–530. DOI: 10.1644/BJK-112
Tvrtković, N. 2006. Hrčak / Common Hamster Cricetus cricetus (Linnaeus, 1758). – In: Tvrtković, N. (ed.) Crve-
na knjiga sisavaca Hrvatske [Red book of mammals of Croatia]. – Ministry of Culture, State Institute for Na-
ture Protection, Republic of Croatia, Zagreb, pp. 87–88. (in Croatian)
Weinhold, U. 2008. Draft European action plan for the conservation of the Common Hamster (Cricetus cricetus
L., 1758). – Convention on the conservation of European wildlife and natural habitats, 28
th
Meeting of the
Standing Committee, Council of Europe, Strasbourg, France, 36 p.
Yom-Tov, Y. & Wool, D. 1997. Do the Contents of Barn Owl Pellets Accurately Represent the Proportion of Prey
Species in the Field? – The Condor 99(4): 972−976. DOI: 10.2307/1370149