Nove knjige / New books
110
Nove knjige
New books
Trilar, T. (2002): Forest Birds of Slovenia. 2 CDs,
Slovenian Museum of Natural History, Ljubljana.
Recordings of 93 forest bird species and booklet
with comments (in English and Slovenian
languages). ISBN 961-6367-04-8. Buying:
www2.pms-lj.si/cdgozd/english.html, Price: 30
EUR.
In 2002, a new CD by Trilar, his second now, was
published by the Slovenian Museum of Natural
History. This double CD is dedicated to Slovenia’s
forest birds, since forest is the most widespread habitat
of birds in the country. All the recordings were made
in Slovenia, with the exception of the Subalpine
Warbler Sylvia cantillans, which was made in
neighbouring Croatia.
The author has collected as many different
vocalisations of birds as possible, e.g. territorial male
song, contact calls, fledgling calls, etc. As every sound
is well explained in the accompanied booklet, the
recordings are easy to follow. The male song, which is
usually used in territorial defence and as part of
courtship behaviour, can vary markedly in some
species of Passeriformes song birds, with a number of
different song types, which can be very confusing for
identification in the field. Tits are the best example in
this respect. On the CD, the Great Tit Parus major is
presented with four different song types, Blue Tit P.
caeruleus with five, and Coal Tit P. ater with seven.
These, however, are not the only song types used by
these species but after careful listening to these
recordings, the listener should also be able to identify
other song types during a forest birdwatching trip.
The most attractive recordings presented on the CD
for me are those of Black Kite Milvus migrans,
Capercaillie Tetrao urogallus, Woodcock Scolopax
rusticola, and Three-toed Woodpecker Picoides
tridactylus. The most valuable comparisons are those
between the male songs of Stock Dove Columba oenas
and Woodpigeon C. palumbus. With attentive
listening, even less experienced birdwatchers will be
able to distinguish between the songs of these two
typical forest pigeon species.
The major problem in observing forest birds is the
fact that we are better able to hear them than to see
them. In most cases we can see them only for a short
period of time, when they are flying through the
canopies. But there is a group of birds for which even
these short sightings are rare, and which can be
identified only on the basis of their voices - owls.
Males of forest owl species call very loudly in the
springtime, when defending their territories. The
loudest among them are males of Tawny Owls Strix
aluco. Individual birds can be distinguished, just as
humans, in the way they vocalise. On the CD, there
are several different hootings of male Tawny Owls
and, by listening carefully to them, even amateurs
should be able to distinguish between them. But it is
not only males who sing. The CD presents an
excellent recording of a female song by Ural Owl S.
uralensis, together with rare twittering calls by Ural
Owls while copulating. The CD also provides the key
to the problem in identifying fledgling calls of the two
most widespread owls in Slovenia, the Tawny Owl
and the Long-eared Owl Asio otus, which are common
species around human settlements.
Finally, I would like to point out an important
feature cited in the accompanying booklet. Under
natural conditions, birds sing in a particular sound
environment. So, the author has presented the
background sounds as well, and described them in the
booklet. Furthermore, the recordings of some birds
that vocalise less frequently, such as Northern
Goshawk Accipiter gentilis, Eurasian Sparrowhawk A.
nisus, Hazel Grouse Bonasa bonasia and Ural Owl,
were not shortened in order to cut out the breaks
between calls. They were left unchanged with the aim
of presenting them in the most authentic manner.
Al Vrezec 
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