ISSN 1062-3590, Biology Bulletin, 2017, Vol. 44, No. 10, pp. 1289–1294. © Pleiades Publishing, Inc., 2017.
Original Russian Text © M.L. Oparin, I.A. Kondratenkov, O.S. Oparina, A.B. Mamayev, E.I. Tikhomirova, 2016, published in Povolzhskii Ekologicheskii Zhurnal, 2016, No. 4,
pp. 424–433.
1289
Statistical Analysis of the Influence of a Disturbance Factor
on Formation of the Spatial Structure of the Great Bustard
(Otis tarda L.) (Otididae, Aves) Population in the Trans-Volga Region
M. L. Oparin*, I. A. Kondratenkov, O. S. Oparina, A. B. Mamayev, and E. I. Tikhomirova
Severtsov Institute of Ecology of Evolution, Saratov Branch, Russian Academy of Sciences,
ul. Rabochaya 24, Saratov, 410028 Russia
*e-mail: oparinml@mail.ru
Received October 27, 2016
Abstract—This paper examines the inf luence of the location of settlements, railroads, and highways on the
spatial structure of the Otis tarda population in the Trans-Volga region that was studied in the years 1998–
2016 in a model area of 12000 km
2
that is located in the southern part of the Saratov Trans-Volga region. The
zone of the impact made by our estimated disturbance factor due to the movement of people and a variety of
ground vehicles along various-purpose roads on the territorial distribution of bustards in autumn can be
denoted as a 300–500 m width band on both sides of the transport communications. Shelterbelts that were
created along transport communications render a beneficial effect on the distribution of O. tarda and reduce
the influence of the disturbance factor. Furthermore, crop rotation fields with side sizes of more than 1 km
can be considered a factor that compensates for the anxiety of birds. We have found that in the Saratov Trans-
Volga region, because of the large size of crop rotation fields and significant development of roadside and
shelter belts, no special measures are required to protect O. tarda such as restrictions on the movement of peo-
ple and vehicles over the territory where this species lives.
Keywords: O. tarda, disturbance factor, transport communications, settlements, spatial structure of the Great
Bustard population, shelter belts, crop rotation fields
DOI: 10.1134/S1062359017100090
INTRODUCTION
The plowing of steppes has burdened many aborig-
inal animals, especially terrestrial vertebrates, with the
difficult task of adapting to the emergent changes.
Among the various forms, an important role is played
by the ability to respond adequately to the danger of
both natural and anthropogenic nature (Vlady-
shevskii, 2004). Yurgenson (1962) was one of the first
to draw attention to the need for a special study of the
“disturbance factor.” Flint (1983) noted that although
the disturbance factor is constantly mentioned as a
significant factor, there are almost no specific data on
the strength of this significance. The disturbance fac-
tor is most often considered in modern literature when
analyzing the reasons for the decrease in the number
of game animals and the largest cautious bird species
(especially cranes and eagles). Not only individual
publications but also special conferences have been
devoted to investigation of this problem (Neufeldt,
1974; Galushin, 1980; Berezovikov, 1981; Kustov,
1981; Golovanova, 1985; Savchenko and Emelyanov,
1995). Another area of research on the problem in
question is to describe birds of anthropogenic land-
scapes. In addition, these works also pay attention to
the role of the disturbance factor as one of the main
causes that determine the characteristics of their pop-
ulation (Teichmann and Flint, 1967; Vladyshevskii,
1975; Bobrov, 1980; Egorova and Frenkina, 1981;
Konstantinov and Babenko, 1981; Tkachenko, 1984;
Nekrasov, 1986; Polushkin, 1986; Shibaev and Glush-
chenko, 1988).
Our article is devoted to study of the impact of dis-
turbance factors on the spatial structure of the Trans-
Volga bustard population (Otis tarda tarda L.). Studies
devoted to the study of bustards frequently mention
the disturbance factor as one of the main limiting fac-
tors for this species, but there are almost no specific
data except for certain speculative conclusions.
MATERIALS AND METHODS
This study is based on data of autumn censuses of
the Trans-Volga bustard population in a stationary
model area of 12000 km
2
, which we carried out
according to the same method from 1998 to the pres-
ent; the main team of counters remained constant all
this time. We carried out counting works in 1998–
2000, 2011–2012, and 2014–2016. The procedure of