1067-4136/02/3304- $27.00 © 2002
Russian Journal of Ecology, Vol. 33, No. 4, 2002, pp. 253–259. Translated from Ekologiya, No. 4, 2002, pp. 271–277.
Original Russian Text Copyright © 2002 by Bliznyuk.
The saiga belongs to the ungulate species that are of
great commercial importance in Russia. According to
the results of censuses, however, the abundance of this
species decreased from 434000 animals in the end of
1997 to only 96000 in 1999 because of mass poaching.
In controlling the state of the saiga population, an
important role is played by the prognosis of the dates of
mass calving. In the Kalmyk population, the ﬁrst new-
borns appear on April 25–27, and mass calving usually
occurs in the ﬁrst ten-day period of May (Lavrovskii,
1950; Adol’f, 1954; Dal’
, 1958; Fandeev, 1960,
1961; Bannikov, 1961). The interval between the ﬁrst
and last births is about one months, and the period of
mass calving is three to ﬁve days or, in some instances,
up to seven days (Bannikov, 1961; Fandeev, 1961;
Bliznyuk, 1982; Zhirnov, 1982).
Further observations showed, however, that the
dates of calving may vary within a wider range. Mass
calving in 1969 took place on April 27–29 (Perovskii,
1974); between 1970 and 1978, this process lasted from
April 24 to May 14. The earliest recorded date of ﬁnd-
ing newborn saigas is April 15, 1970; most of them
appeared in this year between April 20 and 30 (Bliznyuk,
1982). The latest recorded dates of mass calving are May
16, 1959 (Fandeev, 1961; Zhirnov, 1982) and May 18,
1993 (Bliznyuk and Bukreeva, 1993). Only a few
females calve in the second half of May (Fandeev,
1961; Zhirnov, 1982). In Kazakhstan, mass calving
usually takes place between May 4 and 20 (Sludskii and
Fadeev, 1974). The dates of calving in each year depend
on conditions of the rut, the efﬁciency of mating, and
the physiological state of males (Zhirnov, 1982).
Between 1970 and 1978, up to 90% of Kalmyk sai-
gas during mass calving gathered in one to three
large groups (66000–275000 animals) in the area of
(Bliznyuk, 1982). In Kazakhstan, saiga
populations did not form such dense aggregations, and
calving in most regions, except for the Ustyurt Plateau
and western Kazakhstan (Fadeev, 1975), occurred
somewhat later (Bannikov, 1961; Zhirnov, 1982).
Before the onset of mass calving, saigas continu-
ously migrate and cover a distance of 10–20 km (in
some cases, up to 60 km) each day. Migrating groups
are very compact and difﬁcult to locate. When the exact
dates of mass calving are unknown and no special mea-
sures are taken to ﬁnd animal aggregations in due time,
the search for them is often successful when mass calv-
ing has already been completed (migrations cease only
upon the onset of this process). Locating these aggrega-
tions is important for organizing the summer census of
saigas. Such censuses were taken in the 1970s by an
original method (Bliznyuk, 1975, 1977), and this work
was resumed in 1994.
The factors determining the dates of the rut have not
yet been identiﬁed with certainty, although it is known
that commercial hunting in the end of the season can
delay this process. Hence, to estimate the dates of mass
calving from the dates of the rut, it is necessary to per-
form continuous observations throughout December,
when the rut occurs, but this does not ensure correct
determination of its onset and cessation.
The problem of forecasting the dates of mass calv-
ing in the saiga has not been seriously considered in
available publications. The main reason is that the pre-
cise data on the gestation period in this species are still
A Method for Forecasting the Dates of Mass Calving
and Some Characteristics of the Rut and Calving
in the Kalmyk Population of Saiga (
A. I. Bliznyuk
Center for Studies and Sustainable Use of the Kalmyk Population of Saiga,
ul. Lenina 273, Elista, 350000 Russia
Received February 1, 2000
—A method for forecasting the dates of calving in the saiga population on the basis of average fetal
body weight is proposed. The method is based on the relationship between the number of days before calving
and the average weight of fetuses, which obviates the necessity of determining fetal age and exact gestation
period in this species. The average length of gestation, the dates of the rut in the years studied, and the age of
females that have mated immediately upon the onset of the rut and before its cessation have been determined.
It is shown that the duration of mass calving depends on the proportion of mature males in the population.
: saiga, forecasting method, population, dates of calving, the rut.