1067-4136/04/3505- © 2004
Russian Journal of Ecology, Vol. 35, No. 5, 2004, pp. 324–331. Translated from Ekologiya, No. 5, 2004, pp. 366–374.
Original Russian Text Copyright © 2004 by Maklakov, Olenev, Kryazhimskii.
The structure and dynamics of populations as indi-
ces characterizing their state in various animal species
, 2002) are closely related to changes
in the spatial population structure. The spatial structure
of a population manifests itself in a consistent distribu-
tion of individuals and their groups with respect to cer-
tain landscape elements and to each other, reﬂecting a
species-speciﬁc type of area use. This distribution pro-
vides a foundation for all forms of the normal life activ-
ity of populations, ensuring the most efﬁcient use of
environmental resources (food supply, shelters, micro-
climatic conditions, etc.). In addition, spatial structur-
ing is a basic condition for the maintenance of intraspe-
ciﬁc (intrapopulation) contacts between individuals at
an adequate level (Shilov, 1977).
Speciﬁc forms of the spatial distribution of animals
in different seasons and years can noticeably change
depending on environmental conditions. For instance, it
has been shown that the home range size depends on
animal body size (MacNab, 1963; Dol’nik, 1993,
1995), food supply (Harestad and Bunnel, 1979;
Kryazhimskii, 1992; Dobrinskii
, 1994), popula-
tion density (Okulova
, 1971), and a number of
other factors. Moreover, individuals belong to different
intrapopulation groups playing different roles in the
integrated response of the population system to the
state of its environment, and this fact must also be
reﬂected in the pattern of area use. The structural inho-
mogeneity of small mammal populations is strikingly
manifested in the existence of alternative ontogenetic
pathways in rodents (Olenev, 2002).
The purpose of this work was to elucidate the role of
ontogeny type in the formation of spatial population
structure in small rodents and, in particular, in deter-
mining the size of their home ranges.
MATERIAL AND METHODS
Methodologically, this study was based on the con-
cept of the functional approach (Olenev, 1981, 1989,
2002). Its essence is that the main criterion for distin-
guishing intrapopulation groups (structural units) is the
functional state of individuals—speciﬁc features of
growth, development, reproductive state, etc.—deter-
mining their functional unity corresponding to one of
two pathways of ontogeny. On this basis, we proposed
a scheme for distinguishing three main physiological
functional groups (PFG), which is shown in Fig. 1.
Each group consists of individuals that belong to sev-
eral cohorts and are functionally united with respect to
their role in reproduction.
The ﬁrst ontogenetic pathway.
growth. Young animals reproducing in the year of birth
(PFG3). They rapidly grow, mature, and usually die
before the winter of the current year.
The second ontogenetic pathway.
The ﬁrst phase.
Young animals remaining nonreproductive in the year
(PFG2). After a short period of growth in the
ﬁrst phase, the animals cease growing and remain in a
“conserved” state, with a low metabolic rate, until the
The second phase. Overwintered animals
formerly PFG2). After wintering and the spring period
of intensive growth and maturation, most animals par-
ticipate in reproduction.
A major advantage of the functional approach is that
it offers the possibility of analyzing “pure” intrapopu-
lation groups united by a certain functional role in the
maintenance of their population. Such groups are easy
to distinguish, which makes this analysis fairly simple,
convenient, and logical.
This approach has been successfully used in a broad
spectrum of population studies. For instance, the
rodents following different ontogenetic pathways
proved to be clearly differentiated with respect to time-
Types of Ontogeny and Territorial Distribution of Small Rodents
K. V. Maklakov, G. V. Olenev, and F. V. Kryazhimskii
Institute of Plant and Animal Ecology, Ural Division, Russian Academy of Sciences,
ul. Vos’mogo Marta 202, Yekaterinburg, 620144 Russia
Received October 8, 2003
—In small rodents, differences in the average home range size, depending on the type of ontogeny and
animal sex, have been revealed. The dynamics of changes in the spatial structure of populations during the
breeding season are described.
: small rodents, type of ontogeny, home range.