1022-7954/01/3706- $25.00 © 2001
Russian Journal of Genetics, Vol. 37, No. 6, 2001, pp. 649–658. Translated from Genetika, Vol. 37, No. 6, 2001, pp. 791–802.
Original Russian Text Copyright © 2001 by Obukhova.
In most animal species, plumage or coat color is
variable but this variability is typically continuous and
relatively low. However, some species exhibit pro-
nounced and discrete differences in color. Evolutionary
studies of plumage color polymorphism in birds have
long exceeded the limits of phenomenological descrip-
tion of aberrations and geographic variation of gene
frequencies . Detailed investigation of the popula-
tion structure taking into account all demographic
parameters provides the basis for elucidating mecha-
nisms that underlie stable polymorphism [2–4].
In the 1980s, numerous studies of plumage color
polymorphism in populations of the blue rock pigeon
were published [5–8]. They reported
adaptation mechanisms and the direction of selection
favoring different morphs, the population structure, etc.
However, in the last decade the interest to the problem
of maintenance of color polymorphism in this species
was undeservedly lost.
The aim of the present work was summarizing the
results of our long-term studies of geographical varia-
tion in color pattern of the blue rock pigeon from differ-
ent areas and describing the current state of both synan-
thropic and wild populations of this species based on an
analysis of their phenotypic structure.
MATERIALS AND METHODS
We estimated frequencies of different color patterns
in 211 pigeon populations from various geographic
areas. Data from several geographically close (within
200 km) towns or settlements were combined. In some
cases, we combined data from more geographically
distant localities. The areas examined include the fol-
lowing arbitrarily deﬁned regions: (1) European part of
Russia (47 localities); (2) Baltic countries, Ukraine
(30); (3) Kazakhstan, Central Asia (35); (4) Altai, Sibe-
ria, Cisbaikalia and Transbaikalia, Far East (30);
(5) Western Europe, Africa (9).
Phenotypic variability of plumage color pattern in
synanthropic pigeons seems high only at ﬁrst glance. It
can be reduced to six main variants, three of which are
common (wild type, transitory, and melanistic) and the
other three occur less frequently (red, albino, and lilac).
These phenotypes, the color pattern inheritance and
corresponding genes were described in detail in our
previous works [9, 10]. In estimating the general vari-
ability structure in the regions, three patterns of aber-
rant color were combined in the group termed aberrant.
Our ﬁrst attempt to examine geographic differences in
color pattern frequencies in the territory of the Soviet
Union was made in 1978–1984 . In the present work,
the geographical area examined was substantially
extended; data of long-term (22 years) counts from
both earlier examined areas and newly studied regions
beyond the borders of the former Soviet Union. As the
total area of collection was vast, we divided it into ﬁve
large regions (see above).
RESULTS AND DISCUSSION
Analysis of Geographic Differences
in the Frequency Distribution of the Morphs
In the European part of Russia (74 localities), main
bulk of the data was collected in the last decade. No
drastic changes in frequency distribution of major color
phenotypes were recorded in St Petersburg, Tver’,
Moscow oblast, Perm’, and Ekaterinburg. In the north-
west (St Petersburg; Table 1, Fig. 1), the transitory form
is the most frequent (60.2%), the melanistic form ranks
second (29, 59%), and wild-type and aberrant birds
together constitute 10.2%. This distribution changes in
the southeastward direction: in Tver’ oblast, the fre-
Geographic Variation of Color
in the Synanthropic Blue Rock Pigeon
N. Yu. Obukhova
Department of the Evolution Theory, Moscow State University, Moscow, 119899 Russia;
Received March 6, 2000; in ﬁnal form, June 5, 2000
—Variation in plumage color was studied in 211 populations of the blue rock pigeon (
from various geographic zones. The frequency distribution of three common and three rare phenotypes and an
interspeciﬁc hybridization zone of
were described. Different conditions of the origin
of the urban populations of blue rock pigeon and consequent high genetic heterogeneity of this species were
revealed. The key aspect of color polymorphism in blue rock pigeon is synanthropization, i.e., anthropogenic