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TABLE 10.1B
System for Scoring Behavior in Aggressive Fox Population
and Selecting the Most Aggressive Foxes for the Breeding Program
Animal Reaction
Scores
Fox shows teeth, snarls, growls at first sight of human. When experimenter is
near closed cage fox attacks experimenter and other objects in field of view.
Bared teeth and fixed dilated pupils.
4.0
2
When experimenter is near closed cage, fox shows teeth, snarls, growls, tries
to attack both the experimenter and other objects in field of view. Bared
teeth and fixed dilated pupils.
3.5
2
When experimenter is near open cage, fox shows teeth, snarls growls, attacks
experimenter and other objects in the field of view. Bared teeth and fixed
dilated pupils.
2
3.0
When experimenter is near the open cage, fox growls but does not attack.
2
2.5
When experimenter, near the open cage, moves protected arm towards fox,
it growls and tries to bite.
2
2.0
As experimenter opens cage, fox is calm, but attempts to touch the fox
provoke it to show teeth and snarl.
1.5
2
The score is based on the critical distance between the experimenter and the caged fox when the
animal first demonstrates an aggressive reaction to the experimenter's presence. Originally the
scoring system was based on a range from zero (least aggressive) to
4 (most aggressive).
However, after multiple generations of selection, no current individuals exhibit behavior scoring
between
2
1.5 and 0.
Source:
Trut (1980a)
.
2
TABLE 10.2
The Number and Proportion of Elite-Behavior Progeny at
Different Stages of Selection
Year of Study
(Generation of selection)
Number of
Progeny Scored
Out of them, Elite Animals
Number
Proportion (%)
1965 (F
6
)
213
4
1.8
1970 (F
10
)
370
66
17.8
1980 (F
20
)
1438
503
35.0
1990 (F
30
)
1641
804
49.0
2002 (F
42
)
902
642
71.2
Source:
Trut
et al.
(2004)
.
adulthood (
Belyaev et al., 1985; Plyusnina et al., 1991; Trut, 2001
). Tame
foxes developed a novel repertoire of vocalizations toward humans
(
Gogoleva et al., 2009, 2011
). Significant differences in corticosteroid
and neurotransmitter levels were found between tame and control foxes
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