What affects the social dominance in red deer (Cervus elaphus) hinds?
The aim of this study was to test the potential effect of the selected sex hormones on the social dominance of hinds of the red deer (Cervus elaphus). We studied the levels of testosterone (T), estradiol (E2), progesterone (P) and gonadotropins (FSH, LH), and the social dominance in 33 red deer hinds (VÚŽV Podlesko) during five years. We presumed that social rank of the hind will increase with her age, body weight and levels of sex hormones. With the aid of General Linear Mixed Models (GLMM), we analyzed 84 records from the milk hinds and 15 records from the yeld hinds. We found that: (1) the milk hinds were older that than the yeld hinds (milk: 8.33 ± 0.48 years; yeld: 3.93 ± 1.21 years; t = -3.51, p < 0.001); (2) in both groups the social rank of the hind increased with her age (milk: F[1, 54.2] = 50.86, p < 0.0001; yeld: F[1, 5.39] = 9.47, p < 0.03). The effect of hind’s body weigh was not detected (NS). In contrast to our predictions: (a) in the milk hinds the social rank increased with the decreasing levels of T (F[1, 76.4] = 9.33, p < 0.01); and (b) in the yeld hinds the social rank increased with the decreasing levels of LH (F[1, 1.73] = 186.02, p < 0.01). In addition, we found that in the milk hinds the levels of T decreased with the increasing age (r = -0.40, p < 0.0001), but in the yeld hinds the levels of LH did not change with age (NS). We conclude: (1) age and lactation are the key factors that affect dominance relationships in red deer hinds; (2) the assumption of the positive effect of sex hormones on the social dominance in female mammals does not have a general validity.
Dušek Adam, RNDr., Ph.D.
Esattore Bruno, MSc.
Kotrba Radim, Ing., Ph.D.
Kott Tomáš Ing. Ph.D.
VÚŽV v.v.i. > List of our publications >