Reproductive biology of the pampas deer (Ozotoceros bezoarticus): a review

Abstract

The pampas deer (Ozotoceros bezoarticus) is a South American grazing deer which is in extreme danger of extinction. Very little is known about the biology of the pampas deer. Moreover, most information has not been published in peer-reviewed scientific journals, and is only available in local publications, theses, etc. Therefore, our aim was to update and summarize the available information regarding the reproductive biology of the pampas deer. Moreover, in most sections, we have also included new, unpublished information. Detailed descriptions are provided of the anatomy of both the female and the male reproductive tract, puberty onset, the oestrous cycle and gestational length. Birthing and the early postpartum period are described, as are maternal behaviour and early fawn development, seasonal distribution of births, seasonal changes in male reproduction and antler cycle, reproductive behaviour, semen collection, and cryopreservation. Finally, an overview is given and future directions of research are proposed.

Figure 1

Overview of the female reproductive tract of the pampas deer (Ozotoceros bezoarticus).

Figure 2

Circular folds projecting from the cervix into the cervical canal.

Figure 3

Percentage of time spent suckling in relation to total feeding time (grazing, eating ration, leaves, or water abbreviating). Behaviour of 18 fawns was recorded during 2 hours per week (1 hour in the morning and 1 in the afternoon) at the ECFA (unpublished data).

Figure 4

Prepuce and scrotum in male pampas deer (Ozotoceros bezoarticus).

Figure 5

Testis, epididymis and spermatic cord of a prepubertal pampas deer (Ozotoceros bezoarticus).

Figure 6

Monthly distribution of birth percentages in a herd of semi-captive pampas deer (Ozotoceros bezoarticus) at the ECFA, Pan de Azúcar, in southern Uruguay, in a pool of 272 births recorded over 20 years. Grey areas correspond to autumn and spring. Adapted from Ungerfeld et al. [19].

Figure 7

Antler cycle in adult and yearling pampas deer males. Adapted from Ungerfeld et al. [83].

Figure 8

Courtship behavioural events in pampas deer: A) low stretch; B) ostentation; C) anogenital sniffing; and D) smelling urine. See detailed descriptions of each behaviour in Table 1.

Figure 9

Frequency of each courtship behavioural unit in pampas deer (Ozotoceros bezoarticus). LS = low stretch; Os = ostentation; AGS = anogenital sniffing; Ch = chivying; ChN = chivying and nodding; SU = smelling urine; F = flehmen. See detailed descriptions of each behaviour in Table 1. Redrawn from Verdier [83].

Figure 10

Frontal marking on A) tufts of grass; and B) tree branches.

Figure 11

Male agonistic behaviours in male pampas deer(Ozotoceros bezoarticus): A) glare; B) the antler presentthreat; C) nose-touching; D) locking of antlers; E) pursuing asubordinate individual. See detailed descriptions of each behaviour in Table 3.