The dark-ventral-patch of male red deer, a sexual signal that conveys the degree of involvement in rutting behavior

Abstract

Background In polygynous mammals, signalling may play a decisive role in mating behavior, mediating the intensity of male fights and female mate choice. During the rutting season, male red deer may show a visible dark patch in their ventral fur. Recently, this patch has been suggested to act as a flexible sexual signal, due to its relationships with other variables such as age, body size, antler development, volatile compounds, or the competitive environment. The analysis of fur pigmentation at the ventral patch suggests that this might also visually indicate the male intrinsic predisposition to take part in mating competition. Results To assess the possible role of this trait as a communicative signal related to mate competition, we used red deer behavioral observations during the rut in Doñana National Park (Spain) to examine the link between the degree of expression of the dark ventral patch and the rutting activity (assessed from both intra-and-inter-sexual behaviors). Consistent with our predictions, we found in a field study that males with large dark patches showed a higher frequency of rutting behaviors (mainly roaring and flehmen), more interactions with females, and attained larger harem sizes. Conclusions The dark ventral patch was a better predictor of male behavior than antler tines or territory holding, thus standing as a short-term indicator of male willingness to invest in mating competition.

Blinking as a measurement of group vigilance in red deerCervus elaphusand fallow deerDama dama

“…We observed that blink rate in both species decreased as group size increased. The data for this study was collected between February and May, and as a result, individuals could be displaying residual stress and therefore heightened vigilance as a result of the intense male interactions that occur during the rut [30,39,40], further seen with the reduced rate seen in male red deer. In mixed-sex groups, similar to the group observed in this study, vigilance was observed to not decrease as group size increased in Pere David's deer Elaphurus davidianus [40], which the authors attributed to the threatening nature of males during the rut.…”

Alternative Strategy to Improve the Conservation of Javan Deer in Pangandaran Nature Reserve, West Java, Indonesia

“…Javan deer also performed minor seasonal behaviours, for example, rutting. Rutting or mating behaviour would be fighting among adult males (Powell & Evans 2019;de la Peña et al 2021).…”

Plastic sex-trait modulation by differential gene expression according to social environment in male red deer

“…The dark ventral patch is a quality signal that conveys information about the mating effort during the rut [19,22]. Males with larger patches are more involved in the rut and achieve higher mating success than males with small patches [21]. Unlike antlers, which are produced several months before the starting of the rutting season, the ventral patch may be more modulable in the short term [22].…”

“…The mechanism suggested here for a exible trait development and associated behavioral display [21] represents a rare example of adaptive regulation based on gene expression.…”

“…In addition, it is known that under stress conditions, TH is regulated by enzyme induction at the transcriptional level [55]. A sexually competitive situation in red deer entails high stress conditions [21], which suggests that competitive stress might be a potential mechanism triggering gene expression related to the development of traits used in competition. In this sense, experiencing competition and the stress-related conditions might upregulate TH gene expression.…”