No evidence that horn trimming affects white rhinoceros horn use during comfort behaviour and resource access

Abstract

Rhino species use their horns in social interactions but also when accessing resources, rubbing and in interspecific defence. The current poaching crisis has seen southern white rhinos (Ceratotherium simum simum) increasingly dehorned as a conservation management practise, but few studies have evaluated whether the procedure has any behavioural effects. This study sought to document and describe horn-contingent behaviours during resource access, wallowing and rubbing in freeranging white rhinos and establish whether dehorning, also known as horn trimming, impacts on their frequency or function. Data were collected through camera trapping and field observations at two sites in South Africa. The results provide no evidence that dehorning disrupts digging behaviours during mineral consumption or wallowing and suggests that dehorning is unlikely to have a strong biological impact on resource access. Furthermore, the frequency of horn-rubbing behaviours did not appear to be influenced by levels of horn growth. This suggests the procedure has a limited impact on these aspects of the species’ ecology and provides support that dehorning can be employed as a management tool to reduce poaching in freeranging populations of white rhino.

Dehorning impacts white rhinoceros behaviour less than social events: evidence from Botswana

“…Similar observations were made by Penny et al. (2021) who recorded only two horn rubbing events by horned rhinos in contrast to 31 horn rubbing events by dehorned rhinos. Thus, the effects of dehorning might not be detectable through the rare occurrence of the specific behaviours that involve the horn.…”

“…However, Penny et al. (2021) found no effects of dehorning on rubbing and wallowing and Penny (2019) noted no differences in affiliative and aggressive behaviours between horned and dehorned populations. On the other hand, in a study where rhinos were dehorned because of high aggression and observed before and after dehorning, the number of fights between males was reduced by 68% after dehorning (Patton et al., 2018).…”

“…Previous studies found no effects of dehorning on rhino survival and reproduction rates (Chimes et al., 2022; du Toit & Anderson, 2013; Kock & Atkinson, 1993; Lindeque & Erb, 1995; Penny, White, MacTavish, MacTavish, et al., 2020) and hormonal stress responses to dehorning are only short‐term (Badenhorst et al., 2016; Penny, White, MacTavish, Scott, & Pernetta, 2020). Behaviour studies mostly focussed on specific behaviours such as fighting (Patton et al., 2018) and horn rubbing (Penny et al., 2021). With this study, we aim to add an immediate before‐after comparison analysing all occurring rhino daytime behaviours, thereby responding to calls for such research, especially for white rhinos (Badenhorst et al., 2016; du Toit & Anderson, 2013; Lindsey & Taylor, 2011; Patton et al., 2018).…”

Factors affecting the behavior of captive white rhinoceros (Ceratotherium simum) and the accuracy of ad‐hoc keeper data

“…As expected, there were also differences between datasets for uncommon behaviors between detailed researcher and ad hoc keeper data. Horn rubbing (which is known to be rare even for wild rhino and only apparent in detailed datasets that either involve numerous scan samples over a prolonged period or continuous sampling (Penny et al, 2021), was recorded as a rare behavior by researchers but absent from keeper data. This highlights the importance of having detailed data with short times between scans, as found previously by Orban et al (2016) when recording rare behaviors such as pacing (1.4% prevalence) in Giraffe.…”

Research on illegal access behavior control of heterogeneous cloud resources based on lifecycle characteristics

“…Firstly, the lifecycle of the heterogeneous cloud resource platform is divided, and the feature vector is extracted from different lifecycle stages, and the vector is incorporated into the key to generate the public key and the key as the main medium for the user to access the heterogeneous cloud resources. Then encrypt the user access operation and the transmission data of heterogeneous cloud resources [11]. When the user applies for access operation request to the authorization center, the heterogeneous cloud resource transmission data is encrypted in two layers.…”