Atypical for northern ungulates, energy metabolism is lowest during summer in female wild boars (Sus scrofa)

Abstract

Typically, large ungulates show a single seasonal peak of heart rate, a proxy of energy expenditure, in early summer. Different to other large ungulates, wild boar females had peak heart rates early in the year (at ~ April, 1), which likely indicates high costs of reproduction. This peak was followed by a trough over summer and a secondary summit in autumn/early winter, which coincided with the mast seeding of oak trees and the mating season. Wild boars counteracted the effects of cold temperatures by decreasing subcutaneous body temperature by peripheral vasoconstriction. They also passively gained solar radiation energy by basking in the sun. However, the shape of the seasonal rhythm in HR indicates that it was apparently not primarily caused by thermoregulatory costs but by the costs of reproduction. Wild boar farrow early in the year, visible in high HRs and sudden changes in intraperitoneal body temperature of females. Arguably, a prerequisite for this early reproduction as well as for high energy metabolism over winter is the broad variety of food consumed by this species, i.e., the omnivorous lifestyle. Extremely warm and dry summers, as experienced during the study years (2017, 2018), may increasingly become a bottleneck for food intake of wild boar.

One Health challenges for pig reproduction

“…However, recent climatic challenges due to dry and hot summer months, with effects on food availability, were seen as a current bottleneck for life and reproduction of this species, rather than ambient temperature per se (Ruf et al, 2021). The present European/ American domestic pig breeds, however, show a very narrow zone of thermal comfort (Table 1).…”

“…aRemarks regarding growing and gestating pigs according to Robbins (2021), lactating sow according to Vilas Boas Ribeiro et al (2018) and wild boars according to Ruf et al (2021). …”

“…the ancestor of the present pig breeds, is a distinctive seasonal breeder living in the various corners of the globe and shows a high degree of resilience in a multitude of environmental conditions, including notably high and low temperatures (Mauget, 1982). In a recent study in Central Europe, an average ambient temperature of 10°C with an annual variation between −10°C and +30°C was not considered a physiological constraint for this species (Ruf et al, 2021).…”

Providing baseline data for conservation–Heart rate monitoring in captive scimitar-horned oryx

“…Long-term heart rate patterns in mammals are closely tied to changes in metabolic rate as the result of seasonal variation in ambient temperature (Arnold et al, 2004;Arnold et al, 2006;Arnold, 2020), activity (Theil et al, 2004;Graesli et al, 2020b), food availability and nutrition (Arnold et al, 2004;Turbill et al, 2011;Arnold et al, 2018;Arnold, 2020), and reproduction (Arnold et al, 2004;Wascher et al, 2018;Ruf et al, 2021). These patterns are often overlaid, and sometimes masked, by physiological responses to other stressors, mainly intra-and inter-species interactions (e.g., dominance hierarchies, competition, predator avoidance; Chabot et al, 1996;Turbill et al, 2013), extreme environmental events (e.g., hard winters, heat; Das et al, 2016;Arnold et al, 2018), and humancaused disturbance (e.g., roads, hunting; Laske et al, 2011;Ditmer et al, 2015a;Ditmer et al, 2015b;Støen et al, 2015;Graesli et al, 2020a).…”

Biology of Coital Behavior: Looking Through the Lens of Mathematical Genomics

“…We had further grouped these organisms in terms of their class, order and coital behaviour (Figure 1). The mating behavioral pattern of these species were obtained from websites and articles Animal Diversity Web, Primate Info Net, [31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,64,70,71,72,73,74,75,76,77,78,79,...…”