Reproductive characteristics in female Swedish moose (Alces alces), with emphasis on puberty, timing of oestrus, and mating

Physiological and behavioural responses of moose to hunting with dogs

Optimal management of hunted species requires an understanding of the impacts of hunting on both individual animal and population levels. Recent technological advancements in biologging enable us to obtain increasingly detailed information from free-ranging animals, covering longer periods of time, and providing the data needed to assess such impacts. In Sweden, more than 80 000 moose are harvested annually, mostly hunted with the use of baying dogs. The effects of this hunting method on animal welfare and stress are understudied. Here, we evaluated 6 real and 17 experimental hunting approaches with baying dogs [wearing global positioning system (GPS) collars] on 8 adult female moose equipped with ruminal temperature loggers, subcutaneous heart rate (HR) loggers and GPS collars with accelerometers. The obtained data were used to analyse the behavioural and physiological responses of moose to hunting with dogs. Successful experimental approaches (moose and dog were within 240 m for >10 min) resulted in higher maximum body temperature (T_b, 0.88°C higher) and a mean increase in HR of 24 bpm in moose at the day of the approach compared to the day after. The moose rested on average >90 min longer the day after the approach compared to the day of the approach. The moose travelled on average 4.2 km longer and had a 1.3 m/s higher maximum speed the day of the approach compared to the day after. Our results demonstrate that hunting with dogs increase moose energy expenditure and resting time (and consequently decrease time available for foraging) on an individual level. This could possibly affect body condition and reproduction rates if the hunting disturbances occur frequently.

Puberty in female wild boar (Sus scrofa) in Sweden

Background

Since the re-appearance of wild boars in Sweden in the 1970s, the population has increased. Besides having large litter sizes, puberty at an early age is considered as an important factor contributing to the high reproductive potential of wild boar. Although controversial, supplemental feeding is applied to varying extent throughout the wild boar range in Sweden, and its effect on wild boar reproduction is debated. The aim of this study was to investigate the proportion of post-pubertal female wild boar gilts in a population subjected to supplemental feeding, in relation to age, weight, and season. Also, the effect of another definition of puberty (based upon follicular size) on the outcome of the proportion of female wild boar gilts considered to be able to reproduce in a population was illustrated. Between Jan 2013 and Dec 2015 reproductive organs from 592 female wild boars, were collected. Ovaries and uterus were macroscopically examined, and reproductive stage was determined by the presence of ovarian structures and uterus characteristics. Age was estimated using tooth eruption and tooth replacement, and weight was noted. A subset of 175 female wild boars, aged 5–15 months, was included in this study. An animal was considered to be post-pubertal if the ovaries contained one or more corpora lutea (CL) or if the uterus showed signs of previous pregnancy (presence of enlarged blood vessels in the cut surface between the mesometric ligament and the uterus).

Results

In total, 29 (16.6 %) animals were classified as post-pubertal. Field dressed weight ranged from 20.6 to 65.3 kg. Season, weight, and age class significantly influenced the variation in proportion of post-pubertal females. Post-pubertal animals were found in autumn, winter, and spring, but not in the summer season. Another definition of puberty, based on follicle size, lead to different result on proportions of animals considered to have passed puberty.

Conclusions

Season, weight, and age significantly influenced the variation in proportion of post-pubertal wild boar females. The proportion of post-pubertal animals increased with age and weight. However, weight is probably a better proxy for puberty than age group is. The proportion of post-pubertal females also increased from summer to spring suggesting a seasonal reproductive pattern. Different definitions of puberty will result in various outcomes, which high-lights the importance of using adequate definition of puberty.