Do Boars Compensate for Hunting with Higher Reproductive Hormones?

A poster divided in eight blocks entitled “Do boars compensate for hunting with higher reproductive hormones?”.

• First block has a wild boar and ten piglets. The written content is: Do boars compensate for hunting with higher reproductive hormones?
• Second block has two wild boars in a maize field. The written content is: Over the past 40 years, the substantial population increases in wild boar (Sus scrofa) in agricultural, urban and suburban areas have intensified human-boar conflicts worldwide.
• Third block has a wild boar crossing a road between two cars. The written content is: These conflicts have led to elevated economic costs due to disease spill over into livestock and humans, as well as damage to gardens and infrastructure in urban areas and to agricultural crops.
• Fourth block has some piles of wild boars’ carcasses, two hunters, and a hunter house in a forest. The written content is: To minimize conflict with wild boars, the most common and widespread management tool applied throughout the world is hunting. More than 3 million wild boars are hunted every year in Europe. Furthermore, the number of hunted wild boars is constantly rising. Previous research has shown that high hunting pressure stimulates earlier sexual maturity leading juvenile females to reproduce earlier, the mechanism that underlies this earlier sexual maturity under high hunting pressure has not been examined to date.
• Fifth block has a map of Israel with a square highlighting the Study Area – Carmel Coastal Mountain Range, Northern Israel. The written content is:
  • Main predator; wolf, extinct.
  • Hunting is dominant exogenous stress factor.
  • Region exhibits highest hunting pressure in Israel.
  •  Highest reported number of human-wild boar conflicts in agricultural landscapes.

• Sixth block has an envelope and a wild boar in the back. In the envelope is written: date, age, location, sex: F or M, alone or group. The written content is: In this study, researchers investigated the effects of high and low hunting pressures and social structure on stress hormones (cortisol) and reproductive hormones (progesterone) of female wild boars in Northern Israel. They provided paper envelopes to rangers and expert hunters from Israel Nature and Parks Authority (INPA) to collect hair samples of hunted wild boars from fresh carcasses immediately after boars were shot.

• Seventh block has a hand with gloves pipetting samples in a 96-well plate. A table showing that the number of progesterone samples under high hunting pressure was 78 and 17 when there was low hunting pressure. The number of cortisol samples under high hunting pressure was 81 while low hunting pressure was 19. The written content is: In the laboratory, researchers extracted and quantified cortisol and progesterone from the hair of female wild boars. They did statistical analysis of hormonal data to compare differences in the cortisol and progesterone of female wild boars between high and low hunting pressure areas.
• Eighth block has a table about The Findings in female wild boars. Under high hunting pressure, there is a bar of progesterone almost full. While under low hunting pressure, there is a bar of progesterone almost empty. The same profile is represented when wild boars were found in a group or solitary, respectively. The written content is: These elevations in reproductive hormones that were associated with high hunting pressure may lead to a higher reproductive potential in female wild boars. There were no significant differences in cortisol levels between high and low hunting pressure areas. The results suggest that the reproductive hormonal response may be one of the factors leading to the rapid wild boars population growth worldwide, despite the high hunting pressure they are exposed to.

Footnote has the official SEB logo and the written content is: Paper: Davidson et al., Do boars compensate for hunting with higher reproductive hormones?, Conservation Physiology (2021). Artist: Disha Chauhan [www.thevisualstoriesstudio.com]. This project is funded through an outreach grant awarded to Ravindra Palavalli-Nettimi and Krishna Anujan.