Roe deer Capreolus capreolus fawns and mowing ‐ mortality rates and countermeasures

Abstract

Besides red fox Vulpes vulpes predation, mowing is probably the most important mortality factor for roe deer Capreolus capreolus neonates in areas of intensive agriculture. Using radio‐transmitters on roe deer neonates in south‐central Sweden, I estimated mortality caused by mowing and tested and evaluated a traditional method to decrease this kind of mortality. During 1997–1999 fawn mortality caused by mowing was estimated at 25–44% of the yearly recruitment. Fawns were at risk for at least up to one month of age. The method tested uses scaring devices made of plastic sacks that are set out before mowing. The idea is that this will prevent female roe deer from placing their fawns in the field and make them remove the ones already hiding there. Black plastic sacks were attached to approximately 2‐m long poles and placed in hay fields where marked fawns were bedded. During 1998–1999,14 separate experiments were performed. Out of 22 fawns bedded in the vicinity of sacks, 18 were removed the day after the sacks were set out and three were removed on the second day. The fawns were always removed to another field or habitat patch. Fawns in the experiments were removed to a higher degree than fawns used as a control, and they were moved longer distances than both control fawns and the distances moved during the days before the experiment. The results imply that the use of this method is effective in reducing the mortality of roe deer fawns.

Use of unmanned aerial system to assess wildlife (Sus scrofa) damage to crops (Zea mays)

“…UAS can also support thermal imaging, allowing the detection of deer fawns in grasslands (Christiansen et al 2014;Israel 2011) where they are at high risk of mortality during mowing operations (Jarnemo 2002). However, to our knowledge the use of UAS for the specific estimation of crop damage by ungulates has not been assessed.…”

A Uav-Based Roe Deer Fawn Detection System

“…Roe deer (capreolus capreolus) fawns are classic hiders (Espmark, 1969) and therefore frequent victims of agricultural accidents. They lie hidden in seclusion for most of the time during their first two months of life (Jarnemo, 2002). The cultivated pasture farmland is a favored bedsite for the neonate roe deer, because it screens them from the predators' view.…”

“…Because of their innate instinct to remain motionless on the ground, they are often overlooked by farmers. About 25% of the newborn deers are killed during pasture mowing (Jarnemo, 2002). Beside animal welfare there is another reason for the importance to avoid these accidents.…”

Ranging behaviour and reproductive rate in the threatened population of roe deer in Gargano, South Italy

“…The importance of the loss of genetic variability on fertility of this population is unknown. Other factors which may determine early mortality of roe deer fawns are predation (the primary cause of first summer mortality in areas where predators occur, Linnell et al 1995;Jarnemo 2002), weather conditions (i.e. cold and wet) in the post-birth period (Wotschikowsky & Schwab 1994) and road kills .…”