The white-tailed deer has more than just a caudal flag

Anyone with an interest in ungulates knows that the white-tailed deer (Odocoileus virginianus) raises its tail, showing the white underside. However, what is not widely realised is how expansive, complex and versatile the demonstrations of alarm are in this species.

When the foraging white-tailed deer jerks up its head in routine vigilance, it tends to flick the tail each time before lowering the head. When it suspects the approach of a predator, it shows various combinations of 'foot-stamping', tail-flagging and alarm-sneezing. The forefeet are lifted high but not stamped hard, suggesting that the main message sent is olfactory, from the interdigital glands. The tail may be raised to a rigid horizontal position (see https://www.facebook.com/MPGWildlife/videos/753907188442406), and this seems to be a purely visual signal. Or sometimes the tail is flicked up synchronously with each alarm-sneeze, without any piloerection of white fur.

Variation in the repertoire thus depends on the pattern of movement of the tail and whether white fur is piloerected (flared) or not (https://www.youtube.com/watch?v=Bf1j33Ja1so and https://www.youtube.com/watch?v=zAVb_Jj1CC0 and https://www.youtube.com/watch?v=5fM9qlBsMYE). Sometimes the tail remains down but the long fur on the buttocks is piloerected as the animal stands in initial alarm (http://mtnhp.org/thumbnail/defaultGen.aspx?itemid=391827&maxWidth=1024&maxHeight=768 and https://www.olo-7.top/ProductDetail.aspx?iid=62999139&pr=27.99 and https://www.olo-7.top/ProductDetail.aspx?iid=57741456&pr=27.99 and third photo in https://www.mossyoak.com/our-obsession/blogs/deer/how-to-read-whitetail-body-language). As suspense builds, the animal may flick the tail up and down, without piloerection, while walking stiff-legged before running.

Once fleeing begins, the white fur on the underside of the tail and/or that on the buttocks may be piloerected (see https://www.olo-7.top/ProductDetail.aspx?iid=57741356&pr=22.99 and third photo in https://www.welcomewildlife.com/white-tailed-deer/ and https://wdfw.wa.gov/species-habitats/species/odocoileus-virginianus-leucurus). The tail may be wagged from side to side while erect and flared. Sometimes, the animal stots (https://www.flickr.com/photos/conradkuiper/40834012061 and second photo in https://owenslaterphotography.com/category/north-american-wildlife/mammals/white-tailed-deer/).

Erection of the tail and piloerection of the tail/buttocks tend to be most frequent in females and juveniles (https://www.flickr.com/photos/23326338@N04/8988960173/), and in open vegetation. Adult males sometimes tuck their tails in while fleeing, thus showing no caudal flag (https://fineartamerica.com/featured/high-flying-white-tail-deer-gordon-allen.html ); and this may tend to be when females are absent. The sexual difference in displays is consistent with the tendency for males to have relatively short tails and fur on the buttocks.

Posted on June 19, 2021 09:29 AM by milewski