Self-anointing in animals
[1] The functions of self-anointing differ between species, but it may act as self-medication,[2] repel parasites, provide camouflage, aid in communication, or make the animal poisonous.
It is thought to have multiple functions including hygiene, thermoregulation and response to irritation from biting ectoparasites (such as ticks and botfly).
[4][5] Wild wedge-capped capuchin monkeys (Cebus olivaceus) self-anoint with millipedes (Orthoporus dorsovittatus).
The anointment must also involve risks, since benzoquinones are toxic and carcinogenic; however, it is likely that for capuchins, the immediate benefits of self-anointment outweigh the long-term costs.
However, contrary data from captive animals there no difference in the range of sociality for anointing between Cebus and Sapajus in the wild.
[8] Capuchin monkeys at the Edinburgh Zoo rub onions and limes on their skin and into their fur as an antiseptic and insect repellent.
[9][10] White-faced capuchin monkeys sometimes anoint their bodies with mud and plant matter, a natural insect repellent.
With their heads and faces slathered in this mixture, these highly social primates lose their ability to recognise each other and previously friendly monkeys can become fighting foes.
There was a lack of correlation between the occurrence of self-anointing and time of day, season of the year, ambient temperature or humidity, indicating that this behaviour does not function in repelling insects and/or mitigating topical skin infections in this species.
[22] Sambar stags will wallow and dig their antlers in urine soaked soil and then rub against tree trunks.
[23][24] A stag will also mark himself by spraying urine directly in the face with a highly mobile penis, which is often erect during rutting activities.
This type of urination is possibly an indicator of rank and physical condition,[42] and plays an important role in goat reproduction.
Domestic dogs often roll in odoriferous substances, choosing items such as cow manure, a road kill, or rotten fish.
[48] North American brown bears (Ursus arctos) make a paste of Osha roots (Ligusticum porteri) and saliva and rub it through their fur to repel insects or soothe bites.
This plant, locally known as bear root, contains 105 active compounds, such as coumarins that may repel insects when topically applied.
[2] The use of millipedes in self-anointing by birds has been reported for the strong-billed woodcreeper (Xiphocolaptes promeropirhyncus) in Belize, the little shrike-thrush (Colluricincla megarhyncha parvula) in Australia, the black-throated shrikebill (Clytorhynchus nigrogularis) and the jungle mynah (Acridotheres fuscus) in the Fiji Islands, the European robin (Erithacus rubecula) in England and the grey-winged trumpeter (Psophia crepitans) and the pale-winged trumpeter (P. leucoptera) in northern South America.
A common grackle picked one out, extended its left wing and rubbed the mothball up and down the length of the shaft of each of the secondary feathers.
These can act as an insecticide, miticide, fungicide, bactericide, or to make the insects edible by removing the distasteful acid.
Although it has been suggested that anting acts as a way of reducing feather parasites such as mites or in controlling fungi or bacteria, there has been little convincing support for any of the theories.
[51][52] Some cases of anting involved the use of millipedes or puss moth caterpillars, and these too are known to release powerful defensive chemicals.
[53] Another suggested function, based on observation of blue jays, is that the bird makes the insects edible, by discharging the harmful acid onto their feathers.
The metabolic products of the ants may soothe skin irritated by unusually rapid feather replacement.
Twenty-four of 35 owl monkeys were observed to socially anoint, including all ages and both sexes, in bouts which ranged from 5–322 seconds.
