We have summarized two scientific articles where they analyze the scent of giraffes. Both articles relate to the research of Wood and Weldon and therefore contains much of the same content and conclusions. We have also looked up other articles about the same topic and the ones we found were also based on Wood and Weldons findings and theories.
Summary of “The scent of the reticulated giraffe” by William F. Wood and Paul J. Weldon
www.elsevier.com/locate/biochemsyseco:
Biochemical Systematics and Ecology 30 (2002) 913–917
Giraffes emit a very distinguished scent. Some scientists analysed hair samples from selected individuals to find the cause of the smell, its content and possible function.
They started with collecting hair from two adult animals, Giraffa camelopardalis reticulata, one male and one female. Both were born and bred in captivity. The samples were collected by scraping the edge of glass slides against selected areas of the animal to avoid contamination by urine and/or faeces. The samples were stored frozen and then extracted with dichlormethane for analysis. To identify the different components a gas chromatography-mass spectrometer was used.
In both the female and male giraffes eleven volatile compounds were found. Among these were one alkane, four aldehydes, a phenol, two alkaloids, two carboxylic acids and one steroid. It was also found an androstanon, 3,5-androstadien-17-one, that is not previously known from a natural source. These compounds have moderate antimicrobial activity, but together they act synergetically and therefore more powerful.
The strong scent of the giraffes are caused by the two alkaloids, indole and 3-methylindole. These compounds are often used in human perfumes. Indole also inhibits Staphylococcus aureus, Streptococcus mutans, Trichophyton mentagrophytes and Propionibacterium acnes.
The two carboxylic acids, Tetradecanoic and Hexadecanoic acids, prevent Microsporum canis.
Another possible function of these compounds is to repel ectoparasitic arthropods. They might also have an effect on Hematophagous arthropods, but none of these qualities were further examined here.
Summary of "stinky, yet sexy" by Rachel Sheremeta Pepling, C&EN Washington
http://pubs.acs.org/cen/science/8127/8127giraffes.html
by Ingrid H. Knustad and Anne Nessa
It has been long known that giaffes emits a certain scent, described as both pleasant and unpleasant, but was first analyzed chemically by an organic chemistry professor; William F. Wood. He had long been investigating the composition of different animal species, including skunks, deers, antilopes and snakes.
Wood described the giraffes odour as «fecal-like» up close, but more «pleasent» from distance. He found that the main sources of the smell was indole and 3-methylindole. These compunds have a characteristic foul scent at high concentrations, but is more agreeable in lower concentrations. Together with Paul J. Weldon he later found that these indole compounds were the source of the fetid smell emitting from the reticulated giraffes.
Hair samples from both female and male giraffes were collected from neck, shoulder and back. To analyze dichloromethane they used gas chromatography-mass spectrometry.
Wood and Weldon found more compounds, in addition to indole and 3-methylindole, that also contributed to the smell; octane, benzaldehyd, heptanal, octanal, nonanal, p-cresol, tetradecanoic acid, hexadecanoic acid and 3,4-androstadien-17-one. Several of these substances are known to have an antimicrobial effect and contribute to repel microorganisms and ectoparasites from the animal. The results also indicated that the male giraffes had a higher content of the odoriferous substances than the females. Wood suggests that females are attracted to the smell and that «stinky males make better fathers».
It is still unknown exactly how these substances are produced, but oil and sweat glands in the skin are the suspected sources.
References:
The scent of the reticulated giraffe (Giraffa camelopardalis reticulata)
by William F. Wood, Paul J. Weldon, www.elsevier.com/locate/biochemsyseco:Biochemical Systematics and Ecology 30 (2002) 913–917
Stinky, yet sexy
by Rachel Sheremeta Pepling, C&EN Washington, http://pubs.acs.org/cen/science/8127/8127giraffes.html