Odor familiarity and female preferences for males in a threatened primate, the pygmy loris Nycticebus pygmaeus : applications for genetic management of small populations

Abstract

Here we use sexual selection theory to develop a logistically simple, yet effective, method for the manipulation of female reproductive behavior for conservation goals. Mate choice leading to nonrandom mating patterns can exacerbate the loss of genetic diversity in small populations. On theoretical grounds, females should choose high-quality mates. A prediction stemming from chemical communication theory is that competitive males will be better able to saturate an area with scent marks. If this is true, females should mate preferentially with males whose odors they encounter most frequently. We tested this hypothesis with the pygmy loris, Nycticebus pygmaeus, a threatened and poorly studied nocturnal prosimian. For several weeks females were exposed repeatedly to the urine from a particular male, and were then allowed to choose between a male whose odors were familiar and one whose odors were novel. Females showed an unusually strong preference for the familiar-odor male, as indicated by several behavioral measures of mate preference. Conservation managers can use this method as a tool to obtain reproductive pairings that will maximize genetic compatibility and diversity. For example, unsuccessful males may be given the opportunity to reproduce. In captive populations, studbook managers often select pairs in order to optimize outbreeding, but these selected pairings may not coincide with the preferences of the individual animals involved. Although several authors have made theoretical arguments for manipulating mate choice for conservation, this is a novel test of a proximate mechanism that can be manipulated, cultivating applications rather than mere implications.

Olfactory communication and the importance of different odour sources in the ferret (Mustela putorius f. furo)

“…In the same way, Poole (1974) demonstrated that males were more interested in unfamiliar females than familiar ones in a breeding context. However, in these two last experiences, the familiarisation process was different from our experience, since familiar individuals lived in adjacent cages 3 months before the experiment (Thom et al 2004) or were cage-mates (Poole 1974 Randall, 1991), but also in Primates (Nycticebus pygmaeus, Fisher et al, 2003). In the case of the more solitary species of Mustelids, such as the polecat, the stoat or the ferret, olfactory familiarity between neighbouring male and female by the anal scent-marking activities performed all year and distributed all over the home range (Clapperton 1989) may play the same role.…”

Reproductive competition and fecal testosterone in wild male giant pandas (Ailuropoda melanoleuca)

“…In small populations, understanding the mating system is of vital importance for conservation because of the negative impacts reproductive skew can have on effective population size and population viability (Anthony and Blumstein 2000). While evaluation of reproductive skew is best obtained from genetic studies, it is important to understand the underlying behavioral processes so that skew can be managed, when appropriate (Wedekind 2002;Fisher et al 2003). Our findings contribute to this goal, demonstrating the significance of male reproductive competition in pandas and how such competition affects reproductive outcomes.…”

Giant pandas attend to androgen-related variation in male bleats

“…As a result, it may be possible to enhance sexual motivation and/or guide mate choice decisions by presenting females with re-synthesised bleats representing high androgen males, encouraging them to mate with individuals that are deemed appropriate by conservation managers. Experimental manipulation of mate choice has been conducted successfully on other mammals using chemical signals (Fisher et al 2003;Roberts and Gosling 2004) and by supplementing natural communication in this way, conservation managers could include under-represented males in the breeding programme and thus, facilitate the goals of genetic management.…”