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A new study investigates the shared genetic similarities in the individual odours of four sibling species of subterranean mole-rats.

In this investigation, the authors used habituation techniques to explore similarities and differences in the qualities of individual odors from hamsters. In Experiment 1, male Turkish hamsters (Mesocricetus brandti) treated flank-gland odors of 2 males from I litter as similar compared with the odor of a male from another litter, whether the odor donors were familiar or unfamiliar. At the same time, the Turkish hamsters discriminated between the subtle differences in the individual odors of their familiar brothers. In Experiment 2, male Turkish and golden hamsters (Mesocricetus auratus) treated the flank-gland odors of 2 unfamiliar, unrelated conspecifics as similar compared with the flank odor of a heterospecific individual. The results suggest that similarities in individual odors are related to genetic similarity of the odor donors. These similarities could provide a basis for different types of social recognition, including kin and species recognition.

Two scent marking behavior of golden hamsters, namely flank marking and vaginal marking, were studied to elucidate kin recognition of odor cues. The results provided evidence that scent-marking for both sexes may be attributed more to odors from nonsiblings compared to odors from siblings. Moreover, marking caused by odors from unrelated individuals was not influenced by familiarity through common rearing. Similarly, the absence of familiarity with their siblings because of separate rearing did not cause any change in marking due to odors from close kin.

Kin recognition in golden hamsters, Mesocricetus auratus, was investigated by studying the discrimination of flank gland secretion odor among siblings, half-siblings and unrelated individuals. Results indicate that individual golden hamsters discriminate the odors from siblings reared with them but failed to discriminate that of half-siblings reared separately and that of unrelated individuals. The discrimination of siblings through odor recognition may have been brought about by close association during rearing.

The qualitative and quantitative responses to chemosensory stimuli is analyzed in the subterranean mole rat. The urine is tested by the response of smelling and touching odors. Mole rats behave differently towards smelling and touching of their urine. The mole rat neglects the urine after nose contact and not by smelling. The odor of urine is tested by the nasal contact. The mole rats avoid the urine of the potential predators and behave differently towards that of a non-competitor rodent.

Research is presented concerning the use of cross-fostering and scent-marking tests to determine the behavioral mechanisms which influence the differential treatment given by animals to related and non-related individuals.

Reproductive isolation is a fundamental part of speciation processes. The establishing of reproductive isolation in speciation with ongoing gene flow is unlikely unless divergent selection is overruling gene flow homogenization, which seems to be most effective when combined with non-random mating. We explored whether assortative mating via female mate-choice contributes to reproductive isolation between populations of the blind mole rat Spalax galili inhabiting abutting rendzina-soil and basaltic-soil areas in a microsite similar to one in which ecological speciation has recently been suggested as a possible model driving the divergence between mole rats from the different soils. We performed T-maze experiments with mole rats captured in early winter (i.e. premating season) of 2 consecutive years and found no existence of females from either soil type preferring males originating from their own soils based on olfactory cues. In addition, inconsistent preferences for males based on soil type in tests with females that were tested twice were found. This suggests that female mate choice based on olfactory cues is unlikely to be an isolating barrier between the mole rats from the two soil types. In such circumstances, ecological speciation would have to occur through other mechanisms of divergent selection, such as reproductive isolation due to strong habitat (soil) preferences, vocalisation or seismic communication. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2006.04.004 Byline: Josephine Todrank, Giora Heth Author Affiliation: Institute of Evolution, University of Haifa, Israel Article History: Received 25 June 2005; Revised 1 July 2005; Accepted 5 April 2006 Article Note: (miscellaneous) MS. number: AF-30

Mound-building miceMus spicilegusexhibit life-history traits that are unique among theMusspecies complex, such as the cooperative mound-building behaviour that gives the species its common name. In this and other socially coordinated activities, such as those associated with reproduction, these mice should be able to recognize individuals (via discrimination based on kinship, population and species) to mediate their interactions. Our previous studies have provided evidence of population and species recognition inM. spicilegus. The aims of the present study were: (i) to study associations of mice during their reproductive period (in outdoor enclosures), (ii) to investigate whether there is an influence of relatedness of females in these associations, (iii) to determine whether femaleM. spicilegusare able to make kin vs. non-kin discriminations, and (iv) to study certain neurobiological correlates of male–female bonds. Stable male–female associations were found in almost all the experimental groups, both those with unrelated and unfamiliar females and those with unfamiliar sisters. Kinship between females did not affect female associations in our enclosure experiment, but in our kin discrimination experiment females did distinguish between unfamiliar sisters and unfamiliar unrelated females. Shared kinship may not encourage cooperative rearing of pups but could enhance cooperation in building mounds where mice over-winter. Male–female associations could be based on a social bond, as hypothesized from previous laboratory experiments. This was substantiated in this study by increased olfactory bulbar neurogenesis in females that preferred (in two choice tests) their sexual partner 3 weeks after their first mating. Based on these results there is clear evidence to suggest that the mating system ofM. spicilegusis social monogamy. © 2005 The Linnean Society of London,Biological Journal of the Linnean Society, 2005,84, 323–334. [ABSTRACT FROM AUTHOR]