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The aim of this study was to examine whether and how different odorants placed on the bodies of female mice, but having no reward value for the males, affect courtship and mating behaviour of male mice towards females in oestrus and thus emitting female pheromones. In this manner, certain consequences of concurrent activation of the main olfactory system and the vomeronasal system were investigated. Four different odorants (white musk, lavender, peppermint and valerian) were used for swabbing female mice in oestrus. Using a total of 160 sexually naive outbred mice of both sexes, divided for each of 4 odorants into controls (not swabbed with odorant) and two experimental groups, in the experimental group I the females observed previously as controls were swabbed with one of the 4 odorants, while in the experimental group II, new naive females were swabbed with one of the 4 odorants. The females were observed in individual cages for 30 min. each, together with a respective sexually naive male. The latency between introduction of a male into a cage with a previously swabbed female and initiation of courtship and mating behaviours by males (sniffing, circling, misdirected mounting, copulation failures, successful copulation) was recorded. Latency to the occurrence of all sexual behaviours was significantly longer in experimental groups compared to controls. Latency to initiation of courtship behaviour, especially sniffing and circling, was shorter towards females swabbed with peppermint odour than for other odorants, indicating no aversion to this odour. However, the peppermint odour completely inhibited copulation. It is concluded that alien volatile odours with no reward value nevertheless exert differentiated suppressing effects on female mice pheromones inducing courtship and mating behaviour. Thus, it is hypothesized that the activation of the main olfactory system suppresses the accessory vomeronasal system.
The behaviour of active male roe deerCapreolus capreolus Linnaeus, 1758 was studied in a wild population on Storfosna island (Norway), during the pre-territorial and territorial seasons (February–August) of 1994. Observed behaviours were grouped in seven categories (mating, aggression, display, marking, vigilance, moving and maintenance), and the proportion of time spent in each behaviour by three age classes (yearlings, subadults and adults) was compared. Time spent in each behaviour varied significantly between months for all male age classes. From February to August, time spent in maintenance decreased, while time spent in vigilance increased. The time spent in mating increased both in adult and subadults but did not vary significantly for yearlings throughout the months. When comparing age classes within a month, there were no significant differences in time spent in each behaviour. Surprisingly, adult territorial males did not invest significantly more time in mating, with respect to yearlings and subadults. This may be consistent with the oligogynous mating system of roe deer, in which the reproductive success is divided amongst several years and their territoriality, which could be a tactic to reduce the competition for mating.
From late April to the second 10-day period of June 1994—1999, in 76 unmated males the time-budget was measured during 304 hours in a 6.6 km2 area of mature mixed and coniferous forests near Moscow. In 1999, territorial males were counted at least once per pentade throughout the breeding season in a 35 ha plot with 180 nest-boxes. Dark (grades 2-3 on Drost's scale) and pale (grades 5-7) males had similar levels of singing activity, but in cold weather the former had higher song rates than the latter. The singing activity of all the males was relatively low at the beginning of the season (by the mid-May). Dark males sang mainly from open perches (67.6% of songs, compared with 23.2% for pale males). In dark males visual stimulation compensated for the relatively low acoustic activity in early spring when trees were still lacking leaves. The immediate vicinities of nest-boxes occupied by dark males were visited by females significantly more frequently than those of pale ones.
The name Deroceras panormitanum is generally applied to a terrestrial slug that has spread worldwide and can be a pest; earlier this tramp species had been called Deroceras caruanae. Neither name is appropriate. The taxonomic descriptions apply to a species from Sicily and Malta. This true D. panormitanum and the tramp species are distinct in morphology and mating behaviour. For instance, the penial caecum of D. panormitanum is more pointed, everting faster at copulation. The size of the penial lobe varies considerably In preserved specimens but is always prominent at copulation. D. panormitanum is distinct from the Maltese endemic Deroceras golcheri, but a phylogeny based on mtDNA COI sequences implies that they are more closely related than is the tramp species. D. golcheri has a still closer counterpart on Sicily, but we leave the taxonomy of this “species X” unresolved. In interspecific crosses, D. panormitanum may transfer sperm to the partner’s sarcobelum whereas the partner fails to evert its penis (D. golcheri) or to transfer sperm (the tramp species). Names previously applied to the tramp species originally referred to D. panormitanum or are otherwise invalid, so it is here formally redescribed as D. invadens. Deroceras giustianum Wiktor, 1998 is synonymised with D. panormitanum.
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