Urinary volatile profiles of pine vole,Microtus pinetorum,and their endocrine dependency

The volatile compounds identified by combined gas chromatography-mass spectrometry inMicrotus pinetorum urine include alcohols, aldehydes, hydrocarbons, ketones, nitriles, and pyrazines. Several lactone derivatives were found to be characteristic urinary substances of this species. Ovariectomy depressed concentrations of only five out of a great number of profile constituents. Elevating estrogen levels (by exposing females to male-soiled bedding or treating them with estradiol) tends to depress the urinary concentration of a number of selected volatiles. Estrogen implantation provoked a periodic increase in the level of three compounds (nonanal, benzal-dehyde, and an unidentified substance). The volatile profile of castrate male urine was similar to that of intact male urine. Female urine contained -octanoic lactone and two pyrazine derivatives in higher concentrations andp-methyI-propenylbenzene in a lower concentration, when compared to male urine. No qualitative differences between the urinary profiles of males and females were observed.     

Effect of birch (Betula pendula) bark and food protein level on root voles (Microtus oeconomus): I. food consumption,growth, and mortality

The effect of protein and birch bark powder (BBP) content of forage on food consumption and growth of root voles (Microtus oeconomus) was studied by feeding young voles with eight different diets for two weeks. Voles ate more when the protein content of forage was moderate (6%) or low (3%), and when BBP was added to the diets, as compared to a high (12%) protein diet without BBP addition. On high and moderate protein diets voles gained weight, whereas on low protein diets they lost weight. Addition of BBP caused reduced growth or weight loss. Consuming a diet with moderate (6%) protein and high BBP (20%) resulted in high mortality (9 of 10 died). These results show that root voles need at least 6% protein for growth and that the effect of birch bark depends on the protein content of the forage.     

Three highly odorous metabolites from an actinomycete: 2-Isopropyl-3-methoxy-pyrazine,methylisoborneol, and geosmin

The highly odorous metabolites isopropylmethoxypyrazine, methylisoborneol, and geosmin were identified from aStreptomyces sp. Their role in the odor pollution of water is discussed. 2-Isopropyl-3-methoxypyrazine has not been reported previously from actinomycetes.     

Reproduction and Urine Marking in Laboratory Groups of Female Common Voles Microtus arvalis

In laboratory groups of common voles, Microtus arvalis, consisting of one mother, two of her daughters and one male, mainly the mother reproduced. The three females spent most of the time in close body contact. By using a modified method of coloring the urine of the three females by nonmetabolizable, nontoxic dyes, we found that mothers display a higher urine marking intensity than their daughters, and urine marks from the mother were distributed more frequently than those from the daughters. The results suggest that both pheromonal and behavioral mechanisms are involved in the regulation of reproduction in matriarchal groups of common voles.     

Effect of volatiles collected above fecal pellets on behavior of the rabbit,Oryctolagus cuniculus,tested in an experimental chamber

The fecal pellets of rabbits,Oryctolagus cuniculus, are coated with secretion from the anal gland, the odor from which functions as a territorial marker. The total volatiles collected from above fecal pellets and three different fractions prepared by washing the volatiles through either distilled water, 1 M sodium hydroxide, or 1 M hydrochloric acid were tested for their effect on the territorial confidence of individual animals. Tests were based on the neutral pen paradigm used in previous studies but employed a specially designed test chamber, the internal odor environment of which could be fully controlled. In the four series of bioassays a total of 140 separate tests were performed and 64 adult male rabbits were used. The results showed that the presence of the total volatiles influences the outcome of territorial competitions in pairs of male rabbits in favor of the individual from which they were derived. They were comparable with those obtained in earlier studies when fecal pellets were presented in the test pen. The effects of the different washing reagents on the total odor are illustrated by gas chromatograms, and the components most likely to be removed by the different treatments are suggested. The volatiles remaining after passing through distilled water had less effect on the rabbit's behavior than the total odor. Since the washing process not only removed water-soluble compounds but also led to a reduction in the concentrations of water-insoluble components introduced into the test chamber, either of these factors could have been responsible for the weakened effect. Fractions of the odor obtained by washing with either sodium hydroxide or hydrochloric acid did not influence the results of the tests. This suggests that the essential components of the olfactory signal include both basic and acidic compounds.     

Electrocardiographic technique for studying olfactory response in the rock hyraxProcavia capensis L. (Mammalia: Hyracoidea)

Rock hyraces were exposed to the dorsal gland and urinary odors' of conspecifics in a test chamber constructed such that electrocardiographic biopotential could be picked up through the plantar surfaces of the feet. Both heart rate acceleration and deceleration were observed. Female hyraces responded more strongly to odors than males, but no reponse was observed towards the odor of the dorsal gland of sexually inactive males. Electrocardiography allows a more sensitive measurement of response to odor stimuli than has hitherto been reported, and the technique may have a wide applicability in studies on other mammalian species with naked foot soles.     

Effect of volatiles collected above fecal pellets on behavior of the rabbit,Oryctolagus cuniculus,tested in an experimental chamber

Gas chromatographic techniques were used to trap and fractionate the volatile substances emanating from the fecal pellets of wild rabbits,Oryctolagus cuniculus, which incorporate the odor of the anal gland secretion. The volatiles were bubbled through water, trapped on Chromosorb 105, transferred to Silicone SF96 traps, passed through a GC capillary column, and retrapped on SF96. The behavioral effect of trapped and fractionated volatiles was determined in four series of bioassays involving 51 adult, male, wild-type rabbits in 112, ten-minute tests. The bioassay was based on the demonstration of territorial confidence by the rabbits under the influence of their own odor. In the bioassays of the unfractionated volatiles eluted from Chromosorb 105 and SF96 traps the animals were significantly more confident in the presence of the volatiles from their own fecal pellets. One of the two fractions of the total volatiles was ineffective while the effect of the other was less than that of the unfractionated odor. The results demonstrate that the gas chromatographic techniques can be used to manipulate complex mammalian odors with precision. Combined with a discriminative bioassay, this opens up the possibility of identifying the specific combinations of volatile substances involved in the formation of olfactory signals.     

Comparison of release devices for stoat (Mustela ermined) semiochemicals used as montane vole (Microtus montanus) repellents

Fenced enclosures were used to simulate peak populations of montane voles (Microtus montanus) for field bioassays of a stoat (Mustela erminea) scent mixture in various controlled-release devices. A 1 1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane was dispensed in capillary tubes, clay pellets (activated alumina), rubber septa, and plastic rope. Release devices were placed near, or attached to, young apple trees planted in blocks in two enclosures containing high populations of voles. The stoat scent mixture in rubber septa and plastic rope significantly reduced vole attack of trees compared with a control, pellets, and capillary tubes. In terms of complete girdling (tree mortality), this odor in septa and rope also significantly reduced feeding compared with the control, and the rubber septa formulation was more effective than either the pellets or capillary tubes. Fenced populations of voles may be used effectively to conduct field bioassays during low years in vole cycles. Variations of release devices (with this stoat scent mixture) based on rubber septa for broadcast application to depress vole population density and survival, and plastic rope attached to individual trees to generate an avoidance response, should be used for forest and agricultural crop protection.     

Olfactory discrimination ability in short-tailed fruit bat,carollia perspicillata (Chiroptera: Phyllostomatidae)

The olfactory discrimination ability in a fruit-eating bat,Carollia perspicillata, was investigated. In a food-rewarded flight training procedure, four animals were taught to choose one of two odors simultaneously presented in a three-choice apparatus.Carollia chose the odor of ripe banana over that of unripe banana in a spontaneous choice test. With the same method, the bats significantly preferred undiluted banana odor compared to a dilution of 1 10, but did not express a preference between undiluted and 15 dilutions of ripe banana. In a series of reinforced choice tests, the positive stimulus (CS +) was the standardized odor of natural ripe banana. Prominent components of this complex odor were used as CS –, first in monomolecular form and later in combinations (odor cocktails) of increasing similarity to banana odor. In all these tests the bats easily discriminated the natural food odor from the artificial ones. Even a gas Chromatographic congruity of 57% between the major components of natural banana odor and an odor cocktail caused no impairment of the olfactory performance. The olfactory discrimination ability ofCarollia perspicillata supports the assumption that echolocating, frugivorous bats may use their sense of smell to find and select their food.     

Identification of some volatile compounds in the odor of fecal pellets of the rabbit,Oryctolagus cuniculus

A study has been made of the volatile constituents in the vapors collected from fecal pellets of wild rabbits,Oryctolagus cuniculus. Measurements of changes in the heart rates of adult male rabbits exposed to the effluent of a gas chromatographic capillary column were used to indicate the presence of compounds which may be of behavioral significance. Combined with the use of high-resolution columns in gas chromatography and gas chromatography-mass spectrometry, this approach has implicated several classes of compounds, including volatile fatty acids and phenols, which in certain absolute or relative concentrations may be involved in the formation of signals of territorial importance.     

Effect of birch (Betula pendula) bark and food protein level on root voles (Microtus oeconomus): II. detoxification capacity

The effect of protein and birch bark powder (BBP) content of forage on detoxification capacity of root voles (Microtus oeconomus) was studied. Young voles were fed with eight different diets for two weeks. Individuals on low (3%) protein diets had significantly lighter livers and kidneys than those on moderate (6%) or high (12%) protein diets. Birch bark powder addition did not have significant effect on organ weight. Detoxification was significantly induced, apparently due to secondary compounds in BBP. The activity of ethoxyresorufin-O-dealkylase (EROD) was high when protein content or BBP concentration in forage was high as compared to low protein diets or diets containing no BBP. Glucuronidation, on the other hand, was not induced by BBP. High BBP content caused serious physiological stress to the voles. The only individuals surviving were those capable of sufficiently allocating energy and protein to detoxification.     

Lipid components in anal scent sacs of three mongoose species (Helogale parvula,Crossarchus obscurus,Suricata suricatta)

Anal sac secretions of three social mongoose species (Helogale parvula, Crossarchus obscurus, andSuricata suricatta) were chemically analyzed by means of gas chromatography-mass spectrometry. Compounds with high molecular weights (greater than 250) were found to distinguish the three species. Differences in composition suggest a possible species-specific role in scent marking. MaleH. parvula had vitamin E present in the anal sac, whereas it was absent in the females. This suggests a possible sex-specific function of vitamin E inH. parvula. No differences in chemical composition were found between male and femaleS. suricatta. Ten compounds were found in femaleC. obscurus that were not present in the male.     

Chemosensory responses in two species of elephants to constituents of temporal gland secretion and musth urine

This report discusses three areas of investigation: (1) The chemical components in the temporal gland secretion (TGS) of Asian (Elephas maximus) and African (Loxodonta africana) elephants were characterized by radioimmunoassay (RIA) for testosterone (T) and dihydrotestosterone (DHT) levels and by on-column capillary column gas chromatographic analysis of volatiles. An inverse relationship between TGS testosterone levels and (E)-farnesol levels was observed. (2). African elephants responded preferentially toward a particular constituent of African elephant TGS. (3) Urine from Asian bull elephants in musth was partially fractionated by high-performance liquid chromatography. Specific chromatographic regions elicited dramatic avoidance responses from female African elephants. These results support the suggestion that the TGS plays multiple chemocommunicative roles.     

Intermale sexual effect elicited by volatile urinary ether extract inMicrocebus murinus (Prosimian,Primates)

The effect of volatiles of diethyl ether-extracted dominant male mouse lemur urine on conspeciflc testosterone plasma concentrations was determined in an apparatus permitting olfactory isolation of the experimental subjects. Two experimental groups were exposed to air odorized with either ether or aqueous extracts of dominant male urine, while a third group received nonodorant air. Testosterone concentrations were measured before, during, and after the period of stimulation. The group submitted to the lipid fraction of dominant urine (N = 15) showed a significant decrease in testosterone concentrations. In contrast, no difference was observed between the group submitted to the aqueous fraction (N = 10) and the controls (N = 11). This physiological effect, which occurs in response to conditions of persistent stress, appears to be due to lipophilic components present in the urine of dominant males. The results are discussed in terms of the social structure of this primitive primate species.     

Inhibitory effect of parthenium (Parthenium hysterophorus L.) residue on growth of water hyacinth (Eichhornia crassipes Mart Solms.) II. Relative effect of flower,leaf, stem,and root residue

The relative effect of residue of leaf, flower, stem, and root of parthenium (Parthenium hysterophorus L.) on growth of water hyacinth was studied. The inhibitory activity of the residue as shown by its effect on biomass and healthy leaf number (HLN) of treated plants was in the order: leaf and flower >stem >root. Total phenolic acids in the medium after 72 hr of suspending the plant part residue were maximum in flower followed by leaf, root, and stem, successively. The dry leaf powder (DLP) and dry flower powder (DFP) at and above 0.50% (w/v) and dry stem powder (DSP) at 1.00% (w/v) killed water hyacinth in about one month. Dry root powder (DRP) at the highest dose (1.25% w/v) reduced the growth of the treated plants drastically, but the plants recovered after about one month. The DSP at 0.50% (w/v) and DRP at 0.25–0.75% (w/v) supported growth of treated plants, probably due to lower levels of inhibitors, allowing utilization of constituents of the residue as nutrients. Using wheat seedlings as a reference material, it was observed that in aquaculture at different levels of parthenium plant parts residue, water hyacinth plants were much more sensitive to inhibitory activity. Thus, water hyacinth is suggested as a material for bioassay of inhibitory activity of the parthenium plant residue.     

Marking urine and preputial gland secretion of male bank voles (Clethrionomys glareolus L.) chemical analyses and behavioral tests

Urine and preputial gland secretion of male bank voles were analyzed by gas chromatography (GC) and mass spectrometry (MS) (selected ion monitoring, SIM). GC-MS analyses showed the presence of hexadecyl acetate in preputial gland secretion and in marking urine but not in metabolic urine. Female bank voles responded more strongly to marking urine of males than to metabolic urine, and they responded more to preputial gland secretion (pure or added to urine) than to metabolic urine. Dominant males spent more time and marked more frequently in response to hexadecyl acetate-enriched urine than to urine alone. The opposite reaction was shown by subordinate males. The results suggest that the acetate functions in the bank voles' dominance interactions.     

A comparison of the effectiveness of the odors of rabbits,Oryctolagus cuniculus,in enhancing territorial confidence

In 14 series, each of 100 tests, involving 350 individual animals it has been shown that odors derived from the anal, inguinal and chin glands and urine strengthen to different degrees the confidence of European wild rabbits,Oryctolagus cuniculus. In the tests, two rabbits were put together on otherwise neutral ground previously treated with the odor from one of the contestants. The confidence of the rabbits was determined from an assessment of the record of the time to first physical contact, the frequencies of approaches and aggression, the number of attempts to escape, and also by making a subjective assessment of their general deportment. The results confirm earlier conclusions on the territorial functions of the anal and chin glands, the role of inguinal glands in individual identification, and the behavioral role of urine. On otherwise neutral ground the rabbits' own chin secretions were found to be the most effective in stimulating the confidence of males and that of their female partners. The odor of the anal gland secretions of males stimulated a similar but slightly weaker effect. The anal gland secretions of females influenced their own confidence but not that of males. Urine seemed to play a more important role in affecting the confidence of females than of males. Inguinal gland secretions had least effect. Odor from this source generally did not influence the confidence of the experimental animals; secretion from the inguinal glands of males had a slight effect on the behavior of their female partners.     

Sheep food repellents: Efficacy of various products,habituation, and social facilitation

The study of food repulsion in ungulates is of practical importance for controlling browsing damage to forest trees and agricultural crops. Experiments with domestic sheep assessed the repulsive value of three natural and two synthetic products, using a food-choice situation. Animals were individually presented with two troughs, each containing 30 g of maize, one treated with a chemical product, and the other a control. The odor of domestic dog feces appeared to be highly repulsive, as none of the treated food was eaten, whereas 3 g ±9 and 6 g ±10 were eaten, respectively, of food treated with fetal fluids from sheep and odor of pig feces. Synthetic odors of lion feces and a commercial deer repellent were less efficient as repellents with 11 g ±13 and 14 g ±15 of food eaten, respectively. Habituation to three of the repellents was tested for a minimum of seven successive days. With dog feces, no habituation to the odor was observed. On the contrary, significant habituation (P < 0.05) was observed as early as the third trial for sheep fetal fluids and the fourth trial for the commercial repellent. To test for the effects of social facilitation, groups of four sheep including no, one, or two anosmic animals were presented with food treated with the odor of dog feces. No social facilitation was observed as none of the intact sheep ate any of the food, although the anosmic animals actively ate it throughout the test. In individual food choice tests, the odor of dog feces appeared to be an especially efficient repellent when compared with the other natural or synthetic products. Such repulsion was nearly complete, and neither habituation nor social facilitation could be observed.     

Isolation and identification of house fly,Musca domestica L., repellents from pepper tree,Schinus molle L.

Foliage from the pepper tree,Schinus molle L., is traditionally used in Ethiopia to repel house flies,Musca domestica L. The volatile extracts of pepper tree leaves were shown to have repellent and feeding-deterrent activity against house flies in a two-choice laboratory bioassay. High-performance liquid chromatographic fractionation of steam-distilled volatiles from leaves, monitored by laboratory bioassays, demonstrated that bioactivity is associated with two compounds,cis-menth-2-en-1-ol andtrans-piperitol. The absolute configuration of the latter was established as (1S,6S)-piperitol by comparison of acetyl lactate derivatives. Racemic compounds were synthesized from piperitone, and bioassays with house flies indicatedtrans-piperitol to be the most active house fly repellent.