Scent marking in a territorial African antelope: II. The economics of marking with faeces

Faeces may be ideal substances for scent marking because they have a minimal energetic cost to the signaller. However, marking with faeces is also constrained by the animal's ability to produce faeces. This study examined whether limits on the volume of faeces produced by oribi Ourebia ourebi, in Serengeti National Park, Tanzania, caused territorial males to regulate their output and prioritize the placement of faecal marks. Territorial males marked with faeces more often, and with a smaller volume per defecation, than did juvenile males and females. Territorial males also defecated only on established dung middens along borders shared with other territorial males or on top of a female's urine and faeces. In contrast, juvenile males and females defecated randomly with regard to their location in territories. Territorial males with larger harems marked with faeces at higher rates and less volume than males with few or no females. This difference suggests that when males overmark female excretions they reduce the amount of faeces available for marking other preferred sites, such as along territory borders shared with other males. Dominant males with adult subordinates marked with faeces less often, and with a greater volume per mark, than males that defended territories without the aid of subordinates. Dominant males also reduced the volume of marks less as the number of females on their territory increased than did males without subordinates. Territories occupied by more than one adult male also were marked with faeces at higher rates, and with marks of greater volume, than territories held by single males. These results suggest that the presence of subordinate males reduced the demand on dominant males to regulate the volume and placement of faecal marks. Overall, these results suggest that territorial male oribi regulate their faecal marking behaviour in response to a limited supply of faeces. Copyright 1999 The Association for the Study of Animal Behaviour.     

Organochlorine exposure and health effects in stranded Steller sea lions (Eumetopias jubatus) and Pacific harbor seals (Phoca vitulina richardii) from Oregon and southern Washington coasts

Organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) have been detected in a variety of marine mammal species at levels associated with adverse health effects. Little is known about OC levels and impacts on health in pinnipeds with different life histories. We determined the health and levels of 18 OC pesticides and 16 PCB congeners in blubber samples from 20 Steller sea lions and 39 Pacific harbor seals stranded from Oregon and Southern Washington. The most commonly detected OC at the highest concentration was p,p′- dichlorodiphenyldichloroethylene (DDE). PCBs were detected in all samples as well. Hypothesis testing indicated that diseased Steller sea lions (males and females combined) had higher contaminant concentrations than healthy Steller sea lions, and diseased Pacific harbor seals had higher concentrations of total OCs than healthy animals. Differences were also noted between diseased and healthy animals when looking at individual sexes of each species. Diseased Steller sea lions had higher mean contaminant levels than diseased harbor seals and healthy Steller sea lions had higher mean contaminant concentrations than healthy Pacific harbor seals. These results show that species differences exist in both contaminant loads and sensitivity to contaminants, which may be due to differences in life histories and physiology.     

Scent marking and mate choice in the prairie vole, Microtus ochrogaster

Scent marking is common among male and female rodents and might be used in male-male competition and as a mechanism for mate attraction. I tested the hypotheses that females would choose males based on their frequency and placement of scent marks, and that a female would advertise interest in a particular male by placing her scent marks on or near those of a preferred mating partner. In a series of experiments conducted with prairie voles, Microtus ochrogaster, females did not choose mates based on the frequency or placement of scent marks by males nor did they advertise their interest in a particular male through the frequency or placement of scent marks. The number of males chosen that scent-marked more than their opponents did not differ significantly between females exposed (11 of 15) and not exposed (10 of 15) to scents of males. Females exposed and not exposed to scents of males preferred seven of the same males that had scent-marked more than their opponents. When a third group of females was exposed to four times more scent of the less preferred than preferred males, they still chose the preferred males. Thus, the frequency and placement of scent marks by males were not used to assess males for mate choice nor did female prairie voles use scent to advertise their preference for a mating partner. In that scent marking is common in male and female mammals, scent quality might be more important than quantity in male-male competition and mate attraction.Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved .     

Putative chemosignals of the ferret (Mustela furo) associated with individual and gender recognition

Quantitative stir bar sorptive extraction methods, both in the aqueous and headspace modes, followed by thermal desorption gas chromatography-mass spectrometry were used to investigate individual variations in the volatile components of male and female ferret (Mustela furo) urine. The urinary profiles were further compared with volatile profiles of anal gland secretions of breeding male and female ferrets. Thirty volatile compounds were quantified in male and female urine. Among them, 2-methylquinoline was unique to male urine. Four ketones (4-heptanone, 2-heptanone, o-aminoacetophenone, and a dimethoxyacetophenone) and several nitrogen compounds (e.g., 2,5-dimethylpyrazine, quinoline, 4-methylquinazoline) and low levels of three unidentified nonsulfur compounds were significantly more abundant in males than in females. Quantitative comparison of 30 volatile urinary compounds showed several statistically significant differences between the sexes and individuals of the same sex. These findings suggest that ferrets may use urine marking for sex and individual recognitions. Ten of the 26 compounds identified in anal gland secretions from females and males were also found in urine. However, most of the major compounds (thietanes, dithiolanes, and indole) in anal glands were not present in urine. This suggests that urine may convey specific signals that differ from those of anal glands. Additionally, 10 volatiles (two aldehydes, five ketones, benzothiazole, 2-methylquinoline, and 4-methylquinazoline), not previously identified, were found in ferret anal gland secretions. Among the new compounds, o-aminoacetophenone was found only in males, while only traces of this compound were found in females. Similar results were previously obtained in anal glands of three other Mustela species. These findings provide new information about the constituents of urine and volatile components of anal gland secretions in ferrets.     

Habitat selection and feeding ecology of the cheetah (Acinonyx jubatus) in thicket vegetation: is the cheetah a savanna specialist?

Habitat selection and feeding ecology of a reintroduced population of cheetahs Acinonyx jubatus were studied in a 16 000 ha game reserve in the Eastern Cape Province (South Africa). Seventy per cent of the reserve is characterized by very dense thicket vegetation (valley bushveld) and the remainder is open and savanna-like. The results illustrated a strong effect of sex and group size on the behaviour of cheetahs. The coalition (three adult males) killed significantly larger animals (55% of kills weighed more than 65 kg) than single female cheetahs (less than 2% of kills weighed more than 65 kg). Female cheetahs showed temporal and spatial avoidance of lions by hunting at dawn and dusk and positioning their home ranges [95% utilization distribution (UDs)] significantly farther from the pride of lions than did the coalition. The coalition hunted earlier and later than female cheetahs, and 46% of their kills were made in darkness. In addition, their home range overlapped that of the lions and they showed neither temporal nor spatial avoidance of the lions. The rates of kleptoparasitism were lower and the kill retention times were longer than those reported elsewhere in Africa, and it is suggested that this is a consequence of the cover provided by the thicket vegetation and prey size. The home ranges (95% UDs) of female cheetahs incorporated more thicket vegetation than that of the coalition, indicating that the coalition is less susceptible to predation than single females. These data suggest that cheetahs possess greater behavioural flexibility than previously reported, that they can hunt successfully in thicket vegetation, sometimes in darkness, that they are not restricted to killing small to medium-sized prey, and that they may not be savanna specialists.     

Sex- and gonad-affecting scent compounds and 3 male pheromones in the rat

This study was aimed at identifying sex pheromones of the rat (Rattus norvegicus). We characterized the volatiles and semivolatiles of rat preputial gland and voided urine by using gas chromatography-mass spectrometry (GC-MS) and quantified them by their GC areas (abundances) and percentage of GC areas (relative abundances). Although all the compounds other than 4-heptanone and phenol detected were shared by males and females, the quantities for some of these sex-common compounds exhibited sexual dimorphism and decreased with gonadectomy. Thus, these compounds might be sex pheromones. Among them, squalene from preputial glands and 2-heptanone and 4-ethyl phenol from urine were 3 major compounds. They were richer in males and could be suppressed by castration. Adding any of the 3 compounds (at a concentration higher than its physiological level in male urine) to castrated male urine (CMU) increased the attractiveness of CMU to sex-naive females. Adding the 3 together (at the levels in normal male urine) to CMU significantly increased the attractiveness of CMU to females. However, such combination did not fully restore females' preference for urine from intact males, suggesting that some other trace compounds such as 4-heptanone and phenol might also play some roles in sex attractiveness. Thus, squalene, 2-heptanone, and 4-ethyl phenol were indeed male pheromone molecules in rats. Our study also indicates that E,E-beta-farnesene and E-alpha-farnesene, both richer in females than males, might be putative female pheromones.     

Spatial organization of the fat dormouse (Glis glis) in an oak-hornbeam forest during the mating and post-mating season

Home range (HR) size and overlap, movements, and nest site use of fat dormice Glis glis (Linnaeus, 1766) were studied by live-trapping and radiotracking in the Bialowieza Forest in north-eastern Poland. The study was conducted during a mast year of oak Quercus robur (2001) and hornbeam Carpinus betulus (2002). Average HR size measured by 100% minimum convex polygons varied from 3.6 to 7.0 ha in males and from 0.55 to 0.76 ha in females. HR size in males was significantly larger in the hornbeam mast year than in the oak mast year, which was probably due to the lower energy value of hornbeam mast. Males had significantly larger HRs and used more nest sites than females. In contrast to females, HRs of males overlapped extensively. In the mating season, core areas of males overlapped significantly more and they shared their core areas with more males than in the post-mating season. During the mating season, males were found to share nest sites with other males or with a single female. Additionally, groups of 2–3 males were observed aggregating around a female during the mating season. Our data suggest that fat dormice have a promiscuous mating system where the females are territorial, and the non-territorial males directly compete for access to receptive females during the mating season.     

Sex differences in scent marking in Propithecus edwardsi of Ranomafana National Park, Madagascar

In this study we compared the scent-marking rates of females with those of males. Specifically, we examined the ability of season, dominance status, and natal status to explain the frequency of scent marking in female sifakas living wild in Ranomafana National Park, Madagascar, and compared the results with those published for males [Pochron et al., American Journal of Primatology, in press]. We also sought to determine whether vulnerability to infanticide affects marking frequency in adults of either sex, and whether female reproductive status affects female marking behavior. We found that males marked at twice the rate of females, and like males, females in single-female groups marked at the highest rates. Dominant females and non-natal females marked at higher rates than did subordinate females and natal females, a pattern also seen in males. This suggests that scent marks may convey important information about status. Neither females nor males varied their marking frequency with the presence of vulnerable infants. Females did not alter marking frequency with reproductive state, and like males, they marked at higher rates in the period prior to the mating season than they did in the mating season itself. This implies that females may use scent marks more for intrasexual aggression or territoriality than for mate attraction.     

Bacterial Flora of the Hemolymph of the Blue Crab, Callinectes sapidus: Most Probable Numbers

The hemolymph of 290 freshly collected blue crabs from Chincoteague Bay, Va., was sampled over a 15-month period from August 1968 through November 1969 and most probable numbers of bacteria were determined by tube dilution. The hemolymph of 18% of all crabs sampled was found to be sterile, with 16% sterility in summer and 23% in winter samples. Despite individual variations, male crabs as a group had a higher bacterial hemolymph burden than females, and among both sexes summer counts were higher than winter. The hemolymph of crabs with missing appendages had significantly higher counts than uninjured crabs. The annual mean hemolymph most probable numbers per ml was 2,756 for males, 1,300 for females, and 1,876 for both sexes. The higher bacterial levels found in the hemolymph of male crabs may, in part, be explained by the fact that males, which predominated in the summer samples, had a higher incidence of injury and missing appendages than did females.     

Comparative growth of wild male and female lions (Panthera led)

Lion growth was studied by fitting sex specific Von Bertalanffy curves and linear regressions to data on body mass, heart girth, shoulder height and vertebral column length. Measurements were recorded for 344 lions ( Panthera leo ) (158 ♂♂ and 186 ♀♀), from Kruger National Park, South Africa. Growth in mass for males and females was linear up to about 36 months of age 0 = 0–98 and 0–99 respectively). The other age-specific measurements were clearly curvilinear. Mean weights for adult lions (excluding stomach contents) were 187–5 kg (♂♂) and 124–2 kg (♀♀) respectively. Lions tended to continue growing up to about seven years in males and nine to 10 years in females after which they usually started to lose condition. Body mass and heart girth measurements of Kruger Park lions were compared with samples from three other populations. These showed that lions from East Africa were smaller than those from more southern populations in Rhodesia, Kalahari and Kruger Park.     

Effect of host odours on trap catch composition of Glossina pallidipes in Kenya

The effect of odour attractants on the composition of samples of Glossina pallidipes Austen was investigated by comparing the age and nutritional status of flies caught in unbaited biconical traps with those caught in traps baited with cow urine and acetone. For both male and female flies, baited traps caught more flies with significantly higher fat content than did unbaited traps. Thus the samples from baited traps were more representative of the population as a whole: males showed a fuller range of the fat/haematin conditions known to occur in the field and proportionately more females were in later stages of the pregnancy cycle, than from unbaited traps.     

Olfactory responses of tsetse flies to phenols from buffalo urine

Abstract A comparison was made of the EAG responses of males and females of Glossina morsitans morsitans Westwood, G.austeni Newstead and G.tachinoides , Westwood to various doses of compounds known to be components of ox and buffalo urine fractions which are attractive to tsetse in the field (phenol, 3- and 4-methylphenol, 3- and 4-ethylphenol, 4-n-propylphenol, dimethylsulfone). All three species did not respond to dimethylsulfone. The overall responses to the phenolic substances were higher in females than in males in G.m.morsitans and higher in males than in females in G.austeni and G.tachinoides. Response spectra of the species for the phenolic substances suggested that G.m.morsitans and G. austeni were most responsive to 3- and 4-methylphenol and 3-ethylphenol, whereas G. tachinoides was most sensitive to 3-ethylphenol and 3-methylphenol, and only moderately sensitive to 4-methylphenol.
Cross-adaptation experiments, in which l-octen-3-ol, acetone, 4-heptanone and 3-nonanone were also included, revealed that all phenolic compounds stimulated one and the same class of receptors, which differed from the class of receptors activated by l-octen-3-ol. The ketones also had their own receptors. Hence, the flies can obtain information about the presence of attractants by at least three different receptor classes. It was concluded that phenol and any individual alkylphenol found in ox and buffalo urine should be attractive to tsetse flies, provided that stimulus intensity is above threshold and not beyond optimum. One class of receptors may respond more strongly in males than in females, whereas another class is more responsive in females than in males. This may result in a change in sex ratios in catches depending on the odour bait used.     

Scent-marking displays provide honest signals of health and infection

Males of many species produce scent marks and other olfactorysignals that function to intimidate rivals and attract females.It has been suggested that scent marks provide an honest, cheat-proofdisplay of an individual's health and condition. Here we reportseveral findings that address this hypothesis in wild-derivedhouse mice (Mus musculus domesticus). (1) We exposed males tofemale odor, which induces an increase in testosterone, andfound that sexual stimulation significantly increased the males'scent-marking and the attractiveness of their scent marks tofemales. (2) We challenged sexually stimulated males with anonreplicating strain of bacteria (Salmonella enterica C5TS)to activate immunity and found that this significantly decreasedthe males' scent-marking and the attractiveness of their scentmarks to females. (3) We collected scent marks from infectedand sham-infected males when they were sexually stimulated ornot, and we found that females could significantly discriminatethe scent marks of infected versus control males, but only whenthe males were sexually stimulated. Taken together, our resultsindicate that male mice modulate their scent-marking displaydepending on their health and perceived mating opportunities.Increased scent marking enhances males' attractiveness to females,scent marks provide an honest indicator of bacterial infection(and perhaps immune activation), and females are able to assessthe health of males more easily when males mark at a high rate.     

Effect of Sex and Dietary Organic Zinc on Growth Performance, Carcass Traits, Tissue Mineral Content, and Blood Parameters of Broiler Chickens

Zinc (Zn) is an essential mineral for animal development and function. A study was carried out to evaluate the effect of sex and dietary organic zinc (OZ) on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens. A total of 240 1-day-old male and 240 female broiler chicks (Cobb × Cobb) were assigned to two dietary levels of OZ (2 × 2 factorial) with six replicates per treatment (20 birds/replicate pen). The OZ supplementation levels were 0 and 25 ppm. Results showed that OZ supplementation did not affect the growth performance of male and female broilers, but the males showed significantly better (P < 0.05) growth performance than females did. Similarly, OZ supplementation did not affect the thickness of both the back and thigh skin of male and female broilers; however, males had thicker skin than females. Dietary OZ supplementation did not affect collagen contents in the skin and meat samples. Male broilers had higher skin collagen contents than females, but no sex difference was found in meat collagen contents. OZ supplementation did not affect the shear force values of skin and meat samples. Male broilers had higher shear force values of back skin than females, but not in the meat samples. Dietary OZ supplementation increased (P < 0.05) the thigh meat Zn content in both sexes. The plasma Ca content was significantly (P < 0.05) increased by dietary OZ supplementation; however, other blood parameters were not affected by dietary OZ supplementation. Males had higher plasma glucose and cholesterol content than females. It is concluded that dietary OZ supplementation at the level of 25 ppm does not affect the growth performance and skin quality of broiler chickens but increases the Zn content in thigh meat and Ca content in plasma of broiler chickens. Male broilers had better growth performance and skin quality than females.     

The influence of urine from asymptotic laboratory populations on sexual maturation in prairie deermice

Male and female prairie deermice housed singly from weaning (21 days) until 40 days of age had urine from one of the following sources applied daily to their nostrils: sexually mature laboratory population males or females, and sexually mature breeder males or females from our laboratory colony. Other males and females were treated with water. Records were obtained of the weights of the tests, seminal vesicles and bacula of males and the ovaries and uteri of females at 40 days of age. The major results of this study were as follow: Female urine from sexually mature and inhibited population or isolated mice stimulated the development of the male reproductive organs significantly more than water or male urine. Male urine applied to young males did not differentially affect the weights of their reproductive organs compared with water and thus showed no inhibition effects. The reproductive organs of females treated with male urine did not differ significantly in weight from those of females treated with female urine. Females treated with water developed significantly larger uteri than those treated with urine from sexually mature population females (P≤0.02), inhibited population females (P<0.001) and inhibited population males (P<0.007).     

Testing for Links Between Female Urine Odor and Male Sexual Behaviors in Japanese Macaques (<Emphasis Type="Italic">Macaca fuscata</Emphasis>)

Urine is involved in sexual communication in New World monkeys and lemurs, but most studies of the role of olfaction in sexual communication in Old World monkeys have focused on vaginal secretions rather than urine. We investigated whether female urine promotes male sexual behaviors (approaches and inspections of genital area) in Japanese macaques (Macaca fuscata). We used a sequential presentation paradigm in behavioral experiments, presenting unfamiliar female urine and control cotton swabs to males living in a social group with cycling females. We tested whether males (N = 3) showed more processing behaviors (licking, sniffing, tasting) toward female urine (22 stimuli per male from prefertile, fertile, and postfertile phases, based on urinary estrone and progesterone conjugate profiles) than control odor (8 stimuli per male). We then compared male sexual behaviors toward resident females pre- and post-exposure to stimuli and in relation to the females’ reproductive status (perifertile, nonfertile, and pregnancy periods, based on fecal estrone and progesterone conjugate profiles). We found that males showed significantly more processing behaviors toward urine stimuli than to controls but that male behavior did not vary across urine samples from prefertile, fertile, and postfertile phases. Exposure to unfamiliar female urine stimuli did not modulate male approaches to and inspections of resident females at any stage of the female reproductive cycle. Although our study is limited by its small sample size, the results suggest that female urine contains compounds that males detect, but we found no evidence that female urine is related to male sexual behaviors.     

Dominance status of adult male Japanese macaques: Relationship to female dominance status,male mating behaviour,seasonal changes,and developmental changes

Aggressive dominance orders of all adults in a confined troop of Japanese macaques (Macaca fuscata) were determined each mating and birth season during a 4-year interval. Males outranked more females in the mating than in the birth season, and some males shifted back and forth from ranks lower than female ranks in the birth season to ranks higher than female ranks in the mating season. Mating behaviour (number of female partners in mount and ejaculation series and ejaculation frequency) did not differ among males with ranks higher than, as high as, or lower than those of most females, nor did individual males mate more in years, when they were high-ranking than in years when they were not. There was a correlation, however, between ejaculation frequency and the number of females defeated by males. A pattern of increasing male rank with age was found.     

Scent-marking behaviour by male prairie voles,Microtus ochrogaster,in response to the scent of opposite- and same-sex conspecifics

We conducted an experiment using the prairie vole (Microtus ochrogaster) to test predictions associated with the proposed functions of scent marking as a sexual attractant, in reproductive competition, and as a self-advertisement. We allowed an oestrous female, an anoestrous female, and an adult male to scent mark three portions of a clean substrate and then exposed a second male to this substrate for secondary marking. We did not support a sexual attraction hypothesis in that males did not place more scent marks in response to oestrous than anoestrous females. Similarly, we did not support a reproductive competition hypothesis in that males did not place more scent marks in response to marks of males than to those of females or bare substrate. Males did not overmark the scent of males or females and thus we did not support a scent-masking or scent-blending hypothesis. In that males deposited scent similarly in response to males, females, and on bare substrate, our results suggest that the frequency and placement of scent marks by males function primarily to advertise individual identity in an area.     

The ownership signature in mouse scent marks is involatile

Male house mice advertise their territory ownership through urinary scent marks and use individual-specific patterns of major urinary proteins (MUPs) to discriminate between their own scent and that of other males. It is not clear whether recognition occurs through discrimination of the non-volatile proteins or protein-ligand complexes (direct model), or by the detection of volatile ligands that are released from MUPs (indirect model). To examine the mechanism underlying individual scent mark signatures, we compared investigatory and countermarking responses of male laboratory mice presented with male scent marks from a strain with a different MUP pattern, when they could contact the scent or when contact was prevented by a porous nitrocellulose sheet to which proteins bind. Mice investigated scent marks from other males whether these were covered or not, and biochemical analysis confirmed that the porous cover did not prevent the release of volatiles from scent marks. Having gained information through investigation, mice increased their own scent marking only if they had direct contact with another male's urine, failing to do this when contact was prevented. Individual signatures in scent marks thus appear to be carried by non-volatile proteins or by non-volatile protein-ligand complexes, rather than by volatiles emanating from the scent.     

Metabolic profiling of human urine by CE-MS using a positively charged capillary coating and comparison with UPLC-MS

The potential of capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS) using capillaries coated with a triple layer of polybrene-dextran sulfate-polybrene (PB-DS-PB) was evaluated for metabolic profiling of human urine. The method covers various metabolite classes and stable metabolic profiles of urine samples were obtained with favourable migration time repeatability (RSDs <1%). The PB-DS-PB CE-TOF-MS method was used for the analysis of human urine samples from 30 males and 30 females, which had been previously analyzed by reversed-phase UPLC-TOF-MS. Multivariate data analysis of the obtained data provided clear distinction between urine samples from males and females, emphasizing gender differences in metabolic signatures. Nearly all compounds responsible for male-female classification in CE-TOF-MS were different from the classifying compounds in UPLC-TOF-MS. Almost all compounds causing classification in the CE-TOF-MS study were highly polar and did not exhibit retention in the reversed-phase UPLC system. In addition, the CE-TOF-MS classifiers had an m/z value in the range of 50-150, whereas 95% of the classifying features found with UPLC-TOF-MS had an m/z value above 150. The CE-TOF-MS method therefore appears to be highly complementary to the UPLC-TOF-MS method providing classification based on different classes of metabolites.