Patterns of male scent-marking in Propithecus edwardsi of Ranomafana National Park, Madagascar

Scent-marking behavior has been well documented in many primate species. Three common functions attributed to scent-marking in males of multi-male/multi-female lemur species include: 1) advertisement of individual identity, 2) territorial defense, and 3) reproductive suppression. We examined the average number of scent-marks per hour exhibited daily by adult male sifakas (Propithecus edwardsi) and found that patterns of scent-marking changed with season, natal status, and dominance status. Males in single-male groups scent-marked at the highest rate, followed by dominant males, males of equal status, and subordinate males. Non-natal males generally scent-marked at higher rates than natal males, and adult males living in a natal group without a parent marked at higher rates than males living with a parent. All males scent-marked at higher rates in the migration season compared to the other seasons. These patterns were consistent with territorial defense and advertisement to females, and the suggestion that these chemical signals impart information concerning status. Since scent-marking behavior tracked seasons and varied with both dominance and natal status, it may serve multiple functions in males.     

Scent marking within and between groups of wild banded mongooses

Scent marking is commonly described as a territorial behaviour, and scent marks might deter potential intruders from entering occupied areas. Conspecific neighbours present both a reproductive and a territorial threat, thus, determining which, if any, of these threats shapes scent-marking behaviour is difficult. Banded mongooses Mungos mungo provide a rare clear separation between reproductive rivals (found within groups) and territorial rivals (neighbouring groups), because immigration into social groups is extremely rare, and mating occurs almost exclusively within groups. This situation offers an opportunity to assess the relative importance of territorial defence and intra-group competition for mates in shaping scent-marking behaviour. We combined detailed behavioural observations of scent marking, chemical analyses of scent composition and discrimination experiments in the field, and found little evidence for higher rates of scent marking in overlapping areas, a lack of group specificity of scents and a failure of individuals to discriminate between the scents of different groups. Although scent may fulfill some role in territorial demarcation and defence, these results suggest that scent marks and scent-marking patterns are also involved in communicating within social groups.     

The role of scent marking in the social communication of wild golden lion tamarins, Leontopithecus rosalia

The role of scent marking in the social communication of mammals is widely variable. One reason for this variation is that the function of scent marking may vary with different ecological and social conditions. The purpose of this study was to test four nonexclusive hypotheses explaining the role of scent-marking frequency in different ecological and social contexts for wild golden lion tamarins. Relative to ecological contexts, we compared scent-marking frequency during seasons of abundant and scarce food resources. Relative to social contexts, we compared scent-marking frequency when groups were isolated and when groups were in the presence of neighbouring groups. We found that the tamarins used scent marking to mark the location of food resources. Additionally, males used scent marking to communicate intrasexual dominance within their groups, while females did not. Our results also indicate that alpha females increased their scent-marking frequency to communicate to members of other groups, while the presence of members of other groups did not elicit a similar response by alpha males. We did not find evidence for a territorial function of scent marking in golden lion tamarins. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour      

Scent marking strategies of New World primates

This paper reviews recent findings on scent-marking behavior in wild New World primates. These findings are used to examine three functional hypotheses: territoriality, regulation of social and reproductive dominance, and mating competition/mate attraction. Available data provide little evidence for a territorial function of scent-marking behavior in New World primates. Evidence for a function in the regulation of social and reproductive dominance is ambiguous. The patterns of scent marking found so far (i.e., rates of scent marking according to sex and social or reproductive status, and the spatial distribution of scent marks), and the sparse information on responses to scent marks are consistent with a hypothesized function in intrasexual competition and intersexual mate choice. Suggestions for future research are made.     

Scent marking in sifaka: no one function explains it all

Various hypotheses to explain possible functions of scent-marking have been put forth and basically fall into five categories: territorial demarcation, ownership of resources, mate attraction, noncombative fighting, and self-advertisement. Verreaux's sifaka (Propithecus verreauxi verreauxi), like many prosimians, use scent-marking as one form of communication. The goal of this study was to determine the function of scent-marking in sifaka. All-occurrence of scent-marks, scent-mark context, and scent-mark style were collected on 23 sifaka in the Kirindy Forest of western Madagascar for 7 months (September 2001-March 2002). Scent-mark rates were collected using continuous focal animal sampling from November 2000-March 2002. Home range data were collected using monthly censuses and instantaneous focal sampling throughout the 17 months. Scent-marking behavior was exhibited almost exclusively by adults. Scent-mark rates were not related to the number of resident adult males, number of resident adult females, rank, or group size. The majority of scent-marks occurred in the perimeter of the home range; however, less than a quarter of the home range was used by only a single group. Sifaka did not preferentially mark food trees, mark during the mating season, or mark during intergroup encounters. The results from this study indicate that none of the five hypothesized functions best explains all scent-marking in Verreaux's sifaka. Rather, scent-marking may serve different functions for different individuals.     

COVID-19 and systemic lupus erythematosus genetics: A balance between autoimmune disease risk and protection against infection

Genome wide association studies show there is a genetic component to severe COVID-19. We find evidence that the genome-wide genetic association signal with severe COVID-19 is correlated with that of systemic lupus erythematosus (SLE), having formally tested this using genetic correlation analysis by LD score regression. To identify the shared associated loci and gain insight into the shared genetic effects, using summary level data we performed meta-analyses, a local genetic correlation analysis and fine-mapping using stepwise regression and functional annotation. This identified multiple loci shared between the two traits, some of which exert opposing effects. The locus with most evidence of shared association is TYK2, a gene critical to the type I interferon pathway, where the local genetic correlation is negative. Another shared locus is CLEC1A, where the direction of effects is aligned, that encodes a lectin involved in cell signaling, and the anti-fungal immune response. Our analyses suggest that several loci with reciprocal effects between the two traits have a role in the defense response pathway, adding to the evidence that SLE risk alleles are protective against infection.     

Wing pigmentation in territorial male damselflies, Calopteryx haemorrhoidalis: a possible relation to sexual selection

One striking characteristic in adult males of some odonate species is the presence of wing pigmentation. In Calopteryx species, males show a series of pre- and postcopulatory behavioural displays during which they face females while showing their pigmented wings. One hypothesis to explain the precopulatory flying displays and the associated wing pigmentation is that they may serve a sexual selection function. I investigated this in the territorial damselfly Calopteryx haemorrhoidalis. Males of this species defend aquatic substrates that females use for oviposition. Observational evidence indicated that males with a higher proportion of wing pigmentation were more likely to defend a territory, obtained more matings, had fewer gut parasites, survived in the study site and stayed in territories for longer. Experimental evidence suggested that the relationship mating success and wing pigmentation still held when controlling for the size of the substrate defended by territorial males. Similar to other studies in the Calopterygidae, these results suggest that wing pigmentation may be favoured by sexual selection. I discuss, however, whether an alternative function for male copulatory courtship displays and wing pigmentation, as sexual and/or species recognition, may also explain the evolution of these traits. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Processes underlying complex patterns of song trait evolution in a Setophaga hybrid zone

During secondary contact between two species when hybrids are less fit than parents, mating signals are expected to diverge, while aggressive signals are expected to converge. If a single signal trait is used in both mating and aggression, then the dynamics between these two forces could influence the evolutionary trajectory of that trait. We studied such a situation in an avian hybrid zone between two Setophaga species, where birdsong is used in both mate attraction and territory defense. We hypothesized that song modules of the two species will show separate and distinct geographic patterns due to the influence of selective pressures for effective territorial aggression and for effective mate attraction. We conducted geographic cline analyses and playback experiments across this hybrid zone. We found an unexpected geographic pattern of asymmetric introgression of song rhythm, which may be explained by results of the playback experiments that suggest that differences in song rhythm serve a greater role in mate attraction than in territory defense. In contrast, differences in syllable morphology show little evidence of importance in mate attraction or territorial defense. Song features converge in the hybrid zone, yet patterns of trait change suggest that the song production modules may vary in their modes of development and inheritance. Syringeal motor gesturing, which gives rise to syllable morphology, shows a nonclinal mosaic pattern, suggesting that this trait may be predominantly learned. In contrast, respiratory patterning, which forms song rhythm, shows a clinal geographic transition, suggesting that this trait could be more innate. The results indicate that opposing forces act independently on song via distinct modules of the song production mechanism, driving complex patterns of song trait evolution.     

Scent-Marking of Giant Otter in the Southern Pantanal, Brazil

Giant otters live in social groups, consisting of a mating pair and one or two litters. Groups are territorial and mark their territories often with scent-marks. Our objectives were to evaluate the frequencies of marking and over-marking according to the social status of the individuals and to define the different postures used during the marking. We observed four groups, totaling 25 individuals (five alpha males, four alpha females, seven adult females, one adult male and eight juveniles) with group size ranging between four and 13 individuals. The study was conducted between July 2006 and July 2007 in the Vermelho River and in a stretch of the Miranda River, in the Southern Pantanal. We observed the groups for a total of 2006 min and recorded 95 events of marking totaling 84.9 min. Time spent marking varied between groups and ranged from 4.3 to 44.7 min. The alpha males marked more frequently (62% of marking events, 55 min) than the alpha females (17% of marking events, 13.6 min). Of the 59 events of scent-marking by the alpha males, 32 over-marked the marks of other individuals from the group. Of the 16 events of scent-marking of the alpha females, five over-marked that of other females from the same group. When scent-marking, alpha males used the 'stepping' posture most frequently (63%), then 'fore-paw rubbing' (24%), 'latrine use' (7%), and 'body rubbing' (6%). Alpha females used the 'stepping' posture most frequently (65%), then 'latrine use' (19%) and 'fore-paw rubbing' (12%), with only one event of 'body rubbing' observed during marking. Subordinate females used the 'stepping' posture (76%) and 'latrine use' (24%) during marking. Scent-marking can play many roles in mammals and for giant otters, and the main roles appear to be communication of social and sexual status and territorial defense.     

Cheetah behaviour at scent-marking sites indicates differential use by sex and social rank

Scent-marking is an important form of communication for solitary species, as the information remains for the receiver after the sender has left the area. Individuals of different demographic or dominance classes (ranks) need to provide different information to conspecifics. Therefore, the use of scent-marking sites is of particular value for solitary species, but their functional role may vary between demographic classes. Using camera traps, we video-recorded the behaviour of cheetahs at scent-marking sites, assessing how individuals of different sex and social rank use the sites for different roles. We tested hypotheses that these sites are for territorial marking, reproductive signalling and information gathering. We found that females visit the sites infrequently, apparently to signal oestrous events, while males visit the sites frequently for territorial marking and information gathering. Among males, dominant individuals scent-marked the most and reacted to female visitation by vocalizing. In contrast, subordinate males, although also visiting the sites, were not recorded scent-marking nor vocalizing. These differences in the functional use of scent-marking sites among sex and social rank support the hypotheses that cheetah s use these scent-marking sites for both territorial and reproductive signalling, as well as to gather information.     

Faecal DNA typing as a tool for investigating territorial behaviour of badgers (Meles meles)

We use data from three social groups of badgers (Meles meles) to illustrate how faecal DNA genotyping could be used in scent-marking studies. Faecal samples collected from latrines were genotyped to determine the individual identity and sex of badgers engaging in territorial behaviour and the frequency with which those individuals defecated at particular latrines. The method is potentially applicable to other species of carnivores that use latrines to mark their territories.     

Scent-marking and intrasexual competition in a cooperative carnivore with low reproductive skew

Most mammals scent-mark and a variety of hypotheses have been put forward to explain this behaviour. Differences in the main function of scent-marking between species are likely to be related to differences in social systems. Here, we investigate the functions of scent-marking in a cooperatively breeding carnivore. In the banded mongoose ( Mungos mungo ), individuals of both sexes commonly breed in their natal group and reproductive skew within groups is low. Using experimental scent-mark presentations, we tested predictions of the intrasexual competition, self-advertisement to potential mates and dominance assertion hypotheses. Both males and females responded more intensely to scent marks of same-sexed than of opposite-sexed individuals. Dominant individuals counter-marked more than subordinate ones and males showed higher counter-marking rates than females, but only marginally so. During oestrus, responses to scent marks were increased by both sexes. Our findings strongly indicate that scent-marking in the banded mongoose primarily serves a purpose in intrasexual competition both between and within groups. Unlike in other social herpestids and some solitary rodents, we found little evidence for self-advertisement. We suggest that the peculiar social system of the banded mongoose results in self-advertisement losing importance in this species, shifting the main function of scent-marking to intrasexual competition.     

Female Songs of the Nonduetting Javan Gibbons (<Emphasis Type="Italic">Hylobates moloch</Emphasis>) Function for Territorial Defense

Duets in territorial, pair-living primates may function to maintain intragroup cohesion, promote intergroup avoidance, and assist in territorial and resource defense, as well as advertising and reinforcing pair bonds. Despite the absence of duetting in Javan gibbons (Hylobates moloch), recent playback experiments suggested that Javan gibbon songs also play a role in pair-bond advertisement as well as territorial and mate defense. However, playback experiments only assess motivations of the listener, which may not reflect the motivations of the caller. We conducted an observational study of naturally occurring female songs in two groups of Javan gibbons from July 2009 to March 2010 and from March to November 2011 in Gunung Halimun–Salak National Park, Indonesia. We investigated female singing rates in relation to singing location, daily path length, occurrence of intergroup encounters, feeding rate, allogrooming rate, and distance between pair mates. The two females produced 47 songs during 164 observation days. Females in the area of their home range that overlapped with neighboring groups sang more frequently than expected based on time spent in the area of overlap vs. the home range interior. Groups also had longer daily path lengths on days when females sang than on nonsinging days, and on days when they visited the area of overlap than on nonvisiting days. Our findings indicate that, like the duets of other pair-living territorial primates, female Javan gibbon songs function for territorial defense, but we found no support for other functions such as intergroup avoidance, resource defense, and pair-bond reinforcement.     

NLRC5 regulates MHC class I antigen presentation in host defense against intracellular pathogens

NOD-like receptors (NLRs) are a family of intracellular proteins that play critical roles in innate immunity against microbial infection. NLRC5, the largest member of the NLR family, has recently attracted much attention. However, in vitro studies have reported inconsistent results about the roles of NLRC5 in host defense and in regulating immune signaling pathways. The in vivo function of NLRC5 remains unknown. Here, we report that NLRC5 is a critical regulator of host defense against intracellular pathogens in vivo. NLRC5 was specifically required for the expression of genes involved in MHC class I antigen presentation. NLRC5-deficient mice showed a profound defect in the expression of MHC class I genes and a concomitant failure to activate L. monocytogenes-specific CD8⁺ T cell responses, including activation, proliferation and cytotoxicity, and the mutant mice were more susceptible to the pathogen infection. NLRP3-mediated inflammasome activation was also partially impaired in NLRC5-deficient mice. However, NLRC5 was dispensable for pathogen-induced expression of NF-κB-dependent pro-inflammatory genes as well as type I interferon genes. Thus, NLRC5 critically regulates MHC class I antigen presentation to control intracellular pathogen infection.     

Vocal duetting by a mated pair of coral-billed ground-cuckoos (Carpococcyx renauldi) at the Metro Toronto Zoo

During a behavioral study, I recorded vocal duetting by a mated pair of Coral-billed Ground-cuckoos (Carpococcyx renauldi) at the Metro Toronto Zoo. The birds produced three different call types that were combined into four distinct simultaneous and antiphonal duetted sequences. Duetting bouts (n = 12) were always initiated by the male and lasted 1–15 min, although they were generally 2–5 min in length. During longer bouts, both male and female duet elements changed frequently. The loud, clear antiphonal duets were likely associated with long distance communication and could function in territorial defense. These calls were most frequently given as the cuckoos moved around the exhibit, and were often associated with interspecific aggression. Quiet duet sequences were generally uttered when the cuckoos were in close proximity to one another, often from an exposed perch. Close perching and concurrent duetting by this mated pair may also function in spatial defense since it could advertise a coordinated alliance in territorial defense to potential intruders. Zoo Biol 16:179–186, 1997. © 1997 Wiley-Liss, Inc.     

Observations of scent-marking and discriminating self from others by a domestic dog (Canis familiaris): tales of displaced yellow snow

Little is known about what stimuli trigger urinating or scent-marking in domestic dogs, Canis familiaris, or their wild relatives. While it is often suggested that the urine of other animals influences urinating and scent-marking patterns in canids, this has not been verified experimentally. To investigate the role of urine in eliciting urinating and marking, in this pilot study I moved urine-saturated snow ('yellow snow') from place-to-place during five winters to compare the responses of an adult male domestic dog, Jethro, to his own and others' urine. Jethro spent less time sniffing his own urine than that of other males or females, and that while his interest in his own urine waned with time it remained relatively constant for other individuals' urine. Jethro infrequently urinated over or sniffed and then immediately urinated over (scent-marked) his own urine. He marked over the urine of other males more frequently than he marked over females' urine. The method used here can be extended to other species for which experimental data are lacking. Though based on one dog, these novel data may further our knowledge of the role of scent-marking in territorial behavior and of sex differences in territory acquisition and maintenance.     

ER Quality Control Components UGGT and STT3a Are Required for Activation of Defense Responses in Bir1-1

The receptor-like kinase SUPPRESSOR OF BIR1, 1 (SOBIR1) functions as a critical regulator in plant immunity. It is required for activation of cell death and defense responses in Arabidopsis bak1-interacting receptor-like kinase 1,1 (bir1-1) mutant plants. Here we report that the ER quality control component UDP-glucose:glycoprotein glucosyltransferase (UGGT) is required for the biogenesis of SOBIR1 and mutations in UGGT suppress the spontaneous cell death and constitutive defense responses in bir1-1. Loss of function of STT3a, which encodes a subunit of the oligosaccharyltransferase complex, also suppresses the autoimmune phenotype in bir1-1. However, it has no effect on the accumulation of SOBIR1, suggesting that additional signaling components other than SOBIR1 may be regulated by ER quality control. Our study provides clear evidence that ER quality control play critical roles in regulating defense activation in bir1-1.     

Field observations on scent-marking behaviour in saddle-back tamarins, Saguinus fuscicollis (Callitrichidae, Primates)

The scent-marking behaviour of a group of six saddle-back tamarins, Saguinus fuscicollis nigrifrons , was studied in the Amazon rain forest of north-eastern Peru. Three types of scent marking were recognized: anogenital marking, suprapubic marking and sternal marking. Anogenital marking was the most frequent type. Two or more scent-marking acts of the same or different type were generally combined into sequences. Most scent-marking was performed on branches and lianas; trunks were infrequently used. The tamarins mainly marked on horizontal or inclined substrata with diameters between 3 and 10 cm and a height between I and 10 m. The temporal distribution of scent-marking exhibited a maximum in the early morning between 06:00 and 07:00h and a minimum between 16:00 and 17:00h. The majority of scent-marking occurred in the peripheral areas of the home-range. The spatial distribution of scent-marking was correlated with the intensity of home-range use. No elevated frequencies of scent-marking were observed during intergroup encounters. The results of this field study are compared with findings from laboratory studies, and hypotheses concerning the function of scent-marking are discussed.     

Sex difference in the communicatory significance of localized defecation sites in Arabian gazelles (Gazella arabica)

Mammalian scent marking in localized defecation sites (latrines) has often been interpreted in the context of (male) territory defense. However, latrines could have different functions in males and females, especially where territorial males monopolize groups of females with stable social alliances and pronounced home range overlap. We investigated the communicatory significance of latrines in wild Arabian gazelles (Gazella arabica) and assessed the spatial distribution of latrines within home ranges. Latrine density and utilization was highest in the center of female group home ranges, and less frequent in peripheral home range sections, pointing towards communication within groups rather than towards territoriality. When considering male home ranges, latrine densities and utilization were higher in non-overlap zones, contradicting a territorial function. This pattern appears to be caused by more females than territorial males per given area establishing latrines. A subsequent survey of latrine utilization, based on camera trapping, suggests that males use latrines for territory defense: males visited latrines in overlap zones disproportionally more often than females, and successions of two males prevailed. Our study thus highlights that male territorial marking can be masked when males and females use the same marking system for different purposes.     

Impact of season and social challenge on testosterone and corticosterone levels in a year-round territorial bird

Plasma testosterone increases during breeding in many male vertebrates and has long been implicated in the promotion of aggressive behaviors relating to territory and mate defense. Males of some species also defend territories outside of the breeding period. For example, the European nuthatch (Sitta europaea) defends an all-purpose territory throughout the year. To contribute to the growing literature regarding the hormonal correlates of non-breeding territoriality, we investigated the seasonal testosterone and corticosterone profile of male (and female) nuthatches and determined how observed hormone patterns relate to expression of territorial aggression. Given that non-breeding territoriality in the nuthatch relates to the reproductive context (i.e., defense of a future breeding site), we predicted that males would exhibit surges in plasma testosterone throughout the year. However, we found that males showed elevated testosterone levels only during breeding. Thus, testosterone of gonadal origin does not appear to be involved in the expression of non-breeding territoriality. Interestingly, territorial behaviors of male nuthatches were stronger in spring than in autumn, suggesting that in year-round territorial species, breeding-related testosterone elevations may upregulate male-male aggression above non-breeding levels. In females, plasma testosterone was largely undetectable. We also examined effects of simulated territorial intrusions (STIs) on testosterone and corticosterone levels of breeding males. We found that STIs did not elicit a testosterone response, but caused a dramatic increase in plasma corticosterone. These data support the hypothesis that corticosterone rather than testosterone may play a role in the support of behavior and/or physiology during acute territorial encounters in single-brooded species.