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The major histocompatibility complex (MHC) has been intensively studied for the relative effects of different evolutionary forces in recent decades. Pathogen-mediated balancing selection is generally thought to explain the high polymorphism observed in MHC genes, but it is still unclear to what extent MHC diversity is shaped by selection relative to neutral drift. In this study, we genotyped MHC class II DRB genes and 15 neutral microsatellite loci across 26 geographic populations of European badgers (Meles meles) covering most of their geographic range. By comparing variation of microsatellite and diversity of MHC at different levels, we demonstrate that both balancing selection and drift have shaped the evolution of MHC genes. When only MHC allelic identity was investigated, the spatial pattern of MHC variation was similar to that of microsatellites. By contrast, when functional aspects of the MHC diversity (e.g., immunological supertypes) were considered, balancing selection appears to decrease genetic structuring across populations. Our comprehensive sampling and analytical approach enable us to conclude that the likely mechanisms of selection are heterozygote advantage and/or rare-allele advantage. This study is a clear demonstration of how both balancing selection and genetic drift simultaneously affect the evolution of MHC genes in a widely distributed wild mammal.

Global climatic processes have driven an expansion of arid environments, as well as the human populations that depend on these biomes. Human habitation can influence desert ecosystems directly through changes in land use and indirectly through the introduction of alien species that compete with locally adapted fauna. Native species can respond to these processes by spatial or temporal avoidance. Ruppell’s fox is a desert-adapted species inhabiting flat, rocky arid areas that feeds mainly on invertebrates and rodents. We used location data and step selection functions to study the space use of a population in southern Israel. We hypothesized that Ruppell’s fox movement would be influenced by topography due to preference for creeks, where insects and rodents are available, and by human infrastructure as the presence of humans, vehicles and associated animals may induce a fear effect on native species. Ruppell’s fox habitat selection was seasonal. During the dry season, foxes showed preference for flatter areas and creek bottoms and avoided paved roads. During the rainy season, foxes avoided less- trafficked dirt roads. These patterns were likely a consequence of increased territoriality due to denning in the colder season and reduced availability of insects in the dry season. Avoidance of paved and dirt roads may be explained by fear of human presence and perception of risk due to the use of linear features by larger carnivores, such as wolves and red foxes. Our results suggest that current protected, remote and uninhabited areas have an elevated value for the persistence of Ruppell’s fox populations. We recommend limitation of vehicle movement within current reserves and continued monitoring of population trends for this little studied carnivore.

Rhythmic stability (nonrandom temporal structure) is required for many neural and physiological functions, whereas rhythmic irregularities can indicate genetic or developmental deficiencies. Therefore, rhythmic courtship or contest signals are widespread in nature as honest advertisement displays. Examination of bird songs revealed the pervasiveness of categorical rhythmic patterns that can be described as small integer ratios between sequential inter-call intervals. As similar rhythmic profiles are prevalent in human music, it was suggested that a shared functionality could drive both animal songs and human musical rhythms, facilitating synchrony between signallers and enabling easy identification of performance errors. Here we examined whether the rhythmic structure and the rhythmic stability of vocal displays are related to reproductive success in male rock hyraxes (Procavia capensis), which presents an unusual case of a terrestrial singing mammal. We combined long-term parentage analysis of 13 male hyraxes (22 male/years) with an analysis of an audio library of 105 hyrax songs. Male annual reproductive success was determined by the number of offspring that survived to the age of 1 year. The frequency of singing events was used to determine the seasonal singing effort for each male. Songs were analysed for rhythmic structure, focusing on the presence of categorical rhythms and the contribution of rhythmic stability to annual reproductive success. We found that male hyraxes that sing more frequently tend to have more surviving offspring and that the rhythmic profile of hyrax songs is predominantly isochronous with sequential vocal element pairs nearly equally spaced. The ratio of isochronous vocal element transitions (on-integer) to element transitions that deviate from an isochronous pattern (off-integer) in hyrax songs is positively correlated with male reproductive success. Our findings support the notion that isochronous rhythmic stability can serve as an indication of quality in sexually selected signals and is not necessarily driven by the need for multiple caller synchronization. The relative scarcity of nonisochronous rhythmic categories in individually performed hyrax songs raises the question of whether such rhythmic categories could be a product of collective, coordinated signalling, while being selected against in individual performance.

1.Information complexity in animals is an indicator of advanced communication and an intricate socio‐ecology. Zipf's Law of least effort has been used to assess the potential information content of animal repertoires, including whether or not a particular animal communication could be ‘language‐like’. As all human languages follow Zipf's law, with a power law coefficient (PLC) close to −1, animal signals with similar probability distributions are postulated to possess similar information characteristics to language. However, estimation of the PLC from limited empirical datasets (e.g. most animal communication studies) is problematic because of biases from small sample sizes.\ud 2.The traditional approach to estimating Zipf's law PLC is to find the slope of a log–log rank‐frequency plot. Our alternative option uses the underlying equivalence between Shannon entropy (i.e. whether successive elements of a sequence are unpredictable, or repetitive) and PLC. Here, we test whether an entropy approach yields more robust estimates of Zipf's law PLC than the traditional approach.\ud 3.We examined the efficacy of the entropy approach in two ways. First, we estimated the PLC from synthetic datasets generated with a priori known power law probability distributions. This revealed that the estimated PLC using the traditional method is particularly inaccurate for highly stereotyped sequences, even at modest repertoire sizes. Estimation via Shannon entropy is accurate with modest sample sizes even for repertoires with thousands of distinct elements. Second, we applied these approaches to empirical data taken from 11 animal species. Shannon entropy produced a more robust estimate of PLC with lower variance than the traditional method, even when the true PLC is unknown. Our approach for the first time reveals Zipf's law operating in the vocal systems of multiple lineages: songbirds, hyraxes and cetaceans.\ud 4.As different methods of estimating the PLC can lead to misleading results in real data, estimating the balance of a communication system between simplicity and complexity is best performed using the entropy approach. This provides a more robust way to investigate the evolutionary constraints and processes that have acted on animal communication systems, and the parallels between these processes and the evolution of language.

Acoustic and rhythmic temporal patterns may have important roles both in animal vocalizations and in human music. Male rock hyraxes, Procavia capensis, advertise their quality and emotional state by singing a long complex song, comprising repetitive elements. Research has revealed that the temporal structure of hyrax songs is similar to a musical crescendo, as it includes a gradual increase in amplitude, along with several additional acoustic and structural parameters, throughout the song. In hyrax songs, the snort is a relatively rare, low and harsh vocal element, which increases in number as the song progresses. We have previously shown that mean snort harshness is positively linked to both the singer's social status and testosterone levels, possibly reflecting inner arousal. Here, we measured the changes in snort harshness and length during natural hyrax songs. Our results indicate that in mature males, harshness, quantified by shimmer and jitter, increases as the song progresses. We suggest that increasing snort harshness may either (1) indicate the progression of inner excitement or aggression throughout the song or (2) that the harshness may reflect the difficulty of vocal control following increasing effort or the physical fatigue of the vocal cords. In western culture music, such progression is used to increase listener tension and thus retain attention, preventing possible habituation. Thus, understanding the development and progression of challenging elements within animal communication systems may reveal a key fundamental root of modern musical structure, and shed light on the evolutionary basis of musical perception.

A report on the skeletons of two individuals from the Malapa cave site in South Africa attributes them both to a new hominin species,Australopithecus sediba. However, our analysis of the specimens’ mandibles indicates that Australopithecus sedibais not a ‘Homo-like australopith’, a transitional species betweenAustralopithecus africanusandHomo. According to our results, the specimens represent two separate genera: AustralopithecusandHomo. These genera are known to have jointly occupied sites, as seen in several early South African caves, so one cannot rule out the possibility that Malapa also contains remains of the two taxa. Our results lead us to additionally conclude that all theAustralopithecusspecies on which the relevant mandibular anatomy is preserved (not only the ‘robust’ australopiths but also the ‘gracile’ – more generalised – ones) are too specialised to constitute an evolutionary ancestor ofHomo sapiens. Furthermore, given that the Malapa site contains representatives of two hominin branches, one of which appears to beHomo, we must seek evidence of our origins much earlier than the date assigned to Malapa, approximately 2 million years before present. Support for this claim can be found in Ethiopian fossils attributed to the genus Homoand dated at 2.4 and 2.8 million years before present.Significance: The proposed hominin speciesAustralopithecus sediba, from the Malapa Cave in South Africa, seems to actually consist of two species, each of which represents a different hominin genus: Homo and Australopithecus. If, indeed, this is the case,Homomust have originated prior to the Malapa remains, contrary to the scenario suggested in the original report onAu. sediba.

Sex differences in vocalizations are found across the animal kingdom, which may be due to different vocal apparatus, call function, and context. Rock hyraxes (Procavia capensis) of both sexes are vocal, but the sexes differ in repertoire size, call usage, and amplitude. In this study we examined sex differences in vocalization frequencies and predicted that they will be low and that frequency ranges will overlap since sexual size dimorphism in this species is modest (~ 15%). We utilized two datasets: recordings of captive hyraxes using a condenser microphone; and audio files of wild-living individuals recorded via a miniature recorder mounted on a collar. With the exclusion of two proximate call types recorded in the wild, all calls featured an ultrasonic component. However, in females there was an effect of duration on minimal frequency. Warning trills, which are heard by humans far away, featured the highest maximal visible harmonic in both datasets. No relationship was found between calling distance and the maximal harmonic in males, while in wild females, distant calls featured higher frequencies. Our results show sex differences in hyrax vocalization frequencies. Exploring the information encoded in frequencies beyond the human hearing range may expand our understanding of animal communication.

Although males and females share traits, their motivations and needs may be different, due to life-history disparities that lead to divergent selection pressures. Proximate mechanisms underlying differences between the sexes include hormones that mediate the development and activation of suites of traits. Testosterone is associated with morphological features, physiological processes, and social behaviors in both sexes. However, even if present in similar concentrations in the circulation, testosterone often affects males and females differently. We combined behavioral mating observations of the wild polygynandrous rock hyrax (Procavia capensis) with hair testosterone that represents long-term integrated levels. We found that whereas copulation success increases with the rise in testosterone in males it decreases in females. We did not find an association between testosterone and choosiness in either sex. However, we found that males with higher testosterone mate-guarded females with lower testosterone. Our findings show disassortative mating and mate-guarding in respect to testosterone and provide clues to the cost of testosterone for females, in terms of copulation success. These results open up intriguing questions relating to the role of testosterone in mediating a similar trade-off in male and female reproductive success.

The ontogeny of quality-based signals has been studied in numerous animal systems but the degradation of vocal signals with age has received much less attention. Investigating age-related changes in quality-based acoustic signals and the associated social processes (e.g. rank changes, competition intensity) can expand our understanding of the information content of signals and their perception by receivers. To address this issue, we monitored the changes in syntactic complexity of songs in male rock hyraxes, Procavia capensis, over their lifetime. These songs are known to reflect the signallers' identity and quality. We found that age, residency and tenure had a combined effect on the syntactic structure of signals. Progression trends differed according to the signallers’ social status. For mature bachelor males song complexity increased with age, whereas it decreased for resident males, which had performed complex songs at the beginning of their residency tenure. This decline in complexity, potentially indicating fatigue, has also been associated with increased competition pressure, reflected in males' increased tendency to become involved in fights. In previous studies on animal vocal signalling and human speech, no effects of senescence on syntactic complexity were detected. Our current findings, however, suggest that vocal complexity is informative and could be reflective of the condition and competitive abilities of the signallers. However, an alternative explanation of lower signal complexity due to decreasing competitive motivation is also discussed.

Cryptic phylogeographic diversifications provide unique models to examine the role of phylogenetic divergence on the evolution of reproductive isolation, without extrinsic factors such as ecological and behavioural differentiation. Yet, to date very few comparative studies have been attempted within such radiations. Here, we characterize a new speciation continuum in a group of widespread Eurasian amphibians, the Pelobates spadefoot toads, by conducting multilocus (restriction site associated DNA sequencing and mitochondrial DNA) phylogenetic, phylogeographic and hybrid zone analyses. Within the P. syriacus complex, we discovered species‐level cryptic divergences (>5 million years ago [My]) between populations distributed in the Near‐East (hereafter P. syriacus sensu stricto [s.s.]) and southeastern Europe (hereafter P. balcanicus), each featuring deep intraspecific lineages. Altogether, we could scale hybridizability to divergence time along six different stages, spanning from sympatry without gene flow (P. fuscus and P. balcanicus, >10 My), parapatry with highly restricted hybridization (P. balcanicus and P. syriacus s.s., >5 My), narrow hybrid zones (~15 km) consistent with partial reproductive isolation (P. fuscus and P. vespertinus, ~3 My), to extensive admixture between Pleistocene and refugial lineages (≤2 My). This full spectrum empirically supports a gradual build up of reproductive barriers through time, reversible up until a threshold that we estimate at ~3 My. Hence, cryptic phylogeographic lineages may fade away or become reproductively isolated species simply depending on the time they persist in allopatry, and without definite ecomorphological divergence.

Nonindigenous species are considered among the major threats to biodiversity. A deep understanding of the processes underlying invasion is impeded, among others, by insufficient taxonomic and distributional knowledge. The Mediterranean Sea is experiencing a large invasion by Red Sea species as a result of the opening of the Suez Canal, at a rate which far exceeds those in any other open marine system. Here, we focus on a potential Red Sea marine invader into the Mediterranean, the mytilid Brachidontes pharaonis, as a case study, and review alternative explanations for its present distribution in the Mediterranean, Red Sea, and the Indo-Pacific. A previous study showed a significant difference in haplotype composition among the Mediterranean and the northern Red Sea and that most Mediterranean Sea haplotypes were unique (up to 80%). We present updated analyses using mitochondrial DNA (mtDNA) samples from the Persian Gulf (Arabian Sea) and compare them to populations in the Mediterranean, Red Sea, and Sri Lanka. We found that haplotypes collected in the southern Red Sea, Qatar, and Sri Lanka were significantly distinct from all those sampled in the eastern Mediterranean and northern Red Sea. In contrast, the haplotypes from Abu Dhabi, a large, active port, clustered within those from the Mediterranean Sea and the northern Red Sea. Together, the Persian Gulf and the Indian Ocean do not seem to be the sources of the Mediterranean and northern Red Sea populations. The presence of many haplotypes within the Mediterranean and northern Red Sea that are not traceable to other populations (apart from Abu Dhabi) suggests that B. pharaonis is not truly a nonindigenous to the Mediterranean but, rather, is a previously undetected indigenous species. The establishment of the Suez Canal may have brought together divergent lineages and resulted in an admixture of populations, but this scenario alone cannot explain the rich assembly of unique haplotypes in the Mediterranean Sea. Our results lead to a better understanding of the genetic structure of this species. The results of our study suggest that detailed empirical and careful evaluations are needed in order to resolve the correct origin of those classified as nonindigenous species.

Vocal quality allows listeners to derive information on properties of the caller such as body size and state of arousal. Male rock hyraxes advertise themselves by singing. We found that the stability of a single song element can be used to predict both body size and social rank of the singer. We also showed that other hyraxes may consider this information when deciding how to interact with the singer.

Testosterone is a key regulator in vertebrate development, physiology and behaviour. Whereas technology allows extraction of a wealth of genetic information from extant as well as extinct species, ...

Many territorial animals interact less aggressively with neighbours than with strangers, a phenomenon known as the ‘dear enemy’ effect, although some species show the opposite behaviour. Rock hyraxes, Procavia capensis, are social mammals that communicate via a rich acoustic repertoire. Male hyraxes produce elaborate advertisement calls (i.e. songs) both spontaneously and in response to occasional attention-grabbing events (e.g. pup screams, agonistic interaction), as well as to conspecific male songs. When replying to conspecific songs, male hyraxes tend to respond more to familiar males than to strangers, reflecting the ‘nasty neighbour’ effect. Our study relates to the general question of why some species respond aggressively towards neighbours, while others are more aggressive towards strangers. We hypothesized that male hyraxes eventually familiarize themselves with a stranger, subsequently perceiving its intentions as highly threatening and deserving of a vocal response. To simulate the presence of a stranger in the area we exposed wild hyrax groups to playbacks of natural songs of unfamiliar hyraxes. Male rock hyraxes became more likely to reply to a stranger's song over time, but this was independent of the number of times they heard the song. This suggests that either (1) the threat presented by a stranger increases when it is no longer perceived as transient or (2) because listeners do not physically encounter the stranger, they perceive replying aggressively as a low-risk response. Our work implies that species may demonstrate a range of condition-dependent behaviours instead of a dichotomy between the ‘nasty neighbour’ and ‘dear enemy’ strategies.

Dramatic global amphibian declines have recently led to an increased concern for many species of this animal class. The enigmatic Hula painted frog (Latonia nigriventer), the first amphibian to be declared extinct but unexpectedly rediscovered in 2011, has remained one of the rarest and most poorly understood amphibians worldwide. Gathering basic biological information on this species, along with an understanding of its disease-related threats remains fundamental for developing risk assessments and conservation strategies. Our surveys in recent years confirmed that L. nigriventer is a localised species with elusive habits. The species appears to follow an opportunistic breeding phenology and has a tadpole morphology similar to its well-studied sister group Discoglossus. However, the adults’ extended annual presence in the aquatic habitat is a major difference from species of Discoglossus. We detected the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), in northern Israel and on Hula painted frogs but did not observe any signs of chytridiomycosis in this species. Our preliminary data on aspects of the innate immunity of L. nigriventer suggest that the skin mucosome of this species contains antimicrobial peptides and a bacterial community differing from other syntopic frogs (Pelophylax bedriagae). The combined knowledge of both natural history and innate immunity of L. nigriventer provides valuable insights to direct future research and conservation management of this critically endangered frog species.

The complex effects of geography, ambient temperature, and North Atlantic Oscillation on the body size of Arctic hares in Greenland

Diet is central for understanding hominin evolution, adaptation, and environmental exploitation, but Paleolithic plant remains are scarce. A unique macrobotanical assemblage of 55 food plant taxa from the Acheulian site of Gesher Benot Ya'aqov, Israel includes seeds, fruits, nuts, vegetables, and plants producing underground storage organs. The food plant remains were part of a diet that also included aquatic and terrestrial fauna. This diverse assemblage, 780,000 y old, reflects a varied plant diet, staple plant foods, environmental knowledge, seasonality, and the use of fire in food processing. It provides insight into the wide spectrum of the diet of mid-Pleistocene hominins, enhancing our understanding of their adaptation from the perspective of subsistence. Our results shed light on hominin abilities to adjust to new environments, facilitating population diffusion and colonization beyond Africa. We reconstruct the major vegetal foodstuffs, while considering the possibility of some detoxification by fire. The site, located in the Levantine Corridor through which several hominin waves dispersed out of Africa, provides a unique opportunity to study mid-Pleistocene vegetal diet and is crucial for understanding subsistence aspects of hominin dispersal and the transition from an African-based to a Eurasian diet.

Maynard-Smith’s game-theoretical framework suggests that conflicts should be resolved through an exchange of agonistic displays which can be as effective as physical attack in securing contested resources. Hence, participants use signaling tactics that are governed by game-theoretical competition rules to maximize their benefit from the interaction. In rock hyraxes, males initiate singing in response to conspecific male songs, possibly to self-advertise and to facilitate comparison of performance by receivers. We hypothesized that hyrax counter-singing strategy can be explained by resident-intruder model and its outcome is determined by the identity and ability of the participants. Natural hyrax singing events and playback-induced events were classified according to the participants’ residence status—resident or bachelor (i.e., non-resident). As predicted by the resident-intruder model, resident listeners tended to reply to conspecific males at high rates (≈40 %), while bachelors showed low reply rates (17 %) to resident initiators. Unexpectedly, the lowest-ranking bachelors showed a tendency to reply to the highest-ranking residents. One possible explanation for this counter-intuitive behavior might be that weaker individuals exploit a situation in which it is unremunerated for a stronger opponent to retaliate (i.e., Napoleon strategy) and seize a self-advertisement opportunity in front of a large audience attending to the high-ranking males’ signal. Overall, we show that male hyraxes employ different counter-singing tactics depending on the residence and rank differences between the participants. This choice of competition tactics can be based on opponents’ individual recognition or/and on direct decoding of opponents’ traits encoded in the song. In nature, conflicts are usually resolved through signaling rather than by actual fighting. Rock hyrax males often participate in vocal competitions, possibly to reduce the need for physical confrontations. During our study on the dynamics of male hyrax vocal competition, we discovered that hyraxes employ mixed counter-singing strategy dependent on the residence status and social rank differences between the participants. A paradoxical “Napoleon-complex” tactic was observed in interactions between males, when low ranking bachelors were found to interact and challenge the highest-ranking residents. On the other hand, residents were found to interact with opponents regardless of residency and/or rank. On top of the cognitive abilities required to individually recognize an opponent and possibly decode its vocal signals, our results suggest that male hyraxes compare own individual traits to those of the opponent in a mutual signal assessment interaction.

Changing body colour in animals generally reflects a conflict between two selection pressures, camouflage and social signalling. Chameleons are among the few organisms that resolve this conflict by rapid and temporary change in body colour for both background matching and social display. Male common chameleons, Chamaeleo chamaeleon, employ two alternative mating tactics, dominants and subordinates, both of which are associated with long-term body colour patterns and instantaneous colour displays during social encounters. Hence, males present a good model in which to study the influence of mating tactic on the decision of whether to remain cryptic or to signal. We exposed individuals to two conflicting external stimuli: background manipulations, which challenge camouflage, and the presence of a female, which stimulates sexual signalling. No individuals of either mating tactic responded to background manipulation except when the shift was from green to brown background or vice versa. Ambient temperatures affected colour matching but not sexual signalling, while body temperature affected neither. Males ignored the background colour and prioritized being distinctive when encountering females. As such, males were more likely to engage in sexual signalling than crypsis. Subordinate sneakers signalled females more frequently than the dominant, female-guarding males, suggesting that sneakers rapidly signal females their intentions when the dominant is out of range. Conversely, dominant males may gain little by frequent signalling to the females they guard, while possibly gaining more by diverting this energy towards mate guarding. Our results suggest that specific male mating tactics strongly influence the decision to use crypsis or sexual signalling.

To investigate the evolution and biogeography of an endemic group of South American foxes, we examined mitochondrial DNA control region sequences for 118 individuals belonging to all six extant species of the genus Lycalopex. Phylogenetic and molecular dating analyses supported the inference that this genus has undergone a very recent and rapid radiation, stemming from a common ancestor that lived ca. 1 million years ago. The Brazilian endemic L. vetulus was supported as the most basal species in this genus, whereas the most internal group is comprised by the recently diverged (ca. 350,000 years ago) Andean/Patagonian species L. griseus and L. culpaeus. We discuss the inferred phylogenetic relationships and divergence times in the context of the current geographic distributions of these species, and the likely effects of Pleistocene climatic changes on the biogeography of this group. Furthermore, a remarkable finding was the identification of multiple individuals classified as L. gymnocercus bearing mtDNA haplotypes clearly belonging to L. griseus, sampled in regions where the latter is not known to occur. At a minimum, this result implies the need to clarify the present-day geographic distribution of each of these fox species, while it may also indicate an ongoing hybridization process between them. Future testing of this hypothesis with in-depth analyses of these populations is thus a priority for understanding the history, evolutionary dynamics and present-day composition of this endemic Neotropical genus. Fil: Tchaicka, Ligia. Universidade Estadual do Maranhão; Brasil Fil: de Freitas, Thales Renato Ochotorena. Universidade Federal do Rio Grande do Sul; Brasil Fil: Bager, Alex. Universidade Federal de Lavras; Brasil Fil: Luengos Vidal, Estela Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina Fil: Lucherini, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina Fil: Iriarte, Agustín. Pontificia Universidad Católica de Chile; Chile Fil: Novaro, Andres Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Geffen, Eli. Tel Aviv University; Israel Fil: Garcez, Fabricio Silva. Pontificia Universidade Catolica Do Rio Grande Do Sul. Facultad de Biociencias; Brasil Fil: Johnson, Warren H.. Smithsonian Conservation Biology Institute; Estados Unidos Fil: Wayne, Robert K.. University of California at Los Angeles; Estados Unidos Fil: Eizirik, Eduardo. Pontificia Universidade Catolica Do Rio Grande Do Sul. Facultad de Biociencias; Brasil. Instituto Pró-Carnívoro; Brasil

In polygynandrous mating systems, the factors that mediate copulation success and the use of alternative mating tactics, such as mate guarding, are still poorly understood. In the rock hyrax (Procavia capensis), both sexes mate annually with multiple partners during a single month. In order to examine the factors that drive copulation success, we used 494 mating-related observations that were collected over a decade. In our analysis, we used the traits of individual hyraxes as well as the traits of members of their sexual niche, which we defined as their local competitors and potential mates. Using individual traits, we found that overall, female hyraxes rejected copulation attempts more frequently than males, supporting predictions from sexual selection theory. Females who had been mothers in previous years were mate-guarded more by resident males. When we considered the traits of competitors and potential mates in individuals’ sexual niche, we found that when resident males had higher-ranking competitors, their copulation success decreased, irrespective of their own traits. Bachelor male copulation success was not influenced by their competitor’s social status. Female copulation success was positively affected by maternal status and by social network position. Females that were central in the social network and those that had central female competitors had higher copulation success, supporting the benefits of social cohesion and the importance of the social niche. Thus, our results suggest that in polygynandrous mating systems, copulation success is determined not only by individual quality but also by the social and sexual niches that the individual occupies. Social networks describe with whom individuals consort. The complex patterns of sexual relationships in animal societies can also be expressed as networks of mating-related interactions. During our long-term study on the dynamic social relationships of wild rock hyraxes, we observed complex sexual interactions. Our results show that hyraxes choose mating partners from their available mate pool (or sexual niche) taking into account the traits of their actual mates, other potential mates, and those of their competitors. These findings suggest that the sexual niche, describing the subset of available mating partners, is important for mate choice, with significant implications to the study of sexual selection.

We studied the eff ect of the two environmental indices, the sub-polar gyre (SPG), and winter and summer North Atlantic Oscillation (NAO), together with mean annual winter and summer temperatures and geographic location on mandible size and body mass of Arctic foxes in Iceland (6345 and 2732 specimens, respectively) during the year of their death. We predicted that when favorable conditions prevailed, large specimens would be selected for, and vice versa. Body size and body mass were signifi cantly aff ected by the environmental parameters (i.e. SPG, NAO, ambient temperature and cloud cover) prevailing during the year of death. Th e eff ect of environmental conditions on body size was much stronger in the less productive region of eastern Iceland, apparently because in areas where food availability is meager, even a small diff erence in climate may tilt the balance from food suffi ciency to food shortage. Western Iceland comprises only a quarter of the total surface area of the country, but its productive seashores are twice as long as those of all the rest of the country combined. It is interesting to note that the eff ect of the SPG, a marine phenomenon in the oceans surrounding Iceland, is refl ected in the condition of the foxes more than the other climatic variables we used in this study, which are largely land-related. Because Arctic foxes in Iceland feed largely on marine birds and invertebrates, the SPG seems to encompass more accurate information regarding the direct ocean forces that aff ect food availability to the foxes.

Testosterone affects physical and motivational states, both of which may strongly influence vocalization structure and acoustics. The loud complex calls (i.e., songs) of male rock hyraxes (Procavia capensis) are used as honest signals for advertising physical and social states. The snort, a low frequency, noisy element of the song, encodes information on the singer's age and social rank via harshness, as measured by jitter (i.e., acoustic frequency stability) and duration; suggesting that the snort concomitantly advertises both vocal stability and aggression. Our past findings revealed that testosterone levels are related to both vocal elements and social status of male hyraxes, suggesting that hormonal mechanisms mediate the motivation for aggressive and courtship behaviors. Here we examined whether long-term androgen levels are related to snort acoustics and song structure by comparing levels of testosterone in hair with acoustic and structural parameters. We found that songs performed by individuals with higher testosterone levels include more singing bouts and longer, smoother snorts, but only in those songs induced by external triggers. It is possible that hyraxes with higher levels of testosterone possess the ability to perform higher-quality singing, but only invest in situations of high social arousal and potential benefit. Surprisingly, in spontaneous songs, hyraxes with high testosterone were found to snort more harshly than low-testosterone males. The context dependent effects of high testosterone on snort acoustics suggest that the aggressive emotional arousal associated with testosterone is naturally reflected in the jittery hyrax snort, but that it can be masked by high-quality performance.

Morton’s motivation-structural (MS) rules suggest that the acoustic structure of a signal can reflect the caller’s motivation and internal state. In many species, low-frequency and noisy (harsh) sounds have been found to comply with MS rules, accompanying agonistic interactions and functioning as a badge of aggression and dominance. Male rock hyraxes (Procavia capensis) often produce long and complex advertisement calls (songs) both "spontaneously" and in counter-singing sessions with other males. Hyrax songs include a "snort" vocal element, which is a harsh sound produced only by mature, dominant males. We predicted that the number of snort elements in the song would affect the dynamics of male hyrax counter-singing. We performed 3 series of playback experiments of natural and artificially manipulated songs on a wild hyrax population. We found that the probability of initiating counter-singing by nearby males increased together with the number of snorts in the stimulus song. Furthermore, the receivers replied to the synthetic "snort-only" vocal sequences at an equal rate as to their origin song as long as the snort elements maintained their original position within the signal. Our findings suggest that the snort component is one of the main information transfer channels in male hyrax singing and can elicit conspecific singing even when isolated from other vocal elements. In addition, the position of snort elements (their temporal pattern and rhythm) bears a possible significance in keeping the overall signal meaningful. Finally, our findings support previous claims that harsh sounds constitute one of the key components in vocal communication.

Aim In this paper we explore global links between tree canopy height and species richness of amphibians, birds and mammals. We follow the ideas first laid out by MacArthur and MacArthur in 1961 who found that in the eastern USA higher tree canopies supported more bird species, which they attributed to an increase of available niches as forests grow taller. We test if their findings can be generalized over large regions and other taxa by employing novel methods and using current datasets. Location Global Methods We used the global distribution maps of the three above taxa to infer species richness. Our tree canopy height information was derived from remotely sensed LiDAR data. The analysis was conducted globally and within biogeographical realms. We modeled richness, using tree canopy height and other environmental correlates, with generalized additive models and geographically weighted regressions. Results Globally, tree canopy height proved to be of lesser importance in explaining species richness patterns compared to other environmental drivers. Within biogeographical realms, tree canopy height was found to be a more important predictor of diversity in the Neotropic and Australian realms. Regional patterns show that tree canopy height has an important effect on diversity of amphibians throughout the world and in several tropical regions across taxa. Net Primary Productivity (NPP) explains more of the variation in richness both globally and within most regions. Main Conclusions Overall, tree canopy height is not an important predictor of diversity. However we highlight its relative importance in particular locations and settings.

© 2015 Elsevier Ltd. The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus) [1, 2], which is surprising giventhe absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than onemillion years, sufficient to merit formal recognition as different species: C.anthus (African golden wolf)and C.aureus (Eurasian golden jackal). Usingmorphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification. Koepfli etal. assess divergence between golden jackals (Canis aureus) from Africa and Eurasia using data from the mitochondrial and nuclear genomes. They show that African and Eurasian golden jackals are genetically distinct and independent lineages, and that African golden jackals likely represent a separate species.

The goal of vocal communication is the efficient delivery of signals to a target audience. Long and complex vocalizations are especially challenging because they are subject to environmental interference and may incur significant costs for the signaler. One of the various ways of increasing the efficiency of signal delivery is enhancement of communicational efforts only when potential audience is perceived nearby in an attempt to maximize the benefit over the cost of signaling (audience effect). Another way is signaling subsequently to events that intensify individual alertness in order to ensure audience attentiveness and sensitivity to the transmitted information. Rock hyraxes (Procavia capensis) are social mammals that use complex acoustic signals to communicate. Adult male hyraxes produce elaborate vocalizations (known as songs) that serve as honest advertisements of their quality. By combining analysis of male hyrax songs recorded in the field over a period of 11 years and playback experiments, we found that songs performed during and following attention-grabbing events (agonistic interactions, alarm calls, predator presence, and songs performed as a reply to conspecific singing) have an increased structural and syntactic complexity in comparison to spontaneous singing. Male hyraxes demonstrate a cognitive ability to optimize their advertising efforts in response to multiple types of events. This signaling strategy exploits the effective communication window created by attention-grabbing events and by the presence of an alert audience to delivers structurally and syntactically enhanced signal. To our knowledge, this is the first report of syntactic complexity of vocal signaling being altered following various triggers that change conspecifics mental state in terrestrial mammals.