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1.
Animals that deposit aquatically derived nutrients on terrestrial landscapes link food webs and affect a variety of in situ processes. This phenomenon, however, is poorly documented in freshwater habitats, especially where species introductions have drastically changed an ecosystem's trophic structure. In this study, we used stable isotopes to document water-to-land nutrient transport by river otters (Lontra canadensis) around Yellowstone Lake, an ecosystem recently altered by nonnative species invasions. We then investigated the effects of otter fertilization on plant growth and prevalence at latrine (scent-marking) sites and evaluated how the recent changes to the lake's food web could influence these plant responses. Values of delta15N were higher on latrines compared to non-latrine sites in five of seven sample plant taxa. Additionally, latrine grasses had higher percentage N than those from non-latrines. Foliar delta15N positively related to fecal deposition rate for some plants, indicating that increased otter scent-marking led to a rise in these N values. Logistic regression models indicated that otters selected for well-shaded latrines with access to foraging. Atypical latrines, misclassified as non-latrines by the regression models, had values of delta15N similar to correctly classified latrines, suggesting that site effects alone cannot explain elevated N values at otter latrine sites. No difference in plant diversity or percent cover of N-fixing taxa occurred between latrine and nonlatrine sites, though specific genera did differ between site types. Measurements of shoot lengths indicated increased growth of some latrine currants (Ribes sp.). In Yellowstone Lake, a twofold reduction in otter numbers could result in an even greater decline in nutrient deposition at latrines, as otters may become less social in a system with decreased prey availability. Our results highlight the role of animals in linking aquatic and terrestrial habitats in inland freshwater systems and suggest that ongoing changes in the trophic structure of Yellowstone Lake could have unexpected ramifications well beyond the lake itself. 相似文献
2.
Larissa Swedell Liane Leedom Julian Saunders Mathew Pines 《Behavioral ecology and sociobiology》2014,68(2):263-273
Fundamental reproductive interests dictate that females generally benefit most from mate selectivity and males from mate quantity. This can create conflict between the sexes and result in sexual coercion: male use of aggression to garner mating success at a cost to females. Potential fitness costs of sexual coercion, however, can be difficult to measure. Here, we demonstrate benefits to males and costs to females of female defense polygyny in wild hamadryas baboons, cercopithecoid primates in which females are coercively transferred among social units by males, restricting both female choice and bonding among female kin. Of all coercive transfers (takeovers) of females with young infants, 67 % were followed by infant mortality, which was significantly more likely to occur after takeovers than at other times. As expected, infant mortality decreased time to subsequent conception but lengthened intervals between surviving infants. Following infant survival, whether a female had experienced a takeover after the previous birth was a significant predictor of subsequent interbirth interval, with interbirth intervals of females remaining with the same male between births being significantly shorter than those of females incurring takeovers between births. Together, these results reveal that takeovers increase the chance of infant mortality while delaying subsequent conception. Male-driven female defense polygyny in this species is thus costly to females in two ways. These results demonstrate that reproductive strategies benefitting males can evolve despite substantial costs to females. These costs may be mitigated over the long term, however, by female counterstrategies and protective behavior by males. 相似文献
3.
The signature whistle hypothesis states that dolphins produce highly stereotyped, individually distinctive whistles when in isolation. The presence of signature whistles has been called into question by recent studies proposing that dolphins produce a shared, simple upsweep whistle when in isolation, and that whistles produced by socializing dolphins are shared across individuals and social groups. This shared repertoire hypothesis suggests that when two animals produce the same whistle type, it is due to sharing the same common repertoire rather than one animal learning to produce the whistle of another. One difference between studies supporting or denying the existence of signature whistles is the method used to classify whistle types. We examined whistle production by 17 free-ranging bottlenose dolphins while temporarily restrained. We used both a quantitative comparison technique similar to that used to support the shared repertoire hypothesis and human judges to classify whistle types and quantify similarity between types. Contrary to recent studies that emphasize shared whistles, overall whistle sharing between isolated individuals was low (25%) and a simple upsweep did not account for the most common whistle type in half of the animals. Some species of birds, bats, and primates with stable social groups use vocal learning to converge over time to one common group distinctive call type. We examined whistle similarity between adult male dolphins that are partners in a close social alliance in order to test whether vocal learning may enable a similar vocal convergence. Whistle similarity was rated very high between partners and low between non-partners by both the quantitative technique and human observers. This suggests that as in songbirds and some other mammals, adult male bottlenose dolphins may use vocal learning to converge on similar whistles as they develop affiliative social relationships.Communicated by G. Wilkinson 相似文献
4.
Long-distance calls produced by males are common among vertebrate species. Several hypotheses have been proposed to explain features of male long-distance calls and their phylogenetic distribution in primates, but the putative functions of male long-distance calls have yet to be tested comprehensively. We used phylogenetic comparative methods to investigate hypotheses for the function of male long-distance calls. We focused on the mate defense hypothesis, which states that male long-distance calls function in intra-sexual competition for mates, but we also examined factors involving resource defense, mate attraction, and habitat. Phylogenetic reconstruction of male long-distance calls in 158 primate species indicates that the presence of male long-distance calls is the ancestral state. The carrying distance of male long-distance calls is correlated with the size of the home range, which is consistent with the role of male long-distance calls in defending mates, attracting mates, and defending resources. However, measures of male intra-sexual competition were not associated with the evolution of male long-distance calls. Evolutionary transitions were only partly correlated with factors related to mate attraction. Instead, the strongest correlates of male long-distance calls were activity period, body mass, home range, habitat and some measures of resource defense. Our results are consistent with long-distance call production as a costly signal, but detailed study within species is required to assess these costs and the functions of long-distance calls in individual cases. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/. 相似文献
5.
Among sedentary species, mate and site fidelity may be imposed by year-round territoriality and high annual survivorship, both of which theoretically lead to few opportunities to move between mates and breeding territories. We examined mate and territory fidelity in sedentary neotropical buff-breasted wrens (Thryothorus leucotis) in relation to the opportunities to divorce (vacancies on neighbouring territories), breeding experience and site of origin (within vs outside local breeding population). Overall, buff-breasted wrens showed high rates of mate and territory fidelity between years, with individuals significantly more faithful to their territories than to their partners. Mate and territory fidelity was not forced upon buff-breasted wrens, as most individuals had opportunities to switch mates and territories. However, this was not uniform among all individuals. Individuals that had bred together displayed 100% mate and territory fidelity despite the fact that males and females in almost all experienced pairs had opportunities to switch mates and territories. Local recruits (philopatric offspring that acquired territories in the local breeding population) also displayed mate and territory fidelity, but fidelity occurred because recruits rarely had the opportunity to divorce prior to initiating their first breeding attempt. By contrast, almost half of all territorial individuals that originated outside the local breeding population (immigrants) had opportunity to divorce, with approximately two thirds of them switching mates and territories. Divorces occurred within the first 5 months of pairing, suggesting that immigrants may have sampled mates and territories before forming permanent partnerships. 相似文献
6.
Helga Veronica Tinnesand Susan Jojola Andreas Zedrosser Frank Rosell 《Behavioral ecology and sociobiology》2013,67(6):895-904
Olfactory signals can contain information, such as age and social status, and play a vital role in competitor assessment. In many territorial species, subordinates must leave their natal colony to obtain their own territory and mate. These individuals could be aggressive opponents in agonistic encounters, as they will have little to lose (the desperado effect). In this study, we tested the hypothesis that dominance and age are coded in the anal gland secretion (AGS) of the monogamous and highly territorial Eurasian beaver (Castor fiber), and if this information is used by conspecifics to evaluate the potential threat posed by an intruder. Territorial intrusions were simulated by presenting residents with a two-way choice test of AGS from an unknown male territory owner (i.e., dominant) and his son (i.e., subordinate; either 1 or ≥2 years old). Residents spent more time investigating AGS from subordinates than their fathers and responded more aggressively to subordinates than their fathers when subordinates were ≥2 years old. Chemical analyses gas chromatography and multivariate data analysis supported our behavioral findings and revealed differences between chemical profiles of territory owners and subordinates, as well as between the subordinates in different age classes. This study reveals that information about age and social status is coded in AGS of beavers and that this information is used to determine the level of an eventual future response to the signaler. 相似文献
7.
Low willingness to pay (WTP) for environmental quality in developing countries is a key research question in environmental economics. One explanation is that missing credit markets may suppress WTP for environmental improvements that require large up-front investments. We test the impact of microloans on WTP for hygienic latrines via a randomized controlled trial in 30 villages in rural Cambodia. We find that microcredit dramatically raises WTP for improved latrines, with 60% of households in the Financing arm willing to purchase at an unsubsidized price, relative to 25% in the Non-financing arm. Effects on latrine installation are positive but muted by several factors, including a negative peer effect: randomly induced purchases by neighbors reduce a household's probability of installing its own latrine. On methodological grounds, this paper shows that a “decision-focused evaluation” can be integrated into academic analysis to provide insight into questions of general interest. 相似文献
8.
Colby J. Tanner 《Behavioral ecology and sociobiology》2009,63(4):591-603
To gain additional territory while defending existing territory, animals must acquire and use information regarding resource
characteristics and competitive pressure. For social organisms like ants, individual workers have experiences to acquire information,
but territory establishment is a colony level behavior. Colony behavior, in turn, affects community structure. Here, I investigate
how an individual ant’s previous experience affects its future foraging behavior and how individual behaviors can scale up
to community territorial structure for two coexisting Formica species. To do this, I combine a field survey, a multi-agent computer simulation, and a manipulation experiment. The field
survey shows that workers of both species co-occur on many trees early in the season, but ants on trees become segregated
by species as the season progresses. The simulation demonstrates how this segregated spatial distribution can result from
ants using a foraging strategy in which individuals show a preference for foraging sites based on previous experience. The
experiment suggests that these ants are indeed capable of experience-based foraging behavior; ants preferentially return to
sites where they have had positive experiences and avoid sites where they have had negative experiences. Results from this
study suggest that spatially explicit information can be collected and stored by individuals to facilitate colony territorial
structure, and that future investigations of community territory formation should include effects of individual previous experience. 相似文献
9.
Martin N. Muller Melissa Emery Thompson Sonya M. Kahlenberg Richard W. Wrangham 《Behavioral ecology and sociobiology》2011,65(5):921-933
The extent to which active female mating preferences influence male reproductive success in mammals is unclear, particularly
for promiscuously breeding species like chimpanzees (Pan troglodytes). Previous studies from multiple long-term study sites have shown that female chimpanzees mate more restrictively around
ovulation, and this has been taken as evidence for female choice. However, none of these studies rigorously evaluated the
alternative hypothesis that restrictive mating results not from unconstrained choice, but in response to coercive mate guarding,
in which males use punishment and intimidation to reduce female promiscuity and promote their own mating interests. Nor did
they consider evidence for the potential genetic or phenotypic benefits that females might be choosing. Using 11 years of
data from the Kanyawara community in Kibale National Park, Uganda, we previously demonstrated that males achieve elevated
mating success with those females toward whom they direct high levels of aggression. Here we extend those findings to show
that even female copulatory approaches, which have previously been attributed to female choice, are correlated with male aggression.
Specifically, individual females at our site initiated periovulatory copulations most frequently with the males who were most
aggressive toward them throughout their cycles. Those males showed high rates of aggression toward females throughout estrus,
despite achieving high copulation rates, demonstrating a continuing conflict of interest over the exclusivity of mating access.
Because sexual coercion is potentially widespread in primates and other mammals, our results stress the importance of considering
the influence of male aggression in studies of female choice. 相似文献
10.
Jennifer A. Hale Douglas A. Nelson Jacqueline K. Augustine 《Behavioral ecology and sociobiology》2014,68(9):1441-1449
Vocal signaling can be an important component of vertebrate communication during social interactions. If vocalizations vary among individuals but are consistent within a given individual, they may be used to discriminate among individuals. In many species, territorial males use vocalizations to discriminate between neighbors and strangers and either respond more aggressively toward strangers relative to neighbors (“dear enemy” effect) or they respond more aggressively toward neighbors relative to strangers (“nasty neighbor” effect). In the greater prairie-chicken (Tympanuchus cupido), male vocalizations are an integral part of the display males produce on leks. We investigated whether male greater prairie-chickens discriminate among familiar individuals on their own territory, familiar individuals outside their normal territory and strangers from a nearby lek. Vocal characteristics varied among males, suggesting that vocalizations may potentially be used by prairie-chickens to identify individuals. Males responded to playback of prairie-chicken calls by vocalizing at a faster rate and approaching the playback speaker, but did not vary in their response to the vocalizations based on the identity of the caller. Our results suggest that variation is present among the vocalizations of individual male greater prairie-chickens, but males do not appear to discriminate among familiar individuals and strangers based solely on their “boom” vocalizations. Greater prairie-chicken vocalization likely functions as a way of announcing that a territory is occupied and defended, but it may also serve as a way of advertising to conspecifics or as a signal that is secondary to other forms of communication. 相似文献
11.
Peter D. Dijkstra Els M. van der Zee Ton G. G. Groothuis 《Behavioral ecology and sociobiology》2008,62(5):747-755
Mate preferences on male colour have been implicated in generating and maintaining species diversity among haplochromine cichlid
fish. Their lek-like mating system suggests that not only male colour but also territory quality is instrumental in mate choice.
We assessed the relative importance of territory quality and male colour in mate choice by testing whether territory quality
can override the female preference for males of her own colour in the Lake Victoria cichlid genus Pundamilia. First, we showed in experimental groups that the dominant male preferentially monopolised a large tube relative to a small
tube. The situation mimics quality difference in rocky crevices that serves as a focal point for male courtship display. Second,
in mate-choice tests, Pundamilia nyererei females were allowed to choose between closely related P. nyererei and P. pundamilia males; these species differ strikingly in male nuptial coloration, but little else. We gave either both males the same small
tube or one of them a large tube. The preference of P. nyererei females for P. nyererei males in the control situation (where both males had a small tube) was significantly diminished in favour of P. pundamilia males when the latter had the large tube. The results provide experimental evidence that differences in territory quality
can override the female preference for males of her own colour. This finding is critical for a recent hypothesis proposing
that male competition for mating territories can facilitate the process of sympatric speciation by sexual selection. 相似文献
12.
Correlates of female choice in resource-defending antelope 总被引:2,自引:0,他引:2
Summary Where males offer their mates assistance in rearing offspring as well as access to defended resources, female mate choice should be influenced by both male phenotype and resource quality. In contrast, where there is no paternal care the relative importance of choice for male and territory traits is less well understood. We looked at female distribution across male territories in order to assess mate choice criteria in puku Kobus vardoni, and topi Damaliscus lunatus, two antelope where males defend resources but are not involved in parental care. In both species female distribution was correlated with male phenotype as well as the quality of forage and risk of predation on different territories. Male and territory characteristics were intercorrelated, but statistical analysis revealed that male traits, forage quality and predation risk were all significant, independent predictors of female choice in both study species. This is the first demonstration that female choice in mammals might be simultaneously influenced by male phenotype as well as the quality of defended resources.Correspondence to: A. Balmford 相似文献
13.
Bridget J. Stutchbury 《Behavioral ecology and sociobiology》1992,31(1):27-33
Summary I tested the hypothesis that bright breeding plumage in territorial males acts as a badge of fighting ability or aggressive motivation to intimidate intruders. Territorial male purple martins (Progne subis) whose iridescent blue plumage was lightened to mimic the appearance of subadult males did not suffer an increase in intruder pressure or loss of territory compared with control males. Bright plumage color itself did not deter intruders and was not important for successful territory defense. Furthermore, a bright coloration of owners was not associated with an increased level of aggression toward intruders. Results from parallel studies on this species suggest that bright coloration is important in territory acquisition. The effectiveness of badges of fighting ability and aggressive motivation in territory defense is limited by whether intruders benefit from assessing these traits in owners. Differences in signaling systems between species are due in part to differences in floater tactics and the mode of territory acquisition. 相似文献
14.
Patrick Gautier Kurtulus Olgun Nazan Uzum Claude Miaud 《Behavioral ecology and sociobiology》2006,59(6):836-841
Gregarious behaviour (i.e. living in groups in contrast to a solitary life) is commonly observed in mammals, but rarely documented
in amphibians. Environmental features and/or animal mutual attractions can promote the formation of aggregations that may
both reduce the risks of dehydration and predation and increase mate access and fitness. Luschan’s salamander (Mertensiella luschani) lives in permanently arid Mediterranean environments; individuals shelter in cracks and crevices and leave only during favourable
periods. In this study we examined the role of chemical tracks, in self and conspecific recognition (i.e. gregarious/solitary
behaviour), on the social structure of this species. Our results show that juveniles and adults of both sexes use chemical
scents deposited on substrate to relocate their shelter. In contrast to numerous other salamander species, Luschan’s salamanders
also use social information, conveyed by conspecific scents, to identify a safe shelter. Furthermore, this scent marking does
not play a role in sexual attraction but allows sex discrimination. This species exhibits gregarious behaviour (i.e. conspecific
attraction) as a possible adaptation to dry environments. We discuss both ultimate and proximate factors in the evolution
from a solitary to a gregarious life. 相似文献
15.
Socioecological theory suggests that between-group competition is an important factor affecting the nature of primate social relationships. Between-group encounters in macaques may involve female resource defense, male mate defense, and male resource defense. We observed between-group encounters in two groups (a forest group and a temple group) of bonnet macaques (Macaca radiata). We observed 102 encounters in 875 h of observation of the forest group (1.40 per 12-h day) and 58 encounters in 907 h of observation of the temple group (0.77 per 12-h day). Aggressive interactions between groups occurred in 32.4% and 29.3% of encounters in the forest and temple groups, respectively. Overall, we found little support for the female resource defense hypothesis. Females in both groups rarely participated aggressively in between-group encounters. We found support for the male mate defense hypothesis. For example, males of the forest group were more aggressive during encounters in the mating season than in the non-mating season. Males were also aggressive to females from their own group immediately following encounters. We also found partial support for the male resource defense hypothesis. Encounters in the forest group occurred in a feeding context more often than expected based on time budgets. Also, males in the temple group were more often aggressive in food-related encounters than in other encounters. The findings of this study suggest that socioecological models of primate social relationships need to distinguish male and female strategies during between-group encounters and integrate the resulting functional outcomes.Communicated by T. Czeschlik 相似文献
16.
Discrimination of different social companions in spectacled parrotlets (Forpus conspicillatus): evidence for individual vocal recognition 总被引:1,自引:0,他引:1
Ralf Wanker Jasmin Apcin Bert Jennerjahn Birte Waibel 《Behavioral ecology and sociobiology》1998,43(3):197-202
Individual recognition is generally assumed to be a prerequisite for establishing and maintaining a complex social system.
Indeed, there is good evidence that highly social species have complex systems of vocal communication with individual recognition
by acoustic cues. In this study, we provide experimental evidence that vocal class and individual recognition is present in
a non-passerine bird, the spectacled parrotlet (Forpus conspicillatus). Spectacled parrotlets live in a complex system of social relationships. Soon after fledging, the young establish close
sibling relationships which are important for successful socialization, pairing and reproduction. In a series of playback
experiments we tested if spectacled parrotlets use contact calls for vocal recognition. The results showed that spectacled
parrotlets discriminate between the contact calls of different social categories. Adult birds preferred to respond to the
contact calls of their mates. Subadult individuals recognized the contact calls of their siblings. During the period of pair
bond formation, the affiliative contacts to the siblings decrease, but the parrotlets continue to respond to the calls of
their siblings. This is the first evidence that vocal sibling recognition might outlast the period of strong sibling interaction
and extends into the period of pair bond formation. In cases of mate loss or divorce, the acoustic contact to their siblings
might facilitate the re-establishment of close sibling relationships.
Received: 29 October 1997 / Accepted after revision: 5 April 1998 相似文献
17.
Osmo Rätti 《Behavioral ecology and sociobiology》1994,35(3):201-203
Mating with an already mated pied flycatcher (Ficedula hypoleuca) male is costly for a female. Two hypotheses explain why some females still mate with already mated males. The deception hypothesis suggests that some females mate with already mated males since it is difficult to assess perfectly the mating status of a male with separate territories (polyterritoriality). The search cost hypothesis states that females are aware of male mating status but the costs of searching for an unmated male exceed costs associated with the status of secondary female. One potential cue that could disclose a male's mating status is the existence of brief visits to the primary territory by polyterritorial males. To mimic such visits I removed the male from the territory for 60 min soon after female settlement. Only few females abandoned their mates as a consequence of male removal even though they had available unmated males close by. This result is most consistent with the deception hypothesis. Females did not use occasional male absence as a cue to avoid presumably polyterritorial males and in this respect they were not perfect in assessing males. 相似文献
18.
Cristina Lazaro-Perea Charles T. Snowdon Maria de Fátima Arruda 《Behavioral ecology and sociobiology》1999,46(5):313-324
Scent-marking in mammals has been frequently related to within-group social and reproductive dominance and to defense of
territory and resources. We studied the scent-marking behavior of five wild groups of common marmosets, Callithrix jacchus, during 5 months of the fruiting season in northeastern Brazil. Circumgenital marking was the most common type of marking.
Marks were distributed throughout the home range and were deposited mainly during travel and intergroup encounters. Although
marks were commonly deposited at gum trees, there was no evidence that the animals used scent marks to label fruiting trees
or sleeping sites. Contrary to expectations, reproductively dominant females did not mark more than reproductively subordinate
females. Moreover, during intergroup encounters, reproductively subordinate females displayed higher frequencies of scent-marking
than the reproductively dominant females of their group. Our results suggest that scent-marking is not strictly tied to reproductive
dominance or territorial (or resource) defense in common marmosets. Because marks provide information about individual identity
and reproductive condition, scent marks could serve different functions when used by different individuals. The high frequency
of marking by reproductively subordinate females during intergroup encounters suggests that scent-marking might be used to
signal to individuals of neighboring groups. Our data highlight the importance of social and ecological variables in scent-marking
behavior.
Received: 26 October 1998 / Received in revised form: 20 May 1999 / Accepted: 30 May 1999 相似文献
19.
Katie E. Slocombe Tanja Kaller Laurel Turman Simon W. Townsend Sarah Papworth Paul Squibbs Klaus Zuberbühler 《Behavioral ecology and sociobiology》2010,64(12):1959-1966
Chimpanzees produce acoustically distinct calls when encountering food. Previous research on a number of species has indicated
that food-associated calls are relatively widespread in animal communication, and the production of these calls can be influenced
by both ecological and social factors. Here, we investigate the factors influencing the production of food-associated calls
in wild chimpanzees and examine whether male chimpanzees produce food-associated calls selectively in the presence of important
social partners. Male chimpanzees form stable long-term social relationships with each other, and these social bonds are vital
in enabling a range of cooperative activities, such as group hunting and territory defence. Our data show that males were
significantly more likely to produce food-associated calls if an important social partner was nearby, regardless of the size
of the audience or the presence of oestrus females. Call production was also mediated by the size of the food patch and by
whether or not the food could be monopolised. The presence of important social partners explained most of the variation in
male calling behaviour, indicating that food-associated calls are socially directed and serve a bonding function. 相似文献
20.
The importance of behavioral flexibility for understanding primate ecology and evolutionary diversity is becoming increasingly apparent, and yet despite the abundance of long-term studies across diverse sampling localities, we still do not understand the myriad factors responsible for among-site variation in species’ social organization. The goals of our study were to address this question via three main objectives: to quantify social organization flexibility (i.e., across-site intraspecific variation) of well-studied primate species, test the idea that closely related species exhibit similar levels of flexibility, and test hypotheses explaining variation in social organization flexibility among primate species. We obtained data for a total of 175 study sites from 32 primate species representing all major primate clades. We employed phylogenetic principal components analysis to quantify social organization flexibility for each species. We quantified the phylogenetic signal in social organization flexibility and then evaluated the best predictors of flexibility. We found that mean group size was positively related to social organization flexibility. Large social groups may be more flexible because the foraging costs and predation risk associated with adding or subtracting individuals are lower compared to small social groups. There was some support that absolute brain size and the presence of fission–fusion dynamics were also related to high levels of social organization flexibility, suggesting that cognitive ability and/or within-site behavioral flexibility may also lead to increased variation across sites. Our results serve as an early step in understanding the patterns and processes related to social organization flexibility in primates and other social mammals. 相似文献