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1.
A central aim of the study of animal communication is to identify the mode and content of information transferred between individuals. The lateral presentation of the antler palm between male fallow deer has been described as either a signal of individual quality or an attempt to avoid fighting. In the first case two phenotypic features have been proposed by which transmission of individual quality may be facilitated. These are antler size and antler symmetry. The alternative hypothesis proposes that the lateral presentation of antlers occurs as a consequence of averting a threatening posture and may signify a reluctance to fight. We examined whether mature fallow deer use lateral palm presentation as a display during fights to indicate antler size and symmetry. We found no relationship between presentation rate of the antler and antler size and symmetry. Furthermore, males did not preferentially present their larger antler to their opponent. We also investigated whether the rate at which males presented antlers laterally during a fight was related to their ability to win the fight. Our results show that the male who performed more presentations during a fight was more likely to lose it. There were behavioural differences in the way in which a bout of presentation ended; subsequent losers tended to turn their body away from their opponent and subsequent winners tended to lower their antlers to an opponent which we interpret as an invitation to continue fighting. We conclude that the lateral palm presentation serves to de-escalate fighting between mature fallow deer. It is not a mechanism by which to communicate individual quality but rather an indication that a male is less committed to continuing investment in the current contest. 相似文献
2.
Fallow deer leks and single territories often persist in specific locations over many years. In our study area in Tuscany, one site (Lek 1) was used as a lek by fallow deer for at least 30 years. Females passed through the lek year-round while travelling between sheltering and foraging sites. In 1987–89, forestry operations affected areas near the lek that were used by females as travel routes, but the lek site itself was not affected. After the logging operations, very few females traversed the lek site. Over the next 2 years the lek decreased in size (both in terms of number of territories defended and number of territorial males) until it became a single territory, and after two more years it was abandoned. Another lek (Lek 2) whose access routes were unaffected by forest cuts, continued to exist. Territorial males abandoned Lek 1 and moved to Lek 2 when female visits to Lek 1 became rare. Our results suggest that female movement patterns can be affected by habitat manipulations, and that females will not return to traditional mating sites that become external to their home ranges. Male fallow deer may form leks along female movement routes, where they experience a high female encounter rate as predicted by the hotspot model. 相似文献
3.
Despite a low probability of achieving copulations, yearling male (1.5-year-old) fallow deer Dama dama display behavioural changes during rut, interacting with both females and older males. Juvenile interactions in polygynous ungulates may affect further reproductive success through both motor training for future interactions and/or competition for current resources that affect growth. To test this hypothesis, we intensively studied the behaviour of 12 yearling males in two captive populations during a rutting season. Interactions with females were interpreted as motor training aimed at learning to recognize oestrous females, because yearling males rarely interacted with their mother and because interactions essentially consisted of olfactory investigations focused on oestrous females. Because agonistic interactions with older males never involved physical contact and were mainly initiated by the most dominant buck in each population, we concluded that these interactions resulted from the presence of the yearlings close to oestrous females defended by rutting males. Heavier yearlings tended to be dominant over lighter ones and tended to interact more frequently with other animals, suggesting that early growth may influence the ontogeny of social behaviours. 相似文献
5.
Removal of 5 of the 8 most successful males in a fallow deer lek between breeding seasons led to an increase in fighting rate of males and a decrease in mating rate of both sexes. The increase in fighting was likely due to disruption of the social hierarchy. The lower mating rate of females was not due to disruption of copulations by territorial males, nor did it appear to result from disturbance from fights. We suggest that difficulties in mate choice related to an unstable male hierarchy resulted in females either increasing their length of stay in the lek, visiting the lek more than once before mating, or leaving the lek without mating. 相似文献
6.
A nasal, so called ethmoidal, tumor from a fallow deer is described. It appears to be the first reported case of that species. The etiology is discussed. 相似文献
7.
In 19 out of 22 aortas from fallow deer, 15 months to 5½ years, aortic lesions were found. Three types of lesions were observed, fatty streaks were seen in 2, fibrous plaques in 15 and fibrous plaques with complicated lesions (calcification and acid mucopolysaccharides) in 2 of the aortas. Elastic tissue degeneration of the inner two thirds of the tunica media was frequently found in the aorta of the animals > 3½–5½ years of age. There was no statistical evidence for a correlation between age and frequency (P ~ 0.10) but a trend towards age dependence was seen. The percentage of involved surface was found to significantly increase (0.05 > P > 0.01) with age. Lesions were found to start in the abdominal aorta in young animals and to extend cranially to the thoracic aorta with age. The percentage of involved surface in different affected regions, comprising all age groups were, in the posterior abdominal portion, 10.5 %, in the anterior abdominal portion, 4.3 % and in the posterior thoracic portion, 1.04 %. The influence of hemodynamic flow upon the localization of the aortic lesions, the endothelial cell population density and the endothelial nuclear patterns were discussed. 相似文献
8.
An einer halbwilden Herde des Damhirsches (Dama dama) wurde 19 Monate lang das Sozialverhalten, vor allem die Bedeutung frühontogenetischer Erfahrungen für die Entwicklung des arttypischen Verhaltens untersucht. Zahlreiche optische, akustische und Berührungs-Reize dienen der Warnung, der Rangordnung oder der Verständigung zwischen Geschlechtspartnern oder Eltern und Kindern. Isoliert aufgezogene Jungtiere reagierten in typischen Situationen mit den gleichen Signalen wie in der Herde aufgewachsene und beantworteten, in die Herde gebracht, die arttypischen Signale der anderen richtig. Allerdings wurden diese Tiere von der Herde nicht aufgenommen und standen noch nach 3 Jahren abseits. Die isolierte Aufzucht beeinträchtigt also das Sozialleben stark, indem es die Bindung an Artgenossen verhindert. Diese Bindung ist aber wohl nötig, wo bestimmte Verhaltenselemente von Artgenossen gelernt werden müssen. 相似文献
9.
Variation in mating systems of fallow deer ( Dama dama L.) was studied in wild and park populations and could be broadly distinguished into 7 categories: following, harems, dominance groups, stands, temporary stands, multiple stands, and leks. The ecological factors which exerted the greatest influence on mating systems were buck density, doe density, and habitat structure and tree cover, resulting in pronounced changes in the degree and type of territoriality observed. Individual male reproductive success was highly skewed in all systems. A greater range of concurrent mating strategies was observed in wild populations than in parks. 相似文献
10.
Farmed fallow deer suddenly developed disease showing lethargy, weakness, anorexia and several of them died. The animals showed macroscopic lesions in the digestive mucosa characterized by erosions, ulcers and necrotizing lesions. Histo-pathology of the mucous membranes revealed marked inter- and intracellular oedema, erosions, ulcers and intracyto-plasmic inclusions bodies. BVD-virus was demonstrated in 1 deer using an indirect immunofluorescence method. It is suggested that the disease may have been caused by Bovine Virus Diarrhea virus alone or in conjunction with a simultaneous infection by another unidentified virus. 相似文献
11.
Allelic heterogeneity within protein electromorphs at three loci was examined in populations of deer mice ( Peromyscus maniculatus) collected from five localities across North America. We used a variety of electrophoretic techniques (including several starch and acrylamide conditions, gel-sieving, and isoelectric focusing) plus heat denaturation. Of particular interest was the supernatant glutamate oxalate transaminase system (GOT-1; aspartate aminotransferase-1 of some authors), which under standard electrophoretic conditions had been shown to exhibit basically a two-allele polymorphism throughout the range of maniculatus. The use of all of the above techniques failed to uncover any additional variation for GOT-1 in these populations. Similarly, no new scorable variation was resolved at the essentially monomorphic malate dehydrogenase-1 locus by additional conditions of electrophoresis. In marked contrast to the results for the above two enzymes, the use of multiple conditions of electrophoresis resolved the 8 standard-condition electromorphs of esterase-1 into a total of 23 variants showing strong geographic differentiation in frequency. These 23 electromorphs were further divided into a total of 35 variants by thermal stability studies. However, the allelic nature of all of the thermal stability esterase variants remains to be documented. The results of this study, taken together with the remarkable geographic heterogeneity for this species in ecology, morphology, karyotype and mitochondrial DNA sequence, suggest that some form of balancing selection may be acting to maintain the GOT-1 polymorphism. 相似文献
12.
Fighting animals must make a series of decisions, and understanding the proximate causes behind these decisions can give insight into how they are made. For example, fights have been analysed with respect to energetic costs and endocrine changes associated with engaging. However, another mechanism for the control of demanding activity, such as fighting, is the modulation of aerobic capacity by divalent metal ions. Here we examine post‐fight haemolymph concentrations of magnesium (Mg 2+) and calcium (Ca 2+) ions in the common European hermit crab Pagurus bernhardus. Hermit crabs fight over the ownership of gastropod shells, where they adopt two very different roles during the encounter: attacker and defender. Despite the two roles performing different activities, we found that Mg 2+ and Ca 2+ affected them similarly, with concentrations of these ions being highest in successful individuals. Haemolymph concentrations of Mg 2+ and Ca 2+ were also found to increase as a result of fighting, and these elevated levels will, via allosteric interactions, increase the oxygen affinity of the respiratory pigment haemocyanin, enhancing respiratory capacity and therefore fighting ability. Furthermore, the present study revealed that seasonal changes in circulating levels, along with the ability of competitors to respond to them, may ultimately influence an individual’s success in aggressive interactions. 相似文献
13.
Mammals are able to distinguish conspecifics based on vocal cues, and the acoustic structure of mammal vocalizations is directly affected by the anatomy and action of the vocal apparatus. However, most studies investigating individual patterns in acoustic signals do not consider a vocal production‐based perspective. In this study, we used the source‐filter model of vocal production as a basis for investigating the acoustic variability of fallow deer groans. Using this approach, we quantified the potential of each acoustic component to carry information about individual identity. We also investigated if cues to individual identity carry over among the two groan types we describe: common and harsh groans. Using discriminant function analysis, we found that variables related to the fundamental frequency contour and the minimum frequencies of the highest formants contributed most to the identification of a given common groan. Common groans were individually distinctive with 36.6% (53.6% with stepwise procedure) of groans assigned to the correct individual. This level of discrimination is approximately six times higher than that predicted by chance. In addition, univariate anova s showed significant inter‐individual variation in the minimum formant frequencies when common and harsh groans were combined, suggesting that some information about individuality is shared between groan types. Our results suggest that the sound source and the vocal tract resonances act together to determine groan individuality and that enough variation exists to potentially allow individual recognition based on groans. 相似文献
14.
Human cases of hantavirus pulmonary syndrome caused by Sin Nombre virus are the endpoint of complex ecological cascade from
weather conditions, population dynamics of deer mice, to prevalence of SNV in deer mice. Using population trajectories from
the literature and mathematical modeling, we analyze the time lag between deer mouse population peaks and peaks in SNV antibody
prevalence in deer mice. Because the virus is not transmitted vertically, rapid population growth can lead initially to reduced
prevalence, but the resulting higher population size may later increase contact rates and generate increased prevalence. Incorporating
these factors, the predicted time lag ranges from 0 to 18 months, and takes on larger values when host population size varies
with a longer period or higher amplitude, when mean prevalence is low and when transmission is frequency-dependent. Population
size variation due to variation in birth rates rather than death rates also increases the lag. Predicting future human outbreaks
of hantavirus pulmonary syndrome may require taking these effects into account. 相似文献
15.
不足的资金,对于发生蝗灾的大面积草原来说,就像发生了森林火灾,只用几盆水去灭火。 相似文献
17.
In 45 patients with rubella-like illnesses during pregnancy serological tests showed that the clinical diagnosis had been accurate in only 20. Since only 16 of these patients had presented for laboratory investigations within a week of the onset of symptoms, the value of haemagglutination-inhibition tests was considerably reduced; the diagnosis in these cases was confirmed by complement-fixation and rubella-specific IgM tests.Of 172 patients exposed to a rubella-like illness, only 17 were seronegative; 105 sought advice within two weeks of exposure, and therefore the haemagglutination-inhibition antibody tests were useful in determining immunity. Since the clinical diagnosis of rubella was proved incorrect in a number of cases, these pregnancies were saved. Hence both doctors and patients should report both exposure to and rubella-like illnesses as early as possible, so that laboratory investigations may be carried out without delay. 相似文献
18.
In order to promote international understanding and acceptance of the integrated risk assessment process, the World Health Organization/International Programme on Chemical Safety (WHO/IPCS), in collaboration with the U.S. Environmental Protection Agency and the Organization for Economic Cooperation and Development, initiated a number of activities related to integrated risk assessment. In this project, the WHO/IPCS defines integrated risk assessment as a science-based approach that combines the processes of risk estimation for humans, biota, and natural resources in one assessment. This article explores the strengths and weaknesses of integration as identified up to this date and the degree of acceptance of this concept by the global risk assessment/risk management community. It discusses both opportunities and impediments for further development and implementation. The major emerging opportunities for an integrated approach stem from the increasing societal and political pressure to move away from vertebrate testing leading to a demand for scientific integrated approaches to in vitro and in vivo testing, as well as to computer simulations, in so-called Intelligent Testing Strategies. In addition, by weighing the evidence from conventional mammalian toxicology, ecotoxicology, human epidemiology, and eco-epidemiology, risk assessors could better characterize mechanisms of action and the forms of the relationships of exposures to responses. It is concluded that further demonstrations of scientific, economic and regulatory benefits of an integrated approach are needed. As risk assessment is becoming more mechanistic and molecular this may create an integrated approach based on common mechanisms and a common systems-biology approach. 相似文献
19.
Important issues that are still unresolved in the study of animal social groups are how dominance is measured and how individuals are ranked. Based on observations of mule deer ( Odocoileus hemionus hemionus), we constructed hierarchies for the same 26 bucks using five potential correlates of dominance and three measures based on the outcome of agonistic interactions. Data for each of six behavior measures were converted to ranks by six different numerical techniques. Different measures of behavior resulted in different hierarchies. This was especially so when the hierarchy based on sparring rates was compared to hierarchies based on other criteria. Although our results showed that dominance is not a unitary concept, several measures of dominance were highly correlated with one another. Thus, one measure, in some instances, may be a good but imperfect predictor of dominance defined by other criteria. For data sets based on index scores or rates of performing behavior, the mean difference and standard-error difference ranking methods had distinct advantages. Both produced equally weighted ranks that minimized the effects of sampling errors. 相似文献
20.
We investigated the origins of the fallow deer ( Dama dama dama) of Rhodes by both morphological and molecular means. Our results show that these deer have homogeneous phenotypic patterns. All specimens fell within the common colour coat variety typical of the wild form. The Rhodian deer appear to be rather small, especially when compared with specimens from central and northern Europe. We then sequenced the HVR-I of 13 deer from Rhodes and compared these sequences with other 31 samples obtained from different European and Anatolian populations of fallow deer. Out of 44 sequences, 23 haploypes were found. When compared to the Turkish and Italian populations, the population of Rhodes revealed lower values of within population genetic diversity. The fallow deer from Rhodes are characterized by an 80-bp mitochondrial DNA (mtDNA) insertion not found elsewhere. As a consequence, all the deer from Rhodes form a tight cluster, distinct from all other fallow deer populations. This uniqueness makes the conservation and management of the Rhodian population particularly urgent. 相似文献
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