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1.
In territorial species, rivals investment in fights over territories may increase when the availability of suitable areas for defense is low. This should occur because low territory availability may increase the costs to maintain and acquire territories. Although such process occurs in small spatial scales (local scale), territory availability in larger scales (regional scale) may also affect fighting investment, as losers should incur additional dispersing costs to find new territories. In this study, we used males of the hilltopping butterfly Strymon mulucha to evaluate the hypothesis that males should invest more in territorial fights when the costs to find new territories are higher (both at local and at regional scale). We timed male–male contests for territories located in 12 hilltops and measured male density per territory in each hilltop (local scale). We also quantified the distance between hilltops containing suitable areas for territories (regional scale). Male–male contests lasted 21 s on average, and copulations did not occur during the observations. The duration of contests was unrelated to the male density per territory or to the distance among hilltops, indicating that the investment in fights was unaffected by the availability of territorial sites, independent of the spatial scale. As male–male contests in S. mulucha are longer than the mean contest duration in other butterfly species and mating is extremely rare, we suggest that the value of each territory may be high enough to favor males that always invest as much as possible in contests.  相似文献   

2.
Movement s an d habitat use of 7 male and 7 female roe deerCapreolus capreolus (Linnaeus, 1758) were studied by radioteleme try from March 1999 to February 2001. Annual and bimonthly home ranges of males were small (ca 10 ha, 95% kernel), with large overlap among individuals throughout the year. Exclusive core areas (ca 0.4 ha, 25% kernel) were concentrated in the forest, a limited and sought-after resource in the study area. The difference in overlap between male exclusive core areas and female home ranges in the pre-rut and rut periods suggested that females made excursions to search for territorial males during the rut Our results support the mating strategy hypothesis of territorial behaviour Different space use patterns occurred between the sexes, with females apparently playing an active role in mate choice by visiting males at clumps of core areas in the forest.  相似文献   

3.
Along the Mediterranean coast,Posidonia oceanica (L.) Delile meadows have a great ecological and economical importance. However, there is a general regression of these meadows due to human activities such as illegal bottom trawling, may be affecting to overall ecosystem health. We examined changes in the community structure of mobile fauna associated withP. oceanica meadows at different spatial scales and taxonomic levels. The aim of this paper was to identify the most efficient taxonomic level to use in environmental impact studies of bottom trawling. At the macroscale level (10 to 100 m), there were significant differences between sites in the densities of some fish species and also the total fish assemblage structure, at both family and species taxonomical levels. At the microscale (0.1 to 1 m), some species of amphipods and isopods showed significant differences in their population densities. In the overall analysis of community structure, the coarse taxonomical levels, such as phyla and class, did not show significant differences, however amphipods and isopods showed significant differences at family and species levels. From these results, both study scales are required to detect changes onPosidonia meadows' fauna. Monitoring of some fish species such asDiplodus annularis (Linnaeus, 1758) and the overall fish assemblage as well as the structure of the amphipod and isopod communities appears to be the most efficient tool in the assessment of environmental impacts by bottom trawling onP. oceanica meadows.  相似文献   

4.
1. Insects locate mobile resources like prey items or mates using either sit‐and‐wait (‘perching’) or active (‘patrolling’) searching strategies. The sit‐and‐wait strategy can be accompanied by defending and monopolising a site through territorial behaviour. 2. The present study focuses on the territorial perching behaviour in males of the speckled wood butterfly (Pararge aegeria L.). Recent studies suggested that the selection of territories (i.e. sunlit patches on the forest floor) is driven by structural characteristics of the site that affect male visual detection. However, given that adult butterflies are heliothermic organisms and that forests provide a diverse array of light environments, it seems likely that thermal aspects may also be used for territory selection. 3. We tested whether used and unused sunlit patches differed in thermal profile under field conditions in a Belgian woodland. We also used dummy butterflies to quantify variation in operative thoracic temperature and to calculate heating rates within (i.e. different vegetation structures) and between patches. 4. Sunlit patches occupied by a territorial male were larger, and were more frequently characterised by low vegetation structures compared with empty sunlit patches. It took longer to reach optimal thorax temperature (starting from a fixed suboptimal body temperature) in small patches compared with large patches. 5. We suggest that aspects of visual detection need to be combined with thermal aspects to fully understand territory selection in the speckled wood butterfly, as synergetic and/or trade‐off effects of ambient temperature, solar radiation, and canopy/vegetation structure may be involved.  相似文献   

5.
Territorial defense in butterflies may be related to both population density and climatic conditions. If these factors change throughout the year, males are expected to adaptively adjust their behavior in order to maximize reproductive success. In this study, we analyzed the annual dynamics of territory occupation by males of the satyrine butterfly Paryphthimoides phronius at a mildly seasonal subtropical site in southeastern Brazil. We investigated the relationship between the number of defended sites, number of males disputing mating areas, proportion of males adopting alternative mate-locating tactics, and the proportion of time invested in territorial disputes with annual variations in temperature and male density. We found little support for the influence of temperature on the dynamics of territory occupation. On the other hand, the number of defended sites increased with male density, whereas the number of males inside each territory, the proportion of satellite males, and the proportion of time spent in territorial disputes were unrelated to variations in population abundance. Territory defense seems to be adopted whenever possible. We conclude that, instead of increasing the number of individuals disputing the same territory during months of high population abundance, males apparently opt to colonize and defend new and, maybe, suboptimal areas.  相似文献   

6.
Male spacing behaviour of roe deer Capreolus capreolus (Linnaeus, 1758) was studied in a wooded mountainous habitat in the Casentinesi Forest National Park, Italy. Data were collected using radio-tracking techniques from March 1997 to February 1998. Annual, seasonal, and bimonthly home ranges were analysed. Different factors may influence male spacing behaviour throughout the year. Winter home range sizes may be dependent on environmental conditions, while social factors could determine a high level of individual variability during the territorial and reproductive period. Prime age males showed great spatial stability, in contrast to the ranging movements of yearlings.  相似文献   

7.
Only single cells in the carrier fish species Carassius carassius (Linnaeus, 1758) for koi herpesvirus (KHV) are infected in contrast to large numbers in the susceptible species common carp Cyprinus carpio (Linnaeus 1758). Several species of the family Cyprinidae have been described as virus carrier species, showing no clinical signs of a KHV disease but able to transmit the virus to other susceptible fish. In this study, 72 common carp Cyprinus carpio (Linnaeus, 1758), 36 tench Tinca tinca (Linnaeus, 1758), 36 crucian carp Carassius carassius (Linnaeus, 1758) and 36 common roach Rutilus rutilus (Linnaeus, 1758) were experimentally infected with KHV (isolate “Israel”) by immersion and kept at 20°C. The fish were euthanized at 12 timepoints over a period of 90 days and virus DNA was quantified in tissues by a real‐time TaqMan PCR. Whereas KHV‐DNA was found in Cyprinus carpio for up to 90 days, the virus DNA was detectable only in single individuals of Rutilus rutilus, Tinca tinca and Carassius carassius for up to 25 days after experimental virus exposure. Tissue samples of Cyprinus carpio and Carassius carassius were screened by in‐situ hybridization. Positive signals were found in various organs of the common carp tested crucian carp. In the latter species a much smaller number of virus‐positive stained cells was detected compared to the infected carp.  相似文献   

8.
Among polygynous species, males often compete for the possession of mating sites to increase their reproductive success. Weaker individuals frequently adopt alternative non‐territorial mate‐locating tactics, but the adoption of alternative territorial tactics may also occur. Although alternative tactics with territory defence are less common in arthropods, factors that drive its adoption may provide information to understand the organization of different territorial mating systems in the group. Here we investigate the adoption of resource‐based territoriality as an alternative to a non‐resource‐based one by males of the butterfly Paryphthimoides phronius. Male P. phronius commonly defend sunny clearings lacking feeding resources in the forest edge (non‐resource‐based territoriality). However, after experimentally offering fermenting fruit in previously undefended sites, we showed that males also adopt a resource defence tactic. Males in territories with fermenting fruits apparently feed on this resource when they are not defending the territory. However, males in sites without resources did not migrate to territories with resources when given the opportunity. To our knowledge, this is the first experimental investigation to show a non‐resource‐ and an alternative resource‐based mate‐locating tactic in a butterfly. We suggest that this behavioural flexibility may represent an important step to understand the ecological factors responsible for the organization and evolution of different territorial mating systems in insects.  相似文献   

9.
Length–weight and length–length relationships are described for 10 of the most important and most frequent small, middle‐size and large pelagic fish species from the Adriatic Sea, namely Sardina pilchardus Walbaum 1792, Sardinella aurita Valenciennes 1847, Sprattus sprattus Linnaeus 1758, Engraulis encrasicolus Linnaeus 1758, Belone belone Linnaeus 1761, Scomber scombrus Linnaeus 1758, Scomber japonicus Houttuyn 1780, Thunnus thynnus Linnaeus 1758, Auxis rochei Risso 1810 and Sarda sarda Bloch 1793. Length–length equations for converting size measurements: standard length (SL) and fork length (FL) to total length (TL) and vice versa, were linear.  相似文献   

10.
Prey selection by the flounder, Platichthys flesus (Linnaeus, 1758), in an estuarine nursery was investigated and the major factors influencing food choice by this species were assessed. Diet breadth was narrow, reflecting the low prey diversity observed in the benthos. A gradual ontogenetic shift from small prey such as amphipods to larger prey like polychaetes and bivalves was observed. Amphipods had positive electivity values in the upper estuary and negative values in the lower estuary.Polychaetes showed the inverse pattern. Bivalve electivity values were always positive. Differential selectivity throughout the estuary was mainly related to spatial segregation of flounders according to size, with the smaller individuals concentrating in the upper estuary and larger individuals concentrating in the lower estuary. Amphipods such as Corophium spp. play a crucial role in the flounder diet because of their small size, low mobility and diel activity pattern. As prey, the polychaete value increases throughout flounder ontogeny since the flounder size range is compatible with the larger mouth gapes and detection ability of larger fish. Bivalve electivity values for flounder are mainly related to high calorific values. The absence of Crangon crangon (Linnaeus, 1758) in the diet may be due to low water temperature since the cost–benefit involved in the capture of highly mobile prey is too high at low temperatures. It was concluded that flounder must use several sensory features to detect and capture prey in turbid estuarine waters and that field studies provide important background information on the actual predator preferences under natural conditions.  相似文献   

11.
The ‘good genes’ hypothesis of sexual selection predicts that male ornaments are favoured by female mate choice because male ornament reveals genetic quality. In species with different male reproductive tactics, variation in genetic quality among ‘sneaking’ males has rarely been investigated, as usually ‘sneakers’ are thought not to be chosen by females. Here we focused on the alternative reproductive tactic in Atlantic salmon (Salmo salar Linnaeus, 1758) to test whether the skin colour of sneakers may reveal the performance traits of their offspring. A fully factorial breeding design was realized between 20 sneakers and two females using in vitro fertilization. We quantified the red and dark colorations of males and measured the survival of their progeny under semi‐natural conditions. In addition, the size of offspring and their emergence timing from the gravel nest were monitored in the laboratory. We found that darker males sired more viable offspring, whereas red coloration was negatively correlated with offspring survival. Nevertheless, darker and redder male pigmentations were linked to a delay in offspring emergence. These results demonstrate that colours can reveal individual genetic quality in an alternative male reproductive tactic, with male melanin‐based coloration being linked to both beneficial and detrimental effects for the offspring. Our results imply that sneaker ornaments may potentially play a role in both intra‐ and intersexual selection. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 126–135.  相似文献   

12.
Linnaeus described 166 nominal species of Noctuoidea, of which 144 (86.7%) are currently used as valid names, 18 are synonyms, one is a homonym and three taxa remain unknown. Seven taxa were described solely from illustrations in contemporary literature. Lectotypes are designated for 139 (87.4%) of the 159 remaining taxa, 122 of them from the Linnaean collection in London, 13 from the Queen Ludovica Ulrica's collection in Uppsala, Sweden, and four from other contemporary collections. Two Linnaean senior synonyms are introduced: Hada plebeja comb. nov. (Linnaeus, 1761) for the current H. nana (Hufnagel, 1766) and Oeonistis altica (Linnaeus, 1768) comb. nov. for Oe. entella (Cramer, 1779). Erebus occiduus (Linnaeus, 1758) syn. nov. is a junior subjective synonym of E. crepuscularis (Linnaeus, 1758); L. marmorides (Cramer, 1775) Stat. rev. should be reinstated for Letis occidua auct. In two species pairs the Linnaean names have been interpreted incorrectly. The lectotype designation of Phalaena prasinana Linnaeus, 1758, by Lempke (1947) is invalid because the specimen is not syntypic. According to the new lectotype, Pseudoips prasinanus (Linnaeus, 1758) comb. nov. replaces P. faganus (Fabricius, 1781), and Bena bicolorana (Fuessly, 1775) comb. nov. is available for the other species. Abrostola triplasia (Linnaeus, 1758) Stat. rev. replaces A. trigemina (Werneburg, 1864), and for the other species A. triparlila (Hufnagel, 1766) should be reinstated. One neotype designation [Eilema complanum (Linnaeus, 1758)], one lectotype designation [Xylena exsolela (Linnaeus, 1758)], and precedence of a junior synonym [Ophideres fullonia (Clerck, 1764)] over its unused senior synonym are to be referred to the ICZN; until their decision the current usage must be followed. The identity of Mesapamea secalis (Linnaeus, 1758) stat. rev. corresponds to current usage, but, under presence of syntypic material, the recent neotype designation by Lempke (1988) will be referred to the ICZN. The revision is mainly based on the discovery that the insect pins and the way specimens are prepared give evidence of the authenticity of the material. Contrary to the views of earlier authors, Linnaeus had his labels with the specific name pinned against the bottom of the drawers by the specimen pin. Because the labels have been moved twice during subsequent curations, their present position is less indicative of the authenticity than has been previously suggested. The origin of the so-called n-labels is discussed.  相似文献   

13.
The nursery role of the Mondego estuary for marine fish species was studied between June 2003 and May 2004. The spatial and temporal distribution and abundance patterns of 0-group Dicentrarchus labrax (Linnaeus, 1758), Platichthys flesus (Linnaeus, 1758) and Solea solea (Linnaeus, 1758) were analyzed based on monthly sampling surveys in five stations along the estuarine gradient. Fishing took place during the night at low water of spring tides, using a 2 m beam trawl. The spatial patterns of estuarine colonization were different according to species. D. labrax showed a wider distribution, but the main nursery ground was the same as for S. solea. Highest densities of S. solea juveniles were found in oligohaline areas, with muddy bottoms and high benthic invertebrates availability, while P. flesus occurred mainly in the sandy uppermost areas. D. labrax was found in both these areas. Fish abundance in the estuary mainly reflected seasonal changes.  相似文献   

14.
Male vocal displays play an important role in sexual selection through both male–male competition and female choice. While this is supported by numerous studies in birds, much less attention has been paid to the role of such displays in mammals. We investigated the function of vocal displays in a polygynous mammal, the Galápagos sea lion (Zalophus wollebaeki). In our study population a large proportion of mature males are unable to establish a territory, providing the opportunity to compare the vocal behaviour between territorial and non‐territorial males. We examined how seasonal patterns of vocalizations differed between territorial and non‐territorial males and how the number of females present in a territory influenced behaviour of territorial males. We found that territorial males vocalized at higher rates than non‐territorial males, and territorial males vocalized more at the onset than towards the end of territory tenure. During the onset of territory‐tenure vocalizations of territorial males were directed more often towards other males than females. Furthermore, we found that vocalizations of territorial males were not only given in male–male interactions, but were also actively directed towards females. Territorial males vocalized at higher rates when more females were present in their territory. Our results suggest that vocalizations are important in male–male interactions, are relevant in territorial disputes and are used as a proxy for females to assess a male’s quality.  相似文献   

15.
This study reports weight–length relationships (WLR) for Salmo trutta (Linnaeus, 1758), Phoxinus phoxinus (Linnaeus, 1758), Chondrostoma Chondrostoma miegii (Steindachner, 1866), Barbus graellsii (Steindachner, 1866), Barbatula barbatula (Linnaeus, 1758) and Gobio gobio (Linnaeus, 1758). Specimens were collected by electrofishing during summer between 1996 and 1998. The b values in the WLR W = aLb varied between 2.97 and 3.42. To the best knowledge of the authors, this study presents the first reference on WLRs for four of the species in Spanish waters.  相似文献   

16.
For European badgersMeles meles (Linnaeus, 1758), the importance of olfactory signals located at home-range borders in the context of territoriality has been widely accepted. Badgers, however, also scent mark far from their borders, often in the vicinity of their communal sett. Little is known about the significance of these marks in intraspecific communication. Here, we investigated the patterns of object-marking with subcaudal gland secretions close to the sett. Using remote-controlled, battery-powered infra-red video equipment, we recorded 442 incidences of object-marking between April 1996 and June 1997. The frequency of object marking varied significantly in relation to season, sex, age and reproductive status. In both sexes, relative object-marking rates were highest during the mating season, when individuals in reproductive condition marked significantly more often than non-reproductive animals. During the cubrearing season females marked at a significantly higher rate than males, and in both sexes adults scent-marked significantly more frequently than younger individuals. Approximately 30% of all scent-marks received an over-mark within 24 h of their deposit. In males over-marking behaviour was recorded only during the mating season, whereas females over-marked in all seasons at equal rates. Overall, our results suggest that in addition to their territorial functions, subcaudal scent-marks also serve as individual-specific advertisement signals directed at other group-members.  相似文献   

17.
Presented are the length–weight relationships of 12 fish species [ Oncorhynchus mykiss (Walbaum, 1792); Cyprinus carpio, Linnaeus, 1758; Carassius carassius Linnaeus, 1758; Alburnoides bipunctatus (Bloch, 1782); Alburnus adanensis Battalgazi, 1944; Rutilus rutilus , Linnaeus, 1758; Squalis cephalus, Linnaeus, 1758; Tinca tinca (Linnaeus, 1758); Capoeta barroisi (Valenciennes, 1842); Silurus glanis Linnaeus, 1758; Gambussia affinis (Baird and Girard, 1853); and Sander lucioperca (Linnaeus, 1758)] from Seyhan Dam Lake, Turkey. This study provides the first estimation of length–weight relationships for two of the species ( A.   adanensis and C. barroisi ).  相似文献   

18.
We analysed asymmetry in the wings of the speckled wood butterfly (Pararge aegeria)by measuring area, length and width of fore- and hindwings. The type of asymmetry is fluctuating except for fore- and hindwing area, and forewing width in males, where asymmetry is directional. The amount of asymmetry (variance of the left wing minus the right wing) is less in males than in females. Within males asymmetry was directional and less in pale, predominantly territorial males than in melanic, predominantly non-territorial males. Asymmetry was negatively related to growth rate within females, but not within males. Females grew faster than males, but had higher asymmetry, whereas the more asymmetrical melanic males grew more slowly than pale males. The differences in the type and amount of asymmetry between the sexes and colour classes suggest a relationship with sex-specific flight patterns such as the territorial spiralling flight of males. We hypothesize that slightly asymmetrical males turn faster, and therefore are superior in territorial disputes over more symmetrical or extremely asymmetrical males. This implies that sexual selection via male–male competition influences the type and amount of asymmetry. The existence of more extremely asymmetrical individuals in females, and to a lesser extent in non-territorial males, may indicate that there are costs in reducing asymmetry.  相似文献   

19.
The time schedule of mate-locating behavior in the male satyrine butterfly Lethe diana was studied. Males displayed territorial behavior only in the afternoon, but it was not known whether they attempted to locate mates in the morning. In order for males of most butterfly species to mate with a virgin female, it would be most effective to initiate mate-locating behavior in the morning, when synchronous eclosions occur. Males of L.diana flew patrols in the morning and displayed territorial behavior in the afternoon. The cost of territorial behavior is probably less than that of patrolling, as territorial flights are shorter than those when patrolling. The temporal switching of mate-locating behavior is theoretically favored, since the reproductive value of females decreases later in the day, when males perform the less costly mate-locating behavior. Thus, the diurnal switching of male mate-locating behavior may be an adaptive strategy in response to the rapid decline in the reproductive value of females over the course of a day.  相似文献   

20.
Males of several animals increase their reproductive success by territorial behaviour. In butterflies, males may defend a territory (i.e., territorial perching tactic), but this is assumed to be an energetically costly way to locate mates. Limitations of the energy budget may affect fight performance, and may, consequently, force males to adopt an alternative non-territorial searching behaviour (i.e., patrolling tactic) to maximize reproductive success. In this study, we tested to what extent behavioural tactics adopted by adult males of the butterfly Pararge aegeria (L.) were affected by the nutritional conditions during the larval stage. We compared the occurrence of territorial versus patrolling behaviour, lipid mass, flight muscle ratio, metabolic rate and spermatophore production of low quality males that were reared as a larva on drought-stressed host plants and control, high quality males. Low quality males were less likely to adopt the territorial perching tactic and emerged as adults with lower lipid mass than high quality males, but they were able to restore their lipid mass through adult feeding (and perhaps the breakdown of flight muscles). Host plant quality also affected spermatophore size. Independent of the larval food treatment, territorial perching males metabolised more lipids than non-territorial males, produced larger spermatophores and copulated for longer than males adopting non-territorial behaviour. We discuss the results relative to the co-existence of the behavioural tactics (perching and patrolling).  相似文献   

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