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91.
Alpha-male paternity in elephant seals 总被引:3,自引:0,他引:3
A. Rus Hoelzel Burney J. Le Boeuf Joanne Reiter Claudio Campagna 《Behavioral ecology and sociobiology》1999,46(5):298-306
The aim of this study was to assess paternity of males that dominated mating in harems at northern (Mirounga angustirostris) and southern (M. leonina) elephant seal rookeries using DNA fingerprinting and microsatellite DNA analysis. Southern alpha males had greater reproductive
success than most northern alphas at similar-sized harems. Comparison of the relatedness between pups within harems also suggested
that fewer males achieved matings in the southern elephant seal population. This was consistent with behavioral observations
that suggest greater competition for mates in northern elephant seal harems. Reproductive success was consistent with estimates
of mating success in some cases, but lower than expected for some northern elephant seal alpha males. A lower reproductive
success than predicted from mating behavior may arise from a variety of factors including sperm competition, male sperm depletion
from frequent mating, or reduced fertility. The alternatives are discussed in the context of environmental and historical
factors.
Received: 17 August 1998 / Received in revised form: 28 March 1999 / Accepted: 30 May 1999 相似文献
92.
Manfred Ayasse Wolf Engels Gunter Lübke Timo Taghizadeh Wittko Francke 《Behavioral ecology and sociobiology》1999,45(2):95-106
The present paper reports on behavioral experiments and gas chromatographic analysis of chemical communication in the mating
biology of the primitively eusocial sweat bee Lasioglossum (Evylaeus) malachurum. In a dual-choice experiment, a female made odorless was significantly less attractive than an untreated one. Attraction in
L. (Evylaeus) malachurum is therefore mediated by a female-produced sex pheromone. Further bioassays showed that unmated gynes are more attractive
to males than mated ones. Males are able to differentiate between the two groups of females as little as 3 h after mating.
Biotests with different samples obtained from attractive gynes showed surface extracts to be most attractive. Behavioral tests
with synthetic copies of the compounds identified as cuticular constituents of virgin gynes were highly attractive to males;
the volatile bouquets consisting of n-alkanes, n-alkenes and iso- pentenyl esters of unsaturated fatty acids were the most
attractive samples. Isopentenyl esters of unsaturated fatty acids were the key compounds in inducing male inspections as well
as stimulating pounces and copulatory attempts. Virgin and nesting gynes differed clearly in the relative and absolute amounts
of the volatiles on the cuticle. The total amount of volatiles was significantly higher in virgin gynes and decreased in breeding
queens. Hydrocarbons were the dominant group of compounds in both groups of females. The relative amounts of the wax-type
ester, hexadecyl oleate, iso- pentenyl esters, and a hitherto unidentified steroid were higher in attractive virgin gynes,
while the relative proportions of hydrocarbons and lactones dominated in nesting queens. The site of sex pheromone production
in attractive young L. (Evylaeus) malachurum gynes remains unknown. Head glands or Dufour's gland secretions may be involved. Another possible source of the `active principle'
found among the cuticular lipids could be glandular cells of the epidermis. The significance of modulation of female sex pheromone
composition is discussed in terms of a reduction in mating expenditures.
Received: 30 April 1998 / Accepted after revision: 24 July 1998 相似文献
93.
The evolution of empty nuptial gifts in a dance fly, Empis snoddyi (Diptera: Empididae): bigger isn't always better 总被引:2,自引:0,他引:2
Jennifer A. Sadowski Allen J. Moore Edmund D. Brodie III 《Behavioral ecology and sociobiology》1999,45(3-4):161-166
Adaptive female choice is thought to have led to the evolution of nutritionally valuable nuptial gifts in many insect species.
However, in several dance fly species, males offer and females accept “empty gifts” with no nutritional value. In the species
studied here, Empis snoddyi Steyskal, males produce empty balloons comprised of hundreds of silk bubbles and form mating swarms that females approach
to investigate males. Males within the swarm engage in agonistic interactions. The empty balloon has been hypothesized to
be an indicator of male condition such that males with larger balloons are predicted to have higher mating success and be
more successful in male-male interactions than males with smaller balloons. We examined the role of male body size and balloon
size in the context of intersexual and intrasexual selection. We found that neither male body size nor balloon size affected
the outcome of pairwise male-male interactions. Using multiple-regression techniques, we found significant linear selection
for increasing male body size and decreasing balloon size associated with mating success, a surprising result given a positive
relationship between male body size and balloon size. A visualization of selection showed the highest peak of male mating
success for larger males with intermediate-size balloons. These results can be explained by a trade-off between long-range
attraction of females using large balloons and close-range attraction of females via improved flying efficiency associated
with smaller balloons. Both male body size and balloon size are important components in determining male mating success; however,
the empty balloon does not appear to play a typical role as a sexually selected ornament.
Received: 29 December 1997 / Accepted after revision: 7 October 1998 相似文献
94.
Joanna P. Y. Chan Pei Rong Lau Ai Jie Tham Daiqin Li 《Behavioral ecology and sociobiology》2008,62(5):639-646
In experiments that comprised of three phases (fight, choice, and mating) under “seen” and “unseen” conditions, we examined
the effects of the outcomes of male–male contests and female eavesdropping on female mate choice and male mating success in
the fighting spider, Thiania bhamoensis (Salticidae). The results revealed female eavesdropping on agonistic interactions. Females that had watched an aggressive
interaction showed no distinctive preference for the winner over the loser, but they preferred the loser when they had not
observed a fight. Winners, however, achieved a greater mating success than did losers during the mating phase. Gaining access
to females was based on the insistence of the winners in courtship in terms of the number of quivers, rather than on the fighting
behavior of the males. Hence, the outcome of male–male contests may not be an important determinant of a male’s mating success
in T. bhamoensis. Instead, courtship display plays an important role in determining the success of male mating in this species. This study
also suggests that female mate preference may not be a good indicator of eventual female mate choice and male mating success.
Thus, a causal relationship between female mate preference and male mating success cannot be inferred.
Joanna P. Y. Chan, Pei Rong Lau, and Ai Jie Tham contributed equally. 相似文献
95.
In simultaneous hermaphrodites, gender conflicts that arise from two potential mates sharing the same gender preference may
be solved through conditional reciprocity (or gamete trading). Conditional reciprocity had initially been considered widespread,
but recent studies suggest that its real occurrence may have been overestimated, possibly because most mating observations
have been performed on isolated pairs of individuals. Some resulting patterns (e.g., non-random alternation of sexual roles)
were indeed compatible with conditional reciprocity but could also have stemmed from the two partners independently executing
their own mating strategy and being experimentally enforced to do so with the same partner. Non-random alternation of gender
roles was recently documented in the simultaneously hermaphroditic freshwater snail Physa acuta. To distinguish between conditional and unconditional gender alternations, we observed copulations of individually marked
snails reared at three contrasted densities. We showed that density affected the overall frequency of copulations during the
first 2 days of the experiment with high-density boxes showing more copulations than low density boxes, but it did not affect
gender alternation patterns. A change in gender role was observed more often than expected by chance over two successive copulations
by the same individual, confirming previous studies. However, gender switches did not preferentially occur with the same partner.
We conclude that gender alternation is not due to conditional reciprocity in P. acuta. It may rather stem from each individual having a preference for gender alternation. We finally discuss the mechanisms and
the potential extent of this unconditional reciprocity. 相似文献
96.
Large males dominate: ecology,social organization,and mating system of wild cavies,the ancestors of the guinea pig 总被引:1,自引:0,他引:1
Matthias Asher Tanja Lippmann Jörg T. Epplen Cornelia Kraus Fritz Trillmich Norbert Sachser 《Behavioral ecology and sociobiology》2008,62(9):1509-1521
Ecological factors differently affect male and female animals and thereby importantly influence their life history and reproductive
strategies. Caviomorph rodents are found in a wide range of habitats in South America and different social and mating systems
have evolved in closely related species. This permits to study the impact of ecological factors on social evolution. In this
study, we investigated the social organization and the mating system of the wild cavy (Cavia aperea), the ancestor of the domestic guinea pig, in its natural habitat in Uruguay. Based on our laboratory investigations, we
expected a polygynous system with large males controlling access to females. Results from radiotelemetry and direct observations
showed that females occupied small stable home ranges which were largely overlapped by that of one large male, resulting in
a social organization of small harems. In some cases, small satellite males were associated with harems and intermediate-sized
roaming males were occasionally observed on the study site. However, microsatellite analyses revealed that offspring were
exclusively sired by large males of the same or neighboring harems, with a moderate degree of multiple paternity (13–27%).
Thus, the mating system of C. aperea can be described as polygynous and contrasts with the promiscuous organization described for other species of cavies (Cavia magna, Galea musteloides and Microcavia australis) living under different ecological conditions. Our findings stress the strong impact of environmental factors on social evolution
in Caviomorphs as resource distribution determines female space use and, thereby, the ability of males to monopolize females.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
97.
Josef Bryja Hana Patzenhauerová Tomáš Albrecht Ladislav Mošanský Michal Stanko Pavel Stopka 《Behavioral ecology and sociobiology》2008,63(2):251-260
Sexual selection in most vertebrates is based on the evolution of fitness optimization strategies such as multiple-male mating
(MMM). Several ecological correlates of MMM have been identified in bird and fish populations; however, only few studies have
documented the effects of environmental change on promiscuity in mammals. In this study, the 127 pregnant females from four
central European and ecologically diverse species of field mice (genus Apodemus) were studied to assess the role of ecological factors that may have shaped the evolution of particular mating systems. MMM
was found in all analyzed species: in Apodemus uralensis and Apodemus flavicollis, up to two males could be identified as the fathers of a particular litter, while three males sired 9.1% of analyzed litters
of Apodemus sylvaticus and 20.6% of Apodemus agrarius. Furthermore, there were obvious differences between species in relative testes size and the proportion of multiple sired
litters during those seasons when the opportunity for multiple mating was high. The species with the smallest testes and the
least promiscuous was A. uralensis (only 43.5% of multiple sired litters), while the species with the biggest testes and the most promiscuous was A. agrarius (69.2%). MMM was significantly associated with higher litter size in A. flavicollis, and the probability of MMM strongly increased with season in A. agrarius and with abundance in A. uralensis. These results indicate that ecological factors are associated with MMM rates in Apodemus field mice and more research is needed to fully understand the evolution of mating strategies at different levels of biological
resolution. 相似文献
98.
Nga Nguyen Russell C. Van Horn Susan C. Alberts Jeanne Altmann 《Behavioral ecology and sociobiology》2009,63(9):1331-1344
Close associations between adult males and lactating females and their dependent infants are not commonly described in non-monogamous
mammals. However, such associations [sometimes called “friendships” (Smuts 1985)] are regularly observed in several primate species in which females mate with multiple males during the fertile period.
The absence of mating exclusivity among “friends” suggests that males should invest little in infant care, raising questions
about the adaptive significance of friendship bonds. Using data from genetic paternity analyses, patterns of behavior, and
long-term demographic and reproductive records, we evaluated the extent to which friendships in four multi-male, multi-female
yellow baboon (Papio cynocephalus) groups in Amboseli, Kenya represent joint parental care of offspring or male mating effort. We found evidence that mothers
and infants benefited directly from friendships; friendships provided mother–infant dyads protection from harassment from
other adult and immature females. In addition, nearly half of all male friends were the genetic fathers of offspring and had
been observed mating with mothers during the days of most likely conception for those offspring. In contrast, nearly all friends
who were not fathers were also not observed to consort with the mother during the days of most likely conception, suggesting
that friendships between mothers and non-fathers did not result from paternity confusion. Finally, we found no evidence that
prior friendship increased a male’s chances of mating with a female in future reproductive cycles. Our results suggest that,
for many male–female pairs at Amboseli, friendships represented a form of biparental care of offspring. Males in the remaining
friendship dyads may be trading protection of infants in exchange for some resources or services not yet identified. Our study
is the first to find evidence that female primates gain social benefits from their early associations with adult males.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
99.
Male costs and benefits associated with male display size in field populations of an Australian lekking Drosophila species were examined. Results suggested that male mating success increased with display size, since matings appeared to
be more common in large displays, and since the probability of males encountering a female increased as displays contained
more males. Female encounter probabilities did not increase once about 20 males or more were present on a display. Male size
and fighting costs tended to increase with display size. The distribution of males among displays did not follow the ideal
free distribution in the sense that each male did not have equal mating opportunity per unit time. Deviation from an ideal
free distribution may have been due to female preference for mating in aggregations rather than with solitary males, since
in a field experiment females were more willing for mating in an aggregation of five males than with solitary males.
Received: 22 May 1997 / Accepted after revision: 1 November 1997 相似文献
100.
Sperm exchange in a simultaneous hermaphrodite 总被引:3,自引:0,他引:3
Many simultaneously hermaphroditic animals cross-inseminate when copulating, even though unilateral sperm exchange is functionally
possible. The question is why reciprocity is the rule. This study addresses sperm exchange in a hermaphroditic planarian flatworm,
Dugesia polychroa, in which self-fertilisation does not occur. We investigated the availability of self sperm for inseminating a partner, how
self sperm affects the likelihood of sperm donation, and whether sperm donation depends on reciprocation by the partner. The
amount of self sperm depended on body size, duration of isolation and experimental date, and animals that had more self sperm
were more likely to mate. Depletion of allosperm (sperm received from partners) played only an indirect role, suggesting that
animals copulate more to donate sperm rather than to replenish allosperm reserves. Among 60 copulating pairs, reciprocal insemination
was more common (63.3%) than unilateral transfer (18.3%). A surprising 18.3% did not exchange sperm in either direction. Individuals
were more likely to behave like their partners, resulting in more symmetrical matings (either reciprocity or no sperm exchange)
than asymmetrical matings (unilateral sperm donation). The amount of self sperm donated during a copulation depended mainly
on the amount available before the copulation and not on the amount received from the partner. The results suggest that conditional
sperm exchange, or sperm trading, takes place in D. polychroa.
Received: 31 May 1997 / Accepted after revision: 1 December 1997 相似文献