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1.
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
2.
Sexual cohabitation as mate-guarding in the leaf-curling spider Phonognatha graeffei Keyserling (Araneoidea, Araneae) 总被引:1,自引:1,他引:1
The leaf-curling spider Phonognatha graeffei incorporates a twisted leaf into the central hub of its orb-web that is used as a retreat. This species is unusual among orb-weaving
spiders because males cohabit in the leaf retreat with both immature and mature females, mating with the former shortly after
the female molts. Cohabitation appears to be a form of mate-guarding because cohabiting males respond agonistically to rival
males that venture onto the web, and their behaviour depends upon the reproductive status of the female; males defending immature
females are more aggressive than those defending virgin, adult females. Males copulate with previously mated females for significantly
longer than with virgin females. Females may cannibalise cohabiting males, which occurs independently of whether the female
has been deprived of food. Females that cannibalise a single male do not have a higher fecundity than non-cannibalistic females.
Received: 2 February 1996 / Accepted after revision: 27 October 1996 相似文献
3.
Replacement males in the western bluebird: opportunity for paternity, chick-feeding rules, and fitness consequences of male parental care 总被引:2,自引:0,他引:2
In western bluebirds (Sialia mexicana), most pairs remain together for life and share equally in post-hatching parental care. We removed resident males of socially
monogamous pairs during laying and after clutch completion to examine chick-feeding rules used by replacement males and current
and future fitness consequences of paternal care. Replacement males were not infanticidal and 7 (47%) fed nestlings. Feeding
replacement males and the females they joined fed at rates similar to controls. Females without a feeding replacement male
compensated by feeding more themselves so that overall feeding rates were not compromised, but they reduced their brooding
time. Unlike assisted females, unassisted females exhibited reduced nesting success and their 14-day-old chicks weighed less
than controls. Field metabolic rates of unassisted females were 17% higher than those of control females, but the difference
was not statistically significant. Older females were better able to raise young without the male's help than were yearling
females. Female condition was not affected by male provisioning and unassisted females were as likely to survive to the next
breeding season as assisted females. We found no future benefits of provisioning by replacement males; those that fed were
no more likely to breed with the female on her subsequent attempt than were males that did not feed, and subsequent clutch
sizes were not reduced for females rearing young without the male's help. These experiments suggest that male parental care
increases nesting success in western bluebirds and that replacement males use an all-or-none rule to determine whether or
not to feed chicks: if they are present during the fertile period they feed at typical rates; if they are not, they usually
do not feed at all. Because chick-feeding by males is tied to opportunity for paternity, influences success in the current
nest, and does not affect the male's future breeding success, it appears to be parental rather than mating effort.
Received: 8 May 1998 / Accepted after revision: 23 July 1998 相似文献
4.
We studied sexual selection in the red bishop, Euplectes orix, a colonial, polygynous weaverbird widely distributed over sub-Saharan Africa. Male reproductive success measured in terms
of the number of nests accepted by females and the number of eggs and nestlings in all the nests on a male's territory varied
considerably. The standardized variance (variance/mean2) in male reproductive success ranged from 0.505 to 1.737 in different years, indicating a high potential for sexual selection
in this species. An analysis of genetic parentage for 432 nestlings by non-radioactive, multilocus DNA fingerprinting confirmed
that male reproductive success (number of young sired on the territory) in this species can be reliably estimated by the measures
introduced above. In all 4 study years there was a strong positive correlation between male mating success and the total number
of nests that males built in their territories. The number of nests built can be partitioned into the number of weeks a male
held a territory and his nest-building performance. Both factors exert a significant positive effect on male mating success
and in combination explained between 53.3 and 86.3% of the variation in male reproductive success. Male morphological characters
were found to be of no importance. Males that established a territory in the following season built more nests and held their
territories for longer than males that did not establish a territory in the following season, suggesting that these measures
might be indicators of male condition and quality. Male nest-building performance (number of nests built per week) seems to
be unrelated to male condition or quality.
Received: 8 January 1999 / Received in revised form: 7 June 1999 / Accepted: 13 June 1999 相似文献
5.
Akiko Matsumoto-Oda 《Behavioral ecology and sociobiology》1999,46(4):258-266
For female chimpanzees (Pan troglodytes schweinfurthii) in the Mahale Mountains National Park, Tanzania, the most common mating pattern is opportunistic. In such opportunistic
matings, females copulated promiscuously but not randomly. This study describes female mate choice during 1-year observation
of six females who exhibited regular genital-swelling cycles. During the study period, 169 opportunistic matings and four
restrictive matings were recorded over the course of 51 days. As female estrus progressed, mating frequency and the number
of adult male mating partners increased, although the number of potential mating partners did not change. Criteria of female
choice examined were the direction and consent/rejection of courtship, proximity maintenance, and female grooming. Adult-male
courtships were successful more often than those of adolescent males. During the earlier phase of estrus, females copulated
rather promiscuously with many males. But during the later phase of estrus when the likelihood of conception is expected to
be highest, they copulated repeatedly with high-ranking adult males. There was a positive correlation between female grooming
frequency and mating frequency when the likelihood of conception was greatest. Female chimpanzees are thought to choose high-ranking
males as fathers of their offspring. Moreover, female chimpanzees may adopt one or both of two mating strategies, i.e., a
many-male strategy and a best-male strategy.
Received: 23 November 1998 / Received in revised form: 12 April 1999 / Accepted: 26 April 1999 相似文献
6.
Parker's seminal work brought attention to the possibility of postmating sexual selection by non-random fertilization success.
Mechanisms for these processes are still only partly understood and there is clearly a need for more studies of intraspecific
variation in sperm precedence. Here, we report results from an experimental study of the variation in fertilization success
between males of the water strider Gerris lacustris. Genital morphology, male body size, and copulation duration were examined as possible correlates of paternity. The significance
of guarding duration was also analysed. Only male genital morphology was correlated to fertilization success. This is one
of the first studies showing a relationship between male genital traits and fertilization success, supporting the view that
sexual selection may be responsible for the rapid and divergent evolution of genital structures in animals with internal fertilization.
The fertilization success of last males varied considerably after double matings with a short mating interval (10 min). Last-male
priority ranged from 0 to 100% and usually one of the males involved fertilized almost all the eggs. After double matings
with a short mating interval, the proportion of eggs fertilized by the last male averaged 0.68 and was greater than 0.5. In
contrast, the average fertilization success was biased towards the first male when the matings were more spread out over time
(24 h). These results do not support earlier suggestions of a widespread last-male sperm priority in water striders.
Received: 28 July 1998 / Received in revised form: 15 March 1999 / Accepted: 28 March 1999 相似文献
7.
Polyandry and enhanced reproductive success in the harlequin-beetle-riding pseudoscorpion 总被引:1,自引:0,他引:1
J. A. Zeh 《Behavioral ecology and sociobiology》1997,40(2):111-118
The growing molecular evidence that females of many species mate with several males calls for a critical reassessment of
the selective forces which act to shape female mating tactics. In natural populations of the harlequin-beetle-riding pseudoscorpion,
Cordylochernes scorpioides, females are polyandrous and typically produce mixed-paternity broods. Laboratory behavioral analyses and breeding experiments
indicate that polyandry in this pseudoscorpion is an active strategy which increases female reproductive success. Females
restricted to mating with a single male experienced a higher rate of embryo failure and produced significantly fewer offspring
than either females mated to more than one male in the laboratory or females naturally inseminated in the field. Forced copulation,
insufficient sperm from a single mating, male nutrient donations and variation in inherent male genetic quality cannot explain
the greater number of nymphs hatched by polyandrous females in this study. Evidence suggests that, by mating with several
males, C. scorpioides females may exploit postcopulatory mechanisms for reducing the risk and/or cost of embryo failure resulting from fertilization
by genetically incompatible sperm.
Received: 5 May 1996 / Accepted after revision: 16 October 1996 相似文献
8.
David J. Able 《Behavioral ecology and sociobiology》1999,46(6):423-428
Darwin predicted that scramble competition for access to reproductive females would result in sexual dimorphism of locomotory
structures, but direct evidence for this is extremely rare. I examined the relationship between variation in tailfin size
and mating success in a field and laboratory study of red-spotted newts, Notophthalmus viridescens. Over three breeding seasons, male tailfin size was positively correlated with variation in male amplexus frequency, and
indirectly correlated with male insemination frequency. In a laboratory study, I confirmed that males' ability to capture
females is affected by variation in tailfin size. This is the first study to show that naturally occurring variation in male
locomotory structures affects male mating success. It corroborates the prediction that scramble competition leads to sexual
selection on locomotory structures and, potentially, to dimorphism in these structures.
Received: 16 April 1999 / Received in revised form: 16 May 1999 / Accepted: 12 June 1999 相似文献
9.
Sperm economy and limitation in spiny lobsters 总被引:5,自引:0,他引:5
Sperm limitation, when female fertilisation success is constrained by the supply of sperm, is generally perceived to be an
uncommon feature of reproduction in species which directly transfer gametes during copulation. Male size, previous copulations,
and the balance of expected reproductive return and future mating opportunity may, however, limit the amount of sperm males
transfer to females. We used laboratory experiments where mate size could be manipulated and its consequences on spermatophore
size and clutch size determined, to show that in two genera of spiny lobsters (Crustacea: Palinuridae) male reproductive output
limits the size of clutches brooded by females. In Panulirus argus from the Florida Keys, we show that while male size affects spermatophore area, males also vary the amount of ejaculate positively
with female size. Furthermore, the area of the spermatophore has a greater influence than female size on subsequent clutch
weight. In Jasus edwardsii from New Zealand, female size, male size and mate order all affect clutch weight. In both species, clutches fertilised by
small males in the laboratory are significantly smaller than clutches fertilised by large males. These results suggest that
to ensure they receive sufficient sperm, females should either mate several times prior to oviposition, mate as early as possible
in the reproductive season, or choose large, preferably unmated males as partners and thus compete with other females for
preferred males. Sperm-limited female fecundity has the potential to limit the egg production of fished populations where
large males are typically rare.
Received: 18 May 1998 / Received in revised form: 20 November 1998 / Accepted: 30 November 1998 相似文献
10.
Thomas Artiss Wesley M. Hochachka Kathy Martin 《Behavioral ecology and sociobiology》1999,46(6):429-434
For several species of birds, high rates of male vigilance are correlated with high rates of female foraging. This relationship
is thought to ultimately result in higher reproductive success for females paired with highly vigilant males. However, previous
research has not examined the behavioural mechanism that produces the correlation between male vigilance and rates of female
foraging. Foraging females may take advantage of vigilance that males are using for other purposes. Alternatively, the purpose
of male vigilance may be to increase females' ability to forage. We examined these alternatives by testing whether vigilance
preceded or followed bouts of female foraging more often than would occur by chance alone, using simultaneous behaviour observations
of pre-incubation pairs of white-tailed ptarmigan (Lagopus leucurus). Our results indicate that each member of a pair may influence the behaviour of the other. Females were more likely to initiate
foraging bouts after males became vigilant than if their mate remained non-vigilant. Moreover, non-vigilant males were more
likely to become vigilant if their mate was foraging than if she was engaged in some other activity. Despite the possibility
that a sexual conflict exists as each member of a pair attempts to maximize its fitness, both sexes behave as though a major
role of male vigilance is to enhance female foraging opportunities.
Received: 3 May 1999 / Received in revised form: 14 June 1999 / Accepted: 16 June 1999 相似文献
11.
The aim of this study was to investigate reproductive strategies and their consequences in gray mouse lemurs (Microcebus murinus), small solitary nocturnal primates endemic to Madagascar. Previous reports of sexual dimorphism in favor of males and females,
respectively, a high potential for sperm competition and pheromonal suppression of mating activity among captive males, led
us to investigate mechanisms of intrasexual competition in a wild population. Based on 3 years of mark-recapture data, we
demonstrate that sexual dimorphism in this species fluctuated annually as a result of independent changes in male and female
body mass. Male body mass increased significantly prior to the short annual mating season. Because their testes increased
by 100% in the same period and because their canines are not larger than those of females, we suggest that large male size
may be advantageous in searching for estrous females and in enabling them to sustain periods of short-term torpor. In contrast
to reports from captive colonies, we found no evidence for two morphologically distinct classes of males. Finally, we also
show that most adult males are active throughout the cool dry season that precedes the mating season, whereas most adult females
hibernate for several months. This is in contrast to other solitary hibernating mammals, where males typically emerge 1–2
weeks before females. Thus, this first extended field study of M.␣murinus clarified previous conflicting reports on sexual dimorphism and male reproductive strategies in this primitive primate by
showing that their apparent deviation from predictions of sexual selection theory is brought about by specific environmental
conditions which result in sex-specific life history tactics not previously described for mammals. A general conclusion is
that sexual selection can operate more strongly on males without resulting in sexual dimorphism because of independent selection
on the same traits in females.
Received: 6 July 1997 / Accepted after revision: 28 March 1998 相似文献
12.
We present a model of error-prone female choice on leks, and investigate the effects of different degrees of error on the
distribution of mating success among males present at leks of different sizes. At higher levels of error, the best male is
predicted to gain a smaller share of matings, while low-ranking males gain a larger share. Males who are of high rank but
not the most desirable on the lek do best at intermediate levels of error, since the top-ranked male does not then claim all
the matings, but assessment is still sufficiently accurate for females to discriminate between high-ranking and low-ranking
competitors. The effects of error are shown to be more pronounced on larger leks, due to smaller expected differences in mating
value between males of adjacent ranks. This interaction between lek size and error suggests that observed negative relationships
between lek size and mating skew need not be attributed solely to intrasexual competition, as previously suggested, but could
also be a result of imperfect choice.
Received: 20 February 1998 / Accepted after revision: 25 October 1998 相似文献
13.
Mating patterns and reproductive success in the bushy-tailed woodrat (Neotoma cinerea), as revealed by DNA fingerprinting 总被引:1,自引:0,他引:1
The mating patterns and reproductive success of the bushy-tailed woodrat (Neotoma cinerea) were investigated over a 3-year period (1992–1994) using DNA fingerprinting. Paternity was determined by genetic analysis
of 58 juveniles of known maternity from 35 litters. Analysis of DNA fingerprints revealed that all offspring within a litter
were fathered by a single male; the statistical probability of detecting multiple males mating with a female was high, indicating
that multiple paternity would have been detected had it occurred. However, individual males did not father more than one litter
from a given female either within or between years. At least 75% of females and 57% of males successfully produced offspring
each year. The finding that all littermates are first-order relatives may contribute to the high level of female cooperation
in this species.
Received: 28 May 1997 / Accepted after revision: 22 March 1998 相似文献
14.
Ben C. Sheldon Pete Davidson Gabriella Lindgren 《Behavioral ecology and sociobiology》1999,46(3):141-148
There is increasing evidence that sexual selection may be intense even in socially monogamous birds, resulting from both
mate choice and sperm competition. We studied these two modes of sexual selection experimentally by removing paired male collared
flycatchers, Ficedula albicollis, from their mates for 2 days and investigating the factors that influenced the likelihood of a replacement male appearing
and how the removals influenced paternity. Replacement males (usually neighbouring males) appeared at 81% (n = 37) of nests where males were removed. The likelihood of this appearance was unaffected by the probable reproductive value
of the female's clutch to the replacing male. A replacement was, however, less likely when the original male had a large forehead
patch, a trait previously shown to be subject to sexual selection in this population. Experimental removal of males increased
the level of sperm competition: 74% of experimental broods were multiply sired, compared to 29% of unmanipulated broods in
a previous study. Only two factors predicted how paternity was shared between males: removed males fathered more young if
removed closer to laying, and if they had larger forehead patches. The former result is consistent with last-male sperm precedence
determining paternity, whereas the latter adds to other evidence that forehead patch size is the target of female preference
in this species. Our results suggest that females exert some control over male replacement, and also that they may influence
the fertilisation success of males by behavioural means.
Received: 15 July 1998 / Received in revised form: 16 March 1999 / Accepted: 28 March 1999 相似文献
15.
Sexual signalling and viability in a wolf spider (Hygrolycosa rubrofasciata): measurements under laboratory and field conditions 总被引:4,自引:0,他引:4
Janne S. Kotiaho Rauno V. Alatalo Johanna Mappes Silja Parri 《Behavioral ecology and sociobiology》1999,46(2):123-128
This study examined the crucial prediction of the conditional-handicap theory, the relationship between male sexual trait
size and male viability, in the wolf spider Hygrolycosa rubrofasciata. In this species, males court females by drumming dry leaves with their abdomen, and males with the highest drumming rate
enjoy highest mating success. We determined male drumming rate, body mass, and mobility, which reflects mate-searching activity,
in relation to male survival. Because it is often difficult to know how results obtained from laboratory studies reflect the
natural world, particularly when the measured variable is survival, we repeated our study in both laboratory and field conditions.
Males drumming at the highest rate survived better than males drumming at a lower rate in both laboratory and field conditions.
These results are in accordance with the predictions of conditional-handicap models of sexual selection. Survival was independent
of male body mass and there was no significant correlation between male drumming activity and body mass. However, large males
moved further than smaller males, and males moving longer distances lost less mass than those moving shorter distances. These
results suggest that, moving, and consequently mate-searching activity, may be a condition-dependent trait and that there
may be a advantage for large males in mate searching.
Received: 22 October 1998 / Received in revised form: 28 January 1999 / Accepted: 14 February 1999 相似文献
16.
Summary. This study reports on the impact of insecticidal resistance on the diel periodicity of the calling behaviour and pheromone
production of different-aged virgin females of the obliquebanded leafroller (OBL), Choristoneura rosaceana. While both resistant (R) and susceptible (S) females initiated calling on the first night following emergence, the periodicity
of the calling behaviour, as determined by the mean onset time of calling (MOTC) and the mean time spent calling (MTSC) over
the first six nights of calling, differed between the two strains. R females started calling significantly later in the night.
However, as the MOTC of R females advanced with age but did not do so in S individuals, the difference between strains was
more pronounced in younger than older females. Furthermore, R females spent less time calling than S individuals. However,
the MTSC increased as a function of age in both R and S females, so the difference between strains remained fairly constant
for each night of calling. The major component of OBL sex pheromone, the Z11-14: Ac, determined at peak calling activity,
significantly declined with female age. Overall, pheromone production was lower in R females than in S females, with the difference
being more pronounced in younger than in older individuals. Thus, resistant females may have a lower mating success. The mating
success of both R and S strain males did not vary with the number of previous matings acquired. With regard to males, although
there was a significant decline in spermatophore size with successive matings, there was no significant difference between
strains. However, R males are smaller and may be disadvantaged through female choice and/or may respond differently to pheromone
source compared with S individuals. If the reproductive success of both sexes is affected, this may have a profound influence
on the dynamics of insecticidal resistance in the presence or absence of selection in OBL populations.
Received 4 July 2001; accepted 19 October 2001. 相似文献
17.
S. D. Goldsworthy D. J. Boness R. C. Fleischer 《Behavioral ecology and sociobiology》1999,45(3-4):253-267
When closely related species breed in sympatry, and where hybrids have lower fitness, reinforcement theory predicts that
selection should favour mechanisms that reduce the probability of interspecific matings. If this situation arises among species
that exhibit resource defence polygyny where males and females of different species reside in the same territories, there
may be some conflict between mate choice based on territory-holding ability (sexual selection) and mate choice for correct
species. We investigated this in a population of fur seals where three species are sympatric and where some females breed
in the territories of heterospecific males, and where interspecific matings and hybrid pups are observed. The territorial
status of males and the birthing sites of females were determined during daily observations, as were the movements of males
and females, the location of matings and mating partners. DNA extracted from skin samples was used to determine paternities
using DNA fingerprinting and the mtDNA genotype of individuals. Individuals were also classed on the basis of species-typical
phenotype. We found that extra-territory inseminations (ETIs) were significantly more prevalent (67%) when territorial males
and resident females were of different phenotype than when of similar phenotype (27%), but mtDNA genotype had no effect on
the rate of ETIs. ETIs were probably by males with the same phenotype, as pups born to these females in the following season
had the same phenotype as their mothers, suggesting they were not hybrids. These results suggest that within the resource
defence polygynous mating system of these sympatric fur seals, female mate choice is more influenced by male phenotype than
genotype. Contrary to our predictions, our study indicates that potential conflict between mate choice based on sexual selection
and species recognition is unlikely, because females have some capacity to discriminate between males both within and between
species on phenotypic traits additional to those under sexual selection. Although at least 25% of the pups born in this study
were hybrid, this study can only support reinforcement theory if hybrids have reduced fitness. The fitness of hybrids among
the species studied is currently unknown.
Received: 19 January 1998 / Accepted after revision: 12 September 1998 相似文献
18.
Karen S. Oberhauser 《Behavioral ecology and sociobiology》1989,25(4):237-246
Summary I present the results of experiments designed to measure the effects of spermatophores produced by male monarch butterflies on male and female reproductive success. There was wide variation in the number of matings by captive males, suggesting the potential for strong sexual selection on males. Male lifespan was not affected by total number of matings, nor did it differ between males that were allowed to mate and those not exposed to females. Two effects of spermatophores on female behavior or fecundity are reported; (1) Females that received large spermatophores delayed remating longer than those receiving small ones. (2) Females allowed to mate several times laid more eggs than singly-mated females. The relative importance of these effects is discussed in relation to monarch mating patterns. 相似文献
19.
Reproductive biology of a wood-boring isopod, Sphaeroma terebrans, with extended parental care 总被引:1,自引:0,他引:1
M. Thiel 《Marine Biology》1999,135(2):321-333
The isopod Sphaeroma terebrans Bate, 1866 burrows in aerial roots of the red mangrove Rhizophora mangle L. The burrows serve as shelter and as a reproductive habitat, and females are known to host their offspring in their burrows.
I examined the reproductive biology of S. terebrans in the Indian River Lagoon, a shallow lagoon stretching for ∼200 km along the Atlantic coast of Florida, USA. Reproductive
isopods were found throughout the year, but reproductive activity was highest in the fall and during late spring/early summer.
During the latter periods, large numbers of subadults established their own burrows in aerial roots. The average numbers of
S. terebrans per root were high during the fall, but decreased during the winter and reached lowest levels at the end of the summer. Females
reached maturity at a larger size than males, but also grew to larger sizes than the males. The average size of females varied
between 8 and 10 mm, the average size of males between 6.5 and 8.5 mm. The number of embryos female−1 was strongly correlated with female body length. No indication for embryo mortality during development was found. Parental
females (i.e. with juveniles in their burrows) hosted on average between 5 and 20 juveniles in their burrows (range 1 to 59).
Most juveniles found in female burrows were in the manca stage and 2 to 3 mm in body length. Juveniles did not increase in
size while in the maternal burrow, and juveniles of similar sizes could also be found in their own burrows. Males did not
participate in extended parental care, since most of them left the females after copulation. Many females that were born in
the summer produced one brood in the fall and a second during winter/early spring. Females that were born in the fall produced
one brood during spring/early summer, but then probably died. Extended parental care in S. terebrans is short compared to other peracarid crustaceans. It is concluded that this reproductive strategy in S. terebrans serves primarily to shelter small juveniles immediately after they emerge from the female body, when their exoskeleton is
still hardening and their physiological capabilities are still developing. Thus, in S. terebrans, extended parental care probably aids to protect small juveniles from adverse physical conditions in their subtropical intertidal
habitat.
Received: 9 December 1998 / Accepted: 24 June 1999 相似文献
20.
Allison J. Abell 《Behavioral ecology and sociobiology》1997,41(4):217-226
The association between spatial proximity and paternity was studied in a population of the striped plateau lizard, Sceloporus virgatus. The relationship between estimated mating success and male phenotypic traits was examined for a sample of 55 males. DNA
samples were obtained from 13 female-offspring families. The males with the closest spatial proximity to each female were
tested as possible sires within each family. Fingerprinting with two multilocus hypervariable minisatellite probes revealed
a strong correspondence between male-female spatial proximity and actual paternity. Paternity could be assigned for 72 of
the 100 hatchlings. Most hatchlings with identifiable sires were attributed to a male with the highest category of spatial
proximity to the mother. However, there was a low to moderate level of multiple paternity within clutches, and for some clutches
probable sires could not be identified even though the most likely behavioural candidates were tested. Thus, nonterritorial
males or other males lacking strong social and spatial relationships with females may achieve some degree of reproductive
success. Analysis of mating success revealed that male success increased with body size, up to a point beyond which larger
size conferred no advantage.
Received: 7 January 1997 / Accepted after revision: 16 June 1997 相似文献