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1.
Janette Wenrick Boughman 《Behavioral ecology and sociobiology》1997,40(1):61-70
Individually distinctive vocalizations are ubiquitous; however, group distinctive calls have rarely been demonstrated. Under
some conditions, selection should favor calls indicating social group membership in animals that forage in groups. Greater
spear-nosed bats (Phyllostomus hastatus) give calls that appear to facilitate recognition of social group mates who are unrelated. Females give loud broadband (4–18 kHz)
vocalizations termed screech calls when departing on foraging trips and at foraging sites. Screech calls help to establish
foraging groups among social group members, and to maintain contact over the long distances they travel while foraging. I
test two hypotheses about how screech calls may be structured to convey caller identity. Individual calls may be distinct
and group members may learn to recognize each individual's calls and to associate the individual with the social group. Alternatively,
groups may give distinct calls and individuals within groups may share call characteristics. To test these hypotheses I conducted
multivariate acoustic analysis of multiple calls from 28 bats from three social groups. Although the ubiquity of individually
distinctive calls in other taxa makes this result more likely, the results reveal that group calls are highly distinctive.
Individual bats within groups are statistically indistinguishable. Calls appear to decrease slightly in frequency as bats
age. Call convergence among unrelated group mates implies vocal learning in this species.
Received: 28 March 1996 / Accepted after revision: 6 October 1996 相似文献
2.
We investigated competition for food among two groups of six clone amagos (salmonids), Oncorhynchusmasoumacrostomus, in a laboratory experiment with different rates of food input. We examined the effect of temporal clumping of food resources
on the inequality of food sharing between competitors. Monopolization of food by dominants was greater at a low input rate
(one food item per 10 s) than at a high input rate (1 food item per 1 s). Aggressive behavior by dominants was more frequent
at the low input rate than at the high input rate; its purpose was presumably to interfere with the feeding behavior of subordinates.
We assessed the relative importance of three foraging factors (the number of approaches to food items, the chance per approach
and the gain per chance) in enhancing inequality in food gain between individuals. Dominants had a disproportionately high
chance per approach and gain per chance at the low input rate, but not at the high input rate. The chance of obtaining a food
item per approach depended on how many competitors approached simultaneously. The gain per chance depended on the competitive
ability of the approaching fish. There was an interaction between these components, such that the number of approaches affected
the chance per approach and gain per chance. We evaluated the independent effect of the chance per approach, and showed that
it was higher for dominants than for subordinates at the low input rate, but not at the high input rate. This implies that
subordinates changed their behavior and became more likely to avoid approaching food at the same time as dominants at the
low input rate.
Received: 13 August 1996 / Accepted after revision: 30 November 1996 相似文献
3.
Quality-indicating sexually selected traits may have their honesty maintained by their costs or by an inherent “revealing”
nature. Long tails in birds are usually considered to be costly “handicaps”, but may have additional potential as revealing
indicators through the incidence of breakage. Magpies Pica pica with unbroken and less abraded tails paired earlier, but did not nest or fledge young earlier than pairs with tails in poorer
condition. Pairs mated assortatively by tail quality, and magpies with very broken tails remained unmated. Pairs in which
both members had almost undamaged tails fledged more offspring than pairs with poorer tails. Tail quality did not correlate
with the extent of any habitat type in the territory. Tail damage thus honestly indicated a magpie's reproductive potential,
and the data are consistent with its having a role in mate choice, as a revealing element of tail morphology.
Received: 28 March 1996 / Accepted after revision: 9 December 1996 相似文献
4.
José L. Tella Manuela G. Forero José A. Donázar Juan J. Negro Fernando Hiraldo 《Behavioral ecology and sociobiology》1997,40(4):253-260
We examined the causes, costs and benefits of adoption in the altricial lesser kestrel Falco naumanni. Specifically, we tested the intergenerational conflict hypothesis, proposed to explain adoption in some birds. Adoptions
involved 76% of the nests and 51% of the nestlings at a mean age of 25 days (12 days before fledging). Nest-switching nestlings
were not in poorer body condition, more parasitized or younger than their siblings, and body condition and prey delivery rates
of their parents did not differ from those of other parents. In the foster nest, adopted nestlings did not benefit from higher
feeding rates or a prolongation of the nestling period. They did not have fewer nest-mates or achieve higher rank within the
new brood. Thus, adopted nestlings did not improve their body condition and survival. Adult lesser kestrels seemed unable
to finely discriminate beween their own and alien chicks. Foster parents bore the cost of an increase of prey delivery rates,
although it did not affect their survival or subsequent reproductive performance. Therefore, our results do not support the
intergenerational conflict hypothesis, and suggest that adoption in this species is non-adaptive. Traditionally, the lesser
kestrel bred in cliffs where movement among nest-sites was restricted. Nowadays, about half of the colonies are in tiled roofs
which facilitate nest-switching by nestlings. The high rate of adoptions may thus be explained as reproductive errors associated
with the recent occupation of a new breeding habitat.
Received: 3 May 1996 / Accepted after revision: 19 January 1997 相似文献
5.
Ellen J. Censky 《Behavioral ecology and sociobiology》1997,40(4):221-225
Mate choice by females has been documented in a variety of taxa. Female mate choice in species lacking male resource control
or paternal care might occur if preferred males provide protection from harassment. Female mate choice was investigated in
a natural population of the non-territorial lizard Ameiva plei (Teiidae). Consort pairs were allowed to form naturally. Consort males were significantly larger than non-consort males.
After removal of consort males, the “abandoned” female's reaction to the first male who approached her was recorded. Females
rejected all small males. Female preference for large males was significantly higher than preference for small males. Large
males may be better equipped to guard the females from harassment and behavior of large males is less harassing than behavior
of small males, thereby affording the female increased foraging time.
Received: 21 June 1996 / Accepted after revision: 28 December 1996 相似文献
6.
Female mallard mating preferences for multiple male ornaments 总被引:3,自引:1,他引:3
K. E. Omland 《Behavioral ecology and sociobiology》1996,39(6):353-360
Mating preferences were studied in captive wild-stock female mallards. Independent observers scored ornament brightness for
the bill and eight plumage areas of male mallards on a scale of 1 to 6. Ornament scores were generally positively correlated
with each other as indicated by univariate correlations and principal component analysis. Males with higher bill scores were
significantly more likely to obtain pairings. None of eight individual plumage ornaments were significant predictors of pairing
success, but males with higher average plumage scores had significantly higher pairing success. Males that completed the molt
first were also significantly more likely to be paired. Thus females may have paid some attention to plumage brightness. Stepwise
multiple regression produced a model that included only bill and molt, both of which contributed a similar degree (r
2 = 0.39); plumage ornaments and size measurements did not enter the model. These results are interpreted in light of hypotheses
for the evolution of multiple ornaments, and phylogenetic plumage patterns in dabbling ducks.
Received: 18 December 1995 / Accepted after revision: 22 September 1996 相似文献
7.
Carola Borries 《Behavioral ecology and sociobiology》1997,41(3):139-150
In the seasonally breeding langur (Presbytis entellus) population of Ramnagar, South Nepal, where multimale groups prevail, 25 attacks on 11 infants (including one actual killing)
by seven adult males were witnessed in five groups by six observers between 1990 and 1996. Circumstantial evidence also indicates
three additional attempts at infanticide and in seven additional cases infanticide was presumed or likely. Infanticide presumably
accounted for 30.8–62.5% of infant mortality in the first 2 years of life. Most attackers (91.4%) were residents of the infants'
group and had immigrated after the infants had been born (75.0%) or conceived (25.0%). Thus, they were not related to the
victims. The interbirth interval was shortened if an infant died either prior to September of its 1st year of life (mean = 1.2
years), or its 2nd year (mean = 2.0) and even its 3rd year (mean = 2.4). All attackers remained in the group at least until
the next mating season; high-ranking males maintained their dominance rank and lower-ranking males rose in rank. Since rank
and mating success were correlated and rank and reproductive success might be correlated, all attackers had a good chance
of siring the next infant of the victims' mothers and could thus have benefited by their action. Infanticide seems to be a
male reproductive strategy at Ramnagar. Infanticide has never before been reported among seasonally breeding langurs living
at such low densities. This is also the first detailed report of infanticide as a male reproductive strategy in a seasonally
breeding primate population.
Received: 19 December 1996 / Accepted after revision: 7 June 1997 相似文献
8.
Juan Carlos Alonso Luis M. Bautista Javier A. Alonso 《Behavioral ecology and sociobiology》1997,40(6):401-408
We studied the behavior of 13 radiotagged cranes dispersing from a communal roost over days when they changed their main
daily foraging area between consecutive days during two winter seasons. Individuals went to a new foraging zone when on the
previous day their morning food intake had fallen below their mean morning food intake measured over the whole winter. Food
intake on the day before a change in foraging area was positively correlated with dominance rank. Dominant cranes changed
to new zones with higher numbers of birds and food density, while subordinate cranes went to new zones with lower numbers
of birds. As a result, all birds increased their food intake over that of the previous day. Dominant cranes remained more
faithful to their most preferred foraging zone, where they spent 69% of the mornings, while subordinate birds were more mobile,
switching among zones frequently. Dominant birds left the roost later than subordinate birds on the days they changed to a
new zone, which could be used to track the main departing flows. The results suggest that the dynamics that led to a truncated
phenotype-limited distribution were determined by social dominance and food abundance, with dominant cranes shifting to a
new zone to maintain their high intake levels and subordinates changing more frequently whenever their daily intake did not
reach the minimum metabolic requirements.
Received: 16 December 1996 / Accepted after revision: 22 February 1997 相似文献
9.
Correlates of extra-pair fertilization success in hooded warblers 总被引:13,自引:0,他引:13
Bridget J. M. Stutchbury W. H. Piper D. L. Neudorf S. A. Tarof Judith M. Rhymer G. Fuller R. C. Fleischer 《Behavioral ecology and sociobiology》1997,40(2):119-126
We examined correlates of extra-pair fertilization (EPF) success in the hooded warbler (Wilsonia citrina), a species where females pursue extra-pair matings. The good genes hypothesis predicts that females choose extra-pair mates
with morphological or behavioral traits that reflect differences in male genetic quality. EPFs were common, as 35.3% (42/119)
of broods contained extra-pair young (EPY) and 26.7% (95/356) of nestlings were the result of EPFs. There was a strong skew
in male EPF success which increased the variance in annual male mating success 2–3 fold. However, male morphology did not
predict EPF success, as extra-pair males were not older or larger than the males they cuckolded. Likewise, there were no significant
correlations between the proportion of extra-pair young in a brood and male size or age. The good genes hypothesis predicts
that high-quality males will be consistently preferred as genetic mates, but the number of young sired by a male with his
social mate was not consistent from one year to the next. There was a significant negative correlation between female age
and proportion of EPY produced, which could result if older females obtain higher-quality social mates. We found no strong
evidence that females choose extra-pair mates for good genes, but females may use behavioral rather than morphological cues
to assess relative male quality.
Received: 31 May 1996 / Accepted after revision: 17 October 1996 相似文献
10.
Studies of the otariids (fur seals and sea lions), a highly sexually dimorphic group, have provided conflicting evidence of
differential maternal expenditure in male and female offspring and, thus, suggestions that they conform to predictions of
investment theory are equivocal. Since the mid-1970s, a diversity of research on Antarctic fur seals (Arctocephalus gazella) including studies of their reproductive ecology, lactation energetics, and foraging behaviour have been conducted at Bird
Island, South Georgia that have resulted in one of the more complete and diverse data sets for any species of otariid. These
long-term data were reviewed to determine whether there was any evidence to support that differential maternal expenditure
occurred in Antarctic fur seals. Most of the data examined were collected during five consecutive austral summers from 1988
through 1992 and included years in which local food resources were abundant and scarce. We were unable to detect differences
in the sex ratios of pups at birth or sex-biased differences in growth rates estimated from serial data, the number of foraging
trips made, the duration of attendance ashore, diving behaviour, suckling behaviour, or milk consumption in any year and in
the duration of foraging trips or age at weaning in 2 of 3 years. In addition, we found no evidence of greater reproductive
costs between mothers with sons or daughters relative to their reproductive performance the following year. In contrast, sex-biased
differences were only found in the duration of foraging trips in 1990, the age at weaning in 1988, and consistently in growth
rates estimated from cross-sectional data. We suggest that differential maternal expenditure does not occur in Antarctic fur
seals because male pups probably do not gain greater benefit from additional maternal expenditure than female pups. After
weaning, males experience a period of rapid juvenile growth over 3–4 years during which time body mass nearly trebles. This
growth will almost certainly be dependent upon available food resources then rather than on any maternal expenditure received
over the first 4 months of life and, thus, the assumptions of the Trivers and Willard hypothesis are probably invalid for
Antarctic fur seals.
Received: 10 July 1996 / Accepted after revision: 3 March 1997 相似文献
11.
Codas, which are patterned series of clicks, were recorded from female and immature sperm whales (Physeter macrocephalus) in a number of locations around the South Pacific Ocean and in the Caribbean Sea. Using K-means cluster analysis, 3,644 codas were categorized based on the number of clicks and their patterning. There were 30 resulting
types of coda. The numbers of codas of the different types recorded were used to construct repertoires for each recording
session, day, group of whales, place, area, and ocean. Strong group-specific dialects, which seem to persist over periods
of years, were apparent, overlaid on weaker geographical variation. Significant differences in repertoire were found between
the Caribbean and the Pacific Ocean. Sperm whales now join killer whales (Orcinus orca) as the only cetacean species in which dialects (differences in vocal repertoire among neighboring, potentially interacting
groups) have been found.
Received: 13 June 1996 / Accepted after revision: 19 January 1997 相似文献
12.
Control of reproduction in social insect colonies: individual and collective relatedness preferences in the paper wasp, Polistes annularis 总被引:1,自引:0,他引:1
David C. Queller J. M. Peters Carlos R. Solís Joan E. Strassmann 《Behavioral ecology and sociobiology》1997,40(1):3-16
Social insect colonies often have one or a few queens. How these queens maintain their reproductive monopoly, when other
colony members could gain by sharing in the reproduction, is not generally known. DNA microsatellite genotyping is used to
determine reproductive interests of various classes of colony members in the paper wasp, Polistes annularis. The relatedness estimates show that the best outcome for most individuals is to be the reproductive egg-layer. For workers,
this depends on the sex of offspring: they should prefer to lay their own male eggs, but are indifferent if the queen lays
the female eggs. The next-best choice is usually to support the current queen. As a rule, subordinates and workers should
prefer the current queen to reproduce over other candidates (though subordinates have no strong preference for the queen over
other subordinates, and workers may prefer other workers as a source of male eggs). This result supports the theory that reproductive
monopoly stems from the collective preferences of non-reproductives, who suppress each other in favor of the queen. However,
we reject the general hypothesis of collective worker control in this species because its predictions about who should succeed
after the death of the present queen are not upheld. The first successor is a subordinate foundress even though workers should
generally prefer a worker successor. If all foundresses have died, an older worker succeeds as queen, in spite of a collective
worker preference for a young worker. The results support the previous suggestion that age serves as a conventional cue serving
to reduce conflict over queen succession.
Received: 3 May 1996 / Accepted after revision: 22 September 1996 相似文献
13.
The evolution of non-maternal caretaking among anthropoid primates: do helpers help? 总被引:5,自引:0,他引:5
Non-maternal infant care among nonhuman primates has frequently been investigated from the perspective of the caretaker.
Here we examine whether allocaretaking behavior provides direct reproductive benefits to mothers. Comparative analyses that
control for the effects of allometry and phylogeny reveal that allocaretaking behavior correlates with relatively fast infant
growth and reproduction, but is not associated with the production of large infants. These results are consistent with those
from studies of other taxa; primate helpers appear to increase the reproductive success of female breeders. In addition, our
findings contrast with those derived from traditional allometric analyses and underscore the importance of controlling for
the potentially confounding effects of phylogeny in comparative analyses.
Received: 28 May 1996 / Accepted after revision: 16 November 1996 相似文献
14.
Ornamentation predicts reproductive success in female pipefish 总被引:5,自引:0,他引:5
Anders Berglund Gunilla Rosenqvist Patricia Bernet 《Behavioral ecology and sociobiology》1997,40(3):145-150
In the sex-role reversed pipefish Syngnathus typhle females compete for access to males and males are choosy. Females develop a temporary ornament when competing over mates
with other females and when performing nuptial dances with males. This ornament is an amplification of the normal striped
pattern in these fishes. We here show experimentally that (1) the contrast of this normal pattern forecasts the extent to
which the ornament is shown, (2) contrast and ornamentation honestly signal female quality (egg numbers), (3) contrast and
ornamentation accurately predict female mating success, (4) contrast is a phenotypically plastic trait specifically exaggerated
under situations of female – female competition, and (5) neither contrast nor ornament are energetically expensive to the
females (i.e., they are independent of short-term nutritional status). Hence, as predicted in sex-role reversed species, ornament
design is constrained by costs to female fecundity: an energetically demanding ornament would impair on a female's ability
to produce eggs. The type of ornament described here is the expected one, costly for reasons other than being energetically
expensive to produce.
Received: 4 April 1996 / Accepted after revision: 27 October 1996 相似文献
15.
Common goldeneyes adjust maternal effort in relation to prior brood success and not current brood size 总被引:3,自引:0,他引:3
Parental investment theory predicts that parental effort should be related to the reproductive value of the current brood.
This depends on both the number of young and the survival prospects of each of them. Thus parents may provide more care to
larger broods either because of (1) the direct effect of brood size per se on reproductive value (the “brood size” hypothesis)
or because (2) past mortality, reflected in current brood size, predicts future mortality of the brood and hence its reproductive
value (the “brood success” hypothesis). Earlier studies have not attempted to distinguish between these alternatives. We tested
the hypotheses in the precocial, nidifugous common goldeneye Bucephala clangula, a species with uniparental female care. Maternal effort was measured as the time spent by the female in rearing the brood.
We found that brood size itself is not associated with maternal effort, but that females modify their maternal effort according
to the mortality already experienced by the brood, supporting the prediction of the brood success hypothesis. We also found
that brood mortality varied considerably between broods and that previous mortality predicts future mortality within broods,
basic assumptions of the brood success hypothesis.
Received: 30 January 1996 / Accepted after revision: 27 October 1996 相似文献
16.
Bertrand Schatz Jean-Paul Lachaud Guy Beugnon 《Behavioral ecology and sociobiology》1997,40(6):337-349
According to the weight and size of their prey, Ectatomma ruidum workers can employ different recruitment systems (solitary hunting, cooperative hunting and group hunting with recruitment)
when mastering and retrieving prey items from short distances from the nest. Prey size determined the backwards entry typically
adopted by this species, while prey weight determined the predatory strategy selected. After a common initial sequence (search
for prey, detection, localization), predatory sequences varied in terms of the type of approach, the site of seizure, the
reaction after stinging and the type of transport. Nevertheless, irrespective of prey weight and size, seizure was preferentially
oriented towards the head and prey were always stung. Short-range recruitment and mass recruitment without trail laying were
elicited by a large range of heavy prey (> 2.5 times the weight of an individual worker). According to the mortality risk
associated with each prey, hunters exhibited a “prudent” stinging posture associated with an increase in the duration of the
subsequent phase of waiting for prey immobilization. The overall time of capture was positively correlated with the weight
of the prey. When collective hunting strategies were involved, E. ruidum colonies matched the number of recruited hunters to the size and weight of the prey. Compared to solitary hunting strategies,
for short food–nest distances, this graded recruitment appeared to enhance the energetic benefits derived by this species
from the use of recruitment systems: the higher the number of workers involved in the recruitment process, the greater the
energetic benefits obtained. The exhibition or absence of trail laying behavior in the recruitment responses displayed by
E. ruidum workers is discussed in relation to their involvement in scavenging or predatory behavior.
Received: 27 June 1996 / Accepted after revision: 3 March 1997 相似文献
17.
Timothée R. Cook Maike Hamann Lorien Pichegru Francesco Bonadonna David Grémillet Peter G. Ryan 《Marine Biology》2012,159(2):373-387
Knowledge on how divers exploit the water column vertically in relation to water depth is crucial to our understanding of
their ecology and to their subsequent conservation. However, information is still lacking for the smaller-bodied species,
due mostly to size constraints of data-loggers. Here, we report the diving behaviour of a flying diving seabird, the Cape
Cormorant Phalacrocorax capensis, weighing 1.0–1.4 kg. Results were obtained by simultaneously deploying small, high resolution and high sampling frequency
GPS and time-depth loggers on birds breeding on islands off Western South Africa (34°S, 18°E) in 2008. In all, dive category
was assigned to all dives performed by 29 birds. Pelagic dives occurred almost as frequently as benthic dives. Pelagic dives
were shallow (mean: 5 m) and took place over seafloors 5–100 m deep. Benthic dives were deeper, occurring on seafloors mainly
10–30 m deep. Dive shape was linked to dive category in only 60% of dives, while the descent rate, ascent rate and bottom
duration/dive duration ratio of a dive best explained its dive category. This shows that only the concomitant use of tracking
and depth tags can adequately classify diving strategies in a diver like the Cape Cormorant. Diet was mainly Cape Anchovy
Engraulis encrasicolis, suggesting that birds probably displayed two contrasted strategies for capturing the same prey. Flexible foraging techniques
represent an important key to survival inside the highly productive but heterogeneous Benguela upwelling ecosystem. 相似文献
18.
The pattern and characteristics of diving in 14 female northern rockhopper penguins, Eudyptes chrysocome moseleyi, were studied at Amsterdam Island (37°50′S; 77°31′E) during the guard stage, using electronic time–depth recorders. Twenty-nine
foraging trips (27 daily foraging trips and two longer trips including one night) with a total of 16 572 dives of ≥3 m were
recorded. Females typically left the colony at dawn and returned in the late afternoon, spending an average of 12 h at sea,
during which they performed ∼550 dives. They were essentially inshore foragers (mean estimated foraging range 6 km), and mainly
preyed upon the pelagic euphausiid Thysanoessa gregaria, fishes and squid being only minor components of the diet. Mean dive depth, dive duration, and post-dive intervals were 18.4 m
(max. depth 109 m), 57 s (max. dive duration 168 s), and 21 s (37% of dive duration), respectively. Descent and ascent rates
averaged 1.2 and 1.0 ms−1 and were, together with dive duration, significantly correlated with dive depth. Birds spent 18% of their total diving time
in dives reaching 15 to 20 m, and the mean maximum diving efficiency (bottom time:dive cycle duration) occurred for dives
reaching 15 to 35 m. The most remarkable feature of diving behaviour in northern rockhopper penguins was the high percentage
of time spent diving during daily foraging trips (on average, 69% of their time at sea); this was mainly due to a high dive
frequency (∼44 dives per hour), which explained the high total vertical distance travelled during one trip (18 km on average).
Diving activity at night was greatly reduced, suggesting that, as other penguins, E. chrysocome moseleyi are essentially diurnal, and locate prey using visual cues.
Received: 9 December 1998 / Accepted: 3 March 1999 相似文献
19.
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
20.
Multiple-queen (polygyne) colonies of the introduced fire ant Solenopsis invicta present a paradox for kin selection theory. Egg-laying queens within these societies are, on average, unrelated to one another,
and the numbers of queens per colony are high, so that workers appear to raise new sexuals that are no more closely related
to them than are random individuals in the population. This paradox could be resolved if workers discriminate between related
and unrelated nestmate sexuals in important fitness-related contexts. This study examines the possibility of such nepotism
using methods that combine the following features: (1) multiple relevant behavioral assays, (2) colonies with an unmanipulated
family structure, (3) multiple genetic markers with no known phenotypic effects, and (4) a statistical technique for distinguishing
between nepotism and potentially confounding phenomena. We estimated relatedness between interactants in polygyne S. invicta colonies in two situations, workers tending egg-laying queens and workers feeding maturing winged queens. In neither case
did we detect a significant positive value of relatedness that would implicate nepotism. We argue that the non-nepotistic
strategies displayed by these ants reflect historical selection pressures experienced by native populations, in which nestmate
queens are highly related to one another. The markedly different genetic structure in native populations may favor the operation
of stronger higher-level selection that effectively opposes weaker individual-level selection for nepotistic interactions
within nests.
Received: 28 June 1996 / Accepted after revision: 6 October 1996 相似文献