scholarly journals Strategic reduction of help before dispersal in a cooperative breeder

2013 ◽  
Vol 9 (1) ◽  
pp. 20120878 ◽  
Author(s):  
Markus Zöttl ◽  
Lucille Chapuis ◽  
Manuel Freiburghaus ◽  
Michael Taborsky
Keyword(s):  
Life History ◽  
Natural Population ◽  
Cichlid Fish ◽  
The Other ◽  
Neolamprologus Pulcher ◽  
State Dependent ◽  
Territory Defence ◽  
Cooperatively Breeding ◽  
Sexually Mature

In cooperative breeders, sexually mature subordinates can either queue for chances to inherit the breeding position in their natal group, or disperse to reproduce independently. The choice of one or the other option may be flexible, as when individuals respond to attractive dispersal options, or they may reflect fixed life-history trajectories. Here, we show in a permanently marked, natural population of the cooperatively breeding cichlid fish Neolamprologus pulcher that subordinate helpers reduce investment in territory defence shortly before dispersing. Such reduction of effort is not shown by subordinates who stay and inherit the breeding position. This difference suggests that subordinates ready to leave reduce their investment in the natal territory strategically in favour of future life-history perspectives. It seems to be part of a conditional choice of the dispersal tactic, as this reduction in effort appears only shortly before dispersal, whereas philopatric and dispersing helpers do not differ in defence effort earlier in life. Hence, cooperative territory defence is state-dependent and plastic rather than a consistent part of a fixed life-history trajectory.

scholarly journals Dominance network structure across reproductive contexts in the cooperatively breeding cichlid fish Neolamprologus pulcher

2015 ◽  
Vol 61 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Cody J. Dey ◽  
Q.Y. Joanne Tan ◽  
Constance M. O’Connor ◽  
Adam R. Reddon ◽  
J. Ryan Caldwell
Keyword(s):  
Social Networks ◽  
Parental Care ◽  
Random Graph ◽  
Behavioral Ecology ◽  
Cichlid Fish ◽  
Life History Stage ◽  
Neolamprologus Pulcher ◽  
Exponential Random Graph ◽  
Dominance Interactions ◽  
Cooperatively Breeding

Abstract While a large number of studies have described animal social networks, we have a poor understanding of how these networks vary with ecological and social conditions. For example, reproductive periods are an important life-history stage that may involve changes in dominance relationships among individuals, yet no study to date has compared social networks of dominance interactions (i.e. dominance networks) across reproductive contexts. We first analyzed a long-term dataset on captive social groups of the cooperatively breeding cichlid Neolamprologus pulcher, and found that eviction events were significantly more common around reproduction than expected by chance. Next, we compared the structure of dominance networks during early parental care and non-reproductive periods, using one of the first applications of exponential random graph models in behavioral biology. Contrary to our predictions, we found that dominance networks showed few changes between early parental care and non-reproductive periods. We found no evidence that dominance interactions became more skewed towards larger individuals, became more frequent between similar-sized individuals, or became more biased towards a particular sex during parental care. However, we did find that there were relatively more dominance interactions between opposite-sex dyads in the early parental care period, which may be a by-product of increased sexual interactions during this time. This is the first study in behavioral ecology to compare social networks using exponential random graph modeling, and demonstrates a powerful analytical framework for future studies in the field.

Correlates of group size in a cooperatively breeding cichlid fish ( Neolamprologus pulcher )

2001 ◽  
Vol 50 (2) ◽  
pp. 134-140 ◽  
Author(s):  
Sigal Balshine ◽  
Brenda Leach ◽  
Francis Neat ◽  
Hannah Reid ◽  
Michael Taborsky ◽  
...  
Keyword(s):  
Group Size ◽  
Cichlid Fish ◽  
Neolamprologus Pulcher ◽  
Cooperatively Breeding

Isotocin and sociality in the cooperatively breeding cichlid fish, Neolamprologus pulcher

Behaviour ◽  
2014 ◽  
Vol 151 (10) ◽  
pp. 1389-1411 ◽  
Author(s):  
Adam R. Reddon ◽  
Mathew R. Voisin ◽  
Constance M. O’Connor ◽  
Sigal Balshine
Keyword(s):  
Receptor Antagonist ◽  
Cichlid Fish ◽  
Oxytocin Receptor ◽  
Social Contexts ◽  
Neolamprologus Pulcher ◽  
Proximate Mechanisms ◽  
Wide Range ◽  
Cooperatively Breeding ◽  
Broad Generalization ◽  
Study Species

The ultimate functions of sociality, or the tendency to associate with conspecifics and to live within a social group, are increasingly well understood. However, the proximate mechanisms that mediate this behaviour have received less attention. The oxytocin family of nonapeptide hormones (including isotocin in teleost fish) is thought to play an important role in regulating social behaviour across a wide range of taxa and social contexts. In the current study, we investigated the influence of exogenous administration of isotocin and an oxytocin receptor antagonist on sociality in a cooperatively breeding fish, Neolamprologus pulcher. In our first experiment, we found that a high (and a low) dose of peripherally administered exogenous isotocin decreased the time spent associating with conspecifics in N. pulcher, while an intermediate dose had no effect relative to control. In our second experiment, we found that a peripheral administration of an oxytocin receptor antagonist increased grouping preference in male N. pulcher. The results of both experiments suggest that IT may inhibit grouping behaviour in this species. These results contribute to a growing body of literature suggesting that the broad generalization that the oxytocin family of nonapeptides facilitate grouping behaviour is overly simplistic, and that specific behavioural effects depend the study species and testing conditions.

Breeder-Helper Conflict in a Cichlid Fish With Broodcare Helpers: an Experimental Analysis

Behaviour ◽  
1985 ◽  
Vol 95 (1-2) ◽  
pp. 45-75 ◽  
Author(s):  
Michael Taborsky
Keyword(s):  
Experimental Analysis ◽  
Graphical Model ◽  
Cichlid Fish ◽  
Field Evidence ◽  
The Family ◽  
Cooperatively Breeding ◽  
Common Interests ◽  
Relationship Of ◽  
The Relationship ◽  
Sexually Mature

AbstractThis paper reports an experimental analysis of conflicting interests in the cooperatively breeding Lamprologus brichardi (Cichlidae). Helpers clearly prefer to stay in the family territory rather than leave for an aggregation of same-size young or for an unoccupied area-even when their chances of reproducing independently are superior to those in the field. Helpers usually attain independence when the breeders force them to leave the territory. Breeders' toleration of helpers depends on the stage in the reproductive cycle, the size of helpers and the need for helpers. Large, previously expelled helpers are reaccepted when competition is increased. In these circumstances breeders prefer their own former helpers to strange young. Experimental and field evidence suggests that 3 factors are ultimately important for the breeder/helper relationship: reproductive parasitism by mature helpers, eventual cannibalism on breeders' eggs and competition for shelter within the territory. A graphical model shows how the initially common interests of breeders and helpers develop divergently when helpers reach the size at which they become sexually mature and less susceptible to predation. Large helpers pay to stay. The relationship of breeders and large helpers meets the criterion of reciprocal altruism.

A field study of reproductive interactions in Bosca's newt, Triturus boscai

1995 ◽  
Vol 16 (4) ◽  
pp. 357-374 ◽  
Author(s):  
Manuel Mouta Faria
Keyword(s):  
Field Study ◽  
Natural Population ◽  
Wild Population ◽  
Short Circuit ◽  
The Other ◽  
Courtship Behaviour ◽  
Laboratory Studies ◽  
Free Living ◽  
Spermatophore Transfer ◽  
Sexual Interference

AbstractObservations of a free-living population of Bosca's newt, Triturus boscai, show that courtship behaviour in nature is similar to the behaviour observed in earlier laboratory studies. Complementary evidence was obtained on the behaviour called flick, which is sometimes inserted at the end of the static display phase, and may be viewed as an equivalent behaviour to the retreat display of the other small-bodied newt species. Sexual interference in the natural population was mainly caused by males. Two characteristic male behaviour patterns were recognised, the waiting position and the push-tail. Females tend to withdraw from situations of interference. Courtship sequences solely consisting of orientation and spermatophore transfer phases, so-called short-circuit sequences, may be interpreted as a male strategy to avoid the very severe male-to-male interference that exists in a wild population.

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

scholarly journals A test of male infanticide as a reproductive tactic in a cichlid fish

2017 ◽  
Vol 4 (3) ◽  
pp. 160891 ◽  
Author(s):  
Shagun Jindal ◽  
Aneesh P. H. Bose ◽  
Constance M. O'Connor ◽  
Sigal Balshine
Keyword(s):  
Cichlid Fish ◽  
Group Living ◽  
Laboratory Setting ◽  
Dominant Position ◽  
Egg Cannibalism ◽  
Cooperatively Breeding ◽  
Dominant Individual ◽  
Living Species ◽  
Reproductive Tactic ◽  
Relative Body Size

Infanticide and offspring cannibalism are taxonomically widespread phenomena. In some group-living species, a new dominant individual taking over a group can benefit from infanticide if doing so induces potential mates to become reproductively available sooner. Despite widespread observations of infanticide (i.e. egg cannibalism) among fishes, no study has investigated whether egg cannibalism occurs in fishes as a result of group takeovers, or how this type of cannibalism might be adaptive. Using the cooperatively breeding cichlid, Neolamprologus pulcher , we tested whether new unrelated males entering the dominant position in a social group were more likely to cannibalize eggs, and whether such cannibalism would shorten the interval until the female's next spawning. Females spawned again sooner if their broods were removed than if they were cared for. Egg cannibalism occurred frequently after a group takeover event, and was rarer if the original male remained with the group. While dominant breeder females were initially highly aggressive towards newcomer males that took over the group, the degree of resistance depended on relative body size differences between the new pair and, ultimately, female aggression did not prevent egg cannibalism. Egg cannibalism, however, did not shorten the duration until subsequent spawning, or increase fecundity during subsequent breeding in our laboratory setting. Our results show that infanticide as mediated through group takeovers is a taxonomically widespread behaviour.

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.

scholarly journals Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic
Keyword(s):  
Life History ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
White Light ◽  
The Other ◽  
Distilled Water ◽  
Nacl Concentration ◽  
History Of ◽  
Species Specific

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

Sign in / Sign up

Export Citation Format

Share Document