| Records |
| Author |
Cameron, E.Z. |
| Title |
Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism |
Type |
Journal Article |
| Year |
2004 |
Publication |
Proceedings. Biological sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
| Volume |
271 |
Issue |
1549 |
Pages |
1723-1728 |
| Keywords |
Age Factors; Animals; Body Constitution; *Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/*physiology; *Models, Biological; Reproduction/physiology; Seasons; Sex Factors; *Sex Ratio; Time Factors |
| Abstract |
Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios. |
| Address |
Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume  |
|
Series Issue |
|
Edition |
|
| ISSN |
0962-8452 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:15306293 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
413 |
| Permanent link to this record |
| |
|
| |
| Author |
Clutton-Brock, T.H.; Russell, A.F.; Sharpe, L.L.; Brotherton, P.N.; McIlrath, G.M.; White, S.; Cameron, E.Z. |
| Title |
Effects of helpers on juvenile development and survival in meerkats |
Type |
Journal Article |
| Year |
2001 |
Publication |
Science (New York, N.Y.) |
Abbreviated Journal |
Science |
| Volume |
293 |
Issue |
5539 |
Pages |
2446-2449 |
| Keywords |
Animals; Breeding; Carnivora/growth & development/*physiology; *Cooperative Behavior; Feeding Behavior; Female; Male; Survival Rate; *Weight Gain |
| Abstract |
Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups. |
| Address |
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. thcb@hermes.cam.ac.uk |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0036-8075 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:11577235 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
414 |
| Permanent link to this record |
| |
|
| |
| Author |
Hemelrijk, C.K.; Wantia, J. |
| Title |
Individual variation by self-organisation |
Type |
Journal Article |
| Year |
2005 |
Publication |
Neuroscience and biobehavioral reviews |
Abbreviated Journal |
Neurosci Biobehav Rev |
| Volume |
29 |
Issue |
1 |
Pages |
125-136 |
| Keywords |
Aggression; Animals; Behavior, Animal/*physiology; Competitive Behavior/*physiology; Female; Humans; *Individuality; Male; Models, Psychological; Sex Characteristics; *Social Dominance; Time Factors |
| Abstract |
In this paper, we show that differences in dominance and spatial centrality of individuals in a group may arise through self-organisation. Our instrument is a model, called DomWorld, that represents two traits that are often found in animals, namely grouping and competing. In this model individual differences grow under the following conditions: (1) when the intensity of aggression increases and grouping becomes denser, (2) when the degree of sexual dimorphism in fighting power increases. In this case the differences among females compared to males grow too, (3) when, upon encountering another individual, the tendency to attack is 'obligate' and not conditional, namely 'sensitive to risks'. Results resemble phenomena described for societies of primates, mice, birds and pigs. |
| Address |
Theoretical Biology, University of Groningen, NN Haren, The Netherlands. hemelrij@ifi.unizh.ch |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0149-7634 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:15652260 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
443 |
| Permanent link to this record |
| |
|
| |
| Author |
Earley, R.L.; Dugatkin, L.A. |
| Title |
Eavesdropping on visual cues in green swordtail (Xiphophorus helleri) fights: a case for networking |
Type |
Journal Article |
| Year |
2002 |
Publication |
Proceedings. Biological sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
| Volume |
269 |
Issue |
1494 |
Pages |
943-952 |
| Keywords |
*Aggression; Animals; *Behavior, Animal; *Cyprinodontiformes; Female; Male |
| Abstract |
Aggressive contests probably occur in networking environments where information about fighting ability is conveyed both to an opponent and to individuals peripheral to the fight itself, the bystanders. Our primary aim was to investigate the relative influences of eavesdropping and prior social experience on the dynamics of aggressive contests in Xiphophorus helleri. A bystander's ability to witness an encounter was manipulated using clear, one-way mirror, and opaque partitions. After watching (or not watching) the initial contest, the bystander encountered either the winner or loser of the bout. Treatment comparisons of bystander-winner or bystander-loser contest dynamics indicated the presence or absence of winner, loser, or eavesdropping effects. Winner and loser effects had negligible influences on bystander contest dynamics. Eavesdropping significantly reduced the bystander's propensity to initiate aggression, escalate, and win against seen winners regardless of whether the watched bout had escalated or not. Though eavesdropping had relatively little effect on bystander-loser contest dynamics, bystanders were less prone to initiate aggression and win against losers that had escalated in the witnessed bout. Thus, bystanders appear to preferentially retain and utilize information gained about potentially dangerous opponents (winners or persistent losers). Our data lend clear support for the importance of eavesdropping in visually based aggressive signalling systems. |
| Address |
Department of Biology, Life Science, Room 139, University of Louisville, Louisville, KY 40292, USA. rlearl01@athena.louisville.edu |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0962-8452 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:12028778 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
498 |
| Permanent link to this record |
| |
|
| |
| Author |
Peake, T.M.; Terry, A.M.R.; McGregor, P.K.; Dabelsteen, T. |
| Title |
Do great tits assess rivals by combining direct experience with information gathered by eavesdropping? |
Type |
Journal Article |
| Year |
2002 |
Publication |
Proceedings. Biological sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
| Volume |
269 |
Issue |
1503 |
Pages |
1925-1929 |
| Keywords |
Aggression; *Animal Communication; Animals; Male; Songbirds/*physiology; Territoriality; *Vocalization, Animal |
| Abstract |
Animals frequently use signals that travel further than the spacing between individuals. For every intended recipient of a given signal there are likely to be many other individuals that receive information. Eavesdropping on signalling interactions between other individuals provides a relatively cost-free method of assessing future opponents or mates. Male great tits (Parus major) extract relative information from such interactions between individuals unknown to them. Here, we show that male great tits can take information gathering a stage further and obtain more information about a previously unencountered intruder, by the hitherto unknown capability of combining information gathered by eavesdropping with that derived from their own direct interaction with an individual. Prior experience with an intruder (A) was achieved by subjecting a focal male to different levels of intrusion simulated using interactive playback. This intruder (A) then took part in a simulated interaction with an unknown male (B) outside the territorial boundary of the focal males. In response to subsequent intrusion by the second male (B), focal males showed low song output in response to males that had lost to a male that the subject was able to beat. Males of known high quality, or those about which information was ambiguous, elicited a high level of song output by focal males. We discuss the implications of this finding for the evolution of communication and social behaviour. |
| Address |
Department of Animal Behaviour, Zoological Institute, Copenhagen University, Tagensvej 16, DK 2200 Copenhagen N, Denmark. tmpeake@zi.ku.uk |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0962-8452 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:12350255 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
501 |
| Permanent link to this record |
| |
|
| |
| Author |
Dzieweczynski, T.L.; Eklund, A.C.; Rowland, W.J. |
| Title |
Male 11-ketotestosterone levels change as a result of being watched in Siamese fighting fish, Betta splendens |
Type |
Journal Article |
| Year |
2006 |
Publication |
General and comparative endocrinology |
Abbreviated Journal |
Gen Comp Endocrinol |
| Volume |
147 |
Issue |
2 |
Pages |
184-189 |
| Keywords |
Aggression; Animals; Female; Fishes/*blood; Male; Nesting Behavior; *Social Behavior; Social Environment; Testosterone/*analogs & derivatives/blood |
| Abstract |
This study investigated the effects of nesting status and the presence of an audience on 11-ketotestosterone (11KT) levels in male Siamese fighting fish, Betta splendens. Prior studies have demonstrated that both nesting status, an indicator of territory-holding power and reproductive state, and the sex of a conspecific audience lead to differences in male behavior during aggressive encounters. Since behavioral changes have already been demonstrated, we chose to investigate whether 11KT levels were also influenced by nesting status and audience presence as 11KT both stimulates, and is stimulated by, reproductive and aggressive behaviors in male teleosts. Male 11KT levels were measured from water samples taken from containers holding fish both before and after interaction. Males interacted under three treatment conditions: no audience, female audience, and male audience. Within these treatments were two nest paradigms: both males had nests or neither male had a nest. 11KT levels varied depending on nesting status and audience type. In general, 11KT levels were lower in interacting males when a female audience was present or when males had nests. Overall, 11KT showed increases or decreases as aggression increased or decreased, as shown by already established behavioral findings [see Dzieweczynski T.L., Green T.M., Earley R.L., Rowland W.J., 2005. Audience effect is context dependent in Siamese fighting fish, Betta splendens. Behav. Ecol. 16, 1025-1030; Doutrelant, C., McGregor, P.K., Oliveira, R.F., 2001. Effect of an audience on intrasexual communication in male Siamese fighting fish (Betta splendens). Behav. Ecol. 12, 283-286.]. Our results suggest that 11KT levels are influenced by reproductive status, as indicated by nest ownership, and audience presence and are most likely modulated by territorial behavior and social environment. |
| Address |
Department of Psychology, University of New England, Biddeford, ME 04005, USA. tdzieweczynski@une.edu |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0016-6480 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:16473353 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
502 |
| Permanent link to this record |
| |
|
| |
| Author |
Kumar, P.; Timoney, J.F.; Southgate, H.H.; Sheoran, A.S. |
| Title |
Light and scanning electron microscopic studies of the nasal turbinates of the horse |
Type |
Journal Article |
| Year |
2000 |
Publication |
Anatomia, histologia, embryologia |
Abbreviated Journal |
Anat Histol Embryol |
| Volume |
29 |
Issue |
2 |
Pages |
103-109 |
| Keywords |
Animals; Female; Horses/*anatomy & histology; Male; Microscopy, Electron, Scanning; Turbinates/*cytology/ultrastructure |
| Abstract |
The nasal turbinates of 5 young horses were studied by light and scanning electron-microscopy. Stratified cuboidal epithelium lined the rostral part of the dorsal and ventral nasal turbinates of the vestibular region. The polyangular microvillus cells of this region were separated by linear depressions. The mid and caudal parts of the dorsal and ventral nasal turbinates and the rostral part of the ethmoturbinates were lined by pseudostratified columnar ciliated respiratory epithelium. Numerous cilia with dilated blebs on the ciliated cells concealed adjacent non-ciliated supporting cells and goblet cells. The olfactory zone consisting of the olfactory vesicle and a dense network of olfactory cilia localized to the caudal part of the ethmoturbinates. The three regions were delineated from each other by transitional zones. |
| Address |
Gluck Equine Research Center, University of Kentucky, Lexington 40546-0099, USA |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0340-2096 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:10932387 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
505 |
| Permanent link to this record |
| |
|
| |
| Author |
Amdam, G.V.; Csondes, A.; Fondrk, M.K.; Page, R.E.J. |
| Title |
Complex social behaviour derived from maternal reproductive traits |
Type |
Journal Article |
| Year |
2006 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
439 |
Issue |
7072 |
Pages |
76-78 |
| Keywords |
Aging/physiology; Animals; Bees/*physiology; *Evolution; Feeding Behavior/*physiology; Female; Infertility, Female; Maternal Behavior/*physiology; Ovary/physiology; Pollen/metabolism; Reproduction/*physiology; *Social Behavior |
| Abstract |
A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers. |
| Address |
Arizona State University, School of Life Sciences, Tempe, Arizona 85287, USA. Gro.Amdam@asu.edu |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1476-4687 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:16397498 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
531 |
| Permanent link to this record |
| |
|
| |
| Author |
Dunbar, R. |
| Title |
Evolution of the social brain |
Type |
Journal Article |
| Year |
2003 |
Publication |
Science |
Abbreviated Journal |
Science |
| Volume |
302 |
Issue |
5648 |
Pages |
1160-1161 |
| Keywords |
Animals; Animals, Wild; *Cognition; Endorphins/physiology; *Evolution; Female; Grooming; Hierarchy, Social; Language; Neocortex/anatomy & histology/physiology; Papio/physiology/*psychology; *Reproduction; *Social Behavior; Social Dominance; Social Support; Vocalization, Animal |
| Abstract |
|
| Address |
School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, UK. rimd@liv.ac.uk |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1095-9203 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:14615522 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
548 |
| Permanent link to this record |
| |
|
| |
| Author |
Moehlman, P.D. |
| Title |
Endangered wild equids |
Type |
Journal Article |
| Year |
2005 |
Publication |
Scientific American |
Abbreviated Journal |
Sci Am |
| Volume |
292 |
Issue |
3 |
Pages |
74-81 |
| Keywords |
Africa; Americas; Animals; *Animals, Wild/physiology; Asia; *Conservation of Energy Resources; Environment; *Equidae/physiology; Food Chain; Humans; Male; Reproduction |
| Abstract |
|
| Address |
IUCN-The World Conservation Union/Species Survival Commission Equid Specialist Group |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0036-8733 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:15859216 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
551 |
| Permanent link to this record |
