Ahnesjo I, Kvarnemo C, Merilaita S (2001) Using potential reproductive rates to predict mating competition among individuals qualified to mate. Behavioral Ecology 12:397-401 Alados CL (1985) An analysis of vigilance in the Spanish ibex (Capra pyrenaica). Zeitschrift Fur Tierpsychologie-Journal of Comparative Ethology 68:58-64 Alvarez F (1993) Risks of fighting in relation to age and territory holding in Fallow deer. Canadian Journal of Zoology-Revue Canadienne De Zoologie 71:376-383 Andersson M, Iwasa Y (1996) Sexual selection. Trends in Ecology & Evolution 11:53-58 Balshine-Earn S (1996) Reproductive Rates, Operational Sex Ratios, and Mate choice in St. Peter’s Fish. Behavioral Ecology and Sociobiology 39: 107-16. Barki A, Karplus I, Goren M (1992) Effects of size and morphotype on dominance hierarchies and resource competition in the freshwater prawn Macrobrachium rosenhbergii Animal Behaviour 44:547 - 555 Barrette C, Vandal D (1986) Social rank, dominance, antler size, and access to food in snow-bound wild Woodland Caribou. Behaviour 97:118-146 Bates D, Maechler M, Bolker B, Walker S (2015) Fitting Linear Mixed-Effects Models Using lme4. Journal of Statistical Software 67:1-48 Bergerud AT (1974) Rutting behaviour of Newfoundland caribou. In: Geist, Walther F (eds) The behaviour of ungulates and its relation to management. IUCN, Morges, Switzerland, pp 395 Bergerud AT (1975) The reproductive season of Newfoundland caribou. Canadian Journal of Zoology 33:1213-21 Body G, Weladji RB, Holand Ø, Nieminen M (2014) Highly Competitive Reindeer Males Control Female Behavior during the Rut. PLoS ONE 9:1-9 Bro-Jorgensen J (2002) Overt female mate competition and preference for central males in a lekking antelope. Proceedings of the National Academy of Sciences of the United States of America 99:9290-9293 Bro-Jorgensen J (2007) Reversed sexual conflict in a promiscuous antelope. Current Biology 17:2157-2161 Bro-Jorgensen J (2011) Intra- and intersexual conflicts and cooperation in the evolution of mating strategies: lessons learnt from ungulates. Evolutionary Biology 38:28-41 Cameron EZ, Du Toit JT (2005) Social influences on vigilance behaviour in giraffes, Giraffa camelopardalis. Animal Behaviour 69:1337-1344 Caro TM (1987) Cheetah Mothers' Vigilance: Looking out for Prey or for Predators? Behavioral Ecology and Sociobiology 20:351-361 Chuard PJC, Brown GE, Grant JWA (2016) The effects of adult sex ratio on mating competition in male and female guppies (Poecilia reticulata) in two wild populations. Behavioural Processes 129:1-10 Ciuti S, Apollonio M (2016) Reproductive timing in a lekking mammal: male fallow deer getting ready for female estrus. Behavioral Ecology 27:1522-1532 Clutton-Brock T, Huchard E (2013) Social competition and its consequences in female mammals. Journal of Zoology 289:151-171 Clutton-Brock TH (1989) Mammalian mating systems. Proceedings of the Royal Society B: Biological Sciences 236:339-372 Clutton-Brock TH (1998) Introduction: studying reproductive costs. Oikos 83:421-423 Clutton-Brock TH, Albon SD (1979) The Roaring of Red Deer and the Evolution of Honest Advertisement. Behaviour 69:145 Clutton-Brock TH, Guinness FE, Albon SD (1982) Red deer: Behaviour and ecology of two sexes. The University of Chicago Press, Chicago Clutton-Brock TH, Parker GA (1992) Potential reproductive rates and the operation of sexual selection. The Quarterly Review of Biology 67:437-456 Clutton-Brock TH, Parker GA (1995) Sexual coercion in animal societies. Animal Behaviour 49:1345-1365 Clutton-Brock TH, Vincent ACJ (1991) Sexual selection and the potential reproductive rates of males and females. Nature 351:58-60 Coltman DW, Festa-Bianchet M, Jorgenson JT, Strobeck C (2002) Age-dependent sexual selection in bighorn rams. Proceedings of the Royal Society of London Series B-Biological Sciences 269:165-172 Coolen I, Giraldeau LA, Lavoie M (2001) Head position as an indicator of producer and scrounger tactics in a ground-feeding bird. Animal Behaviour 61:895-903 Coulson T, Catchpole EA, Albon SD, Morgan BJT, Pemberton JM, Clutton-Brock TH, Crawley MJ, Grenfell BT (2001) Age, sex, density, winter weather, and population crashes in Soay sheep. Science (Washington D C) 292:1528-1531 Creel S, Schuette P, Christianson D (2014) Effects of predation risk on group size, vigilance, and foraging behavior in an African ungulate community. Behavioral Ecology 25:773-784 Dauphiné TC, McClure RL (1974) Synchronous Mating in Canadian Barren-Ground Caribou. The Journal of Wildlife Management 38:54-66 de Jong K, Forsgren E, Sandvik H, Amundsen T (2012) Measuring mating competition correctly: available evidence supports operational sex ratio theory. Behavioral Ecology 23:1170-1177 de Jong K, Wacker S, Amundsen T, Forsgren E (2009) Do operational sex ratio and density affect mating behaviour? An experiment on the two-spotted goby. Animal Behaviour 78:1229-1238 de Vos A, Brokx P, Geist V (1967). A review of social behavior of the North American Cervids during the reproductive period. The American Midland Naturalist Journal 77:390-417 Denoël M, Hector MP, Poncin P (2005) Courtship behavior in the Alpine newt Triturus alpestris at two different densities of males. Herpetologica 61:373-379 Debuse VJ, Addison JT, Reynolds JD (1999) The effects of sex ratio on sexual competition in the European lobster. Animal Behaviour 58:973-981 Ditchkoff SS, Welch ER, Lochmiller RL, Masters RE, Starry WR (2001) Age-specific causes of mortality among male white-tailed deer support mate-competition theory. Journal of Wildlife management 65:552 Djakovic N, Holand Ø, Hovland AL, Weladji RB, Røed KH, Nieminen M (2015) Effects of males' presence on female behaviour during the rut. Ethology Ecology & Evolution 27:148-160 Dunbar RIM, Dunbar EP (1977) Dominance and reproductive success among female gelada baboons. Nature 266:351-352 Eisenberg J (1981) A Classification of Social Organization. In: The Mammalian Radiations: An Analysis of Trends in Evolution, Adaptation, and Behaviour. University of Chicago Press, Chicago, IL, pp 411 - 425 Emlen ST, Oring LW (1977) Ecology, sexual selection, and the evolution of mating systems. Science 197:215-223 Espmark Y (1964) Rutting behaviour in reindeer (Rangifer tarandus L.). Animal Behaviour 12:159-160 Festa-Bianchet M (1989) Survival of Male Bighorn Sheep in Southwestern Alberta. The Journal of Wildlife Management 53:259-263 Forsgren E, Amundsen T, Borg AA, Bjelvenmark J (2004) Unusually dynamic sex roles in a fish. Nature 429:551-554 Forsyth DM, Duncan RP, Tustin KG, Gaillard JM (2005) A substantial energetic cost to male reproduction in a sexually dimorphic ungulate. Ecology 86:2154-2163 Fournier DA, Skaug HJ, Ancheta J, Inaelli J, Magnusson A, Noelsen M, Sibert J (2012) AD Model Builder: using automatic differentiation for statistical inference of highly parametrized complex nonlinear models Optimization Methods and Software 27:233-249 Geist V (1966) The Evolution of Horn-like Organs. Behaviour 27:175 - 214 Geist V (1999) Deer of the world. Swan Hill Press, Shresbury, England Gittleman JL, Thompson SD (1988) Energy allocation in mammalian reproduction. American Zoologist 28:863-875 Grant JWA, Bryant MJ, Soos CE (1995) Operational sex ratio, mediated by synchrony of female arrival, alters the variance of male mating success in Japanese medaka. Animal Behaviour 49:367-375 Grant JWA, Foam PE (2002) Effect of operational sex ratio on female-female versus male-male competitive aggression. Canadian Journal of Zoology 80:2242-2246 Gross MR (1996) Alternative reproductive strategies and tactics: diversity within sexes. Trends in Ecology & Evolution 11:92-98 Hardin DR, Warnick AC, Fields MJ (1980) Artificial insemination of subtropical commercial beef cattle following synchronization with cloprostenol (ICI 80996): II estrous response. Theriogenology 14:259-268 Head ML, Lindholm AK, Brooks R (2008) Operational sex ratio and density do not affect directional selection on male sexual ornaments Hirotani A (1989) Social relationships of reindeer Rangifer tarandus during rut – implications for female choice. Applied Animal Behaviour Science 24:183-202 Hoem SA, Melis C, Linnell JDC, Andersen R (2007) Fighting behaviour in territorial male roe deer Capreolus capreolus: the effects of antler size and residence. European Journal of Wildlife Research 53:1-8 Hogg JT, Forbes SH (1997) Mating in bighorn sheep: Frequent male reproduction via a high-risk ''unconventional'' tactic. Behavioral Ecology and Sociobiology 41:33-48 Holand Ø, Gjostein H, Losvar A, Kumpula J, Smith ME, Roed KH, Nieminen M, Weladji RB (2004) Social rank in female reindeer (Rangifer tarandus): effects of body mass, antler size and age. Journal of Zoology 263:365-372 Holand Ø, Weladji RB, Røed KH (2012) Shit happens – a glimpse into males’ mating tactics in a polygynous ungulate - the reindeer. In: Rangifer. Holand Ø, Weladji RB, Røed KH, Gjøstein H, Kumpula J, Gaillard JM, Smith ME, Nieminen M (2006) Male age structure influences females' mass change during rut in a polygynous ungulate: the reindeer (Rangifer tarandus). Behavioral Ecology and Sociobiology 59:682-688 Holveck MJ, Gauthier AL, Nieberding CM (2015) Dense, small and male-biased cages exacerbate male-male competition and reduce female choosiness in Bicyclus anynana. Animal Behaviour 104:229-245 Horrocks K, Hunte W (1983) Maternal rank and offspring rank in vervet monkeys: an appraisal of the mechanisms of rank acquisition. Animal Behaviour 31: 772 – 782. Houde AE (2001) Sex roles, ornaments, and evolutionary explanation. Proceedings of the National Academy of Sciences of the United States of America 98:12857-12859 Hunter LTB, Skinner JD (1998) Vigilance behaviour in African ungulates: The role of predation pressure. Behaviour 135:195-211 Iwasa Y, Odendaal, FJ (1984) A theory on the temporal pattern of operational sex ratio. Ecology 65:886-893 Jachowski R (1974) Agonistic Behaviour of the Blue Crab, Callinectus sapidus Behaviour 50:232 - 253 Janicke T, Morrow EH (2018) Operational sex ratio predicts the opportunity and direction of sexual selection across animals. Ecology Letters 21:384 - 391 Jirotkul M (1999) Operational sex ratio influences female preference and male-male competition in guppies. Animal Behaviour 58 Johnson CT (1978) Time to onset of oestrus after the injection of heifers with cloprostenol. The Veterinary record 103:204-206 Johnstone RA, Reynolds JD, Deutsch JC (1996) Mutual mate choice and sex differences in choosiness. Evolution 50:1382-1391 Jönsson KI (1997) Capital and income breeding as alternative tactics of resource use in reproduction. Oikos 78:57 Klemme I, Ylönen H, Eccard JA (2007) Reproductive success of male bank voles (Clethrionomys glareolus): the effect of operational sex ratio and body size. Behavioral Ecology and Sociobiology 61:1911-1918 Klug H, Heuschele J, Jennions MD, Kokko H (2010) The mismeasurement of sexual selection. Journal of Evolutionary Biology 23:447-462 Kojola I (1991) Influence of age on the reproductive effort of male reindeer. Journal of Mammalogy 72:208-210 Kokko H, Monaghan P (2001) Predicting the direction of sexual selection. Ecology Letters 4:159-165 Kokko H, Rankin DJ (2006) Lonely hearts or sex in the city? Density-dependent effects in mating systems. Philosophical Transactions of the Royal Society B-Biological Sciences 361:319-334 Kraaijeveld K, Kraaijeveld-Smit FJL, Komdeur J (2007) The evolution of mutual ornamentation. Animal Behaviour 74:657-677 Kruppa JJ, Shi A (1993) Experimental studies on water strider mating dynamics: spatial variation in density and sex ratio. Behavioral Ecology and Sociobiology 33:107-120 Krebs J, Davies N (1987) An Introduction to Behavioural Ecology, 2nd edn. Sinauer Associates, Inc., Publishers, Sunderland, MA Kvarnemo C, Ahnesjo I (1996) The dynamics of operational sex ratios and competition for mates. Trends in Ecology & Evolution 11:404-408 Kvarnemo C, Forsgren E, Magnhagen C (1995) Effects of sex ratio on intra- and inter-sexual behaviour in sand gobies. Animal Behaviour 50:1455-1461 L'Italien L, Weladji RB, Holand Ø, Røed KH, Nieminen M, Côté SD (2012) Mating group size and stability in reindeer Rangifer tarandus: the effects of male characteristics, sex ratio and male age structure. Ethology 118:783-792 Lauer MJ, Sih A, Krupa JJ (1996) Male density, female density and intersexual conflict in a stream-dwelling insect. Animal Behaviour 52:929-939. Leader-Williams N (1980) Population-dynamics and mortality of reindeer introduced into South Georgia. Journal of Wildlife Management 44:640-657 McLain DK (1992) Population density and the intensity of sexual selection on body length in spatially or temporally restriced natural populations of a seed bug. Behavioral Evcology and Sociobiology 30:347-356 Mainguy J, Cote SD, Cardinal E, Houle M (2008) Mating tactics and mate choice in relation to age and social rank in male mountain goats. Journal of Mammalogy 89:626-635 Martin P, Bateson P (2007) Measuring behaviour: An introductory guide, Third edn. Cambridge University Press, Cambridge, UK McElligott AG, Mattiangeli V, Mattiello S, Verga M, Reynolds CA, Hayden TJ (1998) Fighting tactics of fallow bucks (Dama dama, Cervidae): Reducing the risks of serious conflict. Ethology 104:789-803 McElligott AG, Naulty F, Clarke WV, Hayden TJ (2003) The somatic cost of reproduction: what determines reproductive effort in prime-aged fallow bucks? Evolutionary Ecology Research 5:1239-1250 McEwan EH (1963) Reproduction of barren ground caribou, Rangifer tarandus groenlandicus (Linneaus), with relation to migration. In: Department of Zoology. McGill University, Montreal, Quebec, pp 99 Melnycky NA, Weladji RB, Holand Ø, Nieminen M (2013) Scaling of antler size in reindeer (Rangifer tarandus): sexual dimorphism and variability in resource allocation. Journal of Mammalogy 94:1371-1379 Mills SC, Reynolds JD (2003) Operational sex ratio and alternative reproductive behaviours in the European bitterling, Rhodeus sericeus. Behavioral Ecology and Sociobiology 54:98-104 Milner JM, Nilsen EB, Andreassen HP (2007) Demographic side effects of selective hunting in ungulates and carnivores. Conservation Biology 21:36-47 Milner-Gulland EJ, Bukreevea OM, Coulson T, Lushchekina AA, Kholodova MV, Bekenov AB, Grachev IA (2003) Conservation - Reproductive collapse in saiga antelope harems. Nature 422:135-135 Miquelle DG (1990) Why don't bull moose eat during the rut? Behavioral Ecology and Sociobiology 27:145-151 Mysterud A, Holand Ø, Røed KH, Gjøstein H, Kumpula J, Nieminen M (2003) Effects of age, density and sex ratio on reproductive effort in male reindeer (Rangifer tarandus). Journal of Zoology 261:341-344 Mysterud A, Solberg EJ, Yoccoz NG (2005) Ageing and reproductive effort in male moose under variable levels of intrasexual competition. Journal of Animal Ecology 74:742-754 Mysterud A, Yoccoz NG, Stenseth NC, Langvatn R (2001) Effects of age, sex and density on body weight of Norwegian red deer: evidence of density-dependent senescence. Proceedings of the Royal Society B-Biological Sciences 268:911-919 Odde KG (1990) A review of the synchronization of estrus in postpartum cattle. Journal of Animal Science 68:817-830 Okuda N (1999) Sex roles are not always reversed when the potential reproductive rate is higher in females. American Naturalist 153:540-548. Pelabon C, Komers PE (1997) Time-budget variations in relation to density-dependent social interactions in female and yearling male fallow deer during the rut. Canadian Journal of Zoology-Revue Canadienne De Zoologie 75:971-977 Pelletier F, Festa-Bianchet M (2006) Sexual selection and social rank in bighorn rams. Animal Behaviour 71:649-655 Pelletier F, Mainguy J, Côté SD (2009) Rut-induced hypophagia in male bighorn sheep and mountain goats: foraging under time budget constraints. Ethology 115:141-151 Pitnick S (1993) Operational sex ratio and sperm limitation of Drosophila pachea. Behavioral Ecology and Sociobiology 33:863-891 Pond CM (1977) The Significance of Lactation in the Evolution of Mammals. Evolution 31:177-199 Preston BT, Stevenson IR, Pemberton JM, Coltman DW, Wilson K (2003a) Overt and covert competition in a promiscuous mammal: the importance of weaponry and testes size to male reproductive success. Proceedings of the Royal Society B-Biological Sciences 270:633-640 R Core Team (2017) R: A Language and Environment for Statistical Computing. In. R Foundation for Statistical Computing, Vienna, Austria Raihani NJ, Grutter AS, Bshary R (2010) Punishers benefit from third-party punishment in fish. Science 327: 171. Reboreda JC, Fernandez GJ (1997) Sexual, seasonal and group size differences in the allocation of time between vigilance and feeding in the greater rhea, Rhea americana. Ethology 103:198-207 Reichard M, Jurajda P, Smith C (2004) Male-male interference competition decreases spawning rate in the European bitterling (Rhodeus sericeus). Behavioral Ecology and Sociobiology 56 Ropstad E, Kindahl H, Nilsen TAB, Forsberg M, Sire JE, Pedersen O (1996) The effect of cloprostenol in non-pregnant and pregnant Norwegian semi-domestic reindeer (Rangifer tarandus tarandus). Animal Reproductive Science 29:1 Rosvall KA (2011) Intrasexual competition in females: evidence for sexual selection? Behavioral Ecology 22:1131-1140 Rowell JE, Shipka MP (2009) Variation in gestation length among captive reindeer (Rangifer tarandus tarandus). Theriogenology 72:190-197 Røed KH, Holand Ø, Smith ME, Gjøstein H, Kumpula J, Nieminen M (2002) Reproductive success in reindeer males in a herd with varying sex ratio. Molecular Ecology 11:1239 Saunders FC, McElligott AG, Safi K, Hayden TJ (2005) Mating tactics of male feral goats (Capra hircus): risks and benefits. acta ethologica 8:103-110 Schilder MBH (1992) Stability and Dynamics of Group Composition in a Herd of Captive Plains Zebras. Ethology 90:154-168 Sharp SP, Clutton-Brock TH (2011) Reluctant challengers: why do subordinate female meerkats rarely displace their dominant mothers? Behavioural Ecology 22: 1337 – 1343 Shi JB, Dunbar RIM, Buckland D, Miller D (2003) Daytime activity budgets of feral goats (Capra hircus) on the Isle of Rum: influence of season, age, and sex. Canadian Journal of Zoology-Revue Canadienne De Zoologie 81:803-815 Shine R (1979) Sexual selection and sexual dimorphism in the amphibia. Copeia:297-306 Sjare B, Stirling I (1996) The breeding behavior of Atlantic walruses, Odobenus rosmarus rosmarus, in the Canadian High Arctic. Canadian Journal of Zoology 74:897-911 Skaug H, Fournier D, Nielsen A, Magnusson A, Bolker B (2013) Generalized Linear Mixed Models using AD Model Builder. In, R package version 0.7.5 edn Skogland T (1989) Comparative social organization of wild reindeer in relation to food, mates and predator avoidance. Advances in Ethology 29:1-77 Smith CC, Sargent RC (2007) Independent effects of male and female density on sexual harassment, female fitness, and male competition for mates in the western mosquitofish. Behavioral Ecology and Sociobiology 61:1349-1358 Struhsaker TT (1967) Behavior of Elk (Cervus canadensis) during the Rut. Zeitschrift für Tierpsychologie 24:80-114 Taborsky M (2008) Alternative reproductive tactics in fish. Alternative Reproductive Tactics: An Integrative Approach:251-299 Tennenhouse EM, Weladji RB, Holand Ø, Nieminen M (2012) Timing of reproductive effort differs between young and old dominant male reindeer. Annales Zoologici Fennici 49:152-160 Thiele J, Markussen B (2012) Potential of GLMM in modelling invasive spread. In. CAB Reviews Perspectives in Agriculture Veterinary Science Nutrition and Natural Resources, pp 1-10 Trivers RL (1972) Parental investment and sexual selection. In: Campbell B (ed) Sexual selection and the descent of man. Aldine, Chicago, Illinois, pp 136–179 Underwood R (1982) Vigilance Behaviour in Grazing African Antelopes. Behaviour 79:81-107 Vannoni E, McElligott AG (2009) Fallow bucks get hoarse: vocal fatigue as a possible signal to conspecifics. Animal Behaviour 78:3-10 Verrell PA, Krenz JD (1998) Competition for mates in the mole salamander, Ambystoma talpoideum: tactics that may maximize male mating success. Behaviour 135:121-138 Wacker S, Mobley K, Forsgren E, Myhre LC, de Jong K, Amundsen T (2013) Operational sex ratio and not density affect sexual selection in a fish. Evolution 67:1937-1949 Wang X, Xia D-P (2009) Comparisons on Reproductive and Aggressive Behaviours in Male Tibetan Macaques (Macaca thibetana) of Two Different Operational Sex Ratio Troops at Huangshan, China. Zoological Research 30:83 - 89 Weir LK, Grant JWA, Hutchings JA (2011) The Influence of Operational Sex Ratio on the Intensity of Competition for Mates. American Naturalist 177:167-176 Weladji RB, Body G, Holand O, Meng XX, Nieminen M (2017) Temporal variation in the operational sex ratio and male mating behaviours in reindeer (Rangifer tarandus). Behavioural Processes 140:96-103 Willisch CS, Neuhaus P (2009) Alternative mating tactics and their impact on survival in adult male Alpine Ibex (Capra ibex ibex). Journal of Mammalogy 90:1421-1430 Wittenberger JF (1980) Group Size and Polygamy in Social Mammals. American Naturalist 115:197-222 Wolff JO (1998) Breeding strategies, mate choice, and reproductive success in American bison. Oikos 83:529-544 Ydenberg RC, Dill LM (1986) The economics of fleeing from predators. Advances in the Study of Behavior 16:229-249 Yoccoz NG, Mysterud A, Langvatn R, Stenseth NC (2002) Age- and density-dependent reproductive effort in male red deer. Proceedings of the Royal Society B: Biological Sciences 269:1523 Young AJ, Oosthuizen MK, Lutermann H, Bennett NC (2010) Physiological suppression eases in Damaraland mole-rat societies when ecological constraints on dispersal are relaxed. Hormones and Behaviour 57: 177 – 183. Zhang J, Zhanf Z (2003) Influence of operational sex ratio and density on the copulatory behaviour and mating system of Brandt’s vole Microtus brandti. Acta Theriologica 48:335-346