Search tips
Search criteria 


Logo of procbThe Royal Society PublishingProceedings BAboutBrowse by SubjectAlertsFree Trial
Proc Biol Sci. 2000 September 7; 267(1454): 1771–1779.
PMCID: PMC1690729

The relative roles of density and climatic variation on population dynamics and fecundity rates in three contrasting ungulate species.


The relative influences of density-dependent and -independent processes on vital rates and population dynamics have been debated in ecology for over half a century, yet it is only recently that both processes have been shown to operate within the same population. However, generalizations on the role of each process across species are rare. Using a process-orientated generalized linear modelling approach we show that variations in fecundity rates in populations of three species of ungulates with contrasting life histories are associated with density and winter weather in a remarkably similar manner. However, there are differences and we speculate that they are a result of differences in size between the species. Much previous research exploring the association between vital rates, population dynamics and density-dependent and -independent processes has used pattern-orientated approaches to decompose time-series into contributions from density-dependent and -independent processes. Results from these analyses are sometimes used to infer associations between vital rates, density and climatic variables. We compare results from pattern-orientated analyses of time-series with process-orientated analyses and report that the two approaches give different results. The approach of analysing relationships between vital rates, density and climatic variables may detect important processes influencing population dynamics that time-series methodologies may overlook.

Full Text

The Full Text of this article is available as a PDF (328K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Allard MW, Miyamoto MM, Jarecki L, Kraus F, Tennant MR. DNA systematics and evolution of the artiodactyl family Bovidae. Proc Natl Acad Sci U S A. 1992 May 1;89(9):3972–3976. [PubMed]
  • Bjørnstad ON, Falck W, Stenseth NC. A geographic gradient in small rodent density fluctuations: a statistical modelling approach. Proc Biol Sci. 1995 Nov 22;262(1364):127–133. [PubMed]
  • Chikuni K, Mori Y, Tabata T, Saito M, Monma M, Kosugiyama M. Molecular phylogeny based on the kappa-casein and cytochrome b sequences in the mammalian suborder Ruminantia. J Mol Evol. 1995 Dec;41(6):859–866. [PubMed]
  • Coulson TN, Pemberton JM, Albon SD, Beaumont M, Marshall TC, Slate J, Guinness FE, Clutton-Brock TH. Microsatellites reveal heterosis in red deer. Proc Biol Sci. 1998 Mar 22;265(1395):489–495. [PMC free article] [PubMed]
  • Forchhammer MC, Stenseth NC, Post E, Langvatn R. Population dynamics of Norwegian red deer: density-dependence and climatic variation. Proc Biol Sci. 1998 Feb 22;265(1393):341–350. [PMC free article] [PubMed]
  • Kruuk LE, Clutton-Brock TH, Albon SD, Pemberton JM, Guinness FE. Population density affects sex ratio variation in red deer. Nature. 1999 Jun 3;399(6735):459–461. [PubMed]
  • Leirs H, Stenseth NC, Nichols JD, Hines JE, Verhagen R, Verheyen W. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent. Nature. 1997 Sep 11;389(6647):176–180. [PubMed]
  • Pemberton JM, Smith JA, Coulson TN, Marshall TC, Slate J, Paterson S, Albon SD, Clutton-Brock TH. The maintenance of genetic polymorphism in small island populations: large mammals in the Hebrides. Philos Trans R Soc Lond B Biol Sci. 1996 Jun 29;351(1341):745–752. [PubMed]
  • Post E, Stenseth NC, Langvatn R, Fromentin JM. Global climate change and phenotypic variation among red deer cohorts. Proc Biol Sci. 1997 Sep 22;264(1386):1317–1324. [PMC free article] [PubMed]
  • Stenseth NC, Bjørnstad ON, Saitoh T. A gradient from stable to cyclic populations of Clethrionomys rufocanus in Hokkaido, Japan. Proc Biol Sci. 1996 Sep 22;263(1374):1117–1126. [PubMed]
  • Stenseth NC, Bjørnstad ON, Falck W. Is spacing behaviour coupled with predation causing the microtine density cycle? A synthesis of current process-oriented and pattern-oriented studies. Proc Biol Sci. 1996 Nov 22;263(1376):1423–1435. [PubMed]

Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society