%0 Journal Article %T Irregular timing of population cycles %+ University of Pittsburgh (PITT) %+ McMaster University [Hamilton, Ontario] %+ University of British Columbia (UBC) %+ Laboratoire de Probabilités, Statistique et Modélisation (LPSM (UMR_8001)) %+ Case Western Reserve University [Cleveland] %A Rubin, Jonathan, E %A Hearn, David, J %A Greenwood, Priscilla, E %A Parsons, Todd L. %A Abbott, Karen, C %Z This work was initiated at the ‘Transients in Biological Systems’ Investigative Workshop at the National Institute for Mathematical and Biological Synthesis (NIMBioS), supported by the National Science Foundation through NSF Award DBI-1300426, with additional support from The University of Tennessee, Knoxville. Additional progress was made via a meeting at the University of Pittsburgh supported by the Dietrich School of Arts and Sciences through the Mathematics Research Center. JER acknowledges support from NSF Award DMS-1951095. DJDE was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC). %< avec comité de lecture %@ 0030-1299 %J Oikos %I Nordic Ecological Society %P e09290 %8 2022 %D 2022 %R 10.1111/oik.09290 %K Variable cycle period %K Saddle crawlby %K Rosenzweig-MacArthur %K Predator-prey %K Environmental stochasticity %K Periodic orbits %K Predator-prey dynamics %K Saddle points %Z Life Sciences [q-bio]/Ecology, environment/Symbiosis %Z Statistics [stat]/Applications [stat.AP]Journal articles %X Despite considerable study of population cycles, the striking variability of cycle periods in many cyclic populations has received relatively little attention. Mathematical models of cyclic population dynamics have historically exhibited much greater regularity in cycle periods than many real populations, even when accounting for environmental stochasticity. We contend, however, that the recent focus on understanding the impact of long, transient but recurrent epochs within population oscillations points the way to a previously unrecognized means by which environmental stochasticity can create cycle period variation. Specifically, consumer–resource cycles that bring the populations near a saddle point (a combination of population sizes toward which the populations tend, before eventually transitioning to substantially different levels) may be subject to a slow passage effect that has been dubbed a ‘saddle crawlby'. In this study, we illustrate how stochasticity that generates variability in how close predator and prey populations come to saddles can result in substantial variability in the durations of crawlbys and, as a result, in the periods of population cycles. Our work suggests a new mechanistic hypothesis to explain an important factor in the irregular timing of population cycles and provides a basis for understanding when environmental stochasticity is, and is not, expected to generate cyclic dynamics with variability across periods. %G English %2 https://cnrs.hal.science/hal-03445622v2/document %2 https://cnrs.hal.science/hal-03445622v2/file/Oikos%20-%202022%20-%20Rubin%20-%20Irregular%20population%20cycles%20driven%20by%20environmental%20stochasticity%20and%20saddle%20crawlbys.pdf %L hal-03445622 %U https://cnrs.hal.science/hal-03445622 %~ CNRS %~ GIP-BE %~ LPSM %~ SORBONNE-UNIVERSITE %~ SORBONNE-UNIV %~ SU-SCIENCES %~ UNIV-PARIS %~ UNIVERSITE-PARIS %~ UP-SCIENCES %~ SU-TI %~ ALLIANCE-SU