Abstract
Time series analysis has been used to evaluate the mechanisms regulating population dynamics of mammals and insects, but has been rarely applied to amphibian populations. In this study, the influence of endogenous (density-dependent) and exogenous (density-independent) factors regulating population dynamics of the terrestrial plethodontid salamander Speleomantes strinatii was analysed by means of time series and multiple regression analyses. During the period 1993–2005, S. strinatii population abundance, estimated by a standardised temporary removal method, displayed relatively low fluctuations, and the autocorrelation function (ACF) analysis showed that the time series had a noncyclic structure. The partial rate correlation function (PRCF) indicated that a strong first-order negative feedback dominated the endogenous dynamics. Stepwise multiple regression analysis showed that the only climatic factor influencing population growth rate was the minimum winter temperature. Thus, at least during the study period, endogenous, density-dependent negative feedback was the main factor affecting the growth rate of the salamander population, whereas stochastic environmental variables, such as temperature and rainfall, seemed to play a minor role in regulation. These results stress the importance of considering both exogenous and endogenous factors when analysing amphibian long-term population dynamics.
References
Alford RA, Richards SJ (1999) Global amphibian declines: a problem in applied ecology. Annu Rev Ecol Syst 30:133–165
Beebee TCJ, Griffiths RA (2005) The amphibian decline crisis: a watershed for conservation biology? Biol Conserv 125:271–285
Berryman AA (1999) Principles of population dynamics and their applications. Stanley Thornes, Chelthenam
Berryman AA, Turchin P (2001) Identifying the density-dependent structure underlying ecological time series. Oikos 92:265–270
Brook BW, Bradshaw CJA (2006) Strength of evidence for density dependence in abundance time series of 1198 species. Ecology 87:1445–1451
Davic RD, Welsh HH (2004) On the ecological roles of salamanders. Annu Rev Ecol Evol Syst 35:405–434
Fryxell JM, Falls JB, Falls EA, Brooks RJ (1998) Long-term dynamics of small-mammal populations in Ontario. Ecology 79:213–225
Houlahan JE, Findlay CS, Schmidt BR, Meyer AH, Kuzmin SL (2000) Quantitative evidence for global amphibian population declines. Nature 404:752–755
Jaeger RG (1980a) Fluctuation in prey availability and food limitation for a terrestrial salamander. Oecologia 44:335–341
Jaeger RG (1980b) Density-dependent and density-independent causes of extinction of a salamander population. Evolution 34:617–621
Lanza B, Caputo V, Nascetti G, Bullini L (1995) Morphologic and genetic studies on the European plethodontid salamanders: taxonomic inferences (genus Hydromantes). Monogr 16, Mus Reg Sci Nat, Torino
Lima M, Merritt JF, Bozinovic F (2002) Numerical fluctuations in the northern short-tailed shrew: evidence of non linear feedback signatures on population dynamics and demography. J Anim Ecol 71:159–172
Lima M, Berryman AA, Stenseth NC (2006) Feedback structures of northern small rodent populations. Oikos 112:555–564
Pellet J, Schmidt BR, Fivaz F, Perrin N, Grossenbacher K (2006) Density, climate and varying returning points: an analysis of long-term population fluctuations in the threatened European treefrog. Oecologia 149(1):65–71
Salvidio S (1998) Estimating abundance and biomass of a Speleomantes strinatii (Caudata: Plethodontidae) population by temporary removal sampling. Amphib–Reptil 19:113–124
Salvidio S (2001) Estimating terrestrial salamander abundance in different habitats: efficiency of temporary removal methods. Herpetol Rev 32:21–24
Salvidio S, Pastorino MV (2002) Spatial segregation in the European plethodontid salamander Speleomantes strinatii in relation to age and sex. Amphib-Reptil 23:505–510
Schmidt BR (2002) Declining amphibian populations: the pitfalls of count data in the study of diversity, distributions, dynamics, and demography. Herpetol J 14:167–174
Staub NL, Brown CW, Wake DB (1995) Patterns of growth and movements in a population of Ensatina eschscholtzii platensis (Caudata: Plethodontidae) in the Sierra Nevada, California. J Herpetol 29:593–599
Taub FB (1961) The distribution of the red-backed salamander, Plethodon c. cinereus within the soil. Ecology 42:681–698
Turchin P (1990) Rarity of density dependence or population regulation with lags? Nature 344:660–663
Turchin P (2003) Complex population dynamics. A theoretical/empirical synthesis. Princeton University Press, Princeton
Welsh HH, Droege S (2001) A case for using Plethodontid salamanders for monitoring biodiversity and ecosystem integrity of North American forests. Conserv Biol 15:558–569
White GC, Anderson DR, Burnham KP, Otis DL (1982) Capture–recapture removal methods for sampling closed populations. Los Alamos National Laboratory 8787 NERP, Los Alamos, New Mexico
Acknowledgements
The Italian Ministry of Environment issued capture permits (DPN/IID/2005/6708 for 2005). Thanks are due to Benedikt Schmidt, three anonymous reviewers and the Managing Editor for improving the manuscript.
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Salvidio, S. Population dynamics and regulation in the cave salamander Speleomantes strinatii . Naturwissenschaften 94, 396–400 (2007). https://doi.org/10.1007/s00114-006-0202-2
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DOI: https://doi.org/10.1007/s00114-006-0202-2