Individual diet specialization (IS) has important community‐ and population‐level implications and its ecological drivers are actively investigated. Here, to test the hypothesis that local environmental conditions may influence IS in wild populations, we analyzed the stomach contents of 395 individuals from eight populations of five allopatric species of European cave salamanders (genus Hydromantes ). We assessed whether their degree of individual diet specialization (1) scaled positively with the respective niche widths, in agreement with Van Valen’s niche variation hypothesis (NVH), and (2) could be predicted by satellite‐derived climatic and vegetation characteristics of the sites where the populations live. Consistent with the NVH, the degree of individual diet specialization increased with the populations’ total niche width. Furthermore, two variables describing local nonarboreal vegetation cover and habitat heterogeneity successfully predicted the variation in individual specialization across the eight populations. Climatic factors had a generally low predictive power, with individual specialization in low‐ and high‐elevation populations showing contrasting patterns of co‐variation with air temperature in the warmest quarter of the year. However, independently from elevation, specialization peaked under conditions of high nonarboreal vegetation cover and high precipitation regimes. We discussed the results against two mutually nonexclusive scenarios hypothesizing different mechanisms linking environmental factors to salamanders’ trophic strategy at an individual and population level. We concluded that satellite‐derived climatic and vegetation variables to date generally adopted to model Grinnellian niches might also be useful in predicting spatial variations in dietary habits of populations, that is, their Eltonian niches.

Inter‐specific and inter‐population variation in individual diet specialization : do environmental factors have a role? / E. Lunghi, R. Manenti, F. Cianferoni, F. Ceccolini, M. Veith, C. Corti, G.F. Ficetola, G. Mancinelli. - In: ECOLOGY. - ISSN 0012-9658. - (2020 Apr 22). [Epub ahead of print] [10.1002/ecy.3088]

Inter‐specific and inter‐population variation in individual diet specialization : do environmental factors have a role?

R. Manenti;G.F. Ficetola;
2020

Abstract

Individual diet specialization (IS) has important community‐ and population‐level implications and its ecological drivers are actively investigated. Here, to test the hypothesis that local environmental conditions may influence IS in wild populations, we analyzed the stomach contents of 395 individuals from eight populations of five allopatric species of European cave salamanders (genus Hydromantes ). We assessed whether their degree of individual diet specialization (1) scaled positively with the respective niche widths, in agreement with Van Valen’s niche variation hypothesis (NVH), and (2) could be predicted by satellite‐derived climatic and vegetation characteristics of the sites where the populations live. Consistent with the NVH, the degree of individual diet specialization increased with the populations’ total niche width. Furthermore, two variables describing local nonarboreal vegetation cover and habitat heterogeneity successfully predicted the variation in individual specialization across the eight populations. Climatic factors had a generally low predictive power, with individual specialization in low‐ and high‐elevation populations showing contrasting patterns of co‐variation with air temperature in the warmest quarter of the year. However, independently from elevation, specialization peaked under conditions of high nonarboreal vegetation cover and high precipitation regimes. We discussed the results against two mutually nonexclusive scenarios hypothesizing different mechanisms linking environmental factors to salamanders’ trophic strategy at an individual and population level. We concluded that satellite‐derived climatic and vegetation variables to date generally adopted to model Grinnellian niches might also be useful in predicting spatial variations in dietary habits of populations, that is, their Eltonian niches.
Hydromantes; cave salamanders; climate; dietary specialization; habitat heterogeneity; trophic niche width; vegetation.
Settore BIO/07 - Ecologia
Settore BIO/05 - Zoologia
22-apr-2020
Article (author)
File in questo prodotto:
File Dimensione Formato  
Lunghi_ms_salamanders_ecology_rev2_RM_intermedia.pdf

accesso aperto

Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 1.14 MB
Formato Adobe PDF
1.14 MB Adobe PDF Visualizza/Apri
ecy.3088.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 913.69 kB
Formato Adobe PDF
913.69 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/733302
Citazioni
  • ???jsp.display-item.citation.pmc??? 10
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 18
social impact