The Influence of the Interaction between Climate and Competition on the Distributional Limits of European Shrews

Abstract

It is known that species’ distributions are influenced by several ecological factors. Nonetheless, the geographical scale upon which the influence of these factors is perceived is largely undefined. We assessed the importance of competition in regulating the distributional limits of species at large geographical scales. We focus on species with similar diets, the European Soricidae shrews, and how interspecific competition changes along climatic gradients. We used presence data for the seven most widespread terrestrial species of Soricidae in Europe, gathered from GBIF, European museums, and climate data from WorldClim. We made use of two Joint Species Distribution Models to analyse the correlations between species’ presences, aiming to understand the distinct roles of climate and competition in shaping species’ distributions. Our results support three key conclusions: (i) climate alone does not explain all species’ distributions at large scales; (ii) negative interactions, such as competition, seem to play a strong role in defining species’ range limits, even at large scales; and (iii) the impact of competition on a species’ distribution varies along a climatic gradient, becoming stronger at the climatic extremes. Our conclusions support previous research, highlighting the importance of considering biotic interactions when studying species’ distributions, regardless of geographical scale.

Characterising Mitochondrial Capture in an Iberian Shrew

“…It is difficult to be exactly sure of the ranges of S. araneus , S. coronatus , and S. granarius during the Late Glacial period from the end of the LGM until the beginning of the Holocene—comprising the time interval of approximately 20–10,000 years ago, incorporating the Bølling–Allerød warm period followed by the Younger Dryas cold period [ 25 ]. Both climatic conditions and their competitive interactions, including competitive exclusion, would have been important [ 27 , 28 ]. S. araneus and S. granarius could easily have had different ranges than at present in Iberia and come into contact, creating the opportunity for hybridisation and introgression.…”

First records of the greater white-toothed shrew Crocidura russula from Great Britain.

“…In an area of Norway, with a similar latitude and small mammal community to North East England, a C. russula population first recorded in 2012 was not found to have any significant effects on the occupancy of either S. minutus or S. araneus (Talleraas, 2021). Subtle differences between shrew populations (Browett et al, 2023) and climatic gradients (Neves et al, 2021) are also likely to have significant effects on species co-existence, but how these differences would play out in Great Britain is unpredictable, and the potential for a negative impact similar to that in Ireland is a possibility. As noted above, C. russula has been present in North East England for at least seven years.…”

Characterizing Mitochondrial Capture in an Iberian Shrew

“…It is difficult to be exactly sure of the ranges of S. araneus, S. coronatus and S. granarius during the Late Glacial period from the end of the LGM until the beginning of the Holocene (comprising the time interval of approximately 20 -10,000 years ago, incorporating the Bølling-Allerød warm period followed by the Younger Dryas cold period [24]). Both climatic conditions and their competitive interactions, including competitive exclusion, would have been important [26,27]. S. araneus and S. granarius could easily have had different ranges than at present in Iberia and come into contact, creating the opportunity for hybridization and introgression.…”