1. Understanding effects of invasive alien species (IAS) on native host-parasite relationships is of importance for enhancing ecological theory and IAS management. When IAS and their parasite(s) invade a guild, the effects of interspecific resource competition and/or parasite-mediated competition can alter existing native host-parasite relationships and the dependent biological traits such as native species’ behaviour. 2. We used a natural experiment of populations of native red squirrels (Sciurus vulgaris) that were colonised by the alien grey squirrel (Sciurus carolinensis), comparing repeated measurements of red squirrel parasite infection and personality with those taken in sites where only the native species occurred. 3. We explored two alternative hypotheses: (a) individual differences in personality traits (activity and/or sociability) of native red squirrel positively affect the probability of macroparasite spillover and thus the likelihood to acquire the alien’s parasitic helminth (Strongyloides robustus); (b) the combined effects of grey squirrel presence and parasite infection result in a reduction of costly personality traits (activity and/or exploration). 4. Using data from 323 arena tests across three experimental (native species and IAS) and three control sites (only native species), we found negative correlations between native species’ activity and infection with S. robustus in the sites invaded by the alien species. Activity was also negatively correlated with infection by its native helminth (Trypanoxyuris sciuri) but only when grey squirrels were present, while in the red-only sites there was no relationship of T. sciuri infection with any of the personality traits. Moreover, individuals that acquired S. robustus during the study reduced their activity after infection, while this was not the case for animals that remained uninfected. 5. Our results show that parasite-mediated competition is costly, reducing activity in individuals of the native species, and altering the native host-native parasite relationships.

Spillover of an alien parasite reduces expression of costly behaviour in native host species / F. Santicchia, L.A. Wauters, A.P. Piscitelli, S. Van Dongen, A. Martinoli, D. Preatoni, C. Romeo, N. Ferrari. - In: JOURNAL OF ANIMAL ECOLOGY. - ISSN 1365-2656. - (2020). [Epub ahead of print] [10.1111/1365-2656.13219]

Spillover of an alien parasite reduces expression of costly behaviour in native host species

C. Romeo
Penultimo
;
N. Ferrari
Ultimo
2020

Abstract

1. Understanding effects of invasive alien species (IAS) on native host-parasite relationships is of importance for enhancing ecological theory and IAS management. When IAS and their parasite(s) invade a guild, the effects of interspecific resource competition and/or parasite-mediated competition can alter existing native host-parasite relationships and the dependent biological traits such as native species’ behaviour. 2. We used a natural experiment of populations of native red squirrels (Sciurus vulgaris) that were colonised by the alien grey squirrel (Sciurus carolinensis), comparing repeated measurements of red squirrel parasite infection and personality with those taken in sites where only the native species occurred. 3. We explored two alternative hypotheses: (a) individual differences in personality traits (activity and/or sociability) of native red squirrel positively affect the probability of macroparasite spillover and thus the likelihood to acquire the alien’s parasitic helminth (Strongyloides robustus); (b) the combined effects of grey squirrel presence and parasite infection result in a reduction of costly personality traits (activity and/or exploration). 4. Using data from 323 arena tests across three experimental (native species and IAS) and three control sites (only native species), we found negative correlations between native species’ activity and infection with S. robustus in the sites invaded by the alien species. Activity was also negatively correlated with infection by its native helminth (Trypanoxyuris sciuri) but only when grey squirrels were present, while in the red-only sites there was no relationship of T. sciuri infection with any of the personality traits. Moreover, individuals that acquired S. robustus during the study reduced their activity after infection, while this was not the case for animals that remained uninfected. 5. Our results show that parasite-mediated competition is costly, reducing activity in individuals of the native species, and altering the native host-native parasite relationships.
Helminths; invasive alien species; macroparasites; Mirror Image Stimulation test; Open Field Test; personality traits; Sciurus carolinensis; Sciurus vulgaris
Settore VET/06 - Parassitologia e Malattie Parassitarie degli Animali
Settore BIO/05 - Zoologia
Settore BIO/07 - Ecologia
2020
apr-2020
Article (author)
File in questo prodotto:
File Dimensione Formato  
Santicchia et al_JAE.pdf

accesso aperto

Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 326.5 kB
Formato Adobe PDF
326.5 kB Adobe PDF Visualizza/Apri
1365-2656.13219.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 840.39 kB
Formato Adobe PDF
840.39 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/2434/723472
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 20
social impact