When origin, reproduction ability and diet define the role of birds in invasions

Abstract

The ecological impacts of invasive alien species (IAS) are increasingly documented; however, they are usually studied through the lens of either the IAS or the affected species (IAS-threatened species). A clear understanding of how both protagonists of biological invasions are characterized is still lacking. We investigated the morphology, life history and ecology of birds involved in biological invasions. Evaluating the distribution of 450 IAS-threatened birds and 400 alien birds in a functional space, we found that both groups retained various strategies. Aliens had larger clutches and were more likely to be herbivores than IAS-threatened and worldwide birds, while IAS-threatened birds were more insular endemic from the Australia region than alien and worldwide birds. IAS-threatened species showed opposite strategies to aliens regarding traits related to diet, origin and reproduction. Further comparing traits associated with impact magnitude, we found that even if aliens were mostly herbivorous, those with high impact had more a generalist behaviour and an animal-based diet compared to aliens with low impact. By emphasizing differences relating to the distribution of bird groups in a functional space, we opened new opportunities to identify the role of birds in biological invasions.

Relative importance of exotic species traits in determining invasiveness across levels of establishment: Example of freshwater fish

“…Understanding why some exotic species become established in a new location while others fail remains a challenging question (Enders et al, 2020). Studies have shown that the success of exotic species depends on a combination of different factors involving propagule pressure, the biotic characteristics of the recipient ecosystem and exotic species traits (Allen et al, 2017; Bernery, Bellard, Courchamp, Brosse, & Leroy, 2022; Blackburn et al, 2009; Capellini et al, 2015; Marino & Bellard, 2023; Novoa et al, 2020). For instance, reptiles and amphibians established in exotic environments have larger or more frequent clutches compared with species that fail to establish (Allen et al, 2017).…”

“…Exotic birds that are successfully established mostly present slow life‐history traits (e.g. large body mass and low brood value; Sol et al, 2012), while those with high ecological impacts have large clutch sizes (Marino & Bellard, 2023). In addition, exotic freshwater fish with a broad food spectrum have a greater chance of establishing than species with more specialized diets (Ruesink, 2005), although this varies with the stage of invasion (Bernery, Bellard, Courchamp, Brosse, Gozlan, et al, 2022).…”

“…involving propagule pressure, the biotic characteristics of the recipient ecosystem and exotic species traits (Allen et al, 2017;Blackburn et al, 2009;Capellini et al, 2015;Marino & Bellard, 2023;Novoa et al, 2020). For instance, reptiles and amphibians established in exotic environments have larger or more frequent clutches compared with species that fail to establish (Allen et al, 2017).…”

“…Exotic birds that are successfully established mostly present slow life-history traits (e.g. large body mass and low brood value; Sol et al, 2012), while those with high ecological impacts have large clutch sizes (Marino & Bellard, 2023).…”

Can we predict the predation pressure of owned domestic cats on all birds in the United States?

“…I based this selection on previous evidence linking these traits to prey-predator relationships (Caron et al, 2022; Desjardins-Proulx et al, 2017; Gravel et al, 2013; Kopf et al, 2021; O’Connor et al, 2020) or linking them to domestic cat predation in particular (Woinarski et al, 2017). I sourced seven traits from two databases: body mass (continuous), tail length (continuous), hand wing index (continuous), trophic niche (categorical: granivore, vertivore, aquatic predator, invertivore, omnivore, nectarivore, aquatic herbivore, terrestrial herbivore, frugivore, scavenger) and primary lifestyle (categorical: insessorial, generalist, terrestrial, aerial, aquatic) from the AVONET database (Tobias et al 2022); and clutch size (numeric) from Marino & Bellard (2023). I obtained information about species’ habitat from the IUCN (2022) by adding eight dummy variables for each main habitat (wetlands, shrubland, grassland, wetlands, artificial/terrestrial, rocky, forest), where 0 indicates that the species is absent from this habitat and 1 else.…”