Habitat association and coexistence of endemic and introduced ant species in the Galápagos Islands

Abstract

1. We investigated ant communities in all main vegetation zones of the model island of Santa Cruz in the Galápagos archipelago (155 collection points, spread over 21 sites; 28 ant species collected), and evaluated the distribution, coexistence, and effect of environmental factors in a community composed of endemic, probably endemic, and introduced ants of the New World and exotic origin. 2. Introduced species were the most frequent, occurring in 98% of the samples, yet endemic and probably endemic species still occurred in 54% of the samples, and constituted one of three most common species. The present study revealed that the habitat type along with altitude and the tree cover are the primary factors shaping ant community composition. Little evidence was found for a competitively structured assemblage of ant species. 3. The present study confirmed the predominance of two dominant invasive species, Solenopsis geminata Fabricius and Wasmannia auropunctata Roger, whose abundances are negatively correlated. The abundance of S. geminata is positively correlated with the overall species richness, and with the proportion of other introduced species. The presence of both invasive ants is associated with a low evenness of ant communities. 4. The present study (i) stresses the dominance of introduced species and the relative resistance of endemic species, (ii) highlights the on‐going processes of species introductions and (iii) points out the need for adequate monitoring and conservation of the pristine and threatened environments that constitute the Galápagos Islands.

Temporal variation in ant community assemblages along a rural–urban gradient in the Yaoundé metropolis, Cameroon

“…Five tramp species accounting for more than 50% of the total ant species were found during the two sampling periods. This pattern of dominance is similar to other invaded sites, where tramp ant species generally constitute a much larger percentage of total species (Wauters et al 2015). Wasmannia auropunctata was the most dominant species in 2007 while P. megacephala was dominant in the same areas 10 years later with no W. auropunctata workers collected in any of the traps.…”

“…In our study, ant abundance was highest in urban sites and lowest in both rural and suburban sites. Increase in ant abundance in urban sites were due to an explosion of urban tolerant species, that more than compensate for the loss of species with specific habitat requirements (Wauters et al 2015).…”

Oceanic islands and climate: using a multi-criteria model of drivers of change to select key conservation areas in Galapagos

“…The larvae of the parasitic fly (P. downsi) feeds on the blood of chicks from native and endemic birds, causing high mortality rates (Deem et al 2008;Jiménez-Uzcátegui et al 2007;Lawson et al 2017). Invasive fire ants predate on a variety of Galapagos wildlife, including reptiles, birds, and invertebrates (Causton et al 2006;Herrera and Causton 2008;Wauters et al, 2016Wauters et al, , 2017Wauters et al, , 2018. Introduced mammalian species, mainly goats, rats, cats, and dogs, have decimated the abundance of diverse plant and animal species through predation and competition for the same ecological niches (Wiedenfeld and Jiménez-Uzcátegui 2008; Heleno et al 2012;Renteria et al 2012b).…”

The ants of the Galápagos Islands (Hymenoptera, Formicidae): a historical overview, checklist, and identification key

“…Originally described as Formica melanocephalum (Fabricius, 1793). First published record Emery (1893) , cited also in Wheeler (1919) [ CAS ], Wheeler (1924) , Linsley and Usinger (1966) , Clark et al (1982) [ ICCDRS ], Lubin (1984) [ ICCDRS ], McMullen (1987 1990 , 1993 ), Abedrabbo (1994) [ ICCDRS ], Brandão and Paiva (1994) , de la Vega (1994) , Meier (1994) [ ICCDRS ], Peck et al (1998) , Pezzatti et al (1998) [ ICCDRS ], Roque-Albelo et al (2000) [ ICCDRS ], von Aesch and Cherix (2005) [ ICCDRS ], Boada (2005) [ ICCDRS ], von Aesch (2006) [ ICCDRS ], Causton et al (2006) , McMullen (2009) , Herrera and Causton (2010) [ ICCDRS ], McMullen (2012) , Chamorro et al (2012) [ ICCDRS ], Dekoninck et al (2014) [ ICCDRS , RBINS ], Wauters et al (2016) [ ICCDRS , RBINS ], Herrera (2015 , 2019 ), and Herrera et al (2020) [ ICCDRS , RBINS ].…”