Tama-risk? Avian responses to the invasion of saltcedars (Tamarix ramosissima) in Sonora, Mexico

Abstract

Although exotic plant invasions are one of the most important components of global change, previous studies have found some of the alien species to provide resources and/or conditions to native biota. One example of this is the saltcedar (Tamarix ramosissima). This exotic invasive tree has been related to several dramatic environmental changes in North America. However, previous studies suggest that they offer resources and conditions for native biota, such as the threatened southwestern willow flycatcher (Empidonax traillii). In this study, we surveyed avian communities and bird nests at sites severely invaded by saltcedars, moderately invaded sites, and non-invaded sites in northwestern Mexico. Our results show that although bird species richness and abundances do not differ among the studied conditions, species composition did. Also, bird nest density differed among the studied conditions, with non-invaded sites having the highest functional diversity of nesting birds. We suggest that future studies should gather natural history and ecological information that allows managing this invasive species correctly both in the USA and Mexico.

Group effects of a non‐native plant invasion on rodent abundance

“…Malo et al (2012) found that an invasive shrub bolstered abundance of wood mice (Apodemus sylvaticus) by reducing predation risk from avian predators. Similar patterns with respect to invasive plants have been observed in the avian literature when entire communities (Fischer et al 2012, MacGregor-Fors et al 2013 or Notes: AIC, Akaike's information criteria corrected. Averaged estimate, 95% confidence interval (CI), and relative importance (RI) for each parameter are shown and parameters deemed as influential to rodent abundance italicized.…”

“…, MacGregor‐Fors et al. ) or foraging guilds (French and Zubovic ) are examined. However, with regard to Ord's kangaroo rats in particular, our finding appears to be novel and runs contrary to those of Litt and Steidl (), who found that heteromyid abundance decreased in a linear fashion as cover of a non‐native grass increased.…”

Evaluating the Impact of an Exotic Plant Invasion on Rodent Community Richness and Abundance

“…Due to the changes in cover and forage availability, along with a host of other changes to habitat composition, exotic plants are a large mechanism of disturbance (Knapp 1996, Thompson and Gese 2013, Freeman et al 2014. Support for the intermediate disturbance hypothesis has been observed for several bird communities (Malavasi et al 2009, Fischer et al 2012, MacGregor-Fors et al 2013, but rarely in rodent communities (Malick et al 2012). We feel our observed increase may have been driven by Ord's kangaroo rat, the most abundant species during the study.…”

The genus Tamarix (Tamaricaceae) from archaeological to contemporary landscape

“…Among the various examples reported in the literature, highlighting the role of tamarisks in the alteration of some habitats and in the composition of flora and fauna, we can mention that of Tamarix ramosissima Ledeb. which has been related to several environmental changes in North America, and it negatively affected avian communities and bird nests (MacGregor-Fors & al. 2013).…”