Divergent habitat use of two urban lizard species

Abstract

Faunal responses to anthropogenic habitat modification represent an important aspect of global change. In Puerto Rico, two species of arboreal lizard, Anolis cristatellus and A. stratulus, are commonly encountered in urban areas, yet seem to use the urban habitat in different ways. In this study, we quantified differences in habitat use between these two species in an urban setting. For each species, we measured habitat use and preference, and the niche space of each taxon, with respect to manmade features of the urban environment. To measure niche space of these species in an urban environment, we collected data from a total of six urban sites across four different municipalities on the island of Puerto Rico. We quantified relative abundance of both species, their habitat use, and the available habitat in the environment to measure both microhabitat preference in an urban setting, as well as niche partitioning between the two different lizards. Overall, we found that the two species utilize different portions of the urban habitat. Anolis stratulus tends to use more “natural” portions of the urban environment (i.e., trees and other cultivated vegetation), whereas A. cristatellus more frequently uses anthropogenic structures. We also found that aspects of habitat discrimination in urban areas mirror a pattern measured in prior studies for forested sites in which A. stratulus was found to perch higher than A. cristatellus and preferred lower temperatures and greater canopy cover. In our study, we found that the multivariate niche space occupied by A. stratulus did not differ from the available niche space in natural portions of the urban environment and in turn represented a subset of the niche space occupied by A. cristatellus. The unique niche space occupied by A. cristatellus corresponds to manmade aspects of the urban environment generally not utilized by A. stratulus. Our results demonstrate that some species are merely tolerant of urbanization while others utilize urban habitats in novel ways. This finding has implications for long‐term persistence in urban habitats and suggests that loss of natural habitat elements may lead to nonrandom species extirpations as urbanization intensifies.

Metropolitan lizards? Urbanization gradient and the density of lagartixas (Tropidurus hispidus) in a tropical city

“…For example, in the peri‐urban areas, when perching off the ground, in over 61% of sightings they were usually in walls suggesting the presence of infrastructure and artificial surfaces providing refuges could be critical for their occurrence. Urban Anolis species show striking differences in use of artificial substrates; the most abundant species uses artificial substrates more often and seems much more tolerant to the stress associated with the artificial hard surfaces in cities (Winchell, Carlen, et al, ). Likewise, lizards from urban environments in temperate climates that are able to use artificial substrates also seem to do well in cities (e.g., Koenig et al, ; Littleford‐Colquhoun et al, ; Prosser, Hudson, & Thompson, ).…”

“…The results indicate that lagartixas are urban dwellers (sensu Fischer et al, ). Generalist species, with broad environmental tolerance, apparently are able to exploit novel habitats and succeed under the multiple environmental and ecological scenarios that are common in urban ecosystems (Bonier, Martin, & Wingfield, ; Callaghan et al, ; Ducatez et al, ; Winchell, Carlen, et al, ). This raises the possibility of a rapid adaptive evolution resulting in increased fitness and facilitating urban life (Johnson & Munshi‐South, ; Littleford‐Colquhoun et al, ; Winchell, Maayan, et al, ; Winchell et al, ).…”

“…The combination of these traits, including behavioral flexibility and learning abilities, has been shown to be associated with urban tolerating species (Batabyal & Thaker, ; Callaghan et al, ; Littleford‐Colquhoun, Clemente, Whiting, Ortiz‐Barrientos, & Frere, ; Shochat et al, ; Sol, Gonzalez‐Lagos, Moreira, Maspons, & Lapiedra, ; Sol, Lapiedra, & Gonzalez‐Lagos, ; Winchell, Carlen, Puente‐Rolón, & Revell, ). This understanding, however, is limited as most studies have focused almost completely on birds and mammals (e.g., Chiari, Dinetti, Licciardello, Licitra, & Pautasso, ; Sol et al, ; Santini et al, ; but see Walsh, Goulet, Wong, & Chapple, and Winchell, Carlen, et al, ). Moreover, most studies are restricted to temperate regions (e.g., Beninde, Feldmeier, Veith, & Hochkirch, ; Møller et al, ), while the impact on most of the species of vertebrates that live in tropical cities is practically unknown; we have only a vague idea of how urbanization affects their ecology, morphology, and genetics.…”

“…The combination of these traits, including behavioral flexibility and learning abilities, has been shown to be associated with urban tolerating species (Batabyal & Thaker, 2019;Callaghan et al, 2019;Littleford-Colquhoun, Clemente, Whiting, Ortiz-Barrientos, & Frere, 2017;Shochat et al, 2006;Sol, Gonzalez-Lagos, Moreira, Maspons, & Lapiedra, 2014;Sol, Lapiedra, & Gonzalez-Lagos, 2013;Winchell, Carlen, Puente-Rolón, & Revell, 2018). This understanding, however, is limited as most studies have focused almost completely on birds and mammals (e.g., Chiari, Dinetti, Licciardello, Licitra, & Pautasso, 2010;Sol et al, 2014;Santini et al, 2019; but see Walsh, Goulet, Wong, &Chapple, 2018 andWinchell, Carlen, et al, 2018).…”

“…Urban populations of A. cristatellus, in their native range, have longer limbs relative to body size in urban populations, allowing it to sprint faster and to be more stable on smooth, vertical substrates (Winchell, Maayan, et al, 2018;Winchell et al, 2016). This species also has a preference for using artificial substrates in urban environments, which could lead to increased exploitation of man-made habitats and higher abundance in urban environments (Winchell, Carlen, et al, 2018). Some studies indicate that lizard species more abundant in urban areas tend to use artificial substrates more often (Germaine & Wakeling, 2001;Koenig, Shine, & Shea, 2001;Winchell, Carlen, et al, 2018); thus, I expect lagartixas to use artificial structures regularly.…”