Living in the big city: preference for broad substrates results in niche expansion for urban Anolis lizards

Abstract

preference 8 2 ABSTRACT 9Persistence of animals in urban habitats, a stark environmental contrast to natural 10 habitats, can be explained through evaluating the mechanisms behind organism-habitat 11 interactions. One of the most notable effects of urbanization is the change in structural habitat; 12 vegetation is removed and modified, favoring large trees and adding artificial structures in cities, 13 which may alter how organismal preferences for aspects of the habitat are realized. We evaluated 14 the mechanisms by which structural habitat changes associated with urbanization alter the 15 available vegetation and substrates on which two species of Anolis lizards perch in urban and 16 natural forest sites in Miami, FL. We also experimentally assessed habitat preference in the lab 17 to establish the mechanism behind habitat selection. We found that vegetation was broader in 18 urban areas compared to natural habitats, and artificial structures in urban areas were more than 19 twice the diameter of available natural perches. Lizards expressed their preference for broad 20 perches by selecting broader vegetation and artificial structures compared to their availability in 21 both habitats. With the increased availability of broad substrates in urban areas, perch diameters 22 selected by lizards resulted in an expansion of this aspect of the structural habitat niche for both 23 species. The two species differed, however, in other responses to altered urban habitats. Anolis 24 cristatellus tended to avoid artificial substrates, whereas A. sagrei used both natural and artificial 25 structures in proportion to their availabilities. This study provides a mechanistic explanation for 26 how urbanization alters structural habitats, leading to niche expansion for organisms living in 27 cities.28

Miami heat: Urban heat islands influence the thermal suitability of habitats for ectotherms

“…Anolis cristatellus has lower reported thermal preferences and tolerances than A. sagrei and appears constrained to areas in Miami with high canopy cover (Corn, 1971;Kolbe et al, 2016). Anolis sagrei is widespread throughout urban areas of Miami as well as some natural forest locations (Battles, Moniz, & Kolbe, 2018).…”

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

“…In recent years, however, a growing number of studies have explored how different aspects of urbanization affect lizard's biology (e.g., Kent et al, ) and one of the best studied groups is the New World Anolis lizards. For instance, urbanization causes extreme structural habitat changes that affect locomotor performance and drive shifts in limb morphology and body size in some Anolis species (Battles, Irschick, & Kolbe, ; Kolbe, Battles, & Avilés‐Rodríguez, ; Marnocha, Pollinger, & Smith, ; Winchell, Maayan, Fredette, & Revell, ; Winchell, Reynolds, Prado‐Irwin, Puente‐Rolón, & Revell, ), which might favor niche expansion (Battles, Moniz, & Kolbe, ). The urban environment also tends be hotter, with wider variation in temperature that could affect development, survival, and persistence of Anolis in cities (e.g., Battles & Kolbe, ; Hall & Warner, ; Tiatragul, Hall, Pavlik, & Warner, ).…”

Do structural habitat modifications associated with urbanization influence locomotor performance and limb kinematics in Anolis lizards?

“…Urbanization creates novel environments that significantly change natural habitat in numerous ways, with profound effects for many organisms (McKinney, 2006). Trees, branches and other natural substrates are reduced in density by removal of vegetation, whereas artificial structures, such as metal poles, wooden fences and painted walls, are added (Battles et al, 2018). Arboreal species have an ecological and evolutionary history of moving on natural vegetation in a dense matrix of the forest, and in urban habitats they must instead manoeuvre on human-made structures (Winchell et al, 2018a;Battles et al, 2018).…”

“…Trees, branches and other natural substrates are reduced in density by removal of vegetation, whereas artificial structures, such as metal poles, wooden fences and painted walls, are added (Battles et al, 2018). Arboreal species have an ecological and evolutionary history of moving on natural vegetation in a dense matrix of the forest, and in urban habitats they must instead manoeuvre on human-made structures (Winchell et al, 2018a;Battles et al, 2018). Perhaps one of the greatest contrasts between urban and natural habitats for arboreal animals is the increased frequency of vertical, smooth surfaces in urban areas, such as poles and walls (Kolbe et al, 2016b).…”

“…Both species specialize in similar structural habitats, commonly occupying the ground and perches up to ~2 m (Salzburg, 1984;Losos, 2009), but whether these two species respond in the same manner kinematically to variation in inclination and smoothness is an open question. Furthermore, lizards utilize broad-diameter perches in urban areas, which are frequently artificial, smooth structures (Winchell et al, 2016;Battles et al, 2018).…”