Herpetology Notes, volume 14: 681-690 (2021) (published online on 21 April 2021) Opportunistically collected UV exposure data for some lizards in Cuba and Grand Cayman Lauren Augustine1,2,*, Cristina Macklem1, Avishai Shuter3, and Kevin Torregrosa3 There are over 6000 described species of lizards al., 2017), vitamin D production (Bernard, 1995; Oftedal (Uetz et al., 2020), but their ecology and behaviour are et al., 1997; Acierno et al., 2008; Ferguson et al., 2013), understudied relative to other vertebrate groups (Bonnet et health (Adkins et al., 2003; Ferguson et al., 2010), and al., 2002; Bland and Böhm, 2016; Rosenthal et al., 2017). mate selection and reproduction (Townsend and Cole, With some models projecting lizard diversity declining 1985; LeBas and Marshall, 2000; Font and Molina-Borja, by up to 39% by 2080 (Sinervo et al., 2010), gaps in 2004; Lisboa et al., 2017). Furthermore, because both basic natural history and ecological knowledge that exist under- and over-exposure to the UV spectrum can have for these species remain a hindrance to conservation deleterious effects, it is important for lizards to regulate efforts. As anthropogenic threats continue to alter wild that exposure (Hays et al., 1995; Blaustein et al., 1998; places globally, both habitat protection and conservation Ferguson et al., 2002; Gehrmann, 2006; Baines, 2008; breeding programs are increasingly recommended, and Gardiner et al., 2009). Thus, knowledge of natural UV both are heavily reliant on natural history information exposure levels is important when considering habitat for success. Thus, increasing our understanding of lizard availability and protections for wild lizard populations natural history, ecology, and microhabitat preferences is and to inform husbandry practices for lizards in human crucial to developing conservation strategies to prevent care, including conservation breeding programs for future extirpation and extinction events. threatened and endangered species (Ferguson et al., Exposure to ultraviolet (UV) radiation (light 2010; Selleri and Girolamo, 2012; Baines et al., 2016). wavelengths of 10–400 nm) is biologically and Opportunistic collection of lizard natural history data ecologically crucial for lizards, yet natural exposure may help fill critical gaps in knowledge for conservation data are lacking for most species. Basking behaviour efforts. Here we outline the ease and potential benefits in reptiles has long been associated with exposure to of collecting natural UV exposure data for diurnal infrared light and thermoregulation (Cowles and Bogert, lizards and provide an application of the data using 1944; Huey and Slatkin, 1976; Sievert and Hutchison, Anolis sagrei as an example. While time and funding 1988). However, sunlight is more than just a source of limitations can make collecting sufficient data on heat, with UV light a significant component. Reptiles rare and/or cryptic species a challenge, we hope that utilize both the UVA (320–400 nm) and UVB (290–320 opportunistic data collection by many professionals nm) portions of the solar spectrum, and lizards use UV can eventually provide a meaningful amount of natural light for intraspecific communication and signalling history data for understudied and rare reptile species. (Whiting et al., 2006; Bajer et al., 2010; Pérez i de Lanuza and Font, 2014; Marshall and Stevens, 2014; Driessens et Materials and Methods Study species. We focused on diurnal lizard species encountered in Cuba and Grand Cayman with an emphasis on Anolis sagrei (Fig. 1A), a species common 1 Department of Herpetology, Saint Louis Zoo, One on both islands. Anolis sagrei is a heliophilic and Government Drive, Saint Louis, Missouri 63110, USA. thermophilic species (Landwer et al., 1995; Loew et 2 Smithsonian National Zoological Park, 3001 Connecticut Avenue NW, Washington, DC 20008, USA. al., 2002; Ferguson et al., 2005) and as such, sunlight 3 Department of Herpetology, Wildlife Conservation Society, drives many aspects of this lizard’s behaviour. Light Bronx Zoo, 2300 Southern Boulevard, Bronx, New York cycles serve as a cue for hatching (Nash et al., 2015), 10460, USA. aid in both conspecific communication and territorial * Corresponding Author. E-mail: [email protected] displays (Steffen, 2007; Driessens et al., 2017), and are © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. relied upon for thermoregulation and the synthesis of 682 Lauren Augustine et al. Figure 1. Three of the Cuban species for which we collected UVI exposure data during this study. (A) Anolis sagrei from near El Nicho waterfall, Cienfuegos Province (22.0269°N, 80.1321°W). (B) A. equestris from the 259 km rest stop on the Autopista Nacional, Villa Clara Province (22.3785°N, 80.0504°W). (C) A. allisoni from the Laguna del Tesoro access point, Matanzas Province (22.3665°N, 81.1643°W). Photos by Hinrich Kaiser. UV Exposure in Lizards from Cuba and Grand Cayman 683 vitamin D3 (Holick et al., 1981; Holick, 1989; Carman analysed the data using a Welch’s heteroscedastic F et al., 2000; Ferguson et al., 2005). Anolis sagrei can test because it is more robust than an ANOVA when perceive UV light (Loew et al., 2002), and UV light is variances are unequal; this test is also less sensitive utilized in the dewlap displays of both male and female to differences in sample size between groups (Welch, lizards (Steffen, 2007; Driessens et al., 2017). Given 1951; Dag et al., 2018). Data were analysed using R this species’ propensity to inhabit full sun environments (version 3.6.3; R Core Team, 2020) through the RStudio (Hertz, 1992; Ferguson et al., 2015), A. sagrei is likely (version 1.2.5033; RStudio, 2020) interface. to be naturally exposed to ample amounts of UV light. We include additional data as available for A. equestris Results (Fig. 1B) and A. allisoni (Fig. 1C). A total of 82 natural UV exposure measurements Data Collection and Analysis: While in the field were recorded for seven species of lizards. A total of for an unrelated project, UV index (UVI) readings 56 UV readings were recorded for Anolis sagrei, with were taken opportunistically from the exact location of 49 readings in Cuba and seven in Grand Cayman Island basking lizards from 4–8 November 2019 in Matanzas (Tables 1, 2). Total sampling effort was calculated at Province, Cuba, and from 1–4 December 2019 on 2.73 person hours, or approximately 2 min per record. Grand Cayman Island (Tables 1, 2). Readings were Sample size, UVI ranges, and average exposure, taken using a Solarmeter Model 6.5R Reptile UV Index regardless of island, are summarized in Table 2. Meter (Solar Light Company, Glenside, Pennsylvania, UV exposure was significantly higher for A. sagrei in USA), a tool found to be suitable for measuring the Cuba than on Grand Cayman island (χ2 = 12.97, df = 1, p irradiance from sunlight as it pertains to the needs of = 0.000; Fig. 2). When pooling location data, there was reptiles (Baines et al., 2016). The range of appropriate a moderate negative correlation between UV exposure UVI exposure for species based on predefined Ferguson and time of day (r = –0.41) such that decreasing UV Zones relates UVI to the physiological needs of the exposure levels were associated with increasingly late species, in particular to predict photoproduct conversion daylight hours (Fig. 3). We did not detect a correlation of provitamin D when exposed to UVB (Ferguson et between basking temperature and time of day (r = 0.09). al., 2010). For example, a thermoregulating species that There was a moderate positive correlation (r = 0.42) basks mid-day in full sun would be expected to fit into between UV exposure and basking temperature such Ferguson Zone 4 with a high UVI exposure of 2.6–9.5 that increasing UV exposure levels were associated and a median UVB range of 3.1 (Ferguson et al., 2010). with increasing basking temperatures (Fig. 3). Further In addition to UVI, which is dimensionless and does inquiry into these relationships revealed that basking not have units, the surface temperature at the basking temperature was significantly higher in Cuba than on location (hereafter, the basking temperature) was also Grand Cayman (F = 122.29, p < 0.001). Overall, recorded using an Etekcity Lasergrip 774 Non-contact 1,52 the mean and range of basking temperatures was much Digital Laser Infrared Thermometer Temperature Gun greater during the Cuba surveys than the Grand Cayman (Etekcity, Anaheim, California, USA). Each animal’s surveys, with an average temperature of 34.2°C, immediate habitat and details about the weather at the ranging from 23.3–43.3°C in Cuba, in contrast to a time were also collected but are not represented in this mean temperature of 27.4°C (26.9–28.5°C) in Grand report. We also recorded the amount of time required to Cayman (Fig. 4). take the opportunistic readings. We analysed UVI exposure for A. sagrei by island using Discussion an analysis of variance. We assessed the assumption of normality using a Shapiro-Wilk test and the assumption Despite its time limitations, our study highlights the of homoscedasticity using Bartlett’s and Levene’s tests. ease of collecting opportunistic natural history data The data were non-parametric and, thus, we analysed and identifies areas for future research. While in Cuba the models using a Kruskal-Wallis Rank Sum test. We working on another research project and in the Cayman also used a Pearson correlation coefficient to determine Islands on vacation, we were able to easily collect data how correlated UV exposure was to our time of day while walking to and from field sites, during meal and basking temperature variables. Given that output, breaks, and whenever a lizard was otherwise seen. we analysed A. sagrei basking temperature by island. This opportunistic surveying resulted in 82 natural UV The data violated homoscedasticity and we therefore exposure measurements for seven species of lizards in 684 Lauren Augustine et al.