The influence of land cover and within-pool characteristics on larval, froglet, and adult wood frogs along a rural to suburban gradient Carly J. Eakin 1 & Malcolm L. Hunter Jr 1 & Aram J. K. Calhoun 1 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Urbanization is known to extirpate many species, but far less is known about how suburbanization may affect amphibian pop- ulations. We studied wood frogs (Lithobates sylvaticus) to test the effects of site characteristics (within-pool conditions and land cover indicative of suburbanization within 1000 m) and larval morphology on newly emerged froglets and post-breeding males across a suburbanization gradient in 15 pools in greater Bangor, Maine, USA. We raised field-captured larvae in microcosms and examined froglet morphology and locomotor performance at emergence and one month post-emergence. Larval mass was positively correlated with 50% of froglet responses (survival, size, and locomotor performance) but was negatively associated with adult size. Among site characteristics, egg density had the most salient influence with negative effects on larval survival and morphology as well as on 11 of 14 froglet responses. Vegetation, hydrology, and suburban-associated cover near pools also influenced froglet performance, and hydrology and suburban-associated cover was associated with larger and smaller adult morphology. However the influence of suburban-associated cover on froglet performance and adult morphology was small compared to that of within-pool characteristics. Specifically, our findings support the idea that within-pool conditions experi- enced by larvae can influence terrestrial stages with potentially life-long consequences. Nevertheless, in suburban landscapes where there is evidence of population declines, it is likely that suburbanization has the greatest impact on populations via direct effects on terrestrial stages. We encourage planners to maintain high-quality habitat for aquatic and terrestrial stage wood frogs in suburbanizing landscapes to avoid extirpation. Keywords Vernal pool . Suburbanization . Latent effects . Locomotor performance . Morphology . Conspecific competition Introduction It is well established that intense urbanization and the associated habitat loss can result in the extirpation of many species (Wilcove et al. 1998; McKinney 2008) but the impacts of lower intensities of residential and commercial development are far from clear. For example, high intensity urban development has clear negative impacts on wood frog (Lithobates sylvaticus) populations through the removal of pools necessary for breeding and larval development and large contiguous areas of forest used as non-breeding adult habitat (Gibbs 1998; Homan et al. 2004; Rubbo and Kiesecker 2005; Clark et al. 2008; Windmiller et al. 2008; Nicholls et al. 2017) but suburban development may also harm wood frog populations. In particular, replacement of up- land forest by suburban development near breeding pools is correlated with reduced wood frog breeding pool occupancy (Homan et al. 2004; Clark et al. 2008) and breeding population size (Windmiller et al. 2008; Veysey et al. 2011). The most wide-reaching effects of urbanization on wood frogs may be at the lowest development intensities, where forest is converted to suburban development, typically consisting of light commercial and single-unit residential development. Between 1990 and 2005, suburban expansion at the fringes of core urban areas was the development type primarily responsi- ble for replacing forested areas in New England (Jeon et al. 2014), and by 2000, exurban development – often at the leading Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11252-019-0830-x) contains supplementary material, which is available to authorized users. * Carly J. Eakin carly.eakin@gmail.com Malcolm L. Hunter, Jr mhunter@maine.edu Aram J. K. Calhoun calhoun@maine.edu 1 Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME 04469, USA Urban Ecosystems https://doi.org/10.1007/s11252-019-0830-x