James T. Stroud

Georgia Institute of Technology | GT · School of Biology

Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; " community, " " assemblage, " " guild, "...

Tropical species may be highly vulnerable to climate change [Also see Report by Chan et al. ]

The process of adaptive radiation—the proliferation of species from a single ancestor and diversification into many ecologically different forms—has been of great interest to evolutionary biologists since Darwin. From the middle of the last century, ecological opportunity has been invoked as a potential key to understanding when and how adaptive ra...

Understanding the origins and early stages of diversification is one of the most elusive tasks in adaptive radiation research. Classical approaches, which aim to infer past processes from present-day patterns of biological diversity, are fraught with difficulties and assumptions. An alternative approach has been to study young clades of relatively...

Species’ phenotypic characteristics often remain unchanged over long stretches of geological time. Stabilizing selection—in which fitness is highest for intermediate phenotypes and lowest for the extremes—has been widely invoked as responsible for this pattern. At the community level, such stabilizing selection acting individually on co-occurring s...

Climate change is forcing species to migrate to cooler temperatures at higher elevations, yet many taxa are dispersing slower than necessary. One yet-to-be-tested explanation for inadequate migration rates is that high-elevation environments pose physiological barriers to dispersal, particularly in species with high metabolic demands. By synthesizi...

Positive allometry of signalling traits has often been taken as evidence for sexual selection. However, few studies have explored interspecific differences in allometric scaling relationships among closely related species that vary in their degree of ecological similarity. Anolis lizards possess an elaborate retractable throat fan called a dewlap t...

The idea of ‘key innovations’ has long been influential in theoretical and empirical approaches to understanding adaptive diversification. Despite originally revolving around traits inducing major ecological shifts, the key innovation concept itself has evolved, conflating lineage diversification with trait-dependent ecological shifts. In this opin...

The evolution of key innovations-unique features that enable a lineage to interact with the environment in a novel way-may drive broad patterns of adaptive diversity. However, traditional tests of the key innovation hypothesis, those which attempt to identify the evolutionary effect of a purported key innovation by comparing patterns of diversity b...

Synopsis Every stage of organismal life history is being challenged by global warming. Many species are already experiencing temperatures approaching their physiological limits; this is particularly true for ectothermic species, such as lizards. Embryos are markedly sensitive to thermal insult. Here, we demonstrate that temperatures currently exper...

Determining whether organisms have preferences for certain aspects of the habitat is important for understanding the process of habitat selection. Anolis lizards (anoles) have evolved to occupy distinct parts of the arboreal environment. Depending on the population or species, anoles perch on different aspects of the structural habitat varying in d...

Using a global dataset of contemporary biological invasions, the recent paper by Liu et al. (1) presents a comprehensive test of the niche conservatism hypothesis. Specifically, Liu et al. demonstrate compelling support for climatic niche conservatism in most inva-sive species, even when accounting for differences in ecology and physiology (1). How...

Ecological release, originally conceived as niche expansion following a reduction in interspecific competition, may prompt invasion success, morphological evolution, speciation, and other ecological and evolutionary outcomes. However, the concept has not been recently reviewed. Here, we trace the study of ‘ecological release’ from its inception thr...

Extreme climate events are predicted to increase in frequency and severity due to contemporary climate change. Recent studies have documented the evolutionary impacts of extreme events on single species, but no studies have yet investigated whether such events can drive community-wide patterns of trait shifts. On 22 January 2020, subtropical south...

XENOCHROPHIS TRIANGULIGERUS (Triangle Keelback). DIET and FEEDING BEHAVIOR. The diet of Xenochrophis trianguligerus, a widespread aquatic natricine, has been reported to include frogs, including frogspawn and tadpoles (e.g., Stuebing and Inger 1999. A Field Guide to the Snakes of Borneo. Natural History Publications (Borneo), Kota Kinabalu, Malaysi...

Extreme climate events such as droughts, cold snaps, and hurricanes can be powerful agents of natural selection, producing acute selective pressures very different from the everyday pressures acting on organisms. However, it remains unknown whether these infrequent but severe disruptions are quickly erased by quotidian selective forces, or whether...

1. Seasonal changes in reproduction have been described for many taxa. As reproductive seasons progress, females often shift from greater energetic investment in many small offspring towards investing less total energy into fewer, better provisioned (i.e. larger) offspring. The underlying causes of this pattern have not been assessed in many system...

Adaptive radiation plays a fundamental role in our understanding of the evolutionary process. However, the concept has provoked strong and differing opinions concerning its definition and nature among researchers studying a wide diversity of systems. Here, we take a broad view of what constitutes an adaptive radiation, and seek to find commonalitie...

Understanding how novel environmental conditions presented by urbanization affect the ecology and behavior of species is an important component of global change biology. Behavior is the first way in which organisms respond to novel conditions. We investigated differences in habitat use, movement, and social behavior of invasive adult male Cuban bro...

Tropical biodiversity is under threat from a wide variety of anthropogenic stressors. Understanding the effect of major stressors—most notably land use change, over‐ harvesting, emergence of novel pathogens, and climate change—is a major goal of tropical biology. However, to do so requires baseline data with which to compare present‐day patterns. U...

Widespread human development has led to the proliferation of artificial light at night, an increasingly recognized but poorly understood component of anthropogenic global change. Animals specialized to diurnal activity are presented opportunities to use this night-light niche, but the ecological consequences are largely unknown. While published rec...

Character displacement may facilitate species coexistence through niche partitioning. However, the degree to which character displacement influences broader patterns of community assembly is unclear. Here, we capitalize on a natural experiment of community assembly on the oceanic island of Bermuda. Over the past century, three species of ecological...

It had been nearly a decade since the previous Anolis symposium was held in Cambridge, MA, at the Museum for Comparative Zoology, Harvard. A reunion of anole biologists en masse was long past due and it was decided that this symposium would be slightly different – we were going to hold it somewhere with anoles! And so, on the weekend of 17-18th Mar...

Here we analyze a large dataset of the diet of the brown anole (Anolis sagrei). We asked how the trophic niche varies among populations with the specific goal of testing a long-standing model of adaptive diversification – ecological release. Our results do not support the predicted inverse relationship between community richness and niche breadth....

My dissertation research attempted to test several fundamental ecological and evolutionary hypotheses using communities of introduced non-native Anolis lizards. The idea to use non-native species as ‘natural experiments’ in ecology and evolution certainly isn’t new, in fact I can’t even claim any anole-specific originality to the idea. However, to...

Cuban brown anoles (Anolis sagrei) were first introduced to Miami in the 1950s (Kolbe et al. 2005). Since their initial establishment they have dispersed rapidly and are now present throughout south Florida (Kolbe et al. 2007). Puerto Rican crested anoles (A. cristatellus) were first introduced to the Pinecrest/South Miami neighborhood in south Flo...

While conducting my dissertation research in Miami I found myself in a situation not afforded to all graduate students, especially those that choose to study tropical lizards; I was able to live and walk among a rich and diverse community of my study organisms every day. This fortune wasn’t frivolous – I found myself indirectly familiarizing myself...

Large masses were observed on the head and bodies of non-native Puerto Rican crested anoles (Anolis cristatellus) in Miami, Florida USA. Following examination, the masses were found to be epidermal inclusion cysts. The cysts did not appear to interfere with body condition or behavior. This is the first record of epidermal inclusion cysts in A. cris...

Ecological niche models are commonly used to predict areas of environmental suitability for non-native species. Depending on these models to enact appropriate management plans assumes that they are accurate, however most niche model studies do not provide appropriate validation. South Florida hosts the world's largest and most globally diverse non-...

The partitioning of structural microhabitat among Anolis lizards is a well-studied phenomenon, with replicate patterns observable across independent island radiations (Losos 2011). Though a substantial body of literature describes the predictable nature of habitat partitioning between species, fewer studies have investigated how partitioning within...

Aim Predicting environmentally suitable areas for non‐native species is an important step in managing biotic invasions, and ecological niche models are commonly used to accomplish this task. Depending on these models to enact appropriate management plans assumes their accuracy, but most niche model studies do not provide validation for their model...

Functional traits are increasingly used to understand the ecology of plants and to predict their responses to global changes. Unfortunately, trait data are unavailable for the majority of plant species. The lack of trait data is especially prevalent for hard-to-measure traits and for tropical plant species, potentially owing to the many inherent di...

The tropics have long been a focal point of interest in ecology and evolutionary biology - but where actually are the tropics? Classically, the tropics have been defined as all areas lying between 23.4° North and South as these zones receive direct overhead solar radiation at some point during the year. However, a suite of different environmental a...

Across the globe terrestrial ectotherms-amphibians and non-avian reptiles-are facing a range of emerging challenges. Increasing global temperatures, in particular, are affecting all aspects of ectotherm biology and life history. Embryonic development is a thermally sensitive period of the organismal lifecycle, yet the impacts of thermal stress on t...

ANOLIS CRISTATELLUS (Puerto Rican Crested Anole). CANNIBALISM. Anolis cristatellus is native to Puerto Rico but has been introduced, and become regionally established, in Greater Miami, Florida, USA (Kolbe et al. 2016. Landsc. Ecol. 31:1795–1813). It is a generalist consumer of terrestrial arthropods, although it has been occasionally recorded prey...

Does convergent evolution always result from different lineages experiencing similar evolutionary dynamics? Hagey et al (2017) report the dynamics of adhesive performance evolution to be distinct in two lizard clades (anoles and geckos) despite independent convergence in adhesive toe pad structures, suggesting convergence can occur with dissimilar...

The diverse habitats of central Uzbekistan support a rich herpetofaunal community, but distributions and relative abundances of the species comprising this community remain poorly known. Here, we present an annotated species inventory of this under-explored area, with detailed notes on distributions and population statuses. Fieldwork was concentrat...

Bermuda is an isolated, oceanic island with only one endemic terrestrial vertebrate, the Critically Endangered Bermuda skink (Plestiodon longirostris; Squamata, Scincidae). Major declines in P. longirostris populations have been caused primarily by habitat loss and mortality via invasive species (e.g., predation from birds and cats) and human waste...

Introduced species can have diverse effects on recipient ecosystems. Here we share observations suggesting the formation of a reciprocally positive interaction, seed dispersal, between an introduced lizard and a native palm. We present evidence that the large arboreal lizard (Anolis equestris), native to The West Indies but well-established in sout...

It is critical that we understand the effects of climate change on natural systems if we ever hope to predict or mitigate consequent changes in diversity and ecosystem function. In order to identify coherent ‘fingerprints’ of climate change across Earth's terrestrial and marine ecosystems, various reviews have been conducted to synthesize studies o...

The isolated islands of Bermuda, located ca. 1,000 km east of North Carolina, USA in the Atlantic Ocean, have a rich history of non-native species introductions. Although Bermuda supports only one endemic lizard, the Bermuda Skink (Plestiodon [Eumeces] longirostris), four species of non-native anoles have been introduced and become established over...

Context Urban landscapes are a mixture of built structures, human-altered vegetation, and remnant semi-natural areas. The spatial arrangement of abiotic and biotic conditions resulting from urbanization doubtless influences the establishment and spread of non-native species in a city. Objectives We investigated the effects of habitat structure, the...

Data S1. Methods.

Figure S1. The percent reduction in number of potential future climate analog source populations in Amazonia under 2070 climate projections accounting for climate analogs lost due to deforestation as of 2002 and under future BAU deforestation for 2050. Black represents a 100% reduction in available climate analogs based on losses from deforestation...

Populations occurring at species' range edges can be locally adapted to unique environmental conditions. From a species' perspective, range-edge environments generally have higher severity and frequency of extreme climatic events relative to the range core. Under future climates, extreme climatic events are predicted to become increasingly importan...

Table S1. Survey questionnaire. Table S2. Survey results quantification methods.

Gallagher et al. [1] propose that the niche breadth of a species is a potentially reliable predictor of extinction vulnerability. Species with narrow niches (specialists) generally have lower ecological resistances (i.e., are more sensitive to environmental disturbances) than similar species with broader niches (generalists). Gallagher et al. demon...

Morphological similarity can be used as a predictor of aggressive interactions among anole lizards in a novel community.

The greenhouse gas (GHG) emissions attributable to many scientists, including ecologists and conservation biologists, are often much greater than those attributable to average non-scientists (Fox et al. 2009, Synolakis and Foteinis 2009, Burke 2010, Spinellis and Louridas 2013). The majority of these 'extra' GHG emissions are due to air travel, pri...

Temperature-change trajectories are being used to identify the geographic barriers and thermal ‘cul-de-sacs’ that will limit the ability of many species to track climate change by migrating. We argue that there are many other potential barriers to species’ migrations. These include stable ecotones, discordant shifts in climatic variables, human lan...

Anolis cristatellus is native to Puerto Rico and has been introduced to Florida, USA (Krysko et al. 2003. Florida Sci. 66:74–79; Kraus 2009. Alien Reptiles and Amphibians: A Scientific Compendium and Analysis. Springer, Dordrecht, Netherlands. 563 pp.). Typical A. cristatellus dewlap color and pattern is yellow with orange borders. In Florida there...

Ctenosaura similis is native to Central America, occurring from Mexico through to Panama (Traveset 1990. Am. Midl. Nat. 123:402–404), and has been introduced to several Caribbean islands, and Florida, USA (Krysko et al. 2003. Florida Sci. 66:74-79, Kraus 2009. Alien Reptiles and Amphibians: A Scientific Compendium and Analysis. Springer, [Dordrecht...

Anolis equestris is native to Cuba and has been introduced to Florida, USA (Kraus 2009. Alien Reptiles and Amphibians: A Scientific Compendium and Analysis. Springer, Dordrecht, Netherlands. 563 pp.; Krysko et al. 2003. Florida Sci. 66:74–79). This species consumes a wide variety of animals and plants including vertebrates, invertebrates, and fruit...

Anolis equestris is native to Cuba and A. distichus is native to Hispaniola; both have been introduced to Florida, USA (Kraus 2009. Alien Reptiles and Amphibians: A Scientific Compendium and Analysis. Springer, [Dordrecht, Netherlands], 563 pp.; Krysko et al. 2003. Florida Sci. 66:74–79). Anolis equestris consumes a wide variety of animals and plan...

Although the European adder (Vipera berus) is arguably the most studied terrestrial snake species in the world, little is known about the factors that influence its distribution across a landscape. One of the difficulties in assessing the pattern of a species distribution in a patchy landscape is that surveying is often limited to presence-absence...

Cuban Brown Anoles (Anolis sagrei) are native to Cuba and many Bahamian islands (Schwartz and Henderson1991), but the species has an expansive non-native range, having been introduced and become established in a number of US states (Florida, Georgia, Louisiana, Texas, California), several Lesser Antillean islands (Grenada, St. Vincent, the Grenadin...