Ian M. Latella

ANCIENT COLONIZATION PREDICTS RECENT NATURALIZATION IN ANOLIS LIZARDS

The distributions and characteristics of naturalized species may be explained by novel anthropogenous aspects of world biogeography such as the creation of favorable transport environments for propagules on ships. Conversely, the unprecedented connectivity of humans may simply accelerate omnipresent ecological and evolutionary forces, for example, ships may allow species that are generally good dispersers to disperse more quickly. As a null hypothesis, there may be no human component to species naturalization. The first hypothesis predicts that naturalized species will possess unusual characteristics specific to interactions with humans. The latter two hypotheses predict similarity between ancient colonizers and recently naturalized species. In this article, we present a test of the latter hypotheses and show how they may be reconciled with the former. We show that species of Anolis lizard that are ancient solitary colonizers share characteristics of size, shape, scalation, and phylogeny with naturalized species of Anolis. Characteristics of ancient solitary colonizers predict naturalization approximately as well as characteristics of naturalized species themselves. These results suggest the existence of a general colonizing type of Anolis, and that contemporary patterns of naturalization are at least partially explained by abilities that are unrelated to interactions with humans.

Too dry for lizards: short-term rainfall influence on lizard microhabitat use in an experimental rainfall manipulation within a piñon-juniper

Summary 1.Ectotherms such as lizards are expected to alter their behavior and microhabitat use and experience population declines in response to rising temperatures. But the role of changing rainfall patterns on lizard behavior and microhabitat use is not understood. 2.We used a 5-year rainfall manipulation experiment in a pinon pine-juniper woodland in central New Mexico to study how a lizard species’ microhabitat use varies in four different rainfall treatments. 3.We examined ground temperatures in the sun and shade, and daily rainfall, within each treatment, during lizard activity periods, to address how lizards used sun or shade microhabitats on a daily basis. Our small-scale rainfall and temperature measurements indicate that rainfall, not temperatures, predict lizard microhabitat use. 4.Lizards showed a strong preference for shaded microhabitats during dry periods and used sunny microhabitats following rainfall events, regardless of treatment type. Lizards remained active during dry periods, foraging in the shade of trees. 5.Our study shows that rainfall can influence lizard microhabitat use more than temperature in a pinon pine-juniper woodland and the trees provide important refugia. The loss of pinon pine and juniper trees from prolonged drought threatens to limit the amount of shade available to lizards in the future. This article is protected by copyright. All rights reserved.

Morphology, Phylogeny, and Behavior of Anolis proboscis

Abstract Males of the three species of the Anolis laevis group, so-called proboscis anoles, display a remarkable appendage extending from the snout. All A. laevis group Anolis are poorly known and rarely collected. We redescribe Anolis proboscis based on the type specimen and male and female specimens we collected recently near the town of Mindo, Pichincha Province, Ecuador. We include color notes and additional morphological measures lacking from the original description, natural history data for 11 specimens, an estimate of the phylogenetic relationships of the species, and a description of display behavior and intraspecific interactions incorporating the proboscis.

Traits associated with naturalization in Anolis lizards: comparison of morphological, distributional, anthropogenic, and phylogenetic models

The worldwide spread of invasive species affects native biodiversity and causes economic loss, but also allows better understanding of historical biogeographic patterns. Prediction of likely invaders facilitates economic and conservation decisions and gives insight into characteristics that have allowed natural colonization over evolutionary time. However, it is not clear what types of characters best predict naturalization or even whether naturalization is predictable at all. Squamate reptiles have been understudied subjects for invasion biology. Lizards of the genus Anolis have been highly successful colonizers both recently and over evolutionary time. Nineteen of the approximately 350 described species of Anolis have established naturalized populations. We constructed models of naturalization using morphological, distributional, anthropogenic, and phylogenetic characters and compared these single character class models to each other and to a composite model incorporating all four classes. We show that (1) each class of variables significantly predicts invasion, (2) a composite model significantly outperforms each of the submodels, and (3) the final composite model displays extraordinary ability to objectively identify naturalized species of Anolis.

Too wet for frogs: changes in a tropical leaf litter community coincide with La Nina

Extreme climatic events such as the El Nino Southern Oscillation profoundly affect many plants and animals, including amphibians, which are strongly negatively affected by drought conditions. How amphibians respond to exceptionally high precipitation as observed in La Nina events, however, remains unclear. We document the correlation between the exceedingly wet 2010-2012 La Nina and community-level changes in a leaf litter frog assemblage in Costa Rica. Relative abundances of species shifted, diversity and plot occupancy decreased, and community composition became homogenized with the onset of La Nina. These aspects remained altered for over 20 months but rebounded to pre-La Nina levels after approximately 12 months. We hypothesize that complex ecological cascades associated with excess moisture caused short-term declines in abundances of species and associated changes in community structure. If additional stressors such as disease or habitat loss are not co-occurring, frog communities can rapidly recover to pre-disturbance levels following severe climatic events.

A New Species of Phenacosaur Anolis (Squamata; Iguanidae) from Peru and a Comprehensive Phylogeny of Dactyloa-clade Anolis Based on New DNA Sequences and Morphology

We describe a new species of Anolis from the Andes of northern Peru. This form is similar to species formerly assigned to the genus Phenacosaurus and to Ernest Williams’ tigrinus series. That is, the new species possesses large smooth headscales, cryptic coloration, and short limbs and tail. We present new DNA and morphological data and perform a comprehensive phylogenetic analysis of the Dactyloa clade of Anolis. The new species is estimated to be close to phenotypically similar species from Peru and Venezuela. We revise the taxonomy of Dactyloa based on our estimate. Most previously recognized phylogenetically defined groups are retained with restricted species contents. Several species currently scorable only for morphological data could not be placed in any group with confidence. The species status of the enigmatic mainland form Anolis deltae should be re-examined with reference to the roquet group of southern Lesser Antillean Anolis.

Comparative Evolution of an Archetypal Adaptive Radiation: Innovation and Opportunity in Anolis Lizards

Adaptive radiation is a widely recognized pattern of evolution wherein substantial phenotypic change accompanies rapid speciation. Adaptive radiation may be triggered by environmental opportunities resulting from dispersal to new areas or via the evolution of traits, called key innovations, that allow for invasion of new niches. Species sampling is a known source of bias in many comparative analyses, yet classic adaptive radiations have not been studied comparatively with comprehensively sampled phylogenies. In this study, we use unprecedented comprehensive phylogenetic sampling of Anolis lizard species to examine comparative evolution in this well-studied adaptive radiation. We compare adaptive radiation models within Anolis and in the Anolis clade and a potential sister lineage, the Corytophanidae. We find evidence for island (i.e., opportunity) effects and no evidence for trait (i.e., key innovation) effects causing accelerated body size evolution within Anolis. However, island effects are scale dependent: when Anolis and Corytophanidae are analyzed together, no island effect is evident. We find no evidence for an island effect on speciation rate and tenuous evidence for greater speciation rate due to trait effects. These results suggest the need for precision in treatments of classic adaptive radiations such as Anolis and further refinement of the concept of adaptive radiation.

Empirical test of the native–nonnative distinction: Native and nonnative assemblages of Anolis lizards are similar in morphology and phylogeny

Nonnative (“invasive,” “exotic,” “naturalized”) species frequently are vilified. However, some philosophers and ecologists have questioned whether nonnative species and assemblages are objectively, ahistorically identifiable as different entities relative to native species and assemblages, once selection biases are taken into account. We used an unprecedented dataset of morphology, phylogeny and assemblage content for 336 species of Anolis lizard to compare morphological and phylogenetic characteristics of variability and central tendency between native assemblages and those that include nonnative species. Equivalence tests demonstrated significant similarity between native and nonnative assemblages in trait variability, phylogenetic dispersion and mean trait values except for body size; logistic and zero‐inflated regression failed to distinguish native and nonnative assemblages. For most traits, similarity was not due to assemblages being structured randomly but rather to both native and nonnative assemblages including similar species. Without historical information, a naive observer would be unable to identify Anolis assemblages as native or nonnative based on morphological assemblage structure or most mean assemblage trait values, but would have some success categorizing assemblages based on average body size of species in the assemblage. Significant phylogenetic and morphological clustering in native assemblages likely reflects source pools composed of close relatives that share traits, as well as some environmental filtering effects; the slightly less phylogenetically clustered but equally morphologically clustered nonnative assemblages are less constrained to proximal source pools but still probably subject to filtering. Differences between native and nonnative assemblages in mean body size likely reflect assemblage youth. The ontological status of nonnative species is discussed in the light of these results. A plain language summary is available for this article.