Thomas Akre

• Smithsonian Institution

Protected areas (PAs) are the primary strategy for slowing terrestrial biodiversity loss. Although expansion of PA coverage is prioritized under the Convention on Biological Diversity, it remains unknown whether PAs mitigate declines across the tetrapod tree of life and to what extent land cover and climate change modify PA effectiveness1,2. Here w...

Yucatán Box Turtles (Terrapene yucatana) are the only fully tropical lineage of box turtles (Terrapene spp.). We studied the ecology, movements, behavior, and habitat associations of T. yucatana in northern Yucatán, México, over 218 field days from 2014–2019. We estimated the size of two subpopulations to comprise 36.6 and 3.0 turtles, with corresp...

Conservation interventions are central strategies for achieving sustainable development goals given the inextricable dependence of humanity on nature. Current debate centres on whether interventions such as marine protected areas (MPAs) promote co-benefits or trade-offs among multiple goals such as poverty alleviation, food security and protection...

Landscape context is integral to population ecology, affecting a range of life history parameters, yet very little is known about how landscape structure influences many taxa. We sampled wetlands at 531 sites across 16 states in the eastern U.S. to examine the influence of landscape heterogeneity and anthropogenic land use on the relative abundance...

Abstract Land use is one of the largest threats to biodiversity, ecosystem function, and ecosystem services. These losses can be mitigated through strategic land use planning efforts that balance the social, economic, and environmental needs of society and the ecosystems that support it. A crucial component in the development of strategic plans is...

As a leading cause of forest health degradation, non‐native invasive plant species are a key focus for many forest management and conservation efforts. These efforts come at a high price for resource‐limited agencies and organizations making cost‐effectiveness an important objective of invasion response plans. In this paper, we present an approach...

La biodiversidad de los entornos terrestres y marinos viene experimentando un declive vertiginoso en todo el mundo. Por lo tanto, se necesitan acciones de conservación en todas partes del planeta, incluyendo aquellos paisajes terrestres y marinos ricos en biodiversidad y donde las personas viven y trabajan. Los enfoques integradores para la conserv...

Climate change and land-use change are leading drivers of biodiversity decline, affecting demographic parameters that are important for population persistence. For example, scientists have speculated for decades that climate change may skew adult sex ratios in taxa that express temperature-dependent sex determination (TSD), but limited evidence exi...

Quantifying animal movements is necessary for answering a wide array of research questions in ecology and conservation biology. Consequently, ecologists have made considerable efforts to identify the best way to estimate an animal’s home range, and many methods of estimating home ranges have arisen over the past half century. Most of these methods...

Biodiversity is in precipitous decline globally across both terrestrial and marine environments. Therefore, conservation actions are needed everywhere on Earth, including in the biodiversity rich landscapes and seascapes where people live and work that cover much of the planet. Integrative landscape and seascape approaches to conservation fill this...

The United Nations Sustainable Development Goals (SDGs) provide a global blueprint to end extreme poverty, reduce inequality, and protect the planet. Progress toward these goals is falling short. Achieving the SDGs requires coordination among government, private industry, and nongovernmental organizations to align the actions of multiple sectors wi...

Population projection models are important tools for conservation and management. They are often used for population status assessments, for threat analyses, and to predict the consequences of conservation actions. Although conservation decisions should be informed by science, critical decisions are often made with very little information to suppor...

Turtles are among the most threatened vertebrate groups, and reconstruction of population and distributional trends can be important for evaluating their status and defining conservation targets. Using a two-phase modeling approach along with occurrence records and field surveys, our objectives were to: estimate the potential and current distributi...

Future climate projections of warming, drying, and increased weather variability indicate that conventional agricultural and production practices within the Northern Great Plains (NGP) will become less sustainable, both ecologically and economically. As a result, the livelihoods of people that rely on these lands will be adversely impacted. This is...

Freshwater turtles and tortoises are declining worldwide and currently represent one of the most imperiled major vertebrate groups. Identifying the conditions that promote long-term viable populations is a critical conservation need. However, for most species, there is relatively little or no empirical information about the factors influencing popu...

While the impact of land use/land cover (LULC) change on watersheds has been extensively studied, little attention has been given to the variability of this impact with respect to the projected LULC scenarios at a range of spatial scales. Here, a spatial LULC change model was coupled with the Chesapeake Bay Watershed Model to investigate LULC chang...

This case study describes the application of a framework for developing stakeholder-driven scenarios of the future. The purpose of these scenarios is to inform land use planning toward the protection of ecosystems and derivable ecosystem services in Northwestern Virginia. We held two scenario development workshops with regional experts in conservat...

Background: Speed and distance traveled provide quantifiable links between behavior and energetics, and are among the metrics most routinely estimated from animal tracking data. Researchers typically sum over the straight-line displacements (SLDs) between sampled locations to quantify distance traveled, while speed is estimated by dividing these di...

Finding balance between the needs of people and wildlife is an essential component of planning sustainable landscapes. Because mammals make up a diverse and ecologically important taxon with varying responses to human disturbance, we used representative mammal species to examine how alternative land-use policies might affect their habitats and dist...

Birds that depend on grassland and successional‐scrub vegetation communities are experiencing a greater decline than any other avian assemblage in North America. Habitat loss and degradation on breeding and wintering grounds are among the leading causes of these declines. We used public and private lands in northern Virginia, USA, to explore benefi...

Environmental DNA (eDNA) has been used to record the presence of many different organisms in several different aquatic and terrestrial environments. Although eDNA has been demonstrated as a useful tool for the detection of invasive and/or cryptic and declining species, this approach is subject to the same considerations that limit the interpretatio...

Protected lands are an established method for conserving biodiversity and ecosystem services. Moreover, agencies and organizations are increasingly looking to private lands as places for new protected lands establishment. However, the effectiveness of protected lands in guarding against the loss of species or services can vary based on their covera...

We coupled a spatially-explicit land use/land cover (LULC) change model, Dinamica EGO, (Environment for Geoprocessing Objects), with the Chesapeake Bay Watershed Model (CBWM) to project the impact of future LULC change on loading of total nitrogen (TN), total phosphorous (TP) and total suspended solids (TSS) as well as runoff volume in the watershe...

Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autoc...

Creaser's Mud Turtle (Kinosternon creaseri Hartweg, 1934) is a kinosternid turtle that is widely distributed across the three states of the Yucatán Peninsula in southeastern México. Although its distribution and habitat associations have been established for nearly three decades (Iverson 1988), primarily anecdotal data are available on local popula...

Ecological, historical, and evolutionary hypotheses are important to explain geographical diversity gradients in many clades, but few studies have combined them into a single analysis allowing a comparison of their relative importance. This study aimed to evaluate the relative importance of ecological, historical, and evolutionary hypotheses in exp...

We studied bullsnakes (Pituophis catenifer sayi) in the Sandhills of Nebraska. Females matured at ca. 90-cm snout–vent length after two seasons (ca. 33 months old), ovulated in early June, and oviposited in mid-June–early July. Frequently, females did not reproduce each year. The proportion reproducing was a function of size of body and warmth of p...

There are currently ca. 317 recognized species of turtles and tortoises in the world. Of those that have been assessed on the IUCN Red List, 63% are considered threatened, and 10% are critically endangered, with ca. 42% of all known turtle species threatened. Without directed strategic conservation planning, a significant portion of turtle diversit...

Body size and growth in Bullsnakes (Pituophis catenifer sayi) in the western Nebraska Sandhills were studied from 1987 to 1999. Body size of females was not significantly different from that of males, although the largest individuals were males. Based on eggs hatched in captivity, and size class and recapture data in the field, Nebraska Bullsnakes...

A major focus of geographical ecology and macroecology is to understand the causes of spatially structured ecological patterns. However, achieving this understanding can be complicated when using multiple regression, because the relative importance of explanatory variables, as measured by regression coefficients, can shift depending on whether spat...

Turtle populations are decreasing dramatically due to habitat loss and collection for the food and pet market. This study sought to determine hematologic values in two species of turtles to help assess health status of captive and wild populations. Blood samples were collected from 12 individuals of the Pascagoula map turtle (Graptemys gibbonsi) an...

Based on a thorough review of the literature, we provide a bibliography of papers featuring phylogenetic hypotheses for living turtles, a composite tree of all turtle species based on those hypotheses, a compilation of the most rigorously derived trees from those papers (i.e., using contemporary methods with bootstrapping), and supertrees for selec...