No abstract

We investigated the thermal biology of the lizard Sceloporus merriami in a hot, arid locality in west Texas. The effects of the thermal environment on lizard activity were hypothesized to be extensive because S. merriami body temperatures average lower than the body temperatures of any other North American desert iguanid (32.2°C). To test this hypothesis, we compared lizard thermal microclimate use and rates of lizard movements, feeding, and social displays with estimates of the relative availability of thermal microclimates near 32.2°. These comparisons were made throughout the lizards' morning activity period. The thermal environment had a major impact on S. merriami and restricted individual activities (movement rates, feeding strikes, and social displays) to a 2—h period beginning around local sunrise (1000) and to a brief period in late afternoon. In the morning, rates of activities were maximal within 1 h after local sunrise. This activity maximum coincided with the time that the average available environmental temperature approximated the mean body temperature for S. merriami. Also at this time, lizards occupied thermal microclimates randomly with respect to microclimate availability on their home ranges, whereas when activity rates were lower, lizard microclimate use was a nonrandom. Thus, when thermally favorable microclimates were most available, lizard activity was least constrained. S. merriami timed the initiation, peak, and cessation of overall and microclimate—specific activity to coincide with the overall and microclimate—specific availability of favorable operative temperatures.

Background With data becoming a centerpiece of modern scientific discovery, data sharing by scientists is now a crucial element of scientific progress. This article aims to provide an in-depth examination of the practices and perceptions of data management, including data storage, data sharing, and data use and reuse by scientists around the world. Methods The Usability and Assessment Working Group of DataONE, an NSF-funded environmental cyberinfrastructure project, distributed a survey to a multinational and multidisciplinary sample of scientific researchers in a two-waves approach in 2017-2018. We focused our analysis on examining the differences across age groups, sub-disciplines of science, and sectors of employment. Findings Most respondents displayed what we describe as high and mediocre risk data practices by storing their data on their personal computer, departmental servers or USB drives. Respondents appeared to be satisfied with short-term storage solutions; however, only half of them are satisfied with available mechanisms for storing data beyond the life of the process. Data sharing and data reuse were viewed positively: over 85% of respondents admitted they would be willing to share their data with others and said they would use data collected by others if it could be easily accessed. A vast majority of respondents felt that the lack of access to data generated by other researchers or institutions was a major impediment to progress in science at large, yet only about a half thought that it restricted their own ability to

The value of sharing scientific research data is widely appreciated, but factors that hinder or prompt the reuse of data remain poorly understood. Using the Theory of Reasoned Action, we test the relationship between the beliefs and attitudes of scientists towards data reuse, and their self-reported data reuse behaviour. To do so, we used existing responses to selected questions from a worldwide survey of scientists developed and administered by the DataONE Usability and Assessment Working Group (thus practicing data reuse ourselves). Results show that the perceived efficacy and efficiency of data reuse are strong predictors of reuse behaviour, and that the perceived importance of data reuse corresponds to greater reuse. Expressed lack of trust in existing data and perceived norms against data reuse were not found to be major impediments for reuse contrary to our expectations. We found that reported use of models and remotely-sensed data was associated with greater reuse. The results suggest that data reuse would be encouraged and normalized by demonstration of its value. We offer some theoretical and practical suggestions that could help to legitimize investment and policies in favor of data sharing.

We examine environmental constraints on life history characters among three elevationally distinct populations of the desert lizard Sceloporus merriami in west Texas. We show how environmental gradients in temperature and food abundance interact to constrain body temperatures, daily activity times, growth rates, and age—specific body size. We suggest that these differences resulted in opposite responses from the males and females with respect to their size and age at first reproduction. The highest elevation site, Maple Canyon (1609 m), has more rainfall, higher food availability, and cooler temperatures compared with the lower elevation sites, Grapevine (1036 m) and Boquillas (560 m). Lizards were active throughout the day at Maple Canyon, but were restricted to midday inactivity at the lower sites. Body temperatures (Tb) were higher during inactivity and late—afternoon activity at the lower sites. We suggest that low food availability, fewer hours to forage, and higher Tb constrained the energy budgets of lizards at Boquillas. Consequently, these lizards had low activity rates and low daily growth rates. Paradoxically, lizards at Maple Canyon, the most food—rich site, also exhibited low daily growth rates. This may have resulted from higher daily activity expenditures (longer activity period) and lower food processing rate (low inactive (Tb). Grapevine lizards had the highest individual activity and growth rates. On a seasonal basis, the pattern of activity time was reversed, and Maple Canyon lizards had a shorter annual activity by °1 mo compared with Grapevine and 2 mo compared with Boquillas. Despite low growth rates at Boquillas, a 2—mo longer activity season proximally resulted in the largest yearlings by May–June. Maple Canyon yearlings grew at a similar rate, but over a shorter time period and were the smallest. At Grapevine, high summer growth rates resulted in large yearlings by late summer and largest adults, whereas low summer growth rates at Boquillas and Maple Canyon led to smaller adults. The resulting difference in body size between yearling and older age classes was great at Maple Canyon and at Grapevine, which forced yearling males to delay reproduction until they had grown to a size to compete successfully for breeding territories. However, Boquillas yearlings and age >1 yr lizards were much more similar in size, and many yearlings were able to acquire breeding territories. This suggest that male age of first reproduction was lowest at the low evaluation site. In contrast, more yearling females reproduced earlier at the highest elevation site than at other sites. At Grapevine and Boquillas, females similar in size to breeding females at Maple Canyon did not breed in May–June and instead grew and were reproductively active in July–August. We hypothesize that the brief growing season at Maple Canyon may have constrained females to breed early to allow sufficient time for themselves, as well as for their offspring, to amass winter stores. Also, this would increase the likelihood that their offspri...