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Investigates what would happen if we decide to do nothing about protecting endangered species.

Background During the growth of complex multicellular organisms, chronological age, size and morphology change together in a hierarchical and coordinated pattern. Among extinct species, the growth of Tyrannosaurus rex has received repeated attention through quantitative analyses of relative maturity and chronological age. Its growth series shows an extreme transformation from shallow skulls in juveniles to deep skulls in adults along with a reduction in tooth count, and its growth curve shows that T. rex had a high growth rate in contrast to its closest relatives. However, separately, these sets of data provide an incomplete picture of the congruence between age, size, and relative maturity in this exemplar species. The goal of this work is to analyze these data sets together using cladistic analysis to produce a single hypothesis of growth that includes all of the relevant data. Methods The three axes of growth were analyzed together using cladistic analysis, based on a data set of 1,850 morphological characters and 44 specimens. The analysis was run in TNT v.1.5 under a New Technology search followed by a Traditional search. Correlation tests were run in IBM SPSS Statistics v. 24.0.0.0. Results An initial analysis that included all of the specimens recovered 50 multiple most parsimonious ontograms a series of analyses identified 13 wildcard specimens. An analysis run without the wildcard specimens recovered a single most parsimonious tree (i.e., ontogram) of 3,053 steps. The ontogram is composed of 21 growth stages, and all but the first and third are supported by unambiguously optimized synontomorphies. T. rex ontogeny can be divided into five discrete growth categories that are diagnosed by chronological age, morphology, and, in part, size (uninformative among adults). The topology shows that the transition from shallow to deep skull shape occurred between 13 and 15 years of age, and the size of the immediate relatives of T. rex was exceeded between its 15th and 18th years. Although size and maturity are congruent among juveniles and subadults, congruence is not seen among adults; for example, one of the least mature adults (RSM 2523.8) is also the largest and most massive example of the species. The extreme number of changes at the transition between juveniles and subadults shows that the ontogeny of T. rex exhibits secondary metamorphosis, analogous to the abrupt ontogenetic changes that are seen at sexual maturity among teleosts. These results provide a point of comparison for testing the congruence between maturity and chronological age, size, and mass, as well as integrating previous work on functional morphology into a rigorous ontogenetic framework. Comparison of the growth series of T. rex with those of outgroup taxa clarifies the ontogenetic trends that were inherited from the common ancestor of Archosauriformes.

Examines endangered species, how human activities have contributed to shrinking numbers, and what is being done to protect animals for the future.

The extinct Laysan Rail or Crake (Zapornia palmeri) was a small, flightless rail endemic to Laysan Island in the northwestern chain of the Hawaiian Archipelago. I detail the collections made, including eggs, nests, juveniles, and numerous adults prior to its extinction. The juvenile plumage was seemingly well documented, but my study of a series of juvenile specimens collected in 1891 and 1896 provides hitherto undescribed molt changes, from downy chick to definitive plumage. Morphometric data show that sexual size dimorphism is present with males being slightly more robust in bill, legs, and feet. I provide a detailed review of the literature showing the chronology of events that led to the extinction of the species and how this easily could have been avoided.

From the giant panda of China to Fiji's banded iguana, creatures all over the world are imperiled like never before in human history. Visit all inhabited continents via a series of striking graphic stamps by printmaker Tom Frost, depicting more than thirty species -- some familiar, some you may not have known existed -- all of which are in danger of not existing for much longer. Fact files from conservation biologist Martin Jenkins introduce readers to some of the threatened fauna around the globe. A timely call to arms for animal lovers young and old, this oversize nonfiction book discusses the reasons that so many species are in danger of dying out and what we can do to help them.

Background Amphibians are one of the most susceptible groups to climate change as their development occurs in aquatic environments or in microhabitats with high humidity. Accordingly, our primary objective was to investigate the chronic physiological responses seen in early larval to adult stages of Polypedates cruciger (Common hourglass tree frog) to future climate change based on continuous exposure to elevated temperature and elevated CO 2 -induced low water pH. Free-swimming and free-feeding tadpoles were observed until metamorphosis under four experimental treatments; two elevated temperatures, one elevated CO 2 (reduced pH) and a control maintained at ambient temperature (29 °C ± 1 °C) and CO 2 (pH = 7). Elevated temperature treatments were maintained at 32 °C ± 0.5 °C and 34 °C ± 0.5 °C to represent respectively, the future climate scenarios RCP2.6 (Representative Concentration Pathway 2.6, the ‘base-case’ scenario) and RCP8.5 (‘business-as-usual’ scenario) according to the 5 th Assessment Report of the IPCC. Elevated CO 2 treatment was maintained within the pH range of 5.5–5.6 representing the range expected between RCP8.5 and RCP2.6. Results Compared to the control, elevated CO 2 accelerated phenological progression of tadpoles through Gosner stages, thus resulting in lower body size at metamorphosis. Both elevated temperatures significantly delayed the development and reduced the growth of tadpoles. 100% mortality was observed in 34 °C treatment before metamorphosis (before Gosner stage 36) while all the tadpoles died after metamorphosis (at Gosner stage 46) in 32 °C treatment. Elevated CO 2 increased tadpole activity, in terms of their swimming speed, while both of the elevated temperatures reduced it compared to the control. Catalase activity increased at elevated CO 2 . Ammonia excretion by tadpoles was decreased by elevated CO 2 , but increased under temperature elevation. Both Elevated CO 2 and temperature treatments reduced the white blood cell count and its percentage of thrombocytes. Percentages of lymphocytes, monocytes and neutrophils were increased at 32 °C, while lymphocyte percentage and lysozyme activity were increased at elevated CO 2 . Several deformities were observed in tadpoles at elevated temperature and CO 2 . Conclusions Elevated temperatures and reduced pH due to elevated CO 2 , being major features of climate change, increase the vulnerability of amphibians, who are already one of the most threatened vertebrate groups. Based on our observations on the model amphibian species P. cruciger , increased vulnerability to climate change occurs by reducing their growth, body size and motility while also reducing their immunity and inducing physical deformities. These impacts are highly-likely to reduce the foraging, competitive and reproductive capabilities in their natural habitats. We conclude further that even the ‘best-case’ scenario of future climate change can impose significant physiological impacts that could threaten amphibian populations on broader spatial and temporal scales. Graphical abstract

Readings from a variety of perspectives allows a better understanding of the issues relating to endangered species.

Ayu (Plecoglossus altivelis altivelis) is an important freshwater fisheries resource and popular recreational fishing species in Japan that lives for only 1 year, with a single breeding season. To supplement increased recreational fishing demand for this species, more than 13 million wild‐born landlocked juveniles are translocated every year from Lake Biwa into Japanese rivers, and more than 52 million hatchery‐reared juveniles born from captive‐reared parents have been extensively released. The translocation of landlocked juveniles and hatchery release has continued for more than 100 and 30 generations, respectively. Previous studies have reported that landlocked and amphidromous forms of Ayu easily hybridise, leading to concerns that the fitness of hybrid progeny would be reduced in the wild. However, limited information exists regarding the reproductive success of landlocked Ayu in translocated rivers, and to date no studies have evaluated the effects of translocation on population structure. Demonstrating that hybridisation occurs between the two forms is central to future management and conservation of this species. To address this, a literature search to summarise biological knowledge of Ayu and population genetic data screening was undertaken, and published genetic data sets covering a distribution range in Japan were reanalysed. Analyses provide strong evidence for very high gene flow between sampling locations. Genetic diversity is homogeneous in amphidromous samples. Bayesian admixture analysis infers widespread hybridisation in Japanese rivers (24 ± 8%). Maximum likelihood admixture graphs detect two migration events from Lake Biwa to rivers in the northern Sea of Japan and Hokkaido. Analyses consistently indicate that hybridisation between translocated landlocked juveniles and native amphidromous Ayu occurs throughout Japanese rivers. These results are discussed in relation to the management of this species. Huge numbers of wild‐born landlocked juveniles of a recreationally fished iconic species have been translocated from Lake Biwa into most Japanese amphidromous populations for more than 100 generations. Bayesian admixture analysis infers widespread introgression in Japanese rivers, with a mean introgression proportion of 24%, and TreemMix analysis detects two migration events from Lake Biwa to anadromous populations. Analyses of genetic population structure consistently indicate that hybridisation between translocated landlocked juveniles and native amphidromous Ayu occurs throughout Japanese rivers.

This intriguing book looks at why some animals have become endangered due to changes in their habitat and how we can help them. Examples include animals in the Arctic that rely on ice for hunting face the challenge of melting ice, the populations of animals born only on particular islands are shrinking, and many kinds of ocean animals are being poisoned by water pollution.

As more and more species fall under the threat of extinction, humans are not only taking action to protect critical habitats but are also engaging more directly with species to help mitigate their decline. Through innovative infrastructure design and by changing how we live, humans are becoming more attuned to nonhuman animals and are making efforts to live alongside them. Examining sites of loss, temporal orientations, and infrastructural mitigations, Nestwork blends rhetorical and posthuman sensibilities in service of the ecological care. In this innovative ethnographic study, rhetorician Jennifer Clary-Lemon examines human-nonhuman animal interactions, identifying forms of communication between species and within their material world. Looking in particular at nonhuman species that depend on human development for their habitat, Clary-Lemon examines the cases of the barn swallow, chimney swift, and bobolink. She studies their habitats along with the unique mitigation efforts taken by humans to maintain those habitats, including building “barn swallow gazebos” and artificial chimneys and altering farming practices to allow for nesting and breeding. What she reveals are fascinating forms of rhetoric not expressed through language but circulating between species and materials objects. Nestwork explores what are in essence nonlinguistic and decidedly nonhuman arguments within these local environments. Drawing on new materialist and Indigenous ontologies, the book helps attune our senses to the tragedy of species decline and to a new understanding of home and homemaking.