Contributors: Dundee, Harold A.
Contributors: Dundee, Harold A.
Contributors: Grant, John A., Purdy, Sharon A.
... The occurrence of past habitable conditions in Gale crater is generally associated with lacustrine and alluvial environments present >3 Ga ago, during the Hesperian Period on Mars. However, later-occurring aqueous activity is consistent with superposition relations between some alluvial deposits and bounding materials on the crater walls, preservation of fine-scale morphology on these alluvial deposits, and their superposing crater densities. The alluvial deposits include some not previously considered, and collectively lend confidence to the interpretation that local aqueous activity persisted in Gale crater into the Amazonian, or <2 Ga ago. Our conclusions are generally in accordance with late aqueous activity inferred from geochronology data (Martin et al., 2017), in addition to late alluvial activity elsewhere. Interpreted late aqueous activity points to possible habitable settings in Gale later than previously recognized.
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Contributors: Brandl, Simon J., Tornabene, Luke, Goatley, Christopher H. R., Casey, Jordan M., Morais, Renato A., Côté, Isabelle M., Baldwin, Carole C., Parravicini, Valeriano, Schiettekatte, Nina M. D., Bellwood, David R.
... How coral reefs survive as oases of life in low-productivity oceans has puzzled scientists for centuries. The answer may lie in internal nutrient cycling and/or input from the pelagic zone. Integrating meta-analysis, field data, and population modelling, we show that the ocean's smallest vertebrates, cryptobenthic reef fishes, promote internal reef-fish biomass production through exceptional larval supply from the pelagic environment. Specifically, cryptobenthics account for two-thirds of reef-fish larvae in the near-reef pelagic zone, despite limited adult reproductive outputs. This overwhelming abundance of cryptobenthic larvae fuels reef trophodynamics via rapid growth and extreme mortality, producing almost 60% of consumed reef fish biomass. While cryptobenthics are commonly overlooked, their unique demographic dynamics may make them a cornerstone of ecosystem functioning on modern coral reefs.
Transcriptome profiling with focus on potential key genes for wing development and evolution in Megaloprepus caerulatus, the damselfly species with the world's largest wings
Contributors: Feindt, Wiebke, Oppenheim, Sara J., DeSalle, Robert, Goldstein, Paul Z., Hadrys, Heike
Lithostratigraphy, biostratigraphy and sedimentology of the Upper Paleozoic Sangre De Cristo Formation, southwestern San Miguel County, New Mexico
Contributors: Lucas, Spencer G., Krainer, Karl, Dimichele, William A., Voigt, Sebastian, Berman, David S., Henrici, Amy C., Tanner, Lawrence H., Chaney, Dan S., Elrick, Scott D., Nelson, W. John
Increasing conservation translocation success by building social functionality in released populations
Contributors: Goldenberg, Shifra Z., Owen, Megan A., Brown, Janine L., Wittemyer, George, Oo, Zaw Min, Leimgruber, Peter
... The importance of animal behavior to successful wildlife translocations has been acknowledged in recent decades, and it has been increasingly considered and more frequently incorporated into translocation management and research. However, explicit consideration of social behavior is often overlooked in this context. Social relationships take a variety of forms (e.g., cooperative partners, members of a dominance hierarchy, territorial neighbors) and play important roles in survival, reproduction, and resource exploitation. We review the ways in which concepts from studies of social behavior in wild populations may be leveraged to increase translocation success. Social structure and cohesion, social roles, social learning, and social competency may all be important to consider in building populations that are resilient and likely to persist. We argue that relevant data collected at all stages of translocation, including candidate selection, and during pre-release, release, and post-release monitoring, may inform the establishment of functional social structure post-release in species dependent on social processes. Integrating knowledge of social behavior into management decisions may be particularly useful when comparing the success of alternative release protocols or release candidate behavioral traits. Complementary datasets on a range of fitness-related metrics post-release will further leverage our understanding of social establishment in translocated populations. We illustrate the potential of these ideas using Asian and African elephants as a model. Both species are particularly challenging to manage but are translocated frequently; thus, evidence-based protocols for conservation translocations of elephants are urgently needed. (C) 2019 The Authors. Published by Elsevier B.V.
Demographic Tipping Points as Early Indicators of Vulnerability for Slow-Breeding Megafaunal Populations
Contributors: de Silva, Shermin, Leimgruber, Peter
... Decisions based on trends in population abundance and distribution may fail to protect populations of slow-breeding, long-lived megafauna from irrevocable decline if they ignore demographic constraints. For such taxa, we urge that effort be directed at understanding the interactions among vital rates governing population growth rates, rather than on predicting probabilities of extinction. The proximity of a population to demographic tipping points, i.e., where growth rate switches from positive to negative, can signal vulnerability to perturbation long before numbers drop below a point of no return. We define the "demographic safe space" as the combination of key vital rates that support a non-negative growth rate and illustrate this approach for Asian elephants. Through simulations, we find that even with optimal reproduction, Asian elephant populations cannot tolerate annual female mortality rates exceeding 7.5%. If adult mortality is very low (3%/year), populations can tolerate high annual mortality in calves below age 3 (up to 31.5%/year), or slow female reproduction (primiparity at 30 years or average inter-birth interval of up to 7.68 years). We then evaluate the potential impact of current threats, showing that near-optimal reproduction and high calf survival is necessary to offset even modestly increased mortality among adult female age classes. We suggest that rather than rely on simple counts or "viability" assessments, conservation planners for slow-breeding megafauna should consider demographic tipping points and strive to keep populations within their safe spaces.
The Gateways Project 2018: Surveys in Groswater Bay and Excavations at Hart Chalet, Grand Isle, and Grand Plain
Contributors: Fitzhugh, William W., Fitzhugh, William W.
... This monograph reports archaeological surveys and excavations in Hamilton Inlet and Groswater Bay, Labrador that expand information on the prehistory and recent Innu, Inuit, and settler cultures. Results from the Quebec Lower North Shore include knowledge of 17-18th century Inuit and their interactions with Europeans, including the first evidence of Inuit occupation of the St. Paul River region.
Contributors: Frazier, J.
... The Aldabran giant tortoise is one of the few testudines that feeds in dense herds, and in so doing the animals frequently exhibit a conspicuous orientation away from the sun. This orientation is most marked when ambient temperature is high, and it breaks down when the tortoises are shielded from direct sunlight. It was previously hypothesized that negative heliotaxis is related to thermoregulation-to reduce heat inflow to the exposed anterior appendages and instead expose the protected posterior of the shell. There has been no test of the thermoregulatory function, and pilot experiments indicate that orientation away form the sun occurs to reduce direct glare into the tortoise's eyes. The glare of the sun seems to interfere with accurately oriented biting movements and reduce feeding efficiency. Speed and intensity of reaction to solar glare is inversely related to the animal's body size. The possibility of a thermoregulatory component to the away-from-the-sun orientation cannot be discounted, but it must be investigated directly.