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The fish communities of the Sacramento–San Joaquin Delta and its tributaries in California’s Central Valley have been irreparably altered through introductions of numerous fish species, including Striped Bass (Morone saxatilis), black bass (Micropterus spp.), and catfishes (Ameiurus spp. and Ictalurus spp.). Research into how predation by non-native piscivores affects native anadromous species has focused on the Sacramento and San Joaquin river mainstems and Delta habitats, through which all anadromous species must pass. Yet, the ranges of non-native fishes extend into upstream tributaries. We collected diets from native and non-native piscivores in the Stanislaus River, a tributary to the San Joaquin River and a remaining stronghold for native fishes. Piscivorous fishes primarily consumed invertebrates and the native species fall-run Chinook Salmon (Oncorhynchus tshawytscha) and Pacific Lamprey (Entosphenus tridentatus). Juvenile Chinook Salmon and Pacific Lamprey were consumed at higher frequencies than any other potential fish prey species, particularly by Striped Bass and black bass. The frequency of native fishes in predator diets was similar across years, despite contrasting hydrologic conditions; 2019 (wet year), 2020 (dry year), and 2021 (critically dry year). Our results show that Pacific Lamprey were frequently consumed by native and non-native piscivores, and that juvenile Chinook Salmon experience substantial predation early in their migration, regardless of hydrologic conditions.

Steelhead (Oncorhynchus mykiss expressing an anadromous life history) in the Sacramento and San Joaquin rivers and their tributaries in California’s Central Valley (CCV) belong to a Distinct Population Segment (DPS) that is listed as threatened under the US Endangered Species Act. Although contemporary management and recovery plans include numerous planned and ongoing efforts seeking to aid in DPS recovery—such as gravel augmentation, manipulation of spring flows, and restoration of rearing and spawning habitat—a paucity of data precludes the possibility of evaluating the effect of these actions on populations of Steelhead in CCV streams. Knowledge gaps relating to historic and current abundance, population-specific ratios of resident and anadromous life-history expression, and the influence of hatchery-reared fish remain largely unaddressed. This is partly a result of aspects of Steelhead biology that make them difficult to monitor, including the multitude of factors that contribute to the expression of anadromy, polymorphic populations, and migration periods that coincide with challenging field conditions. However, these gaps in understanding are also partly the result of an institutional focus on Chinook Salmon (Oncorhynchus tshawytscha) and a pervasive notion that actions benefiting Chinook populations will also benefit Steelhead populations. To evaluate these gaps and to suggest approaches for assessing DPS recovery actions, we review available data and existing monitoring efforts, and consider the actions necessary to inform the development of targeted O. mykiss monitoring programs. Current management and recovery goals focus on abundance estimates of Steelhead only, yet current monitoring is insufficient for reliable estimates. We argue that a reallocation of monitoring resources to better understand the interaction between resident O. mykiss and Steelhead would provide better data to estimate the vital rates needed to evaluate the effects of recovery actions.

Environmental change and biodiversity loss are but two of the complex challenges facing conservation practitioners and policy makers. Relevant and robust scientific knowledge is critical for providing decision-makers with the actionable evidence needed to inform conservation decisions. In the Anthropocene, science that leads to meaningful improvements in biodiversity conservation, restoration and management is desperately needed. Conservation Physiology has emerged as a discipline that is well-positioned to identify the mechanisms underpinning population declines, predict responses to environmental change and test different in situ and ex situ conservation interventions for diverse taxa and ecosystems. Here we present a consensus list of 10 priority research themes. Within each theme we identify specific research questions (100 in total), answers to which will address conservation problems and should improve the management of biological resources. The themes frame a set of research questions related to the following: (i) adaptation and phenotypic plasticity; (ii) human-induced environmental change; (iii) human-wildlife interactions; (iv) invasive species; (v) methods, biomarkers and monitoring; (vi) policy, engagement and communication; (vii) pollution; (viii) restoration actions; (ix) threatened species; and (x) urban systems. The themes and questions will hopefully guide and inspire researchers while also helping to demonstrate to practitioners and policy makers the many ways in which physiology can help to support their decisions.

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of 'success stories' is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a 'horizon scan', we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.

Conservation and management of culturally and economically important species rely on monitoring programs to provide accurate and robust estimates of population size. Rotary screw traps (RSTs) are often used to monitor populations of anadromous fish, including fall-run Chinook Salmon (Oncorhynchus tshawytscha) in California’s Central Valley. Abundance estimates from RST data depend on estimating a trap's efficiency via mark-recapture releases. Because efficiency estimates are highly variable and influenced by many factors, abundance estimates can be highly uncertain. An additional complication is the multiple accepted methods for how to apply a limited number of trap efficiency estimates, each from discrete time-periods, to a population’s downstream migration, which can span months. Yet, few studies have evaluated these different methods, particularly with long-term monitoring programs. We used 21 years of mark-recapture data and RST catch of juvenile fall-run Chinook Salmon on the Stanislaus River, California, to investigate factors associated with trap efficiency variability across years and mark-recapture releases. We compared annual abundance estimates across five methods that differed in treatment of trap efficiency (stratified versus modeled) and statistical approach (frequentist versus Bayesian) to assess the variability of estimates across methods, and to evaluate whether method affected trends in estimated abundance. Consistent with short-term studies, we observed negative associations between estimated trap efficiency and river discharge as well as fish size. Abundance estimates were robust across all methods, frequently having overlapping confidence intervals. Abundance trends, for the number of increases and decreases from year to year, did not differ across methods. Estimated juvenile abundances were significantly related to adult escapement counts, and the relationship did not depend on estimation method. Understanding the sources of uncertainty related to abundance estimates is necessary to ensure that high-quality estimates are used in life cycle and stock-recruitment modeling.

Objective: To describe and compare prothrombin time (PT), activated partial thromboplastin time (aPTT), thromboelastography (TEG), HCT, and platelet count measurements in a hemorrhage/over‐resuscitation model. Design: Randomized crossover study. Setting: University teaching hospital. Animals: Six cats. Interventions: Anesthetized cats underwent 3 treatments at 2‐month intervals. The treatments were as follows: NHR—no controlled hemorrhage and sham resuscitation; LRS—controlled hemorrhage and lactated Ringer's solution (LRS) for resuscitation; and Voluven—controlled hemorrhage and 6% tetrastarch 130/0.4 for resuscitation. The LRS and Voluven were administered at 60 and 20 mL/kg/h, respectively, for 120 minutes. Blood samples were drawn for PT, aPTT, TEG, HCT, and platelet count measurements at a healthy check (T − 7d), after controlled hemorrhage (T0), at 60 and 120 minutes of resuscitation (T60 and T120), and at 24 hours after completion of resuscitation (T24h). Data were analyzed using a general linear mixed model approach (significance was P < 0.05). Measurements and Main Results: Total median blood loss (controlled hemorrhage and blood sampling from T0 to T120) at T120 was 11.4, 31.0, and 30.8 mL/kg for NHR, LRS, and Voluven, respectively. PT and aPTT during LRS and Voluven were prolonged at T60 and T120 compared to NHR (P < 0.001). On TEG, the reaction time, kinetic time, and alpha‐angle were within reference intervals for cats at all time points in all treatments, while maximum amplitude was less than the reference interval (40 mm) at T0, T60, and T120 during Voluven and at T60 and T120 during LRS compared to NHR (both P < 0.001). The HCT and platelet count were significantly lower at T60 and T120 during LRS and Voluven compared to NHR (P < 0.001). Conclusions: Hypocoagulopathy was observed during hemorrhage and liberal fluid resuscitation. Prolongation of PT and aPPT and decreased clot strength may have been caused by hemodilution and platelet loss. [ABSTRACT FROM AUTHOR]

This article reports on respiratory function in white rhinoceros (Ceratotherium simum) immobilized with etorphine-azaperone and the changes induced by butorphanol administration as part of a multifaceted crossover study that also investigated the effects of etorphine or etorphine-butorphanol treatments. Six male white rhinoceros underwent two immobilizations by using 1) etorphine-azaperone and 2) etorphine-azaperone-butorphanol. Starting 10 min after recumbency, arterial blood gases, limb muscle tremors, expired minute ventilation, and respiratory rate were evaluated at 5-min intervals for 25 min. Alveolar to arterial oxygen gradient, expected respiratory minute volume, oxygen consumption, and carbon dioxide production were calculated. Etorphine-azaperone administration resulted in hypoxemia and hypercapnia, with increases in alveolar to arterial oxygen gradient, oxygen consumption, and carbon dioxide production, and a decrease in expired minute ventilation. Muscle tremors were also observed. Intravenous butorphanol administration in etorphine-azaperone–immobilized white rhinoceros resulted in less hypoxemia and hypercapnia; a decrease in oxygen consumption, carbon dioxide production, and expired minute ventilation; and no change in the alveolar to arterial oxygen gradient and rate of breathing. We show that the immobilization of white rhinoceros with etorphine-azaperone results in hypoxemia and hypercapnia and that the subsequent intravenous administration of butorphanol improves both arterial blood oxygen and carbon dioxide partial pressures. [ABSTRACT FROM AUTHOR]

The Husab Sand Lizard (Pedioplanis husabensis Berger-Dell'Mour and Mayer, 1989) is a recently described lacertid lizard endemic to a small region in the central Namib Desert. Although this species is of conservation concern, very little is known about how this lizard functions in its environment. We used the doubly labeled water method to measure the field energetics in this lizard species and we report on its foraging behavior. Pedioplanis husabensis had summer field metabolic rates (330 ± 140 J x [d.sup.-1]) that were similar to those of other similarly sized sit-and-wait foraging lizards (360 J x [d.sup.-1]), but only 43% that of an active foraging lizard of the same mass (770 J x [d.sup.-1]), despite using a movement-intensive, active foraging strategy. Additionally, the mean water influx rate (0.06 ± 0.03 mL x [d.sup.-1]) was 67% that of a desert reptile of the same size (0.09 mL x [d.sup.- 1]). Active body temperatures were significantly lower in summer (34.3 ± 1.7°C) than they were in autumn (36.8 ± 1.6°C), and daily activity of lizards increased from 2.6 ± 0.9 h x [d.sup.-1] in summer to 4.3 [+ or -] 1.9 h x [d.sup.-1] in autumn. Relative to other species of actively foraging desert lizards, P. husabensis has lower energy requirements. Key words: Pedioplanis husabensis, Husab Sand Lizard, Namib Desert, field metabolic rate, doubly labeled water. Le lezard Pedioplanis husabensis Berger-Dell'Mour et Mayer, 1989, est un lezard lacertide recemment decrit du centre du desert du Namib. Si l'espece est preoccupante sur le plan de la conservation, on en sait tres peu sur la maniere dont ce lezard fonctionne dans son milieu. Nous avons utilise la methode de l'eau doublement marquee pour mesurer l'energetique de cette espece de lezard sur le terrain et nous faisons etat d'observations sur son comportement d'alimentation. Meme s'ils utilisent une strategie d'alimentation tres active, les P. husabensis presentaient des taux metaboliques estivaux sur le terrain (330 [+ or -] 140 J x [j.sup.-1]) semblables a ceux d'autres lezards de taille semblable employant une approche d'attente aux aguets pour s'alimenter (360 J x [j.sup.-1]), mais correspondant a seulement 43 % du taux d'un lezard a quete de nourriture active de meme masse (770 J x [j.sup.- 1]). En outre, le taux d'apport d'eau moyen (0,06 ± 0,03 mL x [j.sup.-1]) equivalait a 67 % de celui d'un reptile de milieu desertique de meme taille (0,09 mL x [j.sup.-1]). Les temperatures corporelles en action etaient significativement plus faibles en ete (34,3 [+ or -] 1,7°C) qu'en automne (36,8 ± 1,6°C) et l'activite quotidienne des lezards augmentait de 2,6 ± 0,9 h x [j.sup.-1] l'ete a 4,3 ± 1,9 h x [j.sup.-1] l'automne. Comparativement a d'autres especes de lezards de milieu desertique a quete de nourriture active, P. husabensis a des besoins en energie plus faibles. [Traduit par la Redaction] Mots-cles: Pedioplanis husabensis, desert du Namib, taux metabolique sur le terrain, eau doublement marquee., Introduction Some carnivorous lizard species are sit-and-wait foragers, which expend relatively small amounts of energy during the course of ambushing prey. Others species are active foragers that expend more energy [...]