Modeling the effects of El Niño, density-dependence, and disturbance on harbor seal (Phoca vitulina) counts in Drakes Estero, California: 1997–2007

Harbor seal ( Phoca vitulina ) haul-out site use may be affected by natural or anthropogenic factors. Here, we use an 11-yr (1997–2007) study of a seal colony located near a mariculture operation in Drakes Estero, California, to test for natural (El Niño-Southern Oscillation (ENSO), density-dependence, long-term trends) and anthropogenic (disturbance or displacement related to oyster production activities) factors that may influence the use of haul-out subsites. Annual mariculture related seal disturbance rates increased significantly with increases in oyster harvest ( r _s= 0.55). Using generalized linear models (GLMs) ranked by best fit and Akaike's Information Criteria, ENSO and oyster production (as a proxy for disturbance/displacement) best explained the patterns of seal use at all three subsites near the mariculture operations, with effects being stronger at the two subsites closest to operations. Conversely, density-dependence and linear trend effects poorly explained the counts at these subsites. We conclude that a combination of ENSO and mariculture activities best explain the patterns of seal haul-out use during the breeding/pupping season at the seal haul-out sites closest to oyster activities.     

Climate change and amphibian declines: is there a link?

Abstract. Global climates have been changing, sometimes rapidly and dramatically, throughout the evolutionary history of amphibians. Therefore, existing amphibian species have been derived from those that have survived major climatic disturbances. Although recent global climate change has resulted in warming in many regions, temperatures in some areas to date have not changed measurably, or have even cooled. Declines of some amphibian populations have been correlated with climate events, but demonstrations of direct causal relationships need further research. Data are available indicating some indirect effect of climate change on the initiation of breeding activities of some amphibians that occur earlier than in previous springs, but the costs and benefits of these changes are just beginning to be investigated. Climate may also play an indirect role in facilitating epidemics of infectious disease. Regardless of the role that climate changes may have played in past and current amphibian declines, future shifts in climate, should they prove as dramatic as predicted, will certainly pose challenges for surviving amphibian populations and for successful recovery efforts of species that have suffered declines.     

Long‐term change within a Neotropical forest: assessing differential functional and floristic responses to disturbance and drought

Disentangling the relative roles of biotic and abiotic forces influencing forest structure, function, and local community composition continues to be an important goal in ecology. Here, utilizing two forest surveys 20‐year apart from a Central American dry tropical forest, we assess the relative role of past disturbance and local climatic change in the form of increased drought in driving forest dynamics. We observe: (i) a net decrease in the number of trees; (ii) a decrease in total forest biomass by 7.7 Mg ha^?1 but when calculated on subquadrat basis the biomass per unit area did not change indicating scale sensitivity of forest biomass measures; (iii) that the decrease in the number of stems occurred mainly in the smallest sizes, and in more moist and evergreen habitats; (iv) that there has been an increase in the proportion of trees that are deciduous, compound leaved and are canopy species, and a concomitant reduction in trees that are evergreen, simple‐leaved, and understory species. These changes are opposite to predictions based on recovery from disturbance, and have resulted in (v) a uniform multivariate shift from a more mesic to a more xeric forest. Together, our results show that over relatively short time scales, community composition and the functional dominance may be more responsive to climate change than recovery to past disturbances. Our findings point to the importance of assessing proportional changes in forest composition and not just changes in absolute numbers. Our findings are also consistent with the hypothesis that tropical tree species exhibit differential sensitivity to changes in precipitation. Predicted future decreases in rainfall may result in quick differential shifts in forest function, physiognomy, and species composition. Quantifying proportional functional composition offers a basis for a predictive framework for how the structure, and diversity of tropical forests will respond to global change.     

Geolocators reveal migratory connectivity between wintering and breeding areas of Golden‐winged Warblers

The conservation of migratory songbirds is often impeded by a lack of understanding of how populations in breeding and wintering areas are geographically linked (migratory connectivity). In recent years, light‐level geolocators have improved our understanding of migratory connectivity. Such information is valuable for evaluating how conservation efforts align between the breeding and non‐breeding areas of at‐risk species, and help to more effectively prioritize the allocation of conservation funding. Golden‐winged Warblers (Vermivora chrysoptera) are imperiled migratory songbirds, but the extent to which conservation efforts in their breeding and non‐breeding areas coincide with patterns of migratory connectivity are not well known. We used light‐level geolocators to evaluate the extent to which conservation actions targeting Golden‐winged Warblers in Nicaragua and in their breeding range in North America align with patterns of migratory connectivity. We recovered six of 22 geolocators that had been deployed on male Golden‐winged Warblers at the El Jaguar Reserve during the winter of 2015–2016. All six males migrated to breeding areas in the western Great Lakes region that includes eastern Minnesota, northern Wisconsin, southwestern Ontario, and Michigan's Upper Peninsula. All six males also had similar migration routes, with spring stopovers in southern Mexico, Guatemala, and Belize, a trans‐Gulf flight, and a stopover in the region of Louisiana, Arkansas, eastern Oklahoma, and Texas. Our results, in combination with those of previous studies, demonstrate strong migratory connectivity between portions of the breeding and winter distributions of Golden‐winged Warblers currently targeted for conservation. However, additional studies are needed to improve our understanding of the stopover ecology of Golden‐winged Warblers, especially in areas where they remain for extended periods of time. Finally, patterns of migratory connectivity revealed in our study should be used in combination with existing demographic parameters for Golden‐winged Warblers in the western Great Lakes and Nicaragua to help inform full life cycle population models for this imperiled songbird.     

Early onset of cabergoline therapy for prophylaxis from ovarian hyperstimulation syndrome (OHSS): A potentially safer and more effective protocol

Vascular endothelial growth factor (VEGF) is the most important angiogenic mediator in ovarian hyperstimulation syndrome OHSS. Studies proved that cabergoline administration blocks the increase in vascular permeability via dephosphorylation of VEGF receptors and hence can be used as prophylactic agent against OHSS. This study aimed at evaluating the effectiveness of early administration of cabergoline in the prevention of OHSS in high risk cases prepared for ICSI. This case series study was conducted on 126 high risk patients prepared for ICSI using the fixed antagonist protocol. High risk patients were defined as having more than 20 follicles >12 mm in diameter, and/or E2 more than 3000 pg/ml when the size of the leading follicle is more than 15 mm. When the size of the leading follicle reached 15 mm, cabergoline was administered (0.5 mg/day) for 8 days. Patients were followed up clinically, ultrasonographically and hematologically. The final E2 was 6099.5 ± 2730 and the mean number of retrieved oocytes was 19.7 ± 7.8. The clinical pregnancy rate was 62/126 (49.2%). There were no significant changes (p > 0.05) comparing hematological parameters, renal function tests and liver function tests between the day of HCG and the day of blastocyst transfer. The incidence of severe OHSS in this group was 1/126 (0.9%), while moderate OHSS was 12 (9.5%) and there were no cases of critical OHSS. We concluded that early administration of cabergoline is a safe and potentially more effective approach for prophylaxis against OHSS in high risk cases.     

The adaptive potential of plant populations in response to extreme climate events

The frequency and magnitude of extreme climate events are increasing with global change, yet we lack predictions and empirical evidence for the ability of wild populations to persist and adapt in response to these events. Here, we used Fisher's Fundamental Theorem of Natural Selection to evaluate the adaptive potential of Lasthenia fremontii, a herbaceous winter annual that is endemic to seasonally flooded wetlands in California, to alternative flooding regimes that occur during El Niño Southern Oscillation (ENSO) events. The results indicate that populations may exhibit greater adaptive potential in response to dry years than wet years, and that the relative performance of populations will change across climate scenarios. More generally, our findings show that extreme climate events can substantially change the potential for populations to adapt to climate change by modulating the expression of standing genetic variation and mean fitness.     

Political economy and global arts for social change: A comparative analysis of youth orchestras in Venezuela and Chile

An expansive movement comprised of UN Millennium Development Goals, international banks, and hundreds of programs worldwide promotes access to the arts as a creative means of social change. Often grounded in cognitive science and inspired by the model of youth orchestras in Venezuela known as El Sistema, this movement contends that arts training—which can foster empathy, collaboration, academic achievement, and self-esteem—helps alleviate poverty and combat inequality. In contrast to the majority of the literature on public arts programs—impact studies that often assume arts engagement creates social change through universal mechanisms—this study examines the influence of political economy on the implementation of public arts programs. Through a comparative study of youth orchestras with social inclusion goals in Venezuela (1974–2015) and Chile (1964–2015), the scope and intensity of government control, social welfare policy, and competition for public funds are found to shape public arts programs' social goals, daily operations, definitions of success, and impact study procedures. Therefore, scholars, practitioners, and policy makers must reexamine their understanding of arts programs as a development model. Future global efforts to combat inequality should avoid over-standardization. This article offers a new Arts for Social Change Context Framework that places input variables at the center of analysis, with policy implications.     

Pleistocene camelids from the Syrian Desert: The diversity in El Kowm

The family Camelidae has been present in Eurasia since the latest Miocene, and several species are recognized, but their evolution is poorly known. The region of El Kowm, central Syria, includes several sites spanning the Early to Late Pleistocene and provides the only abundant fossil record of camelids in the Middle East. Our preliminary results show that several species are present over the sequence, revealing some surprising evolutionary trends.