Multiple anthropogenic stressors in the Galápagos Islands' complex social-ecological system: Interactions of marine pollution, fishing pressure, and climate change with management recommendations.

For decades, multiple anthropogenic stressors have threatened the Galápagos Islands. Widespread marine pollution such as oil spills, persistent organic pollutants, metals, and ocean plastic pollution has been linked to concerning changes in the ecophysiology and health of Galápagos species. Simultaneously, illegal, unreported, and unregulated fishing are reshaping the composition and structure of endemic and native Galápagos pelagic communities. In this novel review, we discuss the impact of anthropogenic pollutants and their associated ecotoxicological implications for Galápagos species in the face of climate change stressors. We emphasize the importance of considering fishing pressure and marine pollution, in combination with climate-change impacts, when assessing the evolutionary fitness of species inhabiting the Galápagos. For example, the survival of endemic marine iguanas has been negatively affected by organic hydrocarbons introduced via oil spills, and endangered Galápagos sea lions exhibit detectable concentrations of DDT, triggering potential feminization effects and compromising the species' survival. During periods of ocean warming (El Niño events) when endemic species undergo nutritional stress, climate change may increase the vulnerability of these species to the impacts of pollutants, resulting in the species reaching its population tipping point. Marine plastics are emerging as a deleterious and widespread threat to endemic species. The Galápagos is treasured for its historical significance and its unparalleled living laboratory and display of evolutionary processes; however, this unique and iconic paradise will remain in jeopardy until multidisciplinary and comprehensive preventative management plans are put in place to mitigate and eliminate the effects of anthropogenic stressors facing the islands today. We present a critical analysis and synthesis of anthropogenic stressors with some progress from local and international institutional efforts and call to action more precautionary measures along with new management philosophies focused on understanding the processes of change through research to champion the conservation of the Galápagos. Integr Environ Assess Manag 2023;19:870-895. © 2022 SETAC.

A Comparison of Aerodynamic Parameters in Two Subspecies of the American Barn Owl (Tyto furcata).

Aerodynamic parameters, such as wing loading, are important indicators of flight maneuverability. We studied two subspecies of the American Barn owl (Tyto furcata), the North American subspecies, T.f.pratincola, and the Galapagos subspecies, T.f.punctatissima, with respect to aerodynamic parameters and compared our findings with those in other owl and bird species. The body mass of T.f.pratincola is about two times higher than that of T.f.punctatissima. Wing loading between the two subspecies scales allometrically. Wing loading in T.f.pratincola is about 50% higher than in T.f.punctatissima. The scaling of wing length is not statistically different from the prediction for isometric scaling. By contrast, the wing chord in T.f.punctatissima is larger than predicted by isometric scaling, as is the wing area. The scaling of wing loading observed here for T.f.punctatissima differs considerably from the scaling in other owl and bird species as available in the literature. We speculate that the allometric scaling helps T.f.punctatissima to catch smaller prey such, as insects that are found in many pellets of T.f.punctatissima, despite the fact that in both subspecies, small rodents make up most of the diet.

First Report of Blood Parasites in Black-Capped Sparrow (Arremon abeillei) from Neotropical Dry Deciduous Forest.

Avian haemosporidian parasites (Order: Haemosporida) are a diverse group of microorganisms that spend part of their life cycle in the erythrocytes of avian hosts. Parasite presence has been confirmed in all Ecuadorian regions, but some ecosystems, such as the deciduous dry forest of the Coastal region, have not been evaluated for parasite presence. Data on presence or absence, and prevalence, of haemosporidian blood parasites were obtained from avian blood samples collected in two different dry deciduous forests in Guayaquil, Ecuador: Bosque Protector Prosperina and Área Nacional de Recreación Parque Lago. Mist netting was performed between December 2018 and September 2019; blood smears were prepared from blood taken from 35 individuals of 20 bird species and all samples were analyzed by optical microscope observation. Most species showed no evidence of parasite infection, but haemosporidia were found on a blood smear obtained from a Black-capped Sparrow, Arremon abeillei (Passerelleidae), confirming this species as a newly discovered host of blood parasites.

A stable foraging polymorphism buffers Galápagos sea lions against environmental change.

Understanding the ability of animals to cope with a changing environment is critical in a world affected by anthropogenic disturbance.1 Individual foraging strategies may influence the coping ability of entire populations, as these strategies can be adapted to contrasting conditions, allowing populations with foraging polymorphisms to be more resilient toward environmental change.2,3 However, environmentally dependent fitness consequences of individual foraging strategies and their effects on population dynamics have not been conclusively documented.4,5 Here, we use biologging data from endangered Galápagos sea lion females (Zalophus wollebaeki) to show that benthically foraging individuals dig after sand-dwelling prey species while pelagic foragers hunt in more open waters. These specialized foraging behaviors result in distinct and temporally stable patterns of vibrissae abrasion. Using vibrissae length as a visual marker for the benthic versus pelagic foraging strategies, we furthermore uncovered an environment-dependent fitness trade-off between benthic and pelagic foragers, suggesting that the foraging polymorphism could help to buffer the population against the negative effects of climate change. However, demographic projections suggest that this buffering effect is unlikely to be sufficient to reverse the ongoing population decline of the past four decades.6 Our study shows how crucial a deeper understanding of behavioral polymorphisms can be for predicting how populations cope within a rapidly changing world. VIDEO ABSTRACT.

Hormone-mediated foraging strategies in an uncertain environment: Insights into the at-sea behavior of a marine predator.

Hormones are extensively known to be physiological mediators of energy mobilization and allow animals to adjust behavioral performance in response to their environment, especially within a foraging context.Few studies, however, have narrowed focus toward the consistency of hormonal patterns and their impact on individual foraging behavior. Describing these relationships can further our understanding of how individuals cope with heterogeneous environments and exploit different ecological niches.To address this, we measured between- and within-individual variation of basal cortisol (CORT), thyroid hormone T3, and testosterone (TEST) levels in wild adult female Galápagos sea lions (Zalophus wollebaeki) and analyzed how these hormones may be associated with foraging strategies. In this marine predator, females exhibit one of three spatially and temporally distinct foraging patterns (i.e., "benthic," "pelagic," and "night" divers) within diverse habitat types.Night divers differentiated from other strategies by having lower T3 levels. Considering metabolic costs, night divers may represent an energetically conservative strategy with shorter dive durations, depths, and descent rates to exploit prey which migrate up the water column based on vertical diel patterns.Intriguingly, CORT and TEST levels were highest in benthic divers, a strategy characterized by congregating around limited, shallow seafloors to specialize on confined yet reliable prey. This pattern may reflect hormone-mediated behavioral responses to specific risks in these habitats, such as high competition with conspecifics, prey predictability, or greater risks of predation.Overall, our study highlights the collective effects of hormonal and ecological variation on marine foraging. In doing so, we provide insights into how mechanistic constraints and environmental pressures may facilitate individual specialization in adaptive behavior in wild populations.

Integrity of and damage to wings, feather vanes and serrations in barn owls.

The silent flight of owls is well known. It has served as role model for the designs of new airplane wings and ventilators. One of the structural features that underlies silent flight is the serrated leading edge of the wing that is mainly formed by the tenth primary flight feather (P10). We examined here how much the wings, the P10 feather and the serrations in different populations of barn owls reflect the intact situation. First, when the P10 feather molts, no or fewer serrations are present. Furthermore, damage to feathers and serrations may occur. Damage may be due to several factors like broken feather tips, lost rami, barbules, or broken tips of serrations. The latter may cause a narrowing of the outer vane of the P10 feather. We quantitatively assessed damage by counting the number of wings with missing or broken primary feathers, the number of wings with a narrowed outer vane of the P10 feather, and the number of serrations with reduced length. Considerable damage occurred on wings and feathers on both the macroscopic and microscopic levels. The observed damage most likely influences flight performance. More damage occurred in Galapagos barn owls than in North American and European barn owls. The Galapagos population may be more vulnerable than the other populations because it may at least temporarily be in a bad nutritional state and, thus, postpone molt.

Individuality counts: A new comprehensive approach to foraging strategies of a tropical marine predator.

Foraging strategies are of great ecological interest, as they have a strong impact on the fitness of an individual and can affect its ability to cope with a changing environment. Recent studies on foraging strategies show a higher complexity than previously thought due to intraspecific variability. To reliably identify foraging strategies and describe the different foraging niches they allow individual animals to realize, high-resolution multivariate approaches which consider individual variation are required. Here we dive into the foraging strategies of Galápagos sea lions (Zalophus wollebaeki), a tropical predator confronted with substantial annual variation in sea surface temperature. This affects prey abundance, and El Niño events, expected to become more frequent and severe with climate change, are known to have dramatic effects on sea lions. This study used high-resolution measures of depth, GPS position and acceleration collected from 39 lactating sea lion females to analyze their foraging strategies at an unprecedented level of detail using a novel combination of automated broken stick algorithm, hierarchical cluster analysis and individually fitted multivariate hidden Markov models. We found three distinct foraging strategies (pelagic, benthic, and night divers), which differed in their horizontal, vertical and temporal distribution, most likely corresponding to different prey species, and allowed us to formulate hypotheses with regard to adaptive values under different environmental scenarios. We demonstrate the advantages of our multivariate approach and inclusion of individual variation to reliably gain a deeper understanding of the adaptive value and ecological relevance of foraging strategies of marine predators in dynamic environments.

Developmental conditions promote individual differentiation of endocrine axes and behavior in a tropical pinniped.

Between-individual variation in behavior can emerge through complex interactions between state-related mechanisms, which include internal physiological constraints or feedback derived from the external environment. State-related conditions can be especially influential during early life, when parental effort and exposure to social stress may canalize consistent differences in offspring hormonal profiles and foster specific behavioral strategies. Here, we unravel how relevant state variables, including sex, somatic condition, local population density, and maternal traits, contribute to within-cohort differences in stress, sex, and thyroid hormone axes in dependent Galapagos sea lions with the primary goal of understanding downstream effects on boldness, docility, habitat use, and activity. Pups within denser natal sites had higher levels of cortisol and thyroid T4, a prohormone and proxy for metabolic reserves, likely as an adaptive physiological response after exposure to increased numbers of conspecific interactions. Furthermore, considering maternal effects, mothers in better body condition produced pups with higher testosterone yet downregulated basal cortisol and thyroid T4. This hormonal profile was correlated with increased boldness toward novel objects and attenuated stress responsiveness during capture. Intriguingly, pups with increased thyroid T3, the biologically active form, maintained faster somatic growth and were observed to have increased activity and extensively explored surrounding habitats. Collectively, these findings provide comprehensive evidence for several links to hormone-mediated behavioral strategies, highlighted by variation in socio-environmental and maternally derived input during a foundational life stage.

Taxonomic Status of the Streaked Saltator, Saltator striatipectus (Passeriformes: Thraupidae), from Puná Island, Ecuador.

The Streaked Saltator, Saltator striatipectus, is an uncommon to common resident of open areas, cultivated land, gardens, and forest edges, with ten subspecies recognized from west Costa Rica through west Peru (Brewer 2016). Patterns of plumage variation, especially mantle color and streaking pattern below, are complex across subspecies and age classes (Chapman 1926; Ridgely Tudor 2009; Brewer 2016). Until recently, S. striatipectus was considered conspecific with the Lesser Antillean Saltator S. albicollis, but separated on the basis of genetic differentiation despite overall plumage similarities (Seutin et al. 1993). Actually, S. striatipectus and S. albicollis are not each other's closest relatives (Chaves et al. 2013).

Estudios sobre el virus del papiloma humano (VPH) en el Ecuador: parte I / Studies on human papillomavirus (HPV) in Ecuador: part I

Aprovechando la realización de las XL Jornadas Nacionales de Biología Espol en la ciudad de Guayaquil, se realizó una sesión dedicada a la epidemiología del virus de papiloma humano (VPH) y del cáncer cervical. Esta sesión tuvo la participación de varios investigadores provenientes de diferentes zonas del Ecuador. El presente artículo tiene como objeto presentar un resumen de estas charlas, junto a un análisis de la información mostrada además de una reflexión sobre las preguntas que quedan aún por responder en cuanto al perfil epidemiológico de esta patología en el país.

Taking advantage of the realization of theXL National Conference on Espol Biology in the city of Guayaquil, a session was held dedicated to the epidemiology of Human Papilloma Virus (HPV) and cervical cancer. This session was attended by several researchers from different areas of Ecuador. The object of this article is to present a summary of these talks, together with an analysis of the information shown in addition to a reflection on the questions still to be answered regarding the epidemiological profile of this pathology in the country.

On the Challenge of Interpreting Census Data: Insights from a Study of an Endangered Pinniped.

Population monitoring is vital for conservation and management. However, simple counts of animals can be misleading and this problem is exacerbated in seals (pinnipeds) where individuals spend much time foraging away from colonies. We analyzed a 13-year-series of census data of Galapagos sea lions (Zalophus wollebaeki) from the colony of Caamaño, an islet in the center of the Galapagos archipelago where a large proportion of animals was individually marked. Based on regular resighting efforts during the cold, reproductive (cold-R; August to January) and the warm, non-reproductive (warm-nR; February to May) season, we document changes in numbers for different sex and age classes. During the cold-R season the number of adults increased as the number of newborn pups increased. Numbers were larger in the morning and evening than around mid-day and not significantly influenced by tide levels. More adults frequented the colony during the warm-nR season than the cold-R season. Raw counts suggested a decline in numbers over the 13 years, but Lincoln-Petersen (LP-) estimates (assuming a closed population) did not support that conclusion. Raw counts and LP estimates were not significantly correlated, demonstrating the overwhelming importance of variability in attendance patterns of individuals. The probability of observing a given adult in the colony varied between 16% (mean for cold-R season) and 23% (warm-nR season) and may be much less for independent 2 to 4 year olds. Dependent juveniles (up to the age of about 2 years) are observed much more frequently ashore (35% during the cold-R and 50% during the warm-nR seasons). Simple counts underestimate real population size by a factor of 4-6 and may lead to erroneous conclusions about trends in population size.