Extraordinary levels of per- and polyfluoroalkyl substances (PFAS) in vertebrate animals at a New Mexico desert oasis: Multiple pathways for wildlife and human exposure.

Per- and polyfluoroalkyl substances (PFAS) in the environment pose persistent and complex threats to human and wildlife health. Around the world, PFAS point sources such as military bases expose thousands of populations of wildlife and game species, with potentially far-reaching implications for population and ecosystem health. But few studies shed light on the extent to which PFAS permeate food webs, particularly ecologically and taxonomically diverse communities of primary and secondary consumers. Here we conducted >2000 assays to measure tissue-concentrations of 17 PFAS in 23 species of mammals and migratory birds at Holloman Air Force Base (AFB), New Mexico, USA, where wastewater catchment lakes form biodiverse oases. PFAS concentrations were among the highest reported in animal tissues, and high levels have persisted for at least three decades. Twenty of 23 species sampled at Holloman AFB were heavily contaminated, representing middle trophic levels and wetland to desert microhabitats, implicating pathways for PFAS uptake: ingestion of surface water, sediments, and soil; foraging on aquatic invertebrates and plants; and preying upon birds or mammals. The hazardous long carbon-chain form, perfluorooctanosulfonic acid (PFOS), was most abundant, with liver concentrations averaging >10,000 ng/g wet weight (ww) in birds and mammals, respectively, and reaching as high 97,000 ng/g ww in a 1994 specimen. Perfluorohexanesulfonic acid (PFHxS) averaged thousands of ng/g ww in the livers of aquatic birds and littoral-zone house mice, but one order of magnitude lower in the livers of upland desert rodent species. Piscivores and upland desert songbirds were relatively uncontaminated. At control sites, PFAS levels were strikingly lower on average and different in composition. In sum, legacy PFAS at this desert oasis have permeated local aquatic and terrestrial food webs across decades, severely contaminating populations of resident and migrant animals, and exposing people via game meat consumption and outdoor recreation.

Blood Variation Implicates Respiratory Limits on Elevational Ranges of Andean Birds.

AbstractThe extent to which species ranges reflect intrinsic physiological tolerances is a major question in evolutionary ecology. To date, consensus has been hindered by the limited tractability of experimental approaches across most of the tree of life. Here, we apply a macrophysiological approach to understand how hematological traits related to oxygen transport shape elevational ranges in a tropical biodiversity hot spot. Along Andean elevational gradients, we measured traits that affect blood oxygen-carrying capacity-total and cellular hemoglobin concentration and hematocrit, the volume percentage of red blood cells-for 2,355 individuals of 136 bird species. We used these data to evaluate the influence of hematological traits on elevational ranges. First, we asked whether the sensitivity of hematological traits to changes in elevation is predictive of elevational range breadth. Second, we asked whether variance in hematological traits changed as a function of distance to the nearest elevational range limit. We found that birds showing greater hematological sensitivity had broader elevational ranges, consistent with the idea that a greater acclimatization capacity facilitates elevational range expansion. We further found reduced variation in hematological traits in birds sampled near their elevational range limits and at high absolute elevations, patterns consistent with intensified natural selection, reduced effective population size, or compensatory changes in other cardiorespiratory traits. Our findings suggest that constraints on hematological sensitivity and local genetic adaptation to oxygen availability promote the evolution of the narrow elevational ranges that underpin tropical montane biodiversity.

Contrasting drivers of diversity in hosts and parasites across the tropical Andes.

Geographic turnover in community composition is created and maintained by eco-evolutionary forces that limit the ranges of species. One such force may be antagonistic interactions among hosts and parasites, but its general importance is unknown. Understanding the processes that underpin turnover requires distinguishing the contributions of key abiotic and biotic drivers over a range of spatial and temporal scales. Here, we address these challenges using flexible, nonlinear models to identify the factors that underlie richness (alpha diversity) and turnover (beta diversity) patterns of interacting host and parasite communities in a global biodiversity hot spot. We sampled 18 communities in the Peruvian Andes, encompassing ∼1,350 bird species and ∼400 hemosporidian parasite lineages, and spanning broad ranges of elevation, climate, primary productivity, and species richness. Turnover in both parasite and host communities was most strongly predicted by variation in precipitation, but secondary predictors differed between parasites and hosts, and between contemporary and phylogenetic timescales. Host communities shaped parasite diversity patterns, but there was little evidence for reciprocal effects. The results for parasite communities contradicted the prevailing view that biotic interactions filter communities at local scales while environmental filtering and dispersal barriers shape regional communities. Rather, subtle differences in precipitation had strong, fine-scale effects on parasite turnover while host-community effects only manifested at broad scales. We used these models to map bird and parasite turnover onto the ecological gradients of the Andean landscape, illustrating beta-diversity hot spots and their mechanistic underpinnings.

Demographic consequences of foraging ecology explain genetic diversification in Neotropical bird species.

Despite evidence that species' traits affect rates of bird diversification, biogeographic studies tend to prioritise earth history in Neotropical bird speciation. Here we compare mitochondrial genetic differentiation among 56 co-distributed Neotropical bird species with varying ecologies. The trait 'diet' best predicted divergence, with plant-dependent species (mostly frugivores and nectivores) showing lower levels of genetic divergence than insectivores or mixed-diet species. We propose that the greater vagility and demographic instability of birds whose diets rely on fruit, seeds, or nectar  known to vary in abundance seasonally and between years  relative to birds that eat primarily insects, drives episodic re-unification of otherwise isolated populations, resetting the divergence 'clock'. Testing this prediction using coalescent simulations, we find that plant-dependent species show stronger signals of recent demographic expansion compared to insectivores or mixed-diet species, consistent with this hypothesis. Our study provides evidence that localised ecological phenomena scale up to generate larger macroevolutionary patterns.

Detecting turnover among complex communities using null models: a case study with sky-island haemosporidian parasites.

Turnover in species composition between sites, or beta diversity, is a critical component of species diversity that is typically influenced by geography, environment, and biotic interactions. Quantifying turnover is particularly challenging, however, in multi-host, multi-parasite assemblages where undersampling is unavoidable, resulting in inflated estimates of turnover and uncertainty about its spatial scale. We developed and implemented a framework using null models to test for community turnover in avian haemosporidian communities of three sky islands in the southwestern United States. We screened 776 birds for haemosporidian parasites from three genera (Parahaemoproteus, Plasmodium, and Leucocytozoon) by amplifying and sequencing a mitochondrial DNA barcode. We detected infections in 280 birds (36.1%), sequenced 357 infections, and found a total of 99 parasite haplotypes. When compared to communities simulated from a regional pool, we observed more unique, single-mountain haplotypes and fewer haplotypes shared among three mountain ranges than expected, indicating that haemosporidian communities differ to some degree among adjacent mountain ranges. These results were robust even after pruning datasets to include only identical sets of host species, and they were consistent for two of the three haemosporidian genera. The two more distant mountain ranges were more similar to each other than the one located centrally, suggesting that the differences we detected were due to stochastic colonization-extirpation dynamics. These results demonstrate that avian haemosporidian communities of temperate-zone forests differ on relatively fine spatial scales between adjacent sky islands. Null models are essential tools for testing the spatial scale of turnover in complex, undersampled, and poorly known systems.

Extreme and variable torpor among high-elevation Andean hummingbird species.

Torpor is thought to be particularly important for small endotherms occupying cold environments and with limited fat reserves to fuel metabolism, yet among birds deep torpor is both rare and variable in extent. We investigated torpor in hummingbirds at approximately 3800 m.a.s.l. in the tropical Andes by monitoring body temperature (Tb) in 26 individuals of six species held captive overnight and experiencing natural air temperature (Ta) patterns. All species used pronounced torpor, with one Metallura phoebe reaching a minimum Tb of 3.26°C, the lowest yet reported for any bird or non-hibernating mammal. The extent and duration of torpor varied among species, with overnight body mass (Mb) loss negatively correlated with both minimum Tb and bout duration. We found a significant phylogenetic signal for minimum Tb and overnight Mb loss, consistent with evolutionarily conserved thermoregulatory traits. Our findings suggest deep torpor is routine for high Andean hummingbirds, but evolved species differences affect its depth.

Diversity, abundance, and host relationships of avian malaria and related haemosporidians in New Mexico pine forests.

Avian malaria and related haemosporidian parasites (genera Haemoproteus, Plasmodium, and Leucocytozoon) affect bird demography, species range limits, and community structure, yet they remain unsurveyed in most bird communities and populations. We conducted a community-level survey of these vector-transmitted parasites in New Mexico, USA, to describe their diversity, abundance, and host associations. We focused on the breeding-bird community in the transition zone between piñon-juniper woodland and ponderosa pine forests (elevational range: 2,150-2,460 m). We screened 186 birds representing 49 species using both standard PCR and microscopy techniques to detect infections of all three avian haemosporidian genera. We detected infections in 68 out of 186 birds (36.6%), the highest proportion of which were infected with Haemoproteus (20.9%), followed by Leucocytozoon (13.4%), then Plasmodium (8.0%). We sequenced mtDNA for 77 infections representing 43 haplotypes (25 Haemoproteus, 12 Leucocytozoon, 6 Plasmodium). When compared to all previously known haplotypes in the MalAvi and GenBank databases, 63% (27) of the haplotypes we recovered were novel. We found evidence for host specificity at the avian clade and species level, but this specificity was variable among parasite genera, in that Haemoproteus and Leucocytozoon were each restricted to three avian groups (out of six), while Plasmodium occurred in all groups except non-passerines. We found striking variation in infection rate among host species, with nearly universal infection among vireos and no infection among nuthatches. Using rarefaction and extrapolation, we estimated the total avian haemosporidian diversity to be 70 haplotypes (95% CI [43-98]); thus, we may have already sampled ∼60% of the diversity of avian haemosporidians in New Mexico pine forests. It is possible that future studies will find higher diversity in microhabitats or host species that are under-sampled or unsampled in the present study. Fortunately, this study is fully extendable via voucher specimens, frozen tissues, blood smears, parasite images, and documentation provided in open-access databases (MalAvi, GenBank, and ARCTOS).

The Importance of Dog Ownership: Implications for Long-Term Weight Reduction After Gastric Banding.

Gastric banding (GB) is considered an option to support weight loss for individuals who are unable to lose weight through diet and exercise alone. Exercise is an important element of maintaining gradual weight loss following GB. Dog walking may be one method to encourage exercise and contribute to continued weight loss. Over a 5-year period, 24 individuals aged between 31 and 58 years (21 female; 12 dog-owners) were weighed at 7 time points. Intention to treat MANOVA analysis showed both groups lost a significant amount of weight, F(6, 17) = 15.7, P = .001, ηp2 = .85, but no difference was observed between dog owners and non-dog owners, F(6, 17) = 0.66, P = .68, ηp2 = .19, although from 24 months postbanding, data indicated dog owners appear to weigh less than non-dog owners. Further longitudinal research is warranted beyond 5 year post-GB; and encouraging exercise through dog walking may be a useful adjunct to increasing activity and promoting weight loss following GB.

Under and over 50: exploring long-term weight-loss outcomes following laparoscopic adjustable gastric band by age and body mass index group.

BACKGROUND: Laparoscopic adjustable gastric band (LAGB) surgery is used to enable individuals to lose weight. However, the long-term weight loss outcomes for individuals with a body mass index (BMI)≥50 kg/m2 and/or age≥50 years at time of banding remains debated. To date, data reported is largely from populations outside the United Kingdom. OBJECTIVES: To explore long-term weight loss outcomes based on individuals' pre-LAGB age and BMI. SETTING: Data were collected from individuals in the United Kingdom attending a national health service weight loss surgery service. METHOD: Data pertaining to weight were collected in a prospective 5-year study in the United Kingdom. Individuals were grouped according to preoperative age and BMI before analysis. RESULTS: Data from 53 individuals were analyzed. Individuals age≤49 years weighed 142.7±17.4 kg preoperatively, whereas individuals age≥50 years weighed 137.6±19.4 kg. Over the 5 years post-LAGB, significant weight loss was achieved by the whole sample. Additionally, there was an interaction between weight loss and age/BMI group. The sample had a significant percent total weight loss and percent excess weight loss between 6 months and 5 years post-LAGB. However, only individuals age≥50 years with a BMI≥50 kg/m2 preoperatively had continual weight loss over the 5 years. CONCLUSION: Individuals lost weight following LAGB; however, only individuals with a BMI≥50 kg/m2 and age≥50 years before banding appeared to continue to lose weight as time since banding increased, compared with the other groups.

The Impact of Laparoscopic Adjustable Gastric Banding on an NHS Cohort of Type 2 Diabetics: a Prospective Cohort Study.

BACKGROUND: Obesity is an independent risk factor for diabetes, which is associated with significant morbidity and premature death. This study aims to evaluate the impact of laparoscopic adjustable gastric banding (LAGB) on a cohort of morbidly obese diabetics. METHODS: Inclusion and exclusion criteria were applied to consecutive diabetic patients undergoing LAGB. Demographic and disease-specific data were collected at baseline and 6-monthly intervals corresponding to follow-up assessments. Minimum follow-up was 24 months. Normally distributed variables were assessed with one-way analysis of variance/t tests; proportions were analysed with chi-squared/Fisher's exact tests. Follow-up was ≥90 % complete at each time point. RESULTS: One hundred twenty patients with a median age of 43.3 years, mean (± standard deviation (SD)) pre-op body mass index (BMI) of 48.7 (±8) kg/m2, and HbA1c of 8.6 (±2) % were included. BMI reduced significantly, with annual post-operative means of 41.4 ± 7.8, 39.9 ± 7.7, 39.5 ± 7.8, 39.3 ± 7.1 and 36.6 ± 5.4 kg/m(2) (p < 0.001). Corresponding percentage excess body weight lost was 32.8 ± 18, 39.8 ± 21.4, 38.5 ± 21.3, 37.0 ± 22.3 and 43.1 ± 14.1 %. HbA1c was significantly lower at each time point until 30 months post-operatively (p < 0.001). Thereafter, differences were insignificant, and HbA1c was comparable to pre-operative levels by 5 years. Seventy-six (63 %) patients achieved an HbA1c <7 % at 30 months (p < 0.001). Twenty-six (23 %) patients achieved remission from diabetes. The cumulative 5-year cost saving from reductions in anti-diabetes medications was £1650/patient. There were no mortalities, and 18 device explants. CONCLUSIONS: Modest but durable weight loss associated with significant improvements in glycaemic control and anti-diabetic medication use have been demonstrated. Peak effects occur within 24-30 months and diminish thereafter, possibly reflecting progression of pathological processes due to residual obesity.

Breast augmentation in Familial Partial Lipodystrophy: a case report.

Familial Partial Lipodystrophy (or Dunnigan-Kobberling syndrome) is characterised by the progressive loss of peripheral subcutaneous fat, with or without truncal involvement. The resultant physical changes in appearance may be dramatic, especially in women, and their psychological impact underestimated. There are limited reports regarding the role of reconstructive procedures to address the physical defects imposed by the various lipodystrophy syndromes, and much of the work to date has focused around facial lipoatrophy in patients with HIV-1 protease inhibitor induced disease. We, however, present a single case report pertaining to the role of breast augmentation in patients with truncal lipoatrophy, as in Familial Partial Lipodystrophy.

Short-term hurricane impacts on a neotropical community of marked birds and implications for early-stage community resilience.

Populations in fragmented ecosystems risk extirpation through natural disasters, which must be endured rather than avoided. Managing communities for resilience is thus critical, but details are sketchy about the capacity for resilience and its associated properties in vertebrate communities. We studied short-term resilience in a community of individually marked birds, following this community through the catastrophic destruction of its forest habitat by Hurricane Iris in Belize, Central America. We sampled for 58 d immediately before the storm, 28 d beginning 11 d after Hurricane Iris, and for 69 d approximately one year later. Our data showed that the initial capacity for resilience was strong. Many banded individuals remained after the storm, although lower post-hurricane recapture rates revealed increased turnover among individuals. Changes occurred in community dynamics and in abundances among species and guilds. Survivors and immigrants both were critical components of resilience, but in a heterogeneous, species-specific manner. Delayed effects, including higher fat storage and increased species losses, were evident one year later.