Retrospective study on admission trends of Californian hummingbirds found in urban habitats (1991-2016).

BACKGROUND: Hummingbirds are frequently presented to California wildlife rehabilitation centers for medical care, accounting for approximately 5% of overall admissions. Age, sex, and reason for admission could impact hummingbird survivability, therefore identification of these factors could help maximize rehabilitation efforts. METHODS: Mixed-effects logistic regression models were used to identify specific threats to the survival of 6908 hummingbirds (1645 nestlings and 5263 non-nestlings) consisting of five species (Calypte anna, Calypte costa, Selasphorus rufus, Selasphorus sasin, Archilochus alexandri), found in urban settings, and admitted to California wildlife rehabilitation centers over 26 years. RESULTS: In total, 36% of birds survived and were transferred to flight cage facilities for further rehabilitation and/or release. Nestlings were more likely to be transferred and/or released compared to adult hummingbirds. After accounting for age, birds rescued in spring and summer were twice as likely to be released compared to birds rescued in the fall. A high number of nestlings were presented to the rehabilitation centers during spring, which coincides with the nesting season for hummingbirds in California, with the lowest number of nestlings presented in fall. Reasons for presentation to rehabilitation centers included several anthropogenic factors such as window collisions (9.6%) and interactions with domesticated animals (12.9%). Survival odds were lower if a hummingbird was rescued in a "torpor-like state" and were higher if rescued for "nest-related" reasons. Evaluation of treatment regimens administered at wildlife rehabilitation centers identified supportive care, including providing commercial nutrient-rich nectar plus solution, to significantly increase hummingbird survivability. DISCUSSION: Our results provide evidence of threats to hummingbirds in urban habitats, based on reasons for rescue and presentation to rehabilitation centers. Reasons for hummingbird admissions to three California wildlife rehabilitation centers were anthropogenic in nature (i.e., being associated with domestic animals, window collisions, and found inside a man-made structure) and constituted 25% of total admissions. There was a clear indication that supportive care, such as feeding a commercial nectar solution, and medical treatment significantly increased the odds of survival for rescued hummingbirds.

Measurements of the radiographic cardiac silhouette of ospreys (Pandion haliaetus).

OBJECTIVE: To evaluate and report measurements of the radiographic cardiac silhouette of healthy juvenile and adult ospreys (Pandion haliaetus). ANIMALS: 54 ospreys (22 adults, 19 juveniles, and 13 birds of undetermined age) without clinical signs of cardiac disease and with adequate ventrodorsal radiographic images for cardiac silhouette assessment. PROCEDURES: Radiographs of ospreys were assessed to determine cardiac width at the widest point as well as sternal width and thoracic width at the same level. Two-way mixed-effects models were used to evaluate interrater reliability for mean rating. Multivariable linear regression analysis was used to create predictive models of cardiac width and to establish a theoretical reference range for healthy ospreys. RESULTS: Cardiac width of healthy ospreys was approximately 90% to 92% of sternal width and 67% to 69% of thoracic width. Both sternal width and thoracic width were significant predictors of cardiac width in independent predictive models as well as in a combined model after controlling for age. Thirty-four of 41 (83%) measured cardiac widths were within the theoretical reference range. CONCLUSIONS AND CLINICAL RELEVANCE: Ospreys are sentinels used in monitoring environmental health. Environmental factors may have an impact on the cardiac health of ospreys, but reference values for healthy ospreys have not been established for use in assessing cardiomegaly in this species. The radiographic ratios and predictive model obtained in this study may be useful for objective evaluation of cardiomegaly in ospreys.

Wild blueberry (Vaccinium angustifolium)-enriched diet improves dyslipidaemia and modulates the expression of genes related to lipid metabolism in obese Zucker rats.

The present study investigated the potential of a wild blueberry (WB)-enriched diet to improve blood lipid profile and modulate the expression of genes related to lipid homeostasis in obese Zucker rats (OZR), a model of the metabolic syndrome with severe dyslipidaemia. For this purpose, twenty OZR and twenty lean Zucker rats (LZR; controls) were placed either on a control (C) or an 8 % WB diet for 8 weeks. Plasma total cholesterol (TC), HDL-cholesterol and TAG concentrations were determined. The relative expression of six genes involved in lipid metabolism was also determined in both the liver and the abdominal adipose tissue (AAT). Plasma TAG and TC concentrations were significantly lower in the OZR following WB consumption (4228 (sem 471) and 2287 (sem 125) mg/l, respectively) than in those on the C diet (5475 (sem 315) and 2631 (sem 129) mg/l, P< 0·05), while there was no change in HDL-cholesterol concentration. No significant effects were observed for plasma lipids in the LZR. Following WB consumption, the expression of the transcription factors PPARα and PPARγ in the OZR was increased in the AAT, while that of sterol regulatory element-binding protein 1 (SREBP-1) was decreased in the liver and AAT. The expression of fatty acid synthase was significantly decreased in both the liver and AAT and that of ATP-binding cassette transporter 1 was increased in the AAT following WB consumption. In conclusion, WB consumption appears to improve lipid profiles and modulate the expression of key enzymes and transcription factors of lipid metabolism in severely dyslipidaemic rats.

Wild blueberry (Vaccinium angustifolium) consumption improves inflammatory status in the obese Zucker rat model of the metabolic syndrome.

The metabolic syndrome (MetS) is a major public health problem in the United States. Chronic inflammation is a critical component of the MetS, leading to dramatically increased risk of type II diabetes and cardiovascular disease. This study investigates the ability of a wild-blueberry-enriched diet to improve the proinflammatory status associated with MetS in the obese Zucker rat (OZR). Circulating levels of key inflammatory markers and their expression in the liver and abdominal adipose tissue were examined in OZR and its genetic control, the lean Zucker rat (LZR), after feeding a control or an 8% wild blueberry diet (WB) for 8 weeks from age 8 to 16 weeks. In the OZR, WB consumption resulted in decreased plasma concentrations of tumor necrosis factor (TNF)-α (-25.6%, P<.05), interleukin (IL)-6 (-14.9%, P<.05) and C-reactive protein (CRP) (-13.1%, P<.05) and increased adiponectin concentration (+21.8%, P<.05). Furthermore, expression of IL-6, TNF-α and nuclear factor (NF)-kB was down-regulated in both the liver (-65%, -59% and -25%, respectively) and the abdominal adipose tissue (-64%, -52% and -65%), while CRP expression was down-regulated only in the liver (-25%). In the abdominal adipose tissue, similar trends were also observed in LZR following WB treatment, with decreased liver expression of NF-kB, CRP, IL-6 and TNF-α (-24%, -16%, -21% and -50%) and increased adiponectin expression (+25%). Results of this study suggest that wild blueberry consumption exerts an overall anti-inflammatory effect in the OZR, a model of the metabolic syndrome.