22 research outputs found
Changes in Avian Vocalization Occurrence and Frequency Range During the Winter
Human population expansion has led to an increase in vehicle traffic and therefore vehicle noise. Traffic and traffic noise has been shown to affect avian abundance, breeding success, density and species diversity on the landscape. Documented changes in avian vocalizations due to traffic noise include shifts in amplitude, frequency, rate, timing, and duration of vocalizations along with a number of behavioral adaptations. During the winters of 2011–2012 and 2012–2013, we recorded and measured the “chick-a-dee” vocalization of Black-capped Chickadees (Poecile atricapillus) and the “po-ta-to-chip” vocalization of American Goldfinches (Spinus tristis) to determine if bird vocalizations near high traffic noise had higher minimum and maximum frequencies than bird vocalizations near low traffic noise. We found that both the Black-capped Chickadee and American Goldfinch vocalizations have a higher minimum frequency near high traffic noise while the maximum frequency showed no change. This suggests that these species will alter the part of their vocalization that is acoustically masked by traffic noise in order to better transmit the vocalization. However, costs of altering vocalizations include the inability to attract a mate, poor vocal performance, not sounding like conspecifics, and being more easily heard by predators. Chickadees also alter how often they vocalize based on their flock composition. Chickadees vocalize more in mixed-species flocks with other satellite members than in flocks that contained juncos or in single-species flocks of chickadees. Also, single species flocks of Black-capped Chickadees tended to be smaller in size and mixed-species flocks of Dark-eyed Juncos plus individual satellite members tended to be larger in size
Variation in Avian Vocalizations during the Non-Breeding Season in Response to Traffic Noise
Low-frequency traffic noise that leads to acoustic masking of vocalizations may cause birds to alter the frequencies or other components of their vocalizations in order to be heard by conspecifics and others. Altering parts of a vocalization may result in poorer vocal performance or the message contained in the vocalization being received incorrectly. During the winters of 2011–2012 and 2012–2013, we recorded and measured the “chick-a-dee” call of Black-capped Chickadees (Poecile atricapillus) and the “po-ta-to-chip” call of American Goldfinches (Spinus tristis) to determine whether components of the calls produced in areas of high traffic noise and low traffic noise differed in any way. We found that both chickadee and goldfinch calls had higher minimum frequencies in areas with high traffic-noise than in low traffic-noise areas. The maximum frequencies showed no differences in either species’ calls. This suggests that chickadees and goldfinches alter the part of their calls that are acoustically masked by traffic noise in effort to better transmit the vocalization. These differences suggest that increasing anthropogenic noise may influence avian communication and that noise management should be included in conservation planning
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
In Her Words. : Women's Writings in the History of Christian Thought.
Nashville347 p, 23 cm
The Influence of Different Cover Types on American Robin Nest Success in Organic Agroecosystems
There are many opportunities for biodiversity conservation in organic farm systems. Successful and sustainable conservation efforts in organic systems, however, need to measure appropriate outcomes. In particular, data are needed on the breeding success of associated wildlife species. We measured nesting success of the American Robin (Turdus migratorius) in woodlands embedded within eight organic farms in eastern Nebraska. We modeled daily nest survival rate to identify land use and land cover patterns that optimize conservation of birds in organic farm systems. The percentage of a crop in the fields adjacent to linear woodlands best predicted daily survival rate. Daily survival rate was lower in fields adjacent to wheat and greater in woodlands adjacent to soybean fields, though the latter may be a weak effect. There was no evidence that reducing the area allocated to organic crop production would improve daily survival rate but rather an evidence of a patch-matrix interaction. These results suggest that, if suitable nesting sites exist, organic farmers can complement local conservation efforts without losing working farmland