scholarly journals Interacting effects of cold snaps, rain, and agriculture on the fledging success of a declining aerial insectivore

2021 ◽  
Author(s):  
Daniel Roy Garrett ◽  
Fanie Pelletier ◽  
Dany Garant ◽  
Marc Bélisle
Keyword(s):  
Climate Change ◽  
Agricultural Intensification ◽  
Prey Availability ◽  
Tree Swallow ◽  
Landscape Changes ◽  
Population Declines ◽  
Negative Effects ◽  
Fledging Success ◽  
Inclement Weather ◽  
Aerial Insectivore

Climate change predicts the increased frequency, duration, and intensity of inclement weather periods, such as unseasonably low temperatures and prolonged precipitation. Many migratory species have advanced the phenology of important life history stages, and as a result are likely exposed to these periods of inclement spring weather more often, thus risking reduced fitness and population growth. For declining avian species, including aerial insectivores, anthropogenic landscape changes such as agricultural intensification are another driver of population declines. These landscape changes may affect the foraging ability of food provisioning parents, as well as reduce the probability a nestling will survive periods of inclement weather, through for example pesticide exposure impairing thermoregulation and punctual anorexia. Breeding in agro-intensive landscapes may thus exacerbate the negative effects of inclement weather under climate change. We used daily temperatures related to significant reductions of insect prey availability (cold snaps), combined with measures of precipitation, and assessed their impact on Tree Swallow (Tachycineta bicolor) fledging success, a declining aerial insectivore breeding across a gradient of agricultural intensification. Fledging success decreased with the number of cold snap days experienced by a brood, and this relationship was worsened during periods of prolonged precipitation. We further found the overall negative effects of experiencing periods of inclement weather are exacerbated in more agro-intensive landscapes. Our results indicate that two of the primary hypothesized drivers of many avian population declines may interact to further increase the rate of declines in certain landscape contexts.

scholarly journals Negative effects of agricultural intensification on energetic gain rates of a declining aerial insectivore

2021 ◽  
Author(s):  
Daniel R. Garrett ◽  
Fanie Pelletier ◽  
Dany Garant ◽  
Marc Bélisle
Keyword(s):  
Body Condition ◽  
Agricultural Intensification ◽  
Agricultural Practices ◽  
Agricultural Landscapes ◽  
Tree Swallow ◽  
Food Provisioning ◽  
Negative Effects ◽  
Aerial Insectivore ◽  
Provisioning Behavior ◽  
Breeding Grounds

AbstractThe historical rise of intensive agricultural practices is hypothesized to be related to declines of grassland and aerial insectivorous birds. Drivers of declines may also influence the overall abundance and spatial distribution of insects within agricultural landscapes. Subsequently, average energetic gain rates of birds breeding within more agro-intensive landscapes may be impacted. Lower energetic gain rates in agro-intensive landscapes may lead to reduced growth rate, body condition or fledging success of nestlings but also to diminished body condition of food provisioning adults. In this study, we assessed if energetic gain of nestlings and food provisioning behavior of adults varied across a gradient of agricultural intensification in a declining aerial insectivore, the Tree swallow (Tachycineta bicolor). We found that hourly gain rate was lower in agro-intensive landscapes, and yet travel distances were longest within less agro-intensive landscapes. Our results highlight that, in order to maximize long term average gain rates, Tree swallows breeding within agro-intensive landscapes must forage with greater intensity, perhaps at a cost to themselves, or else costs will transfer to growing broods. Our work provides further evidence that agricultural intensification on the breeding grounds can contribute to the declines of aerial insectivores in part through a trophic pathway.

scholarly journals Birds advancing lay dates with warming springs face greater risk of chick mortality

2020 ◽  
Vol 117 (41) ◽  
pp. 25590-25594 ◽  
Author(s):  
J. Ryan Shipley ◽  
Cornelia W. Twining ◽  
Conor C. Taff ◽  
Maren N. Vitousek ◽  
Andrea Flack ◽  
...  
Keyword(s):  
Climate Change ◽  
Reproductive Success ◽  
Egg Laying ◽  
Tree Swallow ◽  
Population Declines ◽  
Chick Survival ◽  
Ambient Temperatures ◽  
Inclement Weather ◽  
Aerial Insectivores

In response to a warming planet with earlier springs, migratory animals are adjusting the timing of essential life stages. Although these adjustments may be essential for keeping pace with resource phenology, they may prove insufficient, as evidenced by population declines in many species. However, even when species can match the tempo of climate change, other consequences may emerge when exposed to novel conditions earlier in the year. Here, using three long-term datasets on bird reproduction, daily insect availability, and weather, we investigated the complex mechanisms affecting reproductive success in an aerial insectivore, the tree swallow (Tachycineta bicolor). By examining breeding records over nearly half a century, we discovered that tree swallows have continuously advanced their egg laying by ∼3 d per decade. However, earlier-hatching offspring are now exposed to inclement weather events twice as often as they were in the 1970s. Our long-term daily insect biomass dataset shows no long-term trends over 25 y but precipitous drops in flying insect numbers on days with low ambient temperatures. Insect availability has a considerable impact on chick survival: Even a single inclement weather event can reduce offspring survival by >50%. Our results highlight the multifaceted threats that climate change poses on migrating species. The decoupling between cold snap occurrence and generally warming spring temperatures can affect reproductive success and threaten long-term persistence of populations. Understanding the exact mechanisms that endanger aerial insectivores is especially timely because this guild is experiencing the steepest and most widespread declines across North America and Europe.

scholarly journals Combined influence of food availability and agricultural intensification on a declining aerial insectivore

2021 ◽  
Author(s):  
Daniel R. Garrett ◽  
Fanie Pelletier ◽  
Dany Garant ◽  
Marc Bélisle
Keyword(s):  
Population Dynamics ◽  
Food Availability ◽  
Agricultural Intensification ◽  
Wing Length ◽  
Prey Availability ◽  
Agricultural Practices ◽  
Agricultural Landscapes ◽  
Fledging Success ◽  
Aerial Insectivore ◽  
Aerial Insectivores

AbstractAerial insectivores show worldwide population declines coinciding with shifts in agricultural practices. Increasing reliance on certain agricultural practices, is thought to have led to an overall reduction in insect abundance that negatively effects aerial insectivore fitness. The relationship between prey availability and the fitness of insectivores may thus vary with the extent of agricultural production. It is therefore imperative to quantify the strength and direction of these associations. Here we used data from an 11-year study monitoring the breeding of Tree swallows (Tachycineta bicolor) and the availability of Diptera (their main prey) across a gradient of agricultural intensification in southern Québec, Canada. More specifically, we evaluated the landscape characteristics affecting prey availability, and how this relationship influences the fledging success, the duration of the nestling period, the fledgling body mass and wing length as these variables are known to influence the population dynamics of this species. Diptera availability was greatest within predominately forested landscapes, yet within principally agricultural landscapes, it was greatest within ones dominated by intensive row crops (corn, soybean and wheat), and, counter to our predictions, lowest within those dominated by forage and pasture fields. Of the measured fitness proxies, only fledging success was positively related to prey availability. The impact of prey availability varied across the agricultural gradient as fledging success improved with increasing prey levels within forage landscapes yet declined in more agro-intensive landscapes. Finally, once conditioning on prey availability, fledging success was lowest, nestling periods were the longest, and wing length of fledglings were shortest within more agro-intensive landscapes. Our results highlight the interacting roles that aerial insect availability and agricultural intensification have on the fitness of aerial insectivores, and by extension how food availability may interact with other aspects of breeding habitats to influence the population dynamics of predators.

scholarly journals Wind and rain are the primary climate factors driving changing phenology of an aerial insectivore

2017 ◽  
Vol 284 (1853) ◽  
pp. 20170412 ◽  
Author(s):  
Rachel D. Irons ◽  
April Harding Scurr ◽  
Alexandra P. Rose ◽  
Julie C. Hagelin ◽  
Tricia Blake ◽  
...  
Keyword(s):  
Climate Change ◽  
Natural Populations ◽  
Climate Change Impacts ◽  
Tree Swallow ◽  
Breeding Phenology ◽  
Climate Conditions ◽  
Aerial Insectivore ◽  
Windy Weather ◽  
Two Measures

While the ecological effects of climate change have been widely observed, most efforts to document these impacts in terrestrial systems have concentrated on the impacts of temperature. We used tree swallow ( Tachycineta bicolor ) nest observations from two widely separated sites in central Alaska to examine the aspects of climate affecting breeding phenology at the northern extent of this species' range. We found that two measures of breeding phenology, annual lay and hatch dates, are more strongly predicted by windiness and precipitation than by temperature. At our longest-monitored site, breeding phenology has advanced at nearly twice the rate seen in more southern populations, and these changes correspond to long-term declines in windiness. Overall, adverse spring climate conditions known to negatively impact foraging success of swallows (wet, windy weather) appear to influence breeding phenology more than variation in temperature. Separate analyses show that short windy periods significantly delay initiation of individual clutches within years. While past reviews have emphasized that increasing variability in climate conditions may create physiological and ecological challenges for natural populations, we find that long-term reductions in inclement weather corresponded to earlier reproduction in one of our study populations. To better predict climate change impacts, ecologists need to more carefully test effects of multiple climate variables, including some, like windiness, that may be of paramount importance to some species, but have rarely been considered as strong drivers of ecological responses to climate alteration.

scholarly journals Predictors of nestling survival during harsh weather events in an aerial insectivore, the Tree Swallow (Tachycineta bicolor)

2019 ◽  
Vol 97 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Ilsa A. Griebel ◽  
Russell D. Dawson
Keyword(s):  
Heat Treating ◽  
Tachycineta Bicolor ◽  
Tree Swallow ◽  
Extreme Weather Events ◽  
Curvilinear Relationship ◽  
Bird Populations ◽  
Inclement Weather ◽  
Aerial Insectivore ◽  
Weather Events ◽  
Nestling Survival

Extreme weather events influence the population dynamics of wild animals. For organisms whose food source is affected by environmental conditions, such as aerial insectivorous birds, periods of inclement weather can have devastating effects. Here, we examine predictors of survival of individual nestlings and whole broods in Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) during an extreme, 2-day harsh weather event in central British Columbia, Canada, which co-occurred with experimental reduction of nest ectoparasite loads using an antiparasite drug (ivermectin) or heat-treating nests. A curvilinear relationship existed between survival and brood age such that middle-aged broods were least likely to survive. Survival of broods and nestlings was higher when raised by males with bluer plumage, whereas nestling survival was lower when female parents had brighter and more UV-reflective plumage. Within broods, smaller nestlings had a lower chance of surviving than their larger siblings. Nestlings in broods where half of the offspring received ivermectin injections had significantly higher chances of surviving than nestlings from nonexperimental broods, suggesting that parasite loads can influence survival during inclement weather. Our results identify several factors influencing resiliency of nestlings to harsh weather and are particularly relevant in the context of declining aerial insectivorous bird populations and climate change.

scholarly journals The Effects of US State-Level Energy and Environmental Policies on Clean Tech Innovation and Employment

2016 ◽  
Vol 6 (2) ◽  
pp. 1 ◽  
Author(s):  
Ross Gittell ◽  
Josh Stillwagon
Keyword(s):  
Climate Change ◽  
Climate Change Policy ◽  
State Level ◽  
Environmental Policies ◽  
Environmental Benefits ◽  
Level Energy ◽  
Negative Effects ◽  
Employment Benefits ◽  
Technology Industry ◽  
Change Policy

<p>This paper explores the influence of US state-level policies meant to address climate change on clean technology industry development. The largest influence of climate change policies is identified as being on energy research employment. Only some policies seem to contribute positively to clean tech employment while other policies appear to discourage employment growth. The magnitudes of the short term effects, even when statistically significant, are modest. Negative impacts on employment are identified for several mandate-oriented, so called command and control, policies including vehicle greenhouse gas standards, energy efficiency resource standards, and renewable portfolio standards with the former two having increasing negative effects over time. The findings suggest that climate change policy advocates should be careful to not assume that there will be positive clean tech employment benefits from state-level energy and environmental policies. Instead, the benefits from these policies may derive primarily from other considerations beyond the scope of this paper, including health and environmental benefits and reduction of dependence on foreign energy sources.</p>

Reforestation can compensate negative effects of climate change on amphibians

2021 ◽  
Vol 260 ◽  
pp. 109187
Author(s):  
Quezia Ramalho ◽  
Luara Tourinho ◽  
Mauricio Almeida-Gomes ◽  
Mariana M. Vale ◽  
Jayme A. Prevedello
Keyword(s):  
Climate Change ◽  
Negative Effects

scholarly journals The effects of modern war and military activities on biodiversity and the environment

2015 ◽  
Vol 23 (4) ◽  
pp. 443-460 ◽  
Author(s):  
Michael J. Lawrence ◽  
Holly L.J. Stemberger ◽  
Aaron J. Zolderdo ◽  
Daniel P. Struthers ◽  
Steven J. Cooke
Keyword(s):  
Military Training ◽  
Structure And Function ◽  
Aquatic Systems ◽  
Ecosystem Structure ◽  
Population Declines ◽  
Exclusion Zone ◽  
Negative Effects ◽  
And Function ◽  
Ecosystem Structure And Function ◽  
Modern War

War is an ever-present force that has the potential to alter the biosphere. Here we review the potential consequences of modern war and military activities on ecosystem structure and function. We focus on the effects of direct conflict, nuclear weapons, military training, and military produced contaminants. Overall, the aforementioned activities were found to have overwhelmingly negative effects on ecosystem structure and function. Dramatic habitat alteration, environmental pollution, and disturbance contributed to population declines and biodiversity losses arising from both acute and chronic effects in both terrestrial and aquatic systems. In some instances, even in the face of massive alterations to ecosystem structure, recovery was possible. Interestingly, military activity was beneficial under specific conditions, such as when an exclusion zone was generated that generally resulted in population increases and (or) population recovery; an observation noted in both terrestrial and aquatic systems. Additionally, military technological advances (e.g., GPS technology, drone technology, biotelemetry) have provided conservation scientists with novel tools for research. Because of the challenges associated with conducting research in areas with military activities (e.g., restricted access, hazardous conditions), information pertaining to military impacts on the environment are relatively scarce and are often studied years after military activities have ceased and with no knowledge of baseline conditions. Additional research would help to elucidate the environmental consequences (positive and negative) and thus reveal opportunities for mitigating negative effects while informing the development of optimal strategies for rehabilitation and recovery.

scholarly journals The effect of climate change on depression in urban areas of western Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hamed Abbasi
Keyword(s):  
Climate Change ◽  
Mental Health ◽  
Urban Areas ◽  
Climate Changes ◽  
Climatic Conditions ◽  
Negative Effects ◽  
Western Iran ◽  
Regime Changes ◽  
Climatic Time Series ◽  
Climatic Elements

Abstract Objective Human is accustomed to climatic conditions of the environment where they are born and live throughout their lifetime. The aim of this study is to examine mood swings and depression caused by sudden climate changes that have not yet given the humans a chance to adapt. Results Our results showed that depression could be affected by climate change and as a result, the behavior of climatic elements and trends has damaged mental health in the western regions of Iran. By investigating the trends and changes of climatic time series and their relationship with the rate of depression in urban areas of western Iran, it can be said that climate change is probably a mental health challenge for urban populations. Climate change is an important and worrying issue that makes the life difficult. Rapid climate changes in western Iran including rising air temperature, changes in precipitation, its regime, changes cloudiness and the amount of sunlight have a negative effects on health. The results showed that type of increasing or decreasing trend, as well as different climatic elements in various seasons did not have the same effect on the rate of depression in the studied areas.

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