scholarly journals Weather and food availability additively affect reproductive output in an expanding raptor population

Oecologia ◽  
2021 ◽  
Author(s):  
Melanie Nägeli ◽  
Patrick Scherler ◽  
Stephanie Witczak ◽  
Benedetta Catitti ◽  
Adrian Aebischer ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Food Availability ◽  
Reproductive Output ◽  
Weather Conditions ◽  
Interactive Effects ◽  
Food Supplementation ◽  
Nestling Development ◽  
Trade Offs ◽  
Adverse Weather ◽  
Expanding Population

AbstractThe joint effects of interacting environmental factors on key demographic parameters can exacerbate or mitigate the separate factors’ effects on population dynamics. Given ongoing changes in climate and land use, assessing interactions between weather and food availability on reproductive performance is crucial to understand and forecast population dynamics. By conducting a feeding experiment in 4 years with different weather conditions, we were able to disentangle the effects of weather, food availability and their interactions on reproductive parameters in an expanding population of the red kite (Milvus milvus), a conservation-relevant raptor known to be supported by anthropogenic feeding. Brood loss occurred mainly during the incubation phase, and was associated with rainfall and low food availability. In contrast, brood loss during the nestling phase occurred mostly due to low temperatures. Survival of last-hatched nestlings and nestling development was enhanced by food supplementation and reduced by adverse weather conditions. However, we found no support for interactive effects of weather and food availability, suggesting that these factors affect reproduction of red kites additively. The results not only suggest that food-weather interactions are prevented by parental life-history trade-offs, but that food availability and weather conditions are crucial separate determinants of reproductive output, and thus population productivity. Overall, our results suggest that the observed increase in spring temperatures and enhanced anthropogenic food resources have contributed to the elevational expansion and the growth of the study population during the last decades.

Food supplementation and abundance estimation in the white-footed mouse

2006 ◽  
Vol 84 (8) ◽  
pp. 1210-1215 ◽  
Author(s):  
Pei-Jen L. Shaner
Keyword(s):  
Population Dynamics ◽  
Food Availability ◽  
Robust Design ◽  
Meta Analysis ◽  
Design Model ◽  
Food Supplementation ◽  
Abundance Estimates ◽  
Abundance Indices ◽  
Consumer Population ◽  
White Footed Mouse

Food availability often drives consumer population dynamics. However, food availability may also influence capture probability, which if not accounted for may create bias in estimating consumer abundance and confound the effects of food availability on consumer population dynamics. This study compared two commonly used abundance indices (minimum number alive (MNA) and number of animals captured per night per grid) with an abundance estimator based on robust design model as applied to the white-footed mouse ( Peromyscus leucopus (Rafinesque, 1818)) in food supplementation experiments. MNA consistently generated abundance estimates similar to the robust design model, regardless of food supplementation. The number of animals captured per night per grid, however, consistently generated lower abundance estimates compared with MNA and the robust design model. Nevertheless, the correlations between abundance estimates from MNA, number of animals captured, and robust design model were not influenced by food supplementation. This study demonstrated that food supplementation is not likely to create bias among these different measures of abundance. Therefore, there is a great potential for conducting meta-analysis of food supplementation effect on consumer population dynamics (particularly in small mammals) across studies using different abundance indices and estimators.

scholarly journals Adverse weather conditions reduce food availability and increase glucocorticoid metabolite levels in barn swallow nestlings

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Carlo Cinque ◽  
Nicholas Moray Williams ◽  
Cristina Bencini ◽  
Roberto Cozzolino
Keyword(s):  
Food Availability ◽  
Weather Conditions ◽  
Barn Swallow ◽  
Adverse Weather Conditions ◽  
Adverse Weather

scholarly journals Food limitation constrains host immune responses to nematode infections

2016 ◽  
Vol 12 (9) ◽  
pp. 20160471 ◽  
Author(s):  
Kristian M. Forbes ◽  
Tapio Mappes ◽  
Tarja Sironen ◽  
Tomas Strandin ◽  
Peter Stuart ◽  
...  
Keyword(s):  
Immune Responses ◽  
Food Availability ◽  
Food Limitation ◽  
Finite Energy ◽  
Innate Immune ◽  
Food Supplementation ◽  
Boreal Winter ◽  
Intestinal Nematode ◽  
Trade Offs ◽  
Parasite Infections

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles ( Microtus agrestis ) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal parasite infections were compared between food-supplemented and non-supplemented voles. Voles with high food availability mounted stronger immune responses against intestinal nematode infections than food-limited voles. No food effects were seen in immune responses to intracellular coccidian parasites, possibly owing to their ability to avoid activation of innate immune pathways. Our findings demonstrate that food availability constrains vole immune responses against nematode infections, and support the concept that spatio-temporal heterogeneity in food availability creates variation in infectious disease susceptibility.

scholarly journals Food provisioning alters infection dynamics in populations of a wild rodent

2015 ◽  
Vol 282 (1816) ◽  
pp. 20151939 ◽  
Author(s):  
Kristian M. Forbes ◽  
Heikki Henttonen ◽  
Varpu Hirvelä-Koski ◽  
Anja Kipar ◽  
Tapio Mappes ◽  
...  
Keyword(s):  
Food Availability ◽  
Population Level ◽  
Bordetella Bronchiseptica ◽  
Interactive Effects ◽  
Food Supplementation ◽  
Boreal Winter ◽  
Infection Prevalence ◽  
Food Provisioning ◽  
Negative Effects ◽  
Pathogen Infection

While pathogens are often assumed to limit the growth of wildlife populations, experimental evidence for their effects is rare. A lack of food resources has been suggested to enhance the negative effects of pathogen infection on host populations, but this theory has received little investigation. We conducted a replicated two-factor enclosure experiment, with introduction of the bacterium Bordetella bronchiseptica and food supplementation, to evaluate the individual and interactive effects of pathogen infection and food availability on vole populations during a boreal winter. We show that prior to bacteria introduction, vole populations were limited by food availability. Bordetella bronchiseptica introduction then reduced population growth and abundance, but contrary to predictions, primarily in food supplemented populations. Infection prevalence and pathological changes in vole lungs were most common in food supplemented populations, and are likely to have resulted from increased congregation and bacteria transmission around feeding stations. Bordetella bronchiseptica- infected lungs often showed protozoan co-infection (consistent with Hepatozoon erhardovae ), together with more severe inflammatory changes. Using a multidisciplinary approach, this study demonstrates a complex picture of interactions and underlying mechanisms, leading to population-level effects. Our results highlight the potential for food provisioning to markedly influence disease processes in wildlife mammal populations.

Food availability in spring influences reproductive output in the seed-preying edible dormouse (Glis glis)

2009 ◽  
Vol 87 (7) ◽  
pp. 555-565 ◽  
Author(s):  
T. Kager ◽  
J. Fietz
Keyword(s):  
Litter Size ◽  
Food Availability ◽  
Reproductive Output ◽  
European Beech ◽  
Food Supplementation ◽  
Lactation Period ◽  
Glis Glis ◽  
Supplemental Food ◽  
Fagus Sylvatica L ◽  
Edible Dormice

Edible dormice ( Glis glis (L., 1766)) display strong annual variation in their reproductive output that is closely related to resource availability, commonly measured through the quantity of seeds produced by their most important food provider, the European beech ( Fagus sylvatica L.). Dormouse mating takes place several weeks before beech seeds ripen, and to the present day it remains unclear how dormice achieve optimized reproductive output in reflection of the quantity of food available in the future. The first aim of this field study carried out over 13 years was thus to investigate the relationship between beech masting and reproductive performance in edible dormice in Germany. If food availability in spring influenced litter size, this would partially explain observed natural variability in offspring numbers. We thus chose an experimental approach and provided supplemental food to edible dormice in the field. Our results showed that numbers and proportions of reproductively active females, as well as litter sizes, between 1993 and 2005 were positively correlated with beech mast. Food supplementation positively affected litter size and litters of food-supplemented females were found to be larger than those of unsupplemented females. Food-supplemented mothers and their offspring gained body mass considerably faster during lactation and were heavier at the end of the lactation period compared with controls. However, juvenile body size, as well as its increase, did not differ between the two treatments. Our results suggest a link between edible dormice reproductive output and food availability after emergence from hibernation.

scholarly journals Experimental food supplementation reveals habitat-dependent male reproductive investment in a migratory bird

2015 ◽  
Vol 282 (1803) ◽  
pp. 20142523 ◽  
Author(s):  
Sara A. Kaiser ◽  
T. Scott Sillett ◽  
Benjamin B. Risk ◽  
Michael S. Webster
Keyword(s):  
Reproductive Success ◽  
Food Availability ◽  
Habitat Quality ◽  
Mating Success ◽  
Reproductive Investment ◽  
Food Supplementation ◽  
Male Mating ◽  
Male Mating Success ◽  
Extrapair Paternity ◽  
Trade Offs

Environmental factors can shape reproductive investment strategies and influence the variance in male mating success. Environmental effects on extrapair paternity have traditionally been ascribed to aspects of the social environment, such as breeding density and synchrony. However, social factors are often confounded with habitat quality and are challenging to disentangle. We used both natural variation in habitat quality and a food supplementation experiment to separate the effects of food availability—one key aspect of habitat quality—on extrapair paternity (EPP) and reproductive success in the black-throated blue warbler, Setophaga caerulescens . High natural food availability was associated with higher within-pair paternity (WPP) and fledging two broods late in the breeding season, but lower EPP. Food-supplemented males had higher WPP leading to higher reproductive success relative to controls, and when in low-quality habitat, food-supplemented males were more likely to fledge two broods but less likely to gain EPP. Our results demonstrate that food availability affects trade-offs in reproductive activities. When food constraints are reduced, males invest in WPP at the expense of EPP. These findings imply that environmental change could alter how individuals allocate their resources and affect the selective environment that drives variation in male mating success.

scholarly journals Factors influencing nest-site occupancy and low reproductive output in the Critically Endangered Yellow-crested Cockatoo Cacatua sulphurea on Sumba, Indonesia

2005 ◽  
Vol 15 (4) ◽  
pp. 347-359 ◽  
Author(s):  
JONATHAN S. WALKER ◽  
ALEXIS J. CAHILL ◽  
STUART J. MARSDEN
Keyword(s):  
National Park ◽  
Reproductive Output ◽  
Nest Site ◽  
Interspecific Interactions ◽  
Site Occupancy ◽  
Weather Conditions ◽  
Nest Site Selection ◽  
Critically Endangered ◽  
Adverse Weather Conditions ◽  
Adverse Weather

We studied nest-site selection and nesting success in the critically endangered Yellow-crested Cockatoo Cacatua sulphurea throughout a breeding season in Manupeu-Tanadaru National Park, Sumba. Within a 6 km2 study area, which supported about 60 birds, cockatoos displayed disproportionate interest in cavities in trees containing other active nests, and cavities already actually occupied by parrots or owls. Actual nesting attempts were made at only eight cavities, and a single chick fledged. Interspecific interactions were observed at every one of these nests. Breeding activity was negatively correlated with monthly rainfall, which was the heaviest for at least 10 years, and it is possible that adverse weather conditions disrupted cockatoo nesting this season. Whether this is the case or not, our study shows how low reproductive output can be in the species and this has serious implications for survival of the population on Sumba.

A tes

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
IJE Manager
Keyword(s):  
Energy Supply ◽  
Fossil Fuels ◽  
Geographical Location ◽  
Weather Conditions ◽  
Past Century ◽  
Solar Pv ◽  
Pv Systems ◽  
Trade Offs ◽  
A Site ◽  
Selection Methodology

In the past century, fossil fuels have dominated energy supply in Indonesia. However, concerns over emissions are likely to change the future energy supply. As people become more conscious of environmental issues, alternatives for energy are sought to reduce the environmental impacts. These include renewable energy (RE) sources such as solar photovoltaic (PV) systems. However, most RE sources like solar PV are not available continuously since they depend on weather conditions, in addition to geographical location. Bali has a stable and long sunny day with 12 hours of daylight throughout the year and an average insolation of 5.3 kWh/m2 per day. This study looks at the potential for on-grid solar PV to decarbonize energy in Bali. A site selection methodology using GIS is applied to measure solar PV potential. Firstly, the study investigates the boundaries related to environmental acceptability and economic objectives for land use in Bali. Secondly, the potential of solar energy is estimated by defining the suitable areas, given the technical assumptions of solar PV. Finally, the study extends the analysis to calculate the reduction in emissions when the calculated potential is installed. Some technical factors, such as tilting solar, and intermittency throughout the day, are outside the scope of this study. Based on this model, Bali has an annual electricity potential for 32-53 TWh from solar PV using amorphous thin-film silicon as the cheapest option. This potential amount to three times the electricity supply for the island in 2024 which is estimated at 10 TWh. Bali has an excessive potential to support its own electricity demand with renewables, however, some limitations exist with some trade-offs to realize the idea. These results aim to build a developmental vision of solar PV systems in Bali based on available land and the region’s irradiation.

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