scholarly journals Do linden trees kill bees? Reviewing the causes of bee deaths on silver linden ( Tilia tomentosa )

2017 ◽  
Vol 13 (9) ◽  
pp. 20170484 ◽  
Author(s):  
Hauke Koch ◽  
Philip C. Stevenson
Keyword(s):  
Optimal Foraging ◽  
Late Summer ◽  
Secondary Compounds ◽  
Food Sources ◽  
Flowering Period ◽  
Behavioural Effects ◽  
Foraging Decisions ◽  
Pollen Chemistry ◽  
Alternative Food Sources ◽  
Tilia Tomentosa

For decades, linden trees (basswoods or lime trees), and particularly silver linden ( Tilia tomentosa ), have been linked to mass bee deaths. This phenomenon is often attributed to the purported occurrence of the carbohydrate mannose, which is toxic to bees, in Tilia nectar. In this review, however, we conclude that from existing literature there is no experimental evidence for toxicity to bees in linden nectar. Bee deaths on Tilia probably result from starvation, owing to insufficient nectar resources late in the tree's flowering period. We recommend ensuring sufficient alternative food sources in cities during late summer to reduce bee deaths on silver linden. Silver linden metabolites such as floral volatiles, pollen chemistry and nectar secondary compounds remain underexplored, particularly their toxic or behavioural effects on bees. Some evidence for the presence of caffeine in linden nectar may mean that linden trees can chemically deceive foraging bees to make sub-optimal foraging decisions, in some cases leading to their starvation.

scholarly journals Effects of Sitka spruce masting on phenology and demography of siskins Spinus spinus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Euan N. Furness ◽  
Robert W. Furness
Keyword(s):  
Native Species ◽  
Late Summer ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Food Sources ◽  
Breeding Ecology ◽  
Cone Production ◽  
Forestry Practices ◽  
Age Ratio ◽  
Alternative Food Sources

AbstractMasting behaviour of Sitka spruce Picea sitchensis may influence Eurasian siskin Spinus spinus breeding ecology as breeding siskins specialize on spruce seeds. We caught siskins and other small passerines over 16 years using mist nets adjacent to large plantations of mature Sitka spruce. We sexed, aged, measured and weighed the birds and collected feather samples from fledglings to measure nitrogen and carbon stable isotope ratios. Siskins departed in late summer, and returned, and bred earlier in years of higher cone abundance. Nitrogen and carbon isotopes indicated that siskins fed their chicks on Sitka spruce seeds in most years, and more so in years of high cone production. More siskins were caught following heavy rainfall, when the cones had closed, encouraging the birds to seek alternative food sources. Fledglings were not heavier or larger in years with higher cone crops but were more numerous. However, the age ratio of siskins caught the following year was unaffected by cone crop. Given their reliance on Sitka spruce seeds, climate change may have a major impact on siskin numbers by altering the availability of Sitka spruce seeds, either through changes in masting patterns or cone opening, or due to climate-related changes in forestry practices. Siskins represent a valuable study system to conservation ecology, where a native species is ecologically reliant on introduced taxa.

scholarly journals Medium-grown daylily flowering in the Republic of Mari El

2020 ◽  
pp. 1-6
Author(s):  
Mariya Aleksandrovna Okach ◽  
Svetlana Valer'evna Mukhametova ◽  
Kseniya Valentinovna Kharisova ◽  
Anastasiya Sergeevna Polkanova ◽  
Gul'nara Il'darovna Yakupova
Keyword(s):  
Late Summer ◽  
Continuous Series ◽  
Herbaceous Plant ◽  
Flowering Period ◽  
State University ◽  
Perennial Herbaceous Plant ◽  
University Of Technology ◽  
Country Club ◽  
Beginning Of Flowering ◽  
The Republic

Daylily (Hemerocallis) is a perennial herbaceous plant widely used in landscape gardening. Daylilies are prized for their long term flowering mainly in late summer and low maintenance cultivation. According to flower spike height, the varieties are divided into runt, medium-growing and tall. The article contains the results of the study of 21 medium-growing daylily varieties’ terms of flowering in the botanic garden of the Volga region State University of Technology (Yoshkar-Ola, the Republic of Mari El). The research was conducted in 2015 - 2017. The calendar dates were converted into a continuous series. All varieties were classified as early, medium or late according to the terms of the beginning and the end of flowering and its duration. During three years of research, the earliest beginning of the phenological phase was registered in 2016, and the latest one  - in 2017. The early beginning and ending of flowering were typical for the varieties “Dr Regel” and “Royal Sovereign”. The late beginning of flowering was registered for the “Country Club” variety, and the late ending - for “Sandalwood”. Other varieties were classified as medium-term. The varieties “Royal Sovereign”, “Tejas”, and “Sugar Candy” are characterized by a short flowering period, while “Sandalwood” and “Derby Bound” - with a long one. It was established that the late-flowering varieties are characterized with a longer flowering period.

scholarly journals Replacing Red Meat with Alternative Food Sources of Protein on Risk of Type 2 Diabetes - Modeling Dietary Changes in a Causal Framework

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1418-1418
Author(s):  
Daniel Ibsen ◽  
Marianne Jakobsen ◽  
Jytte Halkjær ◽  
Erik Parner ◽  
Kim Overvad
Keyword(s):  
Type 2 Diabetes ◽  
Whole Grains ◽  
Red Meat ◽  
Risk Difference ◽  
Alternative Food ◽  
Food Sources ◽  
Incident Type ◽  
Exposure Effect ◽  
Alternative Food Sources

Abstract Objectives We investigated whether decreasing the intake of red meat and simultaneously increasing the intake of alternative food sources of protein affects the risk of type 2 diabetes compared with no changes in the substituted foods. We also examined interaction with the age at which participants changed their diet. Methods We used the Danish Diet, Cancer and Health cohort including men and women, two measures of diet taken roughly 5 years apart using food frequency questionnaires and information on incident type 2 diabetes derived from the Danish National Diabetes Register (n = 39,349; aged 55 to 72 years at the second diet measure; n cases = 3759). The pseudo-observation method was used to estimate the average exposure effect of decreasing the intake of red meat (processed and unprocessed) while increasing the intake of either poultry, fish, cheese, eggs or whole grains compared with no changes in the substituted foods on the subsequent 10-year risk of development type 2 diabetes. Results In multivariable adjusted models, we found that replacing 1 serving/day (100 g) of red meat with 1 serving/day of eggs (50 g) (risk difference −2.4%, 95% confidence interval −3.7 to −1.1%) or whole grains (30 g) (−1.4%, −2.2 to −0.6%) was associated with a reduced risk of type 2 diabetes. No effects were observed for other replacements. In general, the lowest risk was observed for replacements at age 55 years compared with older ages (up to 70 years) for all replacements. Conclusions Replacing red meat with eggs or whole grains may reduce the risk of type 2 diabetes compared with no changes in the substituted foods. Changing red meat intake in midlife may be more beneficial than at older ages. Funding Sources Aarhus University.

Food hoarding: future value in optimal foraging decisions

2004 ◽  
Vol 175 (1) ◽  
pp. 77-85 ◽  
Author(s):  
L.R. Gerber ◽  
O.J. Reichman ◽  
J. Roughgarden
Keyword(s):  
Optimal Foraging ◽  
Food Hoarding ◽  
Foraging Decisions ◽  
Future Value

Color and side preferences in Palestine sunbirds (Nectarinia osea)

2014 ◽  
Vol 60 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Rainee L. Kaczorowski ◽  
Gali Blumenfeld ◽  
Avi Koplovich ◽  
Shai Markman
Keyword(s):  
Food Sources ◽  
Separate Experiment ◽  
Significant Preference ◽  
Floral Color ◽  
Foraging Decisions ◽  
Quality Of Food ◽  
Color Bias ◽  
Preference Experiment ◽  
Side Bias

Floral color is an important cue that converged in many ornithophilous flowers and can be used by nectarivorous birds to make foraging decisions. Wild ornithophilous flowers are frequently red, although they are more often yellow in Israel. The Palestine sunbird (Nectarinia osea) is the only nectarivorous bird in Israel and surrounding Mediterranean areas. Given the prevalence of yellow flowers in their habitats (along with sunbirds' expected sensitivity increase in this region of color vision), we predicted that Palestine sunbirds prefer yellow food sources over red. We examined sunbird foraging behavior when they were presented simultaneously with a yellow and red feeder, each containing the same quantity and quality of food. We investigated whether sunbirds had a side bias in the color preference experiment, but also in a separate experiment where both feeders were white. Sunbirds did not exhibit a significant color bias, while they did have a significant preference for a particular side of the cage. Location appears to be a more important cue than color to Palestine sunbirds, likely because location can offer information on the most rewarding plants and recently depleted flowers. However, color may still provide useful information that could influence foraging decisions in different contexts.

Promoting access to fresh fruits and vegetables through a local market intervention at a subway station

2018 ◽  
Vol 21 (17) ◽  
pp. 3258-3270 ◽  
Author(s):  
Sarah Chaput ◽  
Geneviève Mercille ◽  
Louis Drouin ◽  
Yan Kestens
Keyword(s):  
Low Income ◽  
Public Transportation ◽  
Fruits And Vegetables ◽  
Food Sources ◽  
Subway Station ◽  
Local Market ◽  
Cross Sectional ◽  
Market Intervention ◽  
Alternative Food Sources ◽  
Physical Access

AbstractObjectiveAlternative food sources (AFS) such as local markets in disadvantaged areas are promising strategies for preventing chronic disease and reducing health inequalities. The present study assessed how sociodemographic characteristics, physical access and fruit and vegetable (F&V) consumption are associated with market use in a newly opened F&V market next to a subway station in a disadvantaged neighbourhood.DesignTwo cross-sectional surveys were conducted among adults: (i) on-site, among shoppers who had just bought F&V and (ii) a telephone-based population survey among residents living within 1 km distance from the market.SettingOne neighbourhood in Montreal (Canada) with previously limited F&V offerings.SubjectsRespectively, 218 shoppers and 335 residents completed the on-site and telephone-based population surveys.ResultsAmong shoppers, 23 % were low-income, 56 % did not consume enough F&V and 54 % did not have access to a car. Among all participants living 1 km from the market (n472), market usage was associated (OR; 95 % CI) with adequate F&V consumption (1·86; 1·10, 3·16), living closer to the market (for distance: 0·86; 0·76, 0·97), having the market on the commute route (2·77; 1·61, 4·75) and not having access to a car (2·96; 1·67, 5·26).ConclusionsWhen implemented in strategic locations such as transport hubs, AFS like F&V markets offer a promising strategy to improve F&V access among populations that may be constrained in their food acquisition practices, including low-income populations and those relying on public transportation.

Alternative food sources of native and non-native bivalves in a subtropical eutrophic lake

Hydrobiologia ◽  
2013 ◽  
Vol 735 (1) ◽  
pp. 263-276 ◽  
Author(s):  
Soledad Marroni ◽  
Carlos Iglesias ◽  
Néstor Mazzeo ◽  
Juan Clemente ◽  
Franco Teixeira de Mello ◽  
...  
Keyword(s):  
Eutrophic Lake ◽  
Alternative Food ◽  
Food Sources ◽  
Alternative Food Sources

scholarly journals Artificial selection for predatory behavior results in dietary niche differentiation in an omnivorous mammal

2021 ◽  
Author(s):  
Anni M Hämäläinen ◽  
Mikko Kiljunen ◽  
Esa Koskela ◽  
Pawel Koteja ◽  
Tapio Mappes ◽  
...  
Keyword(s):  
Late Summer ◽  
Niche Differentiation ◽  
Predatory Behavior ◽  
Early Summer ◽  
Food Sources ◽  
Diet Choice ◽  
Behavioral Selection ◽  
Plant Matter ◽  
Dietary Niche ◽  
The Individual

The diet of an individual is a result of the availability of dietary items and the individual's foraging skills and preferences. Behavioral differences may thus influence diet variation, but the evolvability of diet choice through behavioral evolution has not been studied. We used experimental evolution combined with a field enclosure experiment to test whether behavioral selection leads to dietary divergence. We analysed the individual dietary niche via stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) in the hair of an omnivorous mammal, bank vole, from 4 lines selected for predatory behavior and 4 unselected control lines. Predatory voles had higher hair δ15N values than control voles, supporting our hypothesis that predatory voles would consume a higher trophic level diet (more animal vs. plant foods). This difference was significant in the early but not the late summer season. The δ13C values also indicated a seasonal change in the consumed plant matter and a difference in food sources among selection lines in the early summer. These results imply that environmental factors interact with evolved behavioral tendencies to determine dietary niche heterogeneity. Behavioral selection thus has potential to contribute to the evolution of diet choice and ultimately the species' ecological niche breadth.

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