scholarly journals Seasonal variation in exploitative competition between honeybees and bumblebees

Oecologia ◽  
2019 ◽  
Vol 192 (2) ◽  
pp. 351-361 ◽  
Author(s):  
Veronica R. Wignall ◽  
Isabella Campbell Harry ◽  
Natasha L. Davies ◽  
Stephen D. Kenny ◽  
Jack K. McMinn ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Standing Crop ◽  
Foraging Behaviour ◽  
Competitive Exclusion ◽  
Floral Resources ◽  
Competitive Pressure ◽  
Exploitative Competition ◽  
Full Bloom ◽  
Nectar Standing Crop ◽  
Flower Choice

AbstractHoneybees (Apis mellifera) and bumblebees (Bombus spp.) often undergo exploitative competition for shared floral resources, which can alter their foraging behaviour and flower choice, even causing competitive exclusion. This may be strongest in summer, when foraging conditions are most challenging for bees, compared to other times of the year. However, the seasonal dynamics of competition between these major pollinator groups are not well understood. Here, we investigate whether the strength of exploitative competition for nectar between honeybees and bumblebees varies seasonally, and whether competitive pressure is greatest in summer months. We carried out experimental bee exclusion trials from May to late September, using experimental patches of lavender, variety Grosso, in full bloom. In each trial, we compared the numbers of honeybees (HB) foraging on patches from which bumblebees had been manually excluded (bumblebee excluded, BBE) versus control (CON) patches, HB(BBE-CON). This measure of exploitative competition varied significantly with season. As expected, mean HB(BBE-CON) was significantly greater in summer trials than in spring or autumn trials. This was despite high nectar standing crop volumes in BBE patch flowers in spring and autumn trials. Mean HB(BBE-CON) was not different between spring and autumn trials. Our results show that nectar competition between honeybees and bumblebees varies seasonally and is stronger in summer than spring or autumn, adding to current understanding of the seasonality of resource demand and competition between bee species. This information may also help to inform conservation programs aiming to increase floral resources for bees by showing when these resources are most needed.

scholarly journals Exploitative competition for floral resources reduces sugar intake but differently impacts the foraging behaviour of two non‐bee flower visitors

Oikos ◽  
2021 ◽  
Author(s):  
Emma Jeavons ◽  
Ondine Chevrie ◽  
Cécile Le Lann ◽  
David Renault ◽  
Maëva Floch ◽  
...  
Keyword(s):  
Foraging Behaviour ◽  
Floral Resources ◽  
Exploitative Competition ◽  
Flower Visitors ◽  
Sugar Intake

Exploitative competition alters bee foraging and flower choice

2015 ◽  
Vol 69 (10) ◽  
pp. 1731-1738 ◽  
Author(s):  
Nicholas J. Balfour ◽  
Sam Gandy ◽  
Francis L. W. Ratnieks
Keyword(s):  
Exploitative Competition ◽  
Bee Foraging ◽  
Flower Choice

scholarly journals Mexican creeper, Antigonon leptopus Hook. and Arn : An effective bee forage plant to conserve honey bee

2020 ◽  
Vol 15 (2) ◽  
pp. 225-228
Author(s):  
P V Rami Reddy
Keyword(s):  
Ecosystem Services ◽  
Species Diversity ◽  
Honey Bee ◽  
Honey Bees ◽  
Native Species ◽  
Foraging Behaviour ◽  
Apis Cerana ◽  
Floral Resources ◽  
Urban Habitats ◽  
Forage Plant

Decline in honey bee populations has become a matter of concern and their conservation is very essential to sustain essential ecosystem services. They provide making available continuous supply of floral resources is of immense value in conserving honey bees. The effectiveness of an ornamental creeper, Antigonon leptopus Hook. & Arn as a sustainable bee forage plant was evaluated. It attracts four major native species of honey bees viz., Apis cerana, A. florea, A. dorsata and Tetragonula iridipennis. The wild little bee, A. florea was the most dominant forager followed by the Indian bee, A. cerana. The plant is amenable for easy multiplication through seeds as well as cuttings and meets both aesthetic and ecological needs. Using Antigonon, different studies related to honey bees like assessing species diversity, foraging behaviour, temperature driven shifts etc. can be carried out. Popularising perennial bee flora like Antigonon would help in conserving honey bees in both natural and urban habitats. Since Antigonon attracts all species of honey bees throughout the year, it could be utilized as a potential bioindicator of honey bee populations in a given environment.

Sexual and seasonal variation in the diet and foraging behaviour of a sexually dimorphic carnivore, the honey badger (Mellivora capensis)

2003 ◽  
Vol 260 (3) ◽  
pp. 301-316 ◽  
Author(s):  
C. M. Begg ◽  
K. S. Begg ◽  
J. T. Du Toit ◽  
M. G. L. Mills
Keyword(s):  
Seasonal Variation ◽  
Foraging Behaviour ◽  
Sexually Dimorphic

scholarly journals Exploitative competition and displacement mediated by eusocial bees: experimental evidence in a wild pollinator community

2020 ◽  
Vol 74 (12) ◽  
Author(s):  
Veronica R. Wignall ◽  
Matthew Brolly ◽  
Cassandra Uthoff ◽  
Kala E. Norton ◽  
Hannah M. Chipperfield ◽  
...  
Keyword(s):  
Resource Availability ◽  
Resource Competition ◽  
Landscape Management ◽  
Resource Depletion ◽  
Floral Resources ◽  
Exploitative Competition ◽  
Ecological Release ◽  
Pollinator Community ◽  
Eusocial Bees ◽  
Floral Resource

Abstract Eusocial bees are likely to be ecologically important competitors for floral resources, although competitive effects can be difficult to quantify in wild pollinator communities. To investigate this, we excluded honeybees (HBE treatment), bumblebees (BBE) or both (HB&BBE) from wild-growing patches of bramble, Rubus fruticosus L. agg., flowers in two eight-day field trials at separate locations, with complementary mapping of per-site local floral resource availability. Exclusions increased per-flower volume of nectar and visitation rates of non-excluded bees, compared to control patches with no bee exclusions (CON). There was a large increase in average nectar standing crop volume both at Site 1 (+ 172%) and Site 2 (+ 137%) in HB&BBE patch flowers, and no significant change in HBE or BBE, compared to CON patches. Foraging bee responses to exclusion treatments were more pronounced at Site 2, which may be due to lower local floral resource availability, since this is likely to increase the degree of exploitative competition present. Notably, at Site 2, there was a 447% increase in larger-bodied solitary (non-Apis/Bombus) bees visiting HB&BBE patches, suggesting ecological release from competition. Hoverflies showed no response to bee removals. Numbers of other non-bee insect groups were very small and also showed no clear response to exclusions. Our findings reveal patterns of competitive exclusion between pollinator groups, mediated by resource depletion by eusocial bees. Possible long-term implications of displacement from preferred flowers, particularly where alternative forage is reduced, are discussed. Significance statement Understanding patterns of exploitative competition and displacement is necessary for pollinator conservation, particularly for vulnerable or threatened species. In this research, experimental methods reveal underlying patterns of resource competition exerted by eusocial bees in a wild pollinator community. We show that honeybees and bumblebees competitively displace each other and particularly solitary (non-Apis/Bombus) bees from bramble, an important native nectar and pollen source. Effects were stronger where local floral resource availability was identified to be limited. Notably, following experimental exclusion of both honey- and bumblebees from flowers, visitation by solitary bees increased by up to 447%, strongly suggesting ecological release from competition. These results highlight the need for informed landscape management for pollinator wellbeing, including appropriate honeybee stocking densities and improved floral resource availability.

Seasonal variation in foraging behaviour of plains zebra (Equus quagga) may alter contact with the anthrax bacterium (Bacillus anthracis)

2014 ◽  
Vol 92 (4) ◽  
pp. 331-337 ◽  
Author(s):  
Zepee Havarua ◽  
Wendy C. Turner ◽  
John K.E. Mfune
Keyword(s):  
Seasonal Variation ◽  
Bacillus Anthracis ◽  
Foraging Behaviour ◽  
Dry Season ◽  
Wet Season ◽  
Contact Rates ◽  
Bacterium Bacillus ◽  
Environmental Pathogens ◽  
Host Foraging ◽  
Plains Zebra

Pathogens transmitted via the environment are often aggregated in space, and seasonal variation in wildlife foraging behaviour may alter contact rates with environmental pathogens. The soil-borne bacterium Bacillus anthracis Cohn, 1872 causes anthrax, and herbivores acquire gastrointestinal anthrax by ingesting spores. Therefore host foraging behaviour could be a fundamental component of anthrax epidemiology. This study investigated seasonal changes in bite density and diet of plains zebras (Equus quagga Boddaert, 1785) in relation to anthrax seasonality in Etosha National Park, Namibia, where most zebra anthrax cases are observed in wet seasons. The diet of zebras shifted from more short grasses during the wet season to more tall grasses in the dry season, suggesting a greater potential for soil ingestion in wet seasons. Zebras also foraged most intensively in the wet season with the number of bites/step declining through the dry season. This higher bite density in wet seasons may lead individuals to ingest greater concentrations of the pathogen if foraging in a localized infectious area. Although sex and reproductive state affected bite density, no sex difference in anthrax occurrence was observed. This study demonstrates how considering variation in host foraging behaviour may enhance our understanding of disease seasonality for pathogens with foraging-dependent transmission.

scholarly journals Honeybees optimize their foraging behaviour in relation to spatio-temporal changes in nectar and pollen availability

2020 ◽  
Author(s):  
Jan J. Kreider ◽  
Anna Nehrkorn ◽  
Svenja Bänsch ◽  
Carmen Kirsch ◽  
Catrin Westphal
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Foraging Behaviour ◽  
Resource Scarcity ◽  
Floral Resources ◽  
Mass Flowering ◽  
Temporal Shift ◽  
Lime Tree ◽  
Spatio Temporal ◽  
Floral Resource

AbstractIntensified agriculture increasingly threatens wild and managed bees by promoting landscape uniformity and reducing floral resource availability whereas urban areas can provide continuous floral resources within green spaces and private gardens. Mass-flowering events of crops and trees, such as lime trees (Tilia spp.), can provide ample floral resources but only for short time periods. Using waggle dance decoding, pollen analysis and bee abundance recordings, we investigated the temporal shift in honeybee foraging behaviour in response to lime tree mass-flowering. Honeybees in urban areas extended their foraging range during lime tree flowering. Foraging behaviour of honeybees in rural areas did not change to such an extent and honeybees foraged in sown flower strips. Our results suggest that honeybees optimize their foraging behaviour to exploit highly rewarding resources instead of extending foraging ranges in times of floral resource scarcity.

scholarly journals Notes on the flowering and pollination of the endemic grassland Aloe reitzii var. reitzii (Asphodelaceae)

Bothalia ◽  
2017 ◽  
Vol 47 (2) ◽  
Author(s):  
Craig T. Symes
Keyword(s):  
South Africa ◽  
Standing Crop ◽  
Bird Species ◽  
Camera Trap ◽  
Camera Traps ◽  
Pollination Biology ◽  
Nectar Volume ◽  
Invertebrate Species ◽  
Nectar Standing Crop ◽  
Insight Into

Background: Aloe reitzii var. reitzii is a succulent with a restricted distribution in the montane grassland of eastern South Africa. It is a summer (late January–March) flowering succulent that grows on rocky outcrops at 1000 m–1600 m, and the conspicuous inflorescences suggest a pollination system focused towards birds.Objectives: To understand more about the pollination biology of A. reitzii var. reitzii.Methods: Nectar standing crop (flower volume and concentration) and the proportion of plants flowering were recorded. Camera traps and observations were used to record visitors to A. reitzii var. reitzii inflorescences.Results: Nectar volume was 36 μL ± 27 μL per flower (range 6 μL–93 μL; n = 27) and concentration was 16.5% ± 1.7% (range 13.5% – 19.5%). Camera trap observations, where 18.9% of all plants were observed flowering, recorded the three bird species Cape Weaver, Ploceus capensis, Malachite Sunbird, Nectarinia famosa and Greater Double-collared Sunbird, Cinnyris afer (60.4%, 27.1% and 12.5% of plant visits, respectively) visiting inflorescences.Conclusion: Because birds are important pollinators for many Aloe species, it is assumed that the bird species detected visiting A. reitzii var. reitzii are similarly important pollinators. At least 10 invertebrate species and sengi (Elephantulus sp.) were also recorded as visitors to flowers, but they may be less important pollinators than specialist and generalist avian nectarivores. This study provides further insight into the pollination biology of a diverse, and ecologically important, succulent genus in Africa.

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