scholarly journals Nest aggregations of wild bees and apoid wasps in urban pavements: a street life to be promoted in urban planning

2021 ◽  
Author(s):  
Gregoire Noel ◽  
Violette Van Keymeulen ◽  
Yvan Barbier ◽  
Sylvie Smets ◽  
Olivier Van Damme ◽  
...  
Keyword(s):  
Urban Ecology ◽  
Community Dynamics ◽  
Engineering Management ◽  
Floral Resources ◽  
Wild Bees ◽  
Wasp Species ◽  
Management Guidelines ◽  
Nesting Site ◽  
Nesting Sites ◽  
Ground Nesting

In the last 10 years, knowledges of wild bees and apoid wasps community dynamics have gained interest in urban ecology focusing on the availability of floral resources in cities. Although understudied, the urban environment impacts the conditions of their nesting sites. Recent observations in the Brussels-Capital Region (Belgium) showed that urban pavements can be a novel nesting opportunity for Hymenoptera ground-nesting species such as wild bees and apoid wasps. Here, using citizen science, we investigated the richness of ground-nesting species living under urban pavements, the preferences of the sidewalk joint size related to ground-nesting species size and for sidewalk type or for soils texture under the pavements on the nesting site selection. A total of 22 species belonging to 10 Hymenoptera families of wild bees and digger wasps with their associated kleptoparasites were identified on 89 sites in Brussels. Sandstone setts or concrete slabs with an unbound joint size around 1 cm were found to be best suitable urban pavements for the ground-nesting species. The soil texture under the pavement was highly sandy among our samples. Finally, we also suggest engineering management guidelines to support bee and wasp species nesting under urban pavement in highly urbanized areas. Such observations pave the way for much research in the field of urban ecology to conceive multifunctional pavement promoting biodiversity.

scholarly journals Pollination Potential of Riparian Hardwood Forests—A Multifaceted Field-Based Assessment in the Vistula Valley, Poland

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 907
Author(s):  
Andrzej N. Affek ◽  
Edyta Regulska ◽  
Ewa Kołaczkowska ◽  
Anna Kowalska ◽  
Katarzyna Affek
Keyword(s):  
Agricultural Landscape ◽  
Riparian Forest ◽  
Field Measurements ◽  
Threshold Value ◽  
Early Spring ◽  
Hardwood Forests ◽  
Floral Resources ◽  
Vistula River ◽  
Pollinator Abundance ◽  
Nesting Sites

Riparian forests with oaks, ashes and elms, now highly fragmented and rare in Europe, are considered hotspots for ecosystem services. However, their capacity to provide pollination seems to be quite low, although reports from in-situ research supporting this view are scarce. Our goal was therefore to thoroughly assess their pollination potential based on multifaceted field measurements. For this, we selected six test sites with well-developed riparian hardwood forests, located in the agricultural landscape along the middle Vistula River in Poland. We used seven indicators relating to habitat suitability (nesting sites and floral resources) and pollinator abundance (bumblebees and other Apoidea) and propose a threshold value (AdjMax) based on value distribution and Hampel’s test to indicate the level of pollination potential for this type of riparian forest. The obtained AdjMax for bumblebee density was 500 ind. ha−1, for Apoidea abundance—0.42 ind. day−1, while for nectar resources—200 kg ha−1. We demonstrate that the investigated small patches of the riparian hardwood forest have a higher pollination potential than reported earlier for riparian and other broadleaved temperate forests, but the indicators were inconsistent. As forest islands in the agricultural landscape, riparian hardwood forests play an important role in maintaining the diversity and abundance of wild pollinators, especially in early spring when there is still no food base available elsewhere.

scholarly journals Identity of mass-flowering crops moderates functional trait composition of pollinator communities

2021 ◽  
Author(s):  
Nicole Beyer ◽  
Felix Kirsch ◽  
Doreen Gabriel ◽  
Catrin Westphal
Keyword(s):  
Faba Bean ◽  
Management Practices ◽  
Functional Trait ◽  
Flower Morphology ◽  
Landscape Diversity ◽  
Floral Resources ◽  
Wild Bees ◽  
Natural Habitats ◽  
Mass Flowering ◽  
Wild Bee

Abstract Context Pollinator declines and functional homogenization of farmland insect communities have been reported. Mass-flowering crops (MFC) can support pollinators by providing floral resources. Knowledge about how MFC with dissimilar flower morphology affect functional groups and functional trait compositions of wild bee communities is scarce. Objective We investigated how two morphologically different MFC, land cover and local flower cover of semi-natural habitats (SNH) and landscape diversity affect wild bees and their functional traits (body size, tongue length, sociality, foraging preferences). Methods We conducted landscape-level wild bee surveys in SNH of 30 paired study landscapes covering an oilseed rape (OSR) (Brassica napus L.) gradient. In 15 study landscapes faba beans (Vicia faba L.) were grown, paired with respective control landscapes without grain legumes. Results Faba bean cultivation promoted bumblebees (Bombus spp. Latreille), whereas non-Bombus densities were only driven by the local flower cover of SNH. High landscape diversity enhanced wild bee species richness. Faba bean cultivation enhanced the proportions of social wild bees, bees foraging on Fabaceae and slightly of long-tongued bumblebees. Solitary bee proportions increased with high covers of OSR. High local SNH flower covers mitigated changes of mean bee sizes caused by faba bean cultivation. Conclusions Our results show that MFC support specific functional bee groups adapted to their flower morphology and can alter pollinators` functional trait composition. We conclude that management practices need to target the cultivation of functionally diverse crops, combined with high local flower covers of diverse SNH to create heterogeneous landscapes, which sustain diverse pollinator communities.

scholarly journals Comparison of beach profiles conducive for turtle nesting in Andaman

2018 ◽  
Vol 10 (10) ◽  
pp. 12337-12343
Author(s):  
Subramanian Narayani ◽  
Sasidharan Venu ◽  
Andrea Joan D'Silva
Keyword(s):  
Anthropogenic Activities ◽  
Slope Angle ◽  
Vegetation Patterns ◽  
Long Beach ◽  
Single Factor ◽  
High Slope ◽  
Beach Slope ◽  
Nesting Site ◽  
Nesting Sites ◽  
Study Sites

The present study was undertaken to compare beach characteristics associated with turtle nesting in the Andaman group of islands.  Karmatang, Kalipur, Ramnagar, Chidiyatapu, Carbyn’s Cove, and Wandoor were chosen as study sites.  Beach slope, sand grain characteristics, and general vegetation patterns were analysed.  The angle of inclination of the beach slope ranged from 2.06 to 8.3 degrees.  Beaches with a higher angle had a comparatively higher number of nesting sites.  The study shows that a single factor does not make a beach more conducive for nesting.  Chidiyatapu has the widest beach but lacks other features and so it is not a preferred nesting site.  The grain size of sand in Wandoor is highly favourable, but the intertidal region is not long and there are streams that can drown the nests.  Karmatang has a long beach and a higher slope angle.  Ramnagar has a moderate beach length and a high slope angle.  The dominant grains at both the beaches were found to be granules.  The absence of streams and artificial light, fewer number of anthropogenic activities, lack of obstacles, the presence of bordering vegetation, and a conducive beach slope with granular sand grains make Ramnagar, Karmatang, and Kalipur ideal for turtle nesting.

A review on crocodilian nesting habitats and their characterisation via remote sensing

2019 ◽  
Vol 40 (4) ◽  
pp. 403-423 ◽  
Author(s):  
Gabriela Banon ◽  
Eduardo Arraut ◽  
Francisco Villamarín ◽  
Boris Marioni ◽  
Gabriel Moulatlet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Forest Canopy ◽  
Open Water ◽  
Site Distribution ◽  
Nesting Site ◽  
Nesting Sites ◽  
Conservation Actions ◽  
Key Variables ◽  
Reproductive Females ◽  
Remote Sensing Methods

Abstract Crocodilians usually remain inside or near their nests during most vulnerable life stages (as eggs, neonates and reproductive females). Thus, protection of nesting sites is one of the most appropriate conservation actions for these species. Nesting sites are often found across areas with difficult access, making remote sensing a valuable tool used to derive environmental variables for characterisation of nesting habitats. In this study, we (i) review crocodilian nesting habitats worldwide to identify key variables for nesting site distribution: proximity to open-water, open-water stability, vegetation, light, precipitation, salinity, soil properties, temperature, topography, and flooding status, (ii) present a summary of the relative importance of these variables for each crocodilian species, (iii) identify knowledge gaps in the use of remote sensing methods currently used to map potential crocodilian nesting sites, and (iv) provide insight into how these remotely sensed variables can be derived to promote research on crocodilian ecology and conservation. We show that few studies have used remote sensing and that the range of images and methods used comprises a tiny fraction of what is available at little to no cost. Finally, we discuss how the combined use of remote sensing methods – optical, radar, and laser – may help overcome difficulties routinely faced in nest mapping (e.g., cloud cover, flooding beneath the forest canopy, or complicated relief) in a relevant way to crocodilians and to other semiaquatic vertebrates in different environments.

scholarly journals Deciding Where to Sleep: Spatial Levels of Nesting Selection in Chimpanzees (Pan troglodytes) Living in Savanna at Issa, Tanzania

2020 ◽  
Vol 41 (6) ◽  
pp. 870-900 ◽  
Author(s):  
R. Adriana Hernandez-Aguilar ◽  
Trond Reitan
Keyword(s):  
Pan Troglodytes ◽  
Site Selection ◽  
Spatial Scales ◽  
Tree Height ◽  
Important Variable ◽  
Physical Characteristics ◽  
Individual Tree ◽  
Trunk Diameter ◽  
Nesting Site ◽  
Nesting Sites

AbstractTo understand how animals select resources we need to analyze selection at different spatial levels or scales in the habitat. We investigated which physical characteristics of trees (dimensions and structure, e.g., height, trunk diameter, number of branches) determined nesting selection by chimpanzees (Pan troglodytes) on two different spatial scales: individual nesting trees and nesting sites. We also examined whether individual tree selection explained the landscape pattern of nesting site selection. We compared the physical characteristics of actual (N = 132) and potential (N = 242) nesting trees in nesting sites (in 15 plots of 25 m × 25 m) and of all trees in actual and potential nesting sites (N = 763 in 30 plots of 25 m × 25 m). We collected data in May and June 2003 in Issa, a dry and open savanna habitat in Tanzania. Chimpanzees selected both the site they used for nesting in the landscape and the trees they used to build nests within a nesting site, demonstrating two levels of spatial selection in nesting. Site selection was stronger than individual tree selection. Tree height was the most important variable for both nesting site and tree selection in our study, suggesting that chimpanzees selected both safe sites and secure trees for sleeping.

The persistence of moles in nesting at the same site as indicated by mushroom fruiting and nest reconstruction

1993 ◽  
Vol 71 (8) ◽  
pp. 1690-1693 ◽  
Author(s):  
Naohiko Sagara ◽  
Hisashi Abe ◽  
Hiroaki Okabe
Keyword(s):  
Nesting Site ◽  
Nesting Sites

Evidence is presented to show that under certain conditions, three species of Japanese talpine mole, Euroscaptor mizura, Mogera wogura, and Mogera kobeae, persistently use the same nest or nesting site. The moles' nesting sites were detected by the fruiting of an agaric species, Hebeloma radicosum, which specifically colonizes a mole's latrines near its nest. The nests were removed to observe the moles' response. During excavation, the moles often returned to the disturbed sites in search of their nests. The nests were soon reconstructed, followed by refruiting of the mushroom. Thus, one nesting site of E. mizura was used for more than 15 years, despite removal of the nest seven times, and another for more than 5 years, a period ended by the capture of the occupant. Similar results were also obtained with M. wogura and M. kobeae. The occupants may have changed generationally at each site. These persistently used sites seem to be associated with well-drained soil and appropriate vegetation.

scholarly journals Noncrop Habitat Use by Wild Bees (Hymenoptera: Apoidea) in a Mixed-Use Agricultural Landscape

2020 ◽  
Vol 49 (2) ◽  
pp. 502-515 ◽  
Author(s):  
Brianne Du Clos ◽  
Francis A Drummond ◽  
Cynthia S Loftin
Keyword(s):  
United States ◽  
Floral Resources ◽  
Northeastern United States ◽  
Wild Bees ◽  
Wild Bee ◽  
Lowbush Blueberry ◽  
Mixed Use ◽  
Abundance And Diversity ◽  
Bee Communities ◽  
Bee Abundance

Abstract Homogeneous, agriculturally intense landscapes have abundant records of pollinator community research, though similar studies in the forest-dominated, heterogeneous mixed-use landscape that dominates the northeastern United States are sparse. Trends of landscape effects on wild bees are consistent across homogeneous agricultural landscapes, whereas reported studies in the northeastern United States have not found this consistency. Additionally, the role of noncrop habitat in mixed-use landscapes is understudied. We assessed wild bee communities in the mixed-use lowbush blueberry (Vaccinium angustifolium Ait.) production landscape of Maine, United States at 56 sites in eight land cover types across two regional landscapes and analyzed effects of floral resources, landscape pattern, and spatial scale on bee abundance and species richness. Within survey sites, cover types with abundant floral resources, including lowbush blueberry fields and urban areas, promoted wild bee abundance and diversity. Cover types with few floral resources such as coniferous and deciduous/mixed forest reduced bee abundance and species richness. In the surrounding landscape, lowbush blueberry promoted bee abundance and diversity, while emergent wetland and forested land cover strongly decreased these measures. Our analysis of landscape configuration revealed that patch mixing can promote wild bee abundance and diversity; however, this was influenced by strong variation across our study landscape. More surveys at intra-regional scales may lead to better understanding of the influence of mixed-use landscapes on bee communities.

Dynamic ecology of Aldabran seabird communities

1979 ◽  
Vol 286 (1011) ◽  
pp. 231-240 ◽  
Keyword(s):  
Terrestrial Ecosystem ◽  
Western Indian Ocean ◽  
Major Effect ◽  
Relative Population ◽  
The Past ◽  
Bird Droppings ◽  
Nesting Sites ◽  
Barn Owls ◽  
Almost All ◽  
Ground Nesting

The characteristics of the present seabird community of Aldabra are described, and compared briefly with others in the tropics. By comparison with Pacific Ocean communities, Aldabra is deficient especially in petrels and shearwaters, which are poorly represented in the western Indian Ocean generally and are absent probably for zoogeographic reasons. Ground-nesting species are also scarce, especially pelagic feeders that form large colonies, and this is attributed partly to their extermination by rats and partly to the proximity of Assumption, and perhaps Cosmoledo, that offer better nesting sites to these species. Inshore-feeding terns are also scarce on Aldabra, probably owing to insufficient areas of shallow water nearby. Relative population sizes are roughly in agreement with those that would be predicted, except for the fairy tern whose population may have been reduced in the past by barn owls. Almost all Aldabran seabirds nest either in mangroves or on small lagoon islets, the habitats in which birds are least vulnerable to introduced rats, which appear to have had a major effect on nesting distribution. The seabird community is made up of two different trophic guilds, the pelagic feeders which bring in nutrients entirely from outside the ecosystem, and the inshore feeders which cycle nutrients between the intertidal and inshore parts of the system and the terrestrial part. Both result in a net input of nutrients, in the form of bird droppings, to the terrestrial ecosystem. It is estimated that about 1680 t of food are removed from the sea per year, most of the 105 t of guano resulting being channelled into the intertidal, rather than the terrestrial, parts of the ecosystem. The seabird communities likely to have occupied Aldabra in the past are reconstructed on the basis of the known changes in the atoll’s size and structure during the Pleistocene. At most times there would have been more species of seabird using Aldabra than now, and more of their guano would have passed into the terrestrial ecosystem. Probably the most significant event in the recent history of the atoll was the arrival of rats, which exterminated probably quite considerable colonies of ground-nesting seabirds and drove the survivors into the only places where the rats could not survive - the tall mangroves and the tiny lagoon islets. In so doing, the rats destroyed a significant source of nutrient input to the terrestrial ecosystem, with major consequences for the ecology of the atoll as a whole.

scholarly journals Evaluation of Selected Ornamental Asteraceae as a Pollen Source for Urban Bees

2016 ◽  
Vol 60 (2) ◽  
pp. 179-192 ◽  
Author(s):  
Anna Wróblewska ◽  
Ernest Stawiarz ◽  
Marzena Masierowska
Keyword(s):  
Honey Bees ◽  
Pollen Grains ◽  
Bumble Bees ◽  
Floral Resources ◽  
Tagetes Patula ◽  
Single Plant ◽  
Calendula Officinalis ◽  
Wild Bees ◽  
Se Poland ◽  
Urban Conditions

Abstract Offering more floral resources for urban bees can be achieved by growing ornamental bee plants. The aim of the present study was to evaluate selected Asteraceae (Calendula officinalis ‘Persimmon Beauty’ and ‘Santana’, Centaurea macrocephala, Cosmos sulphureus, Dahlia pinnata, Tagetes patula, Tithonia rotundifolia, and Zinnia elegans) as pollen sources for pollinators. Under urban conditions in Lublin, SE Poland, the investigated plants flowered from late June to the end of October. The mass of pollen produced in florets and capitula was found to be species-related. The highest pollen amounts per 10 florets (10.1 mg) as well as per capitulum (249.7 mg) were found for C. macrocephala. The mass of pollen yielded by a single plant depended on both the pollen mass delivered per disk florets and the proportion of disk florets in capitulum, and the flowering abundance of the plants. A single plant of D. pinnata and a single plant of T. rotundifolia each produced the largest pollen mass. Mean pollen yield per 1m2 of a plot ranged from 6.2 g (Z. elegans) to 60.7 g (D. pinnata). Pollen grains are tricolporate, with echinate exine, medium or small in size. They can be categorised as oblatespherical, spherical, and prolatespherical. The principal visitors to C. macrocephala, C. sulphureus, and C. officinalis were honey bees, whereas bumble bees dominated on T. rotundifolia and D. pinnata. A magnet plant for butterflies was Z. elegans. Among the investigated species, D. pinnata, C. macrocephala, and T. rotundifolia were found to be the most valuable sources of pollen flow for managed and wild bees.

scholarly journals Foraging distances in six species of solitary bees with body lengths of 6 to 15 mm, inferred from individual tagging, suggest 150 m-rule-of-thumb for flower strip distances

2020 ◽  
Vol 77 ◽  
pp. 105-117 ◽  
Author(s):  
Michaela M. Hofmann ◽  
Andreas Fleischmann ◽  
Susanne S. Renner
Keyword(s):  
Habitat Fragmentation ◽  
Energy Expenditure ◽  
Solitary Bees ◽  
Wild Bees ◽  
Rule Of Thumb ◽  
Urban Garden ◽  
Nesting Sites ◽  
Males And Females ◽  
Time And Energy ◽  
Foraging Distances

Bees require suitably close foraging and nesting sites to minimize travel time and energy expenditure for brood provisioning. Knowing foraging distances in persistent (‘healthy’) populations is therefore crucial for assessing harmful levels of habitat fragmentation. For small bees, such distances are poorly known because of the difficulty of individual tagging and problems with mark-recapture approaches. Using apiarist’s number tags and colour codes, we marked 2689 males and females of four oligolectic and two polylectic species of Osmiini bees (Megachilidae, genera Chelostoma, Heriades, Hoplitis, Osmia) with body lengths of 6 to 15 mm. The work was carried out in 21 ha-large urban garden that harbours at least 106 species of wild bees. Based on 450 re-sightings, mean female flight distances ranged from 73 to 121 m and male distances from 59 to 100 m. These foraging distances suggest that as a rule of thumb, flower strips and nesting sites for supporting small solitary bees should be no further than 150 m apart.

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