scholarly journals Microclimate Temperatures Impact Nesting Preference in Megachile rotundata (Hymenoptera: Megachilidae)

2020 ◽  
Vol 49 (2) ◽  
pp. 296-303 ◽  
Author(s):  
Elisabeth S Wilson ◽  
Claire E Murphy ◽  
Joseph P Rinehart ◽  
George Yocum ◽  
Julia H Bowsher
Keyword(s):  
Reproductive Investment ◽  
Solitary Bee ◽  
Megachile Rotundata ◽  
Nest Boxes ◽  
The North ◽  
Cavity Nesting ◽  
Alfalfa Field ◽  
3D Printed ◽  
Maximum Temperatures ◽  
Temperature Impacts

Abstract The temperature of the nest influences fitness in cavity-nesting bees. Females may choose nest cavities that mitigate their offspring’s exposure to stressful temperatures. This study aims to understand how cavity temperature impacts the nesting preference of the solitary bee Megachile rotundata (Fabricius) under field conditions. We designed and 3D printed nest boxes that measured the temperatures of 432 cavities. Nest boxes were four-sided with cavity entrances facing northeast, northwest, southeast, and southwest. Nest boxes were placed along an alfalfa field in Fargo, ND and were observed daily for completed nests. Our study found that cavity temperature varied by direction the cavity faced and by the position of the cavity within the nest box. The southwest sides recorded the highest maximum temperatures while the northeast sides recorded the lowest maximum temperatures. Nesting females filled cavities on the north-facing sides faster than cavities on the south-facing sides. The bees preferred to nest in cavities with lower average temperatures during foraging hours, and cavities that faced to the north. The direction the cavity faced was associated with the number of offspring per nest. The southwest-facing cavities had fewer offspring than nests on the northeast side. Our study indicates that the nesting box acts as a microclimate, with temperature varying by position and direction of the cavity. Variation in cavity temperature affected where females chose to nest, but not their reproductive investment.

scholarly journals Surplus nest boxes and the potential for polygyny affect clutch size and offspring sex ratio in house wrens

2006 ◽  
Vol 273 (1595) ◽  
pp. 1751-1757 ◽  
Author(s):  
Natalie S Dubois ◽  
E Dale Kennedy ◽  
Thomas Getty
Keyword(s):  
Reproductive Investment ◽  
Male Reproductive Success ◽  
Offspring Sex Ratio ◽  
House Wrens ◽  
Nest Boxes ◽  
Cavity Nesting ◽  
Offspring Sex ◽  
Investment In Reproduction ◽  
Male House

Females of many species can gain benefits from being choosy about their mates and even exhibit context-dependent investment in reproduction in response to the quality of their breeding situation. Here, we show that if a male house wren is provided with surplus nest boxes in his territory, his mate lays a larger clutch with a significantly higher proportion of sons. This response to a territory characteristic directly associated with male competitive ability, and ultimately to male reproductive success, suggests that male competition over access to high-quality territories with surplus nest boxes (i.e. those able to support polygyny) may influence female reproductive investment decisions. The results of this study have interesting implications, particularly considering the important role that studies of cavity nesting birds utilizing nest boxes have played in advancing our understanding of behaviour, ecology and evolution.

scholarly journals Success factors in the realization of large ice projects in education

2021 ◽  
Vol 36 (1) ◽  
pp. 4-12
Author(s):  
Arno Pronk ◽  
Peng Luo ◽  
Qingpeng Li ◽  
Fred Sanders ◽  
Marjolein overtoom ◽  
...  
Keyword(s):  
Success Factors ◽  
Learning Experience ◽  
Learning By Doing ◽  
University Of Alberta ◽  
The North ◽  
3D Printed ◽  
Good Learning ◽  
The University ◽  
Ice Shell ◽  
Motivation And Learning

There has been a long tradition in making ice structures, but the development of technical improvements for making ice buildings is a new field with just a handful of researchers. Most of the projects were realized by professors in cooperation with their students as part of their education in architecture and civil engineering. The following professors have realized ice projects in this setting: Heinz Isler realized some experiments since the 1950s; Tsutomu Kokawa created in the past three decades several ice domes in the north of Japan with a span up to 25 m; Lancelot Coar realized a number of fabric formed ice shell structures including fiberglass bars and hanging fabric as a mold for an ice shell in 2011 and in 2015 he produced an fabric-formed ice origami structure in cooperation with MIT (Caitlin Mueller) and VUB (Lars de Laet). Arno Pronk realized several ice projects such as the 2004 artificially cooled igloo, in 2014 and 2015 dome structures with an inflatable mold in Finland and in 2016–2019, an ice dome, several ice towers and a 3D printed gridshell of ice in Harbin (China) as a cooperation between the Universities of Eindhoven & Leuven (Pronk) and Harbin (Wu and Luo). In cooperation between the University of Alberta and Eindhoven two ice beams were realized during a workshop in 2020. In this paper we will present the motivation and learning experiences of students involved in learning-by-doing by realizing one large project in ice. The 2014–2016 projects were evaluated by Sanders and Overtoom; using questionnaires among the participants by mixed cultural teams under extreme conditions. By comparing the results in different situations and cultures we have found common rules for the success of those kinds of educational projects. In this paper we suggest that the synergy among students participating in one main project without a clear individual goal can be very large. The paper will present the success factors for projects to be perceived as a good learning experience.

scholarly journals The circadian clock uses different environmental time cues to synchronize emergence and locomotion of the solitary bee Osmia bicornis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Katharina Beer ◽  
Mariela Schenk ◽  
Charlotte Helfrich-Förster ◽  
Andrea Holzschuh
Keyword(s):  
Circadian Clock ◽  
Circadian System ◽  
Evolutionary Adaptation ◽  
Solitary Bee ◽  
Daily Rhythms ◽  
Osmia Bicornis ◽  
Cavity Nesting ◽  
Impact On Survival ◽  
Life On Earth ◽  
And Behavior

AbstractLife on earth adapted to the daily reoccurring changes in environment by evolving an endogenous circadian clock. Although the circadian clock has a crucial impact on survival and behavior of solitary bees, many aspects of solitary bee clock mechanisms remain unknown. Our study is the first to show that the circadian clock governs emergence in Osmia bicornis, a bee species which overwinters as adult inside its cocoon. Therefore, its eclosion from the pupal case is separated by an interjacent diapause from its emergence in spring. We show that this bee species synchronizes its emergence to the morning. The daily rhythms of emergence are triggered by temperature cycles but not by light cycles. In contrast to this, the bee’s daily rhythms in locomotion are synchronized by light cycles. Thus, we show that the circadian clock of O. bicornis is set by either temperature or light, depending on what activity is timed. Light is a valuable cue for setting the circadian clock when bees have left the nest. However, for pre-emerged bees, temperature is the most important cue, which may represent an evolutionary adaptation of the circadian system to the cavity-nesting life style of O. bicornis.

DISTRIBUTION OF TEMPERATURE INDICES OF EXTREME IN THE TERRITORY OF THE EUROPEAN PART OF RUSSIA IN THE PERIOD 1980-2019

2021 ◽  
Vol 31 (4) ◽  
pp. 437-442
Author(s):  
V.V. Guryanov ◽  
A.K. Sungatullin
Keyword(s):  
Temporal Variability ◽  
Statistical Processing ◽  
European Part ◽  
The North ◽  
Hourly Data ◽  
European Part Of Russia ◽  
Spatial Grid ◽  
Temperature Indices ◽  
Spatio Temporal ◽  
Maximum Temperatures

The spatio-temporal variability of the average values of temperature indices of climate extremity in the territory of the European part of Russia (ER) in 1980-2019 is presented. To calculate the extremeness indices, we used hourly data on the maximum and minimum temperatures obtained using the ERA5 reanalysis on a 1°´1° spatial grid. Statistical processing of the index values revealed an increase in the temperature indices TNX, TNN, TXN, TXX, associated with the minimum and maximum temperatures, with the exception of the north and southeast of the region. An increase in the number of sunny days and a decrease in the number of frosty days were also revealed.

A female perspective: testing the effects of noise masking on signal transmission patterns inside the nest box

Behaviour ◽  
2019 ◽  
Vol 157 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Erin E. Grabarczyk ◽  
Sharon A. Gill
Keyword(s):  
Cross Correlation ◽  
Signal Transmission ◽  
Measured Signal ◽  
Signal To Noise ◽  
House Wren ◽  
Noise Masking ◽  
Nest Boxes ◽  
Cavity Nesting ◽  
Song Transmission ◽  
Correlation Factors

Abstract During the breeding season, avian pairs coordinate interactions with songs and calls. For cavity nesting birds, females inside nest boxes may rely on male vocalizations for information. Anthropogenic noise masks male songs, which could affect information gained by females. We explored song transmission from a female house wren (Troglodytes aedon) perspective, testing the hypothesis that noise masking alters songs that reach females inside nest boxes. We broadcast songs at three distances up to 25 m from nest boxes and re-recorded songs using two microphones, positioned inside and outside nest boxes. We measured signal-to-noise ratios and cross-correlation factors to estimate the effects of masking on transmission. In noise, songs received inside nest boxes had lower signal-to-noise ratios and cross-correlation factors than songs recorded outside of boxes, and these effects decreased with distance. For females, noise may reduce information conveyed through male songs and in response pairs may need to adjust their interactions.

scholarly journals Characteristics of Xanthomonas cucurbitae Isolates from Pumpkins and Survival of the Bacterium in Pumpkin Seeds

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1779-1784 ◽  
Author(s):  
X. Zhang ◽  
M. Babadoost
Keyword(s):  
The United States ◽  
Culture Collection ◽  
Colony Development ◽  
North Central Region ◽  
North Central ◽  
The North ◽  
Significant Difference ◽  
Optimum Ph ◽  
Pumpkin Seeds ◽  
Maximum Temperatures

This study was conducted to determine characteristics of Xanthomonas cucurbitae, the causal agent of bacterial spot of pumpkin, and survival of the bacterium in pumpkin seeds. Fourteen X. cucurbitae isolates from the north central region of the United States, along with the X. cucurbitae strain 23378 from the American Type Culture Collection, were included in this study. The range of minimum, optimum, and maximum temperatures for colony development of X. cucurbitae were 4 to 6°C, 24 to 30°C, and 34 to 36°C, respectively. Optimum pH for colony development ranged from 6.5 to 8.0. Leaves of 3-week-old pumpkins ‘Howden’ and ‘Dickinson’ were inoculated with X. cucurbitae isolates (108 CFU/ml). There was a significant difference in the postinoculation periods for appearance of bacterial lesions on the leaves among the isolates; however, there was no significant difference in diameters of the lesions on each of the pumpkin cultivar 7 days after inoculation. Four of the isolates caused significantly larger lesions on ‘Dickinson’ leaves than ‘Howden’ leaves. Naturally infected ‘Howden’ pumpkin and inoculated ‘Dickinson’ pumpkin seeds with X. cucurbitae were stored at 4 and 22°C. X. cucurbitae was isolated from both naturally infected and inoculated seeds 24 months after storage at both 4 and 22°C, and the isolated bacteria were pathogenic.

scholarly journals Composition of Cavity-Nesting Bird Communities in Montane Aspen Woodland Fragments: The Roles of Landscape Context and Forest Structure

The Condor ◽  
2002 ◽  
Vol 104 (4) ◽  
pp. 890-896 ◽  
Author(s):  
Joshua J. Lawler ◽  
Thomas C. Edwards
Keyword(s):  
Populus Tremuloides ◽  
Bird Communities ◽  
Landscape Context ◽  
Glaucomys Sabrinus ◽  
Northern Flying Squirrel ◽  
Nest Boxes ◽  
Cavity Nesters ◽  
Cavity Nesting ◽  
Structure Tree ◽  
Species Richness And Abundance

Abstract We compared cavity-nesting bird communities in aspen (Populus tremuloides) woodland fragments classified on the basis of vegetation structure (tree density) and landscape context (surrounding vegetation). We found very few cavity nesters in fragments predominantly surrounded by forests. Fragments adjacent to meadows contained more species and a greater abundance of cavity nesters. Species richness and abundance were higher in sparsely than in densely treed meadow fragments. Because secondary cavity nesters are often limited by cavity availability, we augmented natural cavities with nest boxes. Although only five boxes contained bird nests, these were all in sparse aspen fragments predominantly surrounded by meadows. However, we found 25 northern flying squirrel (Glaucomys sabrinus) nests in boxes, none of which were in sparse meadow fragments. In addition to highlighting the importance of landscape context in avian and mammalian habitat relationships, our results suggest that predator or competitor interactions may help structure this cavity-nester community. Composición de las Comunidades de Aves que Nidifican en Cavidades en los Fragmentos de Bosque Montano de Álamo: El Papel del Contexto del Paisaje y la Estructura del Bosque Resumen. Comparamos comunidades de aves que nidifican en cavidades en fragmentos de bosque de álamo (Populus tremuloides) clasificados en base a la estructura de la vegetación (densidad de árboles) y al contexto del paisaje (vegetación circundante). Encontramos muy pocas aves que nidifican en cavidades en los fragmentos rodeados predominantemente por bosque. Los fragmentos adyacentes a prados presentaron más especies y mayor abundancia de aves. La riqueza y la abundancia de especies fueron mayores en fragmentos con baja densidad de árboles que estuvieron rodeados por prados. Debido a que las aves que nidifican en cavidades secundarias están a menudo limitadas por la disponibilidad de cavidades, aumentamos las cavidades naturales con cajas de anidaje. Aunque solamente cinco cajas contuvieron nidos de aves, éstas estuvieron todas en los fragmentos con baja densidad de álamos rodeados predominantemente por prados. Sin embargo, encontramos 25 nidos de ardillas voladoras norteñas (Glaucomys sabrinus) en las cajas de anidaje, de las cuales ninguna estuvo en fragmentos con baja densidad de árboles rodeados por prado. Nuestros resultados destacan la importancia del contexto del paisaje en las relaciones entre el hábitat y las aves y mamíferos, y sugieren que las interacciones con depredadores o competidores pueden influenciar la estructura de la comunidades de aves que anidan en cavidades.

Evaluation of trends in extreme temperatures simulated by HighResMIP models across Europe

2020 ◽  
Author(s):  
Gerard van der Schrier ◽  
Antonello Squintu ◽  
Else van den Besselaar ◽  
Eveline van der Linden ◽  
Enrico Scoccimarro ◽  
...  
Keyword(s):  
High Resolution ◽  
Western Europe ◽  
Extreme Values ◽  
Maximum Temperature ◽  
Western Balkans ◽  
North West ◽  
The Balkans ◽  
The North ◽  
Summer Maximum ◽  
Maximum Temperatures

<p>The comparison of simulated climate with observed daily values allows to assess their reliability and the soundness of their projections on the climate of the future. Frequency and amplitude of extreme events are fundamental aspects that climate simulations need to reproduce. In this work six models developed within the High Resolution Model Intercomparison Project are compared over Europe with the homogenized version of the observational E-OBS gridded dataset. This is done by comparing averages, extremes and trends of the simulated summer maximum temperature and winter minimum temperatures with the observed ones.</p><p>Extreme values have been analyzed making use of indices based on the exceedances of percentile-based thresholds. Winter minimum temperatures are generally underestimated by models in their averages (down to -4 deg. C of difference over Italy and Norway) while simulated trends in averages and extreme values are found to be too warm on western Europe and too cold on eastern Europe (e.g. up to a difference of -4% per decade on the number of Cold Nights over Spain). On the other hand the models tend to underestimate summer maximum temperatures averages in Northern Europe and overestimate them in the Mediterranean areas (up to +5 deg. C over the Balkans). The simulated trends are too warm on the North West part and too cold on the South East part of Europe (down to -3%/dec. on the number of Warm Days over Italy and Western Balkans).</p><p>These results corroborate the findings of previous studies about the underestimation of the warming trends of summer temperatures in Southern Europe, where these are more intense and have more impacts.  A comparison of the high resolution models  with the corresponding version in CMIP5 has been performed comparing the absolute biases of extreme values trends. This has shown a slight improvement for the simulation of winter minimum temperatures, while no signs of significant progresses have been found for summer maximum temperatures.</p>

DNA fingerprinting analysis in the solitary bee Megachile rotundata: variability and nest mate genetic relationships

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 681-688 ◽  
Author(s):  
Alain Blanchetot
Keyword(s):  
Genetic Variability ◽  
Dna Fingerprinting ◽  
Genetic Relationships ◽  
Globin Gene ◽  
Hypervariable Region ◽  
Enzyme Polymorphism ◽  
Solitary Bee ◽  
Megachile Rotundata ◽  
Wide Range ◽  
Oligonucleotide Sequence

The most conventional approach for evaluating genetic variability in an insect population involves assessing the degree of enzyme polymorphism. Hymenoptera display a relatively low level of genetic variability compared with most insect species. DNA probes consisting of tandemly repeated sequences are powerful tools for detecting polymorphisms when employed to develop DNA fingerprinting (DNAfp) profiles in a wide range of organisms. This report describes genetic variability in the solitary bee species Megachile rotundata as assessed by DNAfp using the Ml3 sequence and a synthetic oligonucleotide sequence homologous to a hypervariable region of the α-globin gene. DNAfp comparisons among offspring were used to analyze genealogical structure in M. rotundata nests. The results indicate that polyandry, by a large number of males, is not a common phenomenon in M. rotundata bee species. In the present analysis, it is likely that the broods raised in single nests are mostly the offspring of one singly mated female. However, the data does not preclude that for certain nests two males could have been involved in the mating process.Key words: Megachile rotundata, DNA fingerprinting, M13 sequence, α-globin hypervariable sequence, intra-nest genetic relationships.

Are avian ectoparasites more numerous in nest boxes with old nest material?

1996 ◽  
Vol 74 (10) ◽  
pp. 1819-1825 ◽  
Author(s):  
Wallace B. Rendell ◽  
Nicolaas A. M. Verbeek
Keyword(s):  
Positive Association ◽  
Winter Survival ◽  
Tree Swallow ◽  
Nest Sites ◽  
Nest Boxes ◽  
Cavity Nesting ◽  
Ornithonyssus Sylviarum ◽  
Nest Microclimate ◽  
One Year

Researchers may reduce the numbers of haematophagous ectoparasites in nest boxes of cavity-nesting birds by removing old nests from boxes and, as a result, eliminate an important selective pressure that could influence the results from nest-box studies of birds. We recorded the numbers of parasites in tree swallow (Tachycineta bicolor) boxes in which we manipulated the presence, amount, and quality of old nests. Bird fleas (Ceratophyllus idius) were more numerous in boxes with old nests, and there was a positive correlation between nest volume and flea numbers. In one year, there was a positive association between fowl mite (Ornithonyssus sylviarum) numbers and nest volume; otherwise, fowl mites and blow flies (Protocalliphora sialia) were equally numerous in all nest types. We conclude that ectoparasites whose over-winter survival depends on old nests are more numerous in boxes with old nests, whereas parasites whose over-winter survival is independent of old nests infect nest sites randomly. Also, reinfection and nest microclimate likely contributed to variance in parasite numbers between nest types and years, respectively. We recommend caution when speculating about the possible effects of cleaning boxes on parasites that occur in nests because different species of parasites are not influenced similarly by old nests.

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