scholarly journals Diel scent and nectar rhythms of an African orchid in relation to bimodal activity patterns of hawkmoth pollinators

2020 ◽  
Vol 126 (7) ◽  
pp. 1155-1164
Author(s):  
Marco G Balducci ◽  
Timotheüs Van der Niet ◽  
Steven D Johnson
Keyword(s):  
Activity Patterns ◽  
Accurate Information ◽  
Foraging Activity ◽  
Pollinator Visitation ◽  
Diel Rhythms ◽  
Diel Patterns ◽  
Direct Observations ◽  
Flower Visitation ◽  
Temporal Dimensions ◽  
Nectar Availability

Abstract Background and Aims The temporal dimensions of floral adaptation to pollinators are not yet well understood, partly because we lack accurate information on the diel rhythms of flower visitation for many pollinators. We investigated whether diel patterns of pollinator visitation to flowers of the African woodland orchid Bonatea polypodantha are synchronized with rhythms of floral anthesis, scent emission and nectar availability. Methods Direct observations and motion-activated cameras were used to identify pollinators of B. polypodantha and to document their activity periods. The timing of pollinaria removal from flowers, emission of scent and availability of nectar was also measured. Results We found that B. polypodantha is pollinated exclusively by short-tongued hawkmoths. Pollinaria of the orchid are affixed between the labial palps of the moths and brush over the protruding stigmatic arms. The flowers also receive visits by long-tongued hawkmoths, but these act as nectar thieves. Tracking of pollinaria removal from flowers confirmed that pollination occurs only at night. Camera footage revealed a striking crepuscular pattern of foraging by short-tongued hawkmoths with peaks of activity during the twilight periods at dusk and at dawn. In contrast, long-tongued hawkmoths were found to visit flowers throughout the night. Flowers of B. polypodantha exhibit unimodal peaks of anthesis, scent emission (dominated by nitrogenous aromatics) and nectar availability before or around dusk. Conclusions Flowers of B. polypodantha are pollinated exclusively by short-tongued hawkmoths, which show crepuscular foraging activity at dusk and dawn. Floral phenophases of the orchid are closely synchronized with the peak of pollinator activity at dusk.

scholarly journals Trade-Off between Foraging Activity and Infestation by Nest Parasites in the Primitively Eusocial BeeHalictus scabiosae

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Andrea Lienhard ◽  
Lea Mirwald ◽  
Thomas Hötzl ◽  
Ilse Kranner ◽  
Gerald Kastberger
Keyword(s):  
Ambient Temperature ◽  
Time Windows ◽  
Activity Patterns ◽  
Small Time ◽  
Foraging Activity ◽  
Morning Temperature ◽  
Eastern Austria ◽  
Halictine Bees ◽  
Primitively Eusocial ◽  
Match Factor

Diurnal activities ofHalictus scabiosaebees and their nest parasites (major bee-flies, cuckoo wasps, ichneumon wasps,Sphecodesbees, and velvet ants) were investigated at a study site with 159 nests in Eastern Austria. Foraging activity correlated with ambient temperature only before midday and decreased in the afternoon. The activity of nest-infesting parasites increased during the day and correlated with ambient temperature. The match factorfmbetween the ratios of the foraging activities ofH. scabiosaeand the ratios of aspects of morning temperature was assessed on three consecutive days with different weather. The activity patterns of halictine bees and their nest parasites differed: the parasites exhibited only small time windows in which their activities were synchronised with those of their hosts. The bees exhibited an anticyclic behaviour and collected food in times of low parasite pressure and decreased foraging activity when parasite pressure increased.

Activity patterns and habitat preferences of insectivorous bats in a West African forest–savanna mosaic

2004 ◽  
Vol 20 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Christoph F. J. Meyer ◽  
Christian J. Schwarz ◽  
Jakob Fahr
Keyword(s):  
Open Space ◽  
Activity Patterns ◽  
Habitat Preferences ◽  
Light Trap ◽  
Negative Influence ◽  
Foraging Activity ◽  
The Moon ◽  
Constant Frequency ◽  
Insectivorous Bats ◽  
Bat Activity

We studied activity patterns and habitat use by insectivorous bats in Comoé National Park, Ivory Coast. Bat foraging activity was quantified along five transects representing three different habitat types using acoustic monitoring and captures with mist nets and harp traps. Aerial insect abundance was assessed using a light trap; in addition shrub and tree arthropods were sampled. Bat activity was significantly and positively related to insect availability and ambient temperature, whereas increased visibility of the moon had a negative influence on flight activity. Together, these factors best explained both total bat activity and activity of bats hunting in open space and edge habitats. The interaction between temperature and light intensity was the best predictor of activity by species foraging in obstacle-rich forest habitats, however, the regression model had a low predictive value. Overall, a large proportion (c. 50%) of the variation in bat activity appeared to be a consequence of transect- and/or habitat-specific influences. We found a significant non-linear relationship between the activity of QCF (quasi-constant frequency) and FM–QCF (frequency modulated – quasi-constant frequency) bats and the phase of the moon, with lowest levels of activity occurring near full moon. We interpret this lunar-phobic behaviour as a reflection of a higher predation risk during moonlit periods. For FM (steep frequency modulated) and CF (constant frequency) bats, no significant correlation was found, although there was a trend suggesting that these bats at least were not negatively affected by bright moonlight. Foraging activity of bats was positively correlated with the abundance of atympanate moths; however, no such correlation was found for tympanate moths.

scholarly journals Day and night in the subterranean: measuring daily activity patterns of subterranean rodents (Ctenomys aff. knighti) using bio-logging

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Milene G Jannetti ◽  
C Loren Buck ◽  
Veronica S Valentinuzzi ◽  
Gisele A Oda
Keyword(s):  
Daily Activity ◽  
Activity Patterns ◽  
Extreme Environments ◽  
Total Duration ◽  
Time Of Day ◽  
Constant Darkness ◽  
Subterranean Rodents ◽  
Monte Desert ◽  
Direct Observations ◽  
Desert Rodents

Abstract While most studies of the impacts of climate change have investigated shifts in the spatial distribution of organisms, temporal shifts in the time of activity is another important adjustment made by animals in a changing world. Due to the importance of light and temperature cycles in shaping activity patterns, studies of activity patterns of organisms that inhabit extreme environments with respect to the 24-hour cyclicity of Earth have the potential to provide important insights into the interrelationships among abiotic variables, behaviour and physiology. Our previous laboratory studies with Argentinean tuco-tucos from the Monte desert (Ctenomys aff. knighti) show that these subterranean rodents display circadian activity/rest rhythms that can be synchronized by artificial light/dark cycles. Direct observations indicate that tuco-tucos emerge mainly for foraging and for removal of soil from their burrows. Here we used bio-logging devices for individual, long-term recording of daily activity/rest (accelerometry) and time on surface (light-loggers) of six tuco-tucos maintained in outdoor semi-natural enclosures. Environmental variables were measured simultaneously. Activity bouts were detected both during day and night but 77% of the highest values happened during the daytime and 47% of them coincided with time on surface. Statistical analyses indicate time of day and temperature as the main environmental factors modulating time on surface. In this context, the total duration that these subterranean animals spent on surface was high during the winter, averaging 3 h per day and time on surface occurred when underground temperature was lowest. Finally, transport of these animals to the indoor laboratory and subsequent assessment of their activity rhythms under constant darkness revealed a switch in the timing of activity. Plasticity of activity timing is not uncommon among desert rodents and may be adaptive in changing environments, such as the desert where this species lives.

Preliminary observations on factors affecting foraging activity in the limpet Patella vulgata

1990 ◽  
Vol 70 (1) ◽  
pp. 181-195 ◽  
Author(s):  
Colin Little ◽  
David Morritt ◽  
David M. Paterson ◽  
Penny Stirling ◽  
Gray A. Williams
Keyword(s):  
Relative Humidity ◽  
Heavy Rainfall ◽  
Feeding Activity ◽  
Activity Patterns ◽  
High Water ◽  
Irish Sea ◽  
Foraging Activity ◽  
Factors Affecting ◽  
Calm Water ◽  
Lough Hyne

Activity patterns of limpets were studied at two adjacent sites in an Irish sea lough, Lough Hyne, in order to relate timing of activity to physical and biological influences. Activity was suppressed during heavy rainfall, and osmotic stress from dilution appears to have led to increased mortality in transplanted limpets. Activity increased as tides progressed from neaps to springs, and for limpets low on the shore it was enhanced by wave action. It is suggested that lack of activity in calm water may reduce predation pressure from crabs, which caused high mortality in transplanted limpets. Either low relative humidity or dryness of the rock diminished activity of low-water limpets. Differences in feeding activity between low-water limpets and high-water limpets may relate to food supply, since more food was available low on the shore, and the guts of low-water limpets contained more diatoms than those of high-water individuals. Differences between the two sites are at present unexplained but may relate to differences in micro habitats.

scholarly journals On the Dynamics of the LAGEOS-I Spin Vector: High Precision Direct Observations and Comparisons to Theoretical Modeling

1997 ◽  
Vol 165 ◽  
pp. 341-346
Author(s):  
D. Currie ◽  
K. Kissell ◽  
P. Avizonis ◽  
D. Wellnitz
Keyword(s):  
Short Pulse ◽  
Laser Ranging ◽  
Accurate Information ◽  
Spin Vector ◽  
Spin Motion ◽  
Crustal Motion ◽  
Orbital Parameters ◽  
Short Pulse Laser ◽  
Direct Observations ◽  
Gyroscopic Effects

AbstractLAGEOS I is a high-density geodetic satellite launched by NASA on 4 May 1976 (Johnson et al., 1976). Using a network of laser ranging stations, GSFC/NASA has maintained extremely accurate information on the orbital motions of LAGEOS I, and the later LAGEOS II and on the time-dependent evolution of their orbital parameters. The development of short-pulse laser ranging systems, and better models for atmospheric refractive effects, have dramatically improved the ability to locate the spacecraft or measure geodetic position and terrestrial crustal motion, but these systems do not measure the satellite rotational motion or gyroscopic effects, thought initially unimportant. Primarily as a result of technical strides in orbit determination, it is now recognized that the spin-motion is critical to understanding weak but important interactions with the environment.

scholarly journals Activity patterns and feeding behaviour of hyrax (Procavia capensis) in the Mountain Zebra National Park

1987 ◽  
Vol 6 (3) ◽  
pp. 118-122
Author(s):  
L. J. Fourie ◽  
I. G. Horak ◽  
M. R. Perrin
Keyword(s):  
Feeding Behaviour ◽  
National Park ◽  
Activity Patterns ◽  
Extended Time ◽  
Behavioural Thermoregulation ◽  
Late Afternoon ◽  
Direct Observations ◽  
Group Feeding ◽  
Inactive Phase ◽  
Procavia Capensis

The activity patterns of marked hyrax in the Mountain Zebra National Park were quantified by direct observations. Extended periods are spent on basking during winter (6,8 h) and summer (5,3 h) respectively. At least 80 % of each day is spent in an inactive phase. The more extended time spent on movement and time spent within refuges during summer (0,4 and 2,7 h), compared to winter (0,2 and 0,9 h), can possibly be interpreted in terms of behavioural thermoregulation. Distinct differences between the feeding behaviour of juveniles (< 6 months) and older hyrax were observed. Foraging of juveniles was limited to a distance of 40 m or less from refuges and took place under the surveilance of adults. Foraging of older hyrax frequently occurred for extended distances (up to 500 m) from refuges. These hyrax frequently visited riparian thickets. Foraging excursions of individual hyrax lasted for 0,5 - 8 h. The reported early and late afternoon group feeding sessions for hyrax older than 5 months could not be confirmed.

scholarly journals Light intensity regulates flower visitation in Neotropical nocturnal bees

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rodolfo Liporoni ◽  
Guaraci Duran Cordeiro ◽  
Paulo Inácio Prado ◽  
Clemens Schlindwein ◽  
Eric James Warrant ◽  
...  
Keyword(s):  
Light Intensity ◽  
Strong Dependence ◽  
Foraging Activity ◽  
Know How ◽  
Minimum Light ◽  
Light Levels ◽  
Flower Visitation ◽  
Five Factors ◽  
Main Variable ◽  
Dim Light

Abstract The foraging activity of diurnal bees often relies on flower availability, light intensity and temperature. We do not know how nocturnal bees, which fly at night and twilight, cope with these factors, especially as light levels vary considerably from night to day and from night to night due to moon phase and cloud cover. Given that bee apposition compound eyes function at their limits in dim light, we expect a strong dependence of foraging activity on light intensity in nocturnal bees. Besides being limited by minimum light levels to forage, nocturnal bees should also avoid foraging at brighter intensities, which bring increased competition with other bees. We investigated how five factors (light intensity, flower availability, temperature, humidity, and wind) affect flower visitation by Neotropical nocturnal bees in cambuci (Campomanesia phaea, Myrtaceae). We counted visits per minute over 30 nights in 33 cambuci trees. Light intensity was the main variable explaining flower visitation of nocturnal bees, which peaked at intermediate light levels occurring 25 min before sunrise. The minimum light intensity threshold to visit flowers was 0.00024 cd/m2. Our results highlight the dependence of these nocturnal insects on adequate light levels to explore resources.

Pollinator visitation, pollen limitation, and selection on flower size through female function in contrasting habitats within a population of Campanula persicifolia

2006 ◽  
Vol 84 (3) ◽  
pp. 412-420 ◽  
Author(s):  
Vivi-Irèn Hansen ◽  
Ørjan Totland
Keyword(s):  
Seed Production ◽  
Structural Equation ◽  
Pollen Limitation ◽  
Phenotypic Selection ◽  
Flower Size ◽  
Pollinator Visitation ◽  
Pollinator Attraction ◽  
Female Function ◽  
Flower Visitation ◽  
Visitation Rates

We looked at whether flower visitation rates, pollen limitation on seed production, and phenotypic selection on flower size through female function varied across a sharp gradient in light intensity (open meadow vs. forest) within a population of the perennial plant Campanula persicifolia L. (Campanulaceae). Flower visitation rates of putative pollinators were similar in both habitats. Seed number per fruit was strongly pollen limited, with no difference in the magnitude of pollen limitation between the two habitats. This strong pollen limitation set the basis for significant phenotypic selection, through female function, on a trait that probably is important for pollinator attraction: flower size. This was revealed by path analysis and structural equation modelling. The lack of difference in pollen limitation on seed production in the two habitats may be explained by the similarity in flower visitation rates in the two habitats. Moreover, the similarity in pollen limitation in the two habitats probably resulted in a similar magnitude and direction of selection on flower size through female function. Our results suggest that pollen limitation and selection through female function may vary little across space within a popualtion despite large variation in the environmental conditions experienced by plants.

scholarly journals The forgotten flies: the importance of non-syrphid Diptera as pollinators

2015 ◽  
Vol 282 (1805) ◽  
pp. 20142934 ◽  
Author(s):  
Katherine A. Orford ◽  
Ian P. Vaughan ◽  
Jane Memmott
Keyword(s):  
Transport Networks ◽  
Pollinator Visitation ◽  
Pollen Loads ◽  
Flower Visitation ◽  
Pollen Transport ◽  
Significant Difference ◽  
Pollen Vectors ◽  
Total Pollen ◽  
Flower Visiting

Bees, hoverflies and butterflies are taxa frequently studied as pollinators in agricultural and conservation contexts. Although there are many records of non-syrphid Diptera visiting flowers, they are generally not regarded as important pollinators. We use data from 30 pollen-transport networks and 71 pollinator-visitation networks to compare the importance of various flower-visiting taxa as pollen-vectors. We specifically compare non-syrphid Diptera and Syrphidae to determine whether neglect of the former in the literature is justified. We found no significant difference in pollen-loads between the syrphid and non-syrphid Diptera. Moreover, there was no significant difference in the level of specialization between the two groups in the pollen-transport networks, though the Syrphidae had significantly greater visitation evenness. Flower visitation data from 33 farms showed that non-syrphid Diptera made up the majority of the flower-visiting Diptera in the agricultural studies (on average 82% abundance and 73% species richness), and we estimate that non-syrphid Diptera carry 84% of total pollen carried by farmland Diptera. As important pollinators, such as bees, have suffered serious declines, it would be prudent to improve our understanding of the role of non-syrphid Diptera as pollinators.

scholarly journals Litter Surface Temperature: A Driving Factor Affecting Foraging Activity in Dinoponera lucida (Hymenoptera: Formicidae)

Sociobiology ◽  
2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Flávio Curbani ◽  
Cássio Zocca ◽  
Rodrigo B. Ferreira ◽  
Cecilia Waichert ◽  
Tathiana Guerra Sobrinho ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Activity Patterns ◽  
Red List ◽  
Foraging Activity ◽  
Mean Flow ◽  
Lowland Forest ◽  
Habitat Temperature ◽  
Eastern Brazil ◽  
Forest Remnant ◽  
The Mean

Dinoponera lucida is a poneromorph ant endemic to the Atlantic Forest of Brazil. The species is classified as endangered in Brazil’s Red List due to its peculiar reproductive biology and high habitat fragmentation. Herein, we characterize D. lucida foraging activity and response to litter surface temperature in a lowland forest remnant in south-eastern Brazil. The mean flow of workers at nest openings was 3.8 ± 0.6 per hour, mean foraging trip was 14.2 ± 2.2 min, and mean foraging distance was 3.8 ± 0.4 m. The time spent per foraging trip and litter surface temperature were positively correlated. Flow of workers at nest openings was higher with mean temperature of litter surface between 21.0 and 27.0 °C. Our results show that D. lucida has a diurnal foraging activity related to habitat temperature. Our data contribute to the knowledge about the ecology of D. lucida and support the hypothesis of optimal food foraging regulated by habitat temperature. In addition, the better understanding of D. lucida activity patterns can assist on conservation planning of this endangered and endemic ant.

Sign in / Sign up

Export Citation Format

Share Document