Seasonal variation in the length of the daily activity period in buffy-headed marmosets (Callithrix flaviceps): An important consideration for the analysis of foraging strategies in observational field studies of primates

2013 ◽  
Vol 76 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Stephen F. Ferrari ◽  
Renato R. Hilário
Keyword(s):  
Seasonal Variation ◽  
Daily Activity ◽  
Field Studies ◽  
Foraging Strategies ◽  
Activity Period ◽  
Callithrix Flaviceps

scholarly journals Daily activity of four tropical intertidal hermit crabs from Southeastern Brazil

2003 ◽  
Vol 63 (3) ◽  
pp. 537-544 ◽  
Author(s):  
A. Turra ◽  
M. R. Denadai
Keyword(s):  
High Activity ◽  
Activity Pattern ◽  
Daily Activity ◽  
Activity Patterns ◽  
High Tide ◽  
Hermit Crabs ◽  
Activity Period ◽  
Southeastern Brazil ◽  
Intertidal Flat ◽  
Circadian Activity

This study describes the daily activity in a simulated high tide situation of four species of hermit crabs (Pagurus criniticornis, Clibanarius antillensis, C. sclopetarius, and C. vittatus) that coexist in an intertidal flat in southeastern Brazil. Observations were done in two-hour intervals during two subsequent days (48 h) in three replicate pools with thirty crabs each. Among species (between and within genera) there was an evident variation in activity patterns, of which three could be distinguished. The circadian activity patterns of C. antillensis and C. vittatus could be characterized as evening and nocturnal, with resting peaks during the morning and afternoon. The circadian activity pattern of C. sclopetarius was characterized by two marked peaks of inactivity, corresponding to dawn and evening, which could represent an intrinsic association with the semi-lunar tidal cycles of the study area. Pagurus criniticornis showed high activity not influenced by day/night conditions during the entire observed period. These activity pattern variations of the studied hermit crabs should be taken into account in designing further experiments. More precise and accurate interspecific behavioral comparisons among species could be achieved in nocturnal experiments, the high activity period of all species.

Factors Influencing Flight Activity of Colonies of the Stingless Bee Trigona-Carbonaria (Hymenoptera, Apidae)

1993 ◽  
Vol 41 (4) ◽  
pp. 343 ◽  
Author(s):  
TA Heard ◽  
JK Hendrikz
Keyword(s):  
Daily Activity ◽  
Daily Variation ◽  
Stingless Bee ◽  
Flight Activity ◽  
Activity Period ◽  
Diel Pattern ◽  
Experimental Site ◽  
Factors Influencing ◽  
The Hours ◽  
Trigona Carbonaria

Temporal patterns of flight activity and influence of climatic variables on activity of colonies of the potentially useful crop pollinator, Trigona carbonaria Smith, were investigated. Colonies of T. carbonaria were active all the year at the experimental site but the daily activity period was longer in the warmer months. Intensity of daily flight activity was greatest in September and least in May. Temperature and radiation were the most important variables affecting flight activity. They impose thresholds on activity, with flight occurring only at temperatures greater than 18-degrees-C and radiation greater than 15 W m-2. Temperature and radiation also influence the intensity of activity above the thresholds. Relative humidity, vapour pressure, cloud cover and wind speed had no significant effect. A variable measuring the hours from daily peak of activity was significantly correlated with flight activity, indicating an intrinsic diel pattern of activity. Daily variation in flight activity, representing the influence of unmeasured variables, was also significant.

Testosterone and Daily Activity Period in Laboratory-Housed Mountain Spiny Lizards, Sceloporus jarrovi

2004 ◽  
Vol 38 (1) ◽  
pp. 120-124 ◽  
Author(s):  
Matthew Klukowski ◽  
Betty Ackerson ◽  
Craig E. Nelson
Keyword(s):  
Daily Activity ◽  
Activity Period ◽  
Sceloporus Jarrovi

scholarly journals Seasonal Variation in the Response of `Valencia' Orange to Two Abscission Compounds

HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 226-229 ◽  
Author(s):  
U. Hartmond ◽  
J.D. Whitney ◽  
J.K. Burns ◽  
W.J. Kender
Keyword(s):  
Seasonal Variation ◽  
Active Ingredient ◽  
Citrus Sinensis ◽  
Field Studies ◽  
Separate Experiment ◽  
Fruit Removal ◽  
Metsulfuron Methyl ◽  
Valencia Orange ◽  
Leaf Drop ◽  
Before And After

Two field studies were conducted to evaluate the effect of metsulfuron-methyl and 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole) on abscission of `Valencia' orange [Citrus sinensis (L.) Osbeck] during the 3-month harvest season. Solutions of metsulfuron-methyl at 0.5, 1, and 2 mg·L-1 active ingredient (a.i.) were applied at 10-day intervals beginning on 13 Feb. and ending 18 May 1998. Early in the harvest season, 1 or 2 mg·L-1 metsulfuron-methyl significantly reduced fruit detachment force (FDF) 14 days after application. Metsulfuron-methyl was less effective during a 4- to 6-week period following bloom (“less-responsive period”). After this period, metsulfuron-methyl regained the ability to loosen fruit. Applications of 2 mg·L-1 a.i. were more effective than 1 mg·L-1 in reducing FDF and causing leaf drop, but 0.5 mg·L-1 a.i. had little or no effect on FDF. Flowers and leaflets on developing shoots and young fruit completely abscised with 1 and 2 mg·L-1 a.i. Defoliation and twig dieback was extensive at all concentrations and spray dates, eliminating metsulfuron-methyl as a commercially viable abscission agent for citrus. In a separate experiment CMN-pyrazole at 50 and 100 mg·L-1 a.i. and metsulfuronmethyl at 0.5 mg·L-1 a.i. were applied to `Valencia' trees to determine fruit removal with a trunk shake and catch harvesting system. Application of both abscission materials before and after the “less-responsive period” resulted in a 10% to 12% increase in fruit removal when compared to control trees. Less than a 35% reduction in FDF was sufficient to significantly increase fruit removal. Only 100 mg·L-1 a.i. CMN-pyrazole significantly increased fruit removal when applied during the “less-responsive period.” Chemical names used: Methyl-2-(((((4-Methoxy-6-Methyl-1,3,5-Triazin-2-yl)-Amino)Carbonyl) Amino)Sulfonyl)Benzene (Metsulfuron-methyl); 5-Chloro-3-methyl-4-nitro-1-H-pyrazole (CMN-pyrazole).

scholarly journals DNA metabarcoding reveals adaptive seasonal variation of individual trophic traits in a critically endangered fish

2021 ◽  
Author(s):  
Kurt Villsen ◽  
Emmanuel Corse ◽  
Emese Meglécz ◽  
Gaït Archambaud-Suard ◽  
Hélène Vignes ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Habitat Management ◽  
Optimal Foraging Theory ◽  
Trophic Niche ◽  
Modelling And Simulation ◽  
Critically Endangered ◽  
Foraging Strategies ◽  
Endangered Fish ◽  
Niche Variation ◽  
Trophic Traits

AbstractDietary studies are critical for understanding foraging strategies and have important applications in conservation and habitat management. We applied a robust metabarcoding protocol to characterize the diet of the critically endangered freshwater fish Zingel asper and conducted modelling and simulation analyses to characterize and identify some of the drivers of individual trophic trait variation in this species. We found that intra-specific competition and ontogeny had minor effects on the trophic niche of Z. asper. Instead, our results suggest that the majority of trophic niche variation was driven by seasonal variation in ecological opportunity (in our case, the seasonal variation in the availability of preferred prey types). Overall, our results are in line with the optimal foraging theory and suggest that Z. asper is specialized on a few ephemeropteran prey species (Baetis fuscatus and Ecdyonurus) but adapts its foraging by becoming more opportunistic as its favoured prey seasonally decline. Despite the now widespread usage of metabarcoding, very few studies have attempted to study inter- and intra-populational individual trophic traits variation with metabarcoding data. This study illustrates how metabarcoding data obtained from feces can be combined with modelling and simulation approaches to test hypotheses in the conventional analytic framework of trophic analysis.

scholarly journals Reproduction, seasonal morphology, and juvenile growth in three Malagasy fruit bats

2021 ◽  
Author(s):  
Angelo Andrianiaina ◽  
Santino Andry ◽  
Anecia Gentles ◽  
Sarah Guth ◽  
Jean-Michel Heraud ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Body Mass ◽  
Conservation Status ◽  
Severe Disease ◽  
Species Conservation ◽  
Field Studies ◽  
Population Viability ◽  
Critical Data ◽  
Birth Pulse ◽  
Fruit Bat

The island nation of Madagascar is home to three endemic species of Old World Fruit Bat in the family Pteropodidae: Pteropus rufus, Eidolon dupreanum, and Rousettus madagascariensis, all three of which are IUCN Red Listed under some category of threat. To inform conservation efforts to model population viability for these threatened species, as well understand the mechanisms underpinning persistence of several potentially zoonotic pathogens hosted by these bats, we here define the seasonal limits of a staggered annual birth pulse across the three species. Our field studies in central-eastern Madagascar indicate that this annual birth pulse takes place in September/October for P. rufus, November for E. dupreanum, and December for R. madagascariensis. Juvenile development periods vary across the three Malagasy pteropodids, resulting in near-synchronous weaning of pups for all species in late January-February at the height of the fruiting season for Madagascar, a pattern characteristic of most mammalian frugivores on the island. We here document the size range in morphological traits for the three Malagasy fruit bat species; these traits span the range of those known for pteropodids more broadly, with P. rufus and E. dupreanum among the larger of recorded species and R. madagascariensis among the smaller. All three species demonstrate subtle sexual dimorphism in observed traits with larger-bodied males vs. females. We explore seasonal variation in adult body condition by comparing observed body mass with body mass predicted by forearm length, demonstrating that pregnant females add weight during staggered gestation periods and males lose weight during the nutritionally-deficit Malagasy winter. Finally, we quantify forearm, tibia, and ear length growth rates in juvenile bats, demonstrating both faster growth and more protracted development times for the largest P. rufus species. The longer development period for the already-threatened P. rufus further jeopardizes this species' conservation status as human hunting of bats for subsistence is particularly detrimental to population viability during reproductive periods. The more extreme seasonal variation in the mass to forearm relationship for P. rufus may also modulate immune function, an important consideration given these bats' roles as reservoir hosts for several high profile viral families known to cause severe disease in humans. Our work highlights the importance of longitudinal field studies in collecting critical data for mammalian conservation efforts and human public health alike.

Diet variability and foraging strategies in brown trout (Salmo trutta): an analysis from subpopulations to individuals

1995 ◽  
Vol 52 (12) ◽  
pp. 2543-2552 ◽  
Author(s):  
Emily E. Bridcut ◽  
Paul S. Giller
Keyword(s):  
Graphical Models ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Spatial Scales ◽  
Field Studies ◽  
Diet Analysis ◽  
Foraging Strategies ◽  
Feeding Strategies ◽  
Brown Trout Salmo Trutta ◽  
Over Time

Field studies were conducted to examine intra- and inter-individual diet variation in subpopulations of brown trout (Salmo trutta) at different spatial scales (between sites, between habitats (riffle and pool) within a site, and between individuals within a habitat) and different temporal scales (within subpopulations and within individuals over time) at four sites in the Glenfinish River, County Cork, Ireland. Electrofishing and stomach flushing techniques were used whereby fish larger than 85 mm were uniquely coded, allowing for repeated capture and diet analysis of individuals. A considerable degree of variation within and between subpopulations and individual diets was apparent. On the basis of novel and recent graphical models of feeding strategies, the trend was for a generalized strategy amongst trout subpopulations occupying riffles throughout most seasons, whilst specialization tended to be more frequent amongst trout occupying pools during summer and autumn. Using similarity indices and dendrograms, we illustrate that individual fish showed both feeding strategies within one habitat over time.

scholarly journals Seasonal variations of locomotor activity rhythms in melatonin-proficient and -deficient mice under seminatural outdoor conditions

2021 ◽  
Author(s):  
◽  
Joshua Metzger
Keyword(s):  
Locomotor Activity ◽  
Ambient Temperature ◽  
Daily Activity ◽  
Activity Patterns ◽  
Laboratory Mouse ◽  
Activity Period ◽  
Mouse Strains ◽  
Frankfurt Am Main ◽  
Seasonal Differences ◽  
Laboratory Conditions

Locomotor activity patterns of laboratory mice are widely used to analyze circadian mechanisms, but most investigations have been performed under standardized laboratory conditions. Outdoors, animals are exposed to daily changes in photoperiod and other abiotic cues that might influence their circadian system. To investigate how the locomotor activity patterns under outdoor conditions compare to controlled laboratory conditions, we placed 2 laboratory mouse strains (melatonin-deficient C57Bl and melatonin-proficient C3H) in the garden of the Dr. Senckenbergische Anatomie in Frankfurt am Main. The mice were kept singly in cages equipped with an infrared locomotion detector, a hiding box, nesting material, and with food and water ad libitum. The locomotor activity of each mouse was recorded for 1 year, together with data on ambient temperature, light, and humidity. Chronotype, chronotype stability, total daily activity, duration of the activity period, and daily diurnality indices were determined from the actograms. C3H mice showed clear seasonal differences in the chronotype, its stability, the total daily activity, and the duration of the activity period. These pronounced seasonal differences were not observed in the C57Bl. In both strains, the onset of the main activity period was mainly determined by the evening dusk, whereas the offset was influenced by the ambient temperature. The actograms did not reveal infra-, ultradian, or lunar rhythms or a weekday/weekend pattern. Under outdoor conditions, the 2 strains retained their nocturnal locomotor identity as observed in the laboratory. Our results indicate that the chronotype displays a seasonal plasticity that may depend on the melatoninergic system. Photoperiod and ambient temperature are the most potent abiotic entraining cues. The timing of the evening dusk mainly affects the onset of the activity period; the ambient temperature during this period influences the latter’s duration. Humidity, overall light intensities, and human activities do not affect the locomotor behavior.

Temperature and exudativory as drivers of the marmoset ( Callithrix spp.) daily activity period

2021 ◽  
Author(s):  
Renato R. Hilário ◽  
Saulo M. Silvestre ◽  
Filipa Abreu ◽  
Raone Beltrão‐Mendes ◽  
Carla S. S. Castro ◽  
...  
Keyword(s):  
Daily Activity ◽  
Activity Period

Seasonal Variation of Paraquat Photodegradation Rate on Polyethylene Mulch

2006 ◽  
Vol 20 (2) ◽  
pp. 315-318 ◽  
Author(s):  
James P. Gilreath ◽  
Bielinski M. Santos ◽  
Steven J. Duranceau
Keyword(s):  
Seasonal Variation ◽  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Field Studies ◽  
Sunlight Exposure ◽  
The Other ◽  
Herbicide Application ◽  
Photodegradation Rate ◽  
The Difference ◽  
Polyethylene Mulch

Field studies were conducted to determine the effect of season of the year, sunlight exposure time, and mulch color on paraquat photodegradation rate on polyethylene mulch. Experiments were established in winter, spring, and summer, with white and black polyethylene mulch, and paraquat-applied films were exposed to sunlight for 1, 4, 8, 24, 30, 48, 72, or 96 h after herbicide application. There was significant effect of the season by mulch color by time of exposure interaction on paraquat concentration recovered from mulch eluants. Winter paraquat photodegradation was lower than during the other seasons. At 48 h of sunlight exposure, predicted photodegradation on white mulch was 67, 83, and 88%, during winter, spring, and summer, respectively, whereas these values were 66, 82, and 84% on black mulch. The difference in paraquat photodegradation in winter with respect to the other seasons may be attributed to reduced ultraviolet radiation in winter, when solar radiation has to penetrate a larger atmosphere mass. In practical terms, transplanting on paraquat-applied mulch requires a minimum of 96 h during the spring and summer seasons, when concentrations were 5% or less, whereas a longer waiting period might be necessary in the winter.

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