Soaring flight of monarch butterflies, Danaus plexippus (Lepidoptera: Danaidae), during the late summer migration in southern Ontario

1979 ◽  
Vol 57 (7) ◽  
pp. 1393-1401 ◽  
Author(s):  
David L. Gibo ◽  
Megan J. Pallett
Keyword(s):  
Danaus Plexippus ◽  
Late Summer ◽  
Performance Parameters ◽  
Wing Loading ◽  
Main Mode ◽  
Southern Ontario ◽  
Average Mass ◽  
Blowing Up ◽  
Maximum Range ◽  
Soaring Flight

Adult Danaus plexippus in southern Ontario frequently engage in soaring flight during their late summer migration. They utilize both ascending air currents (lift) produced by winds blowing up slopes and thermals (bubbles or columns of air that are rising because they are warmer and lighter than the surrounding air). The butterflies appear to be very efficient and exhibit different flying techniques when encountering various types of lift. When the weather is favourable, soaring is the main mode of flight and the butterflies achieve heights above the ground of at least 300 m. Extended soaring flight in thermals was always associated with tail winds.A sample of 18 specimens gave an average mass of 566 ± 81 mg and an average wing loading of 0.018 ± 0.002 g/cm2 (1.77 N/m2). Gliding performance parameters were measured for two specimens ballasted to 450 mg and the results were extrapolated to 600-mg individuals. The energetic advantages of utilizing soaring flight in terms of extension of maximum range is discussed.

Lipid accumulation by migrating monarch butterflies (Danaus plexippus L.)

1993 ◽  
Vol 71 (1) ◽  
pp. 76-82 ◽  
Author(s):  
David L. Gibo ◽  
Jody A. McCurdy
Keyword(s):  
Lipid Accumulation ◽  
Seasonal Changes ◽  
Late Phase ◽  
Danaus Plexippus ◽  
Late Summer ◽  
Dry Mass ◽  
Middle Phase ◽  
Southern Ontario ◽  
Lipid Mass ◽  
Peak Abundance

The migration of Danaus plexippus during the late summer in southern Ontario in 1986 lasted for about 8 weeks and consisted of three phases, an early phase characterized by increasing abundance, a middle phase of peak abundance, and a late phase characterized by declining abundance. As the season progressed, systematic changes were observed in wet mass, dry mass, lean dry mass, lipid mass, and forewing length. Wet mass, lean dry mass, and forewing length were similar for early- and middle-phase individuals, but declined in late-phase migrants. Lipid mass peaked in the middle phase of the migration and then declined abruptly in the late phase. Dry mass also peaked in the middle phase, reflecting changes in lipid mass and lean dry mass. We hypothesize that the observed changes in lipid mass and lean dry mass over the 8 weeks resulted from changes in population structure as well as seasonal changes in the weather, and in availability of nectar. Opposing conclusions reached in previous studies of lipid accumulation in D. plexippus are probably the result of failure to control for phase of migration.

Survey and control of small mammal populations on two hardwood plantations in southern Ontario

1974 ◽  
Vol 50 (5) ◽  
pp. 181-185 ◽  
Author(s):  
Andrew Radvanyi
Keyword(s):  
Small Mammal ◽  
Late Summer ◽  
Control Measures ◽  
Effective Control ◽  
Southern Ontario ◽  
Live Trapping ◽  
Surrounding Areas ◽  
And Control ◽  
Rodent Populations ◽  
Ingredient Cost

Live trapping and tagging methods were employed to assess small mammal populations within two hardwood plantations in southern Ontario. Excessive girdling damage in past years to young planted trees necessitated an evaluation of rodent populations and development of effective control measures. The application of an anticoagulant rodenticide to oat groats bait broadcast over the study area at an ingredient cost of approximately three dollars per acre virtually wiped out the small mammals. Reinvasion from surrounding areas was, however, fairly rapid, particularly during late summer. Further research on longer term control measures using poisoned bait feeder stations is recommended.

scholarly journals Tracking multi-generational colonization of the breeding grounds by monarch butterflies in eastern North America

2013 ◽  
Vol 280 (1768) ◽  
pp. 20131087 ◽  
Author(s):  
D. T. Tyler Flockhart ◽  
Leonard I. Wassenaar ◽  
Tara G. Martin ◽  
Keith A. Hobson ◽  
Michael B. Wunder ◽  
...  
Keyword(s):  
North America ◽  
Danaus Plexippus ◽  
Late Summer ◽  
Breeding Habitat ◽  
Eastern North America ◽  
Distribution Models ◽  
Monarch Butterflies ◽  
Breeding Distribution ◽  
Breeding Grounds ◽  
Isotope Measurements

Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies ( Danaus plexippus ) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km 2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America.

The life histories of north-temperate populations of the crayfish Cambarus robustus and Cambarus bartoni

1985 ◽  
Vol 63 (10) ◽  
pp. 2313-2322 ◽  
Author(s):  
Premysl Hamr ◽  
Michael Berrill
Keyword(s):  
Life History ◽  
Life Histories ◽  
Carapace Length ◽  
Late Summer ◽  
Temperate Climate ◽  
Free Living ◽  
Southern Ontario ◽  
The Third ◽  
Early Fall ◽  
First Time

The life histories of the crayfish Cambarus robustus and Cambarus bartoni were studied in the Kawartha Lakes region of southern Ontario. There were marked differences in their breeding and molting cycles compared with the familiar pattern of the Orconectes species of this region. Egg extrusion occurred later (July in C. robustus, June in C. bartoni), and juveniles therefore did not become free living until late summer or early fall. With little growing time in their first summer, they measured only 5–10 mm in carapace length (CPL) before growth ceased for the winter. At the end of their second summer the still immature crayfish measured 17–26 mm CPL in C. robustus and 13–20 mm CPL in C. bartoni. Maturity was therefore not attained until the end of the third summer, when most C. robustus matured at 34–45 mm CPL and C. bartoni at 25–30 mm CPL. The majority of individuals apparently reproduced for the first time during their fourth summer; a few apparently survived into another summer, reaching carapace lengths greater than 50 mm in C. robustus and 30 mm in C. bartoni. In males of both species, form 1 and form 2 occur throughout the summer. Although lacking the synchrony of Orconectes species, breeding and molting activities are still confined to the period between April and October. The timing of the life-history events observed in these two Cambarus species may be adaptations to seasonal stresses of the swift water environments that these species inhabit as well as to the relative harshness of the northern temperate climate.

Autumnal body mass reduction in Antechinus swainsonii (Dasyuridae) in the Snowy Mountains.

2001 ◽  
Vol 23 (1) ◽  
pp. 31 ◽  
Author(s):  
K Green
Keyword(s):  
Snow Cover ◽  
Body Mass ◽  
Lean Mass ◽  
Late Summer ◽  
Mass Reduction ◽  
Average Mass ◽  
Increase Body Mass ◽  
Fat Reserves ◽  
The Difference ◽  
Body Mass Reduction

Autumnal body mass reduction in a seasonally snow-covered environment is reported for Antechinus swainsonii (Marsupialia: Dasyuridae), thus extending the phylogenetic spectrum in which this phenomenon is known. Above 1600 m altitude the average mass of individual A. swainsonii falls from 48.6 g to 42.6 g (a 12.3% loss) from April to May. The difference in mass results from a reduction in lean mass rather than a metabolisation of fat reserves. In A. swainsonii, the need to increase body mass in late summer only to lose it in autumn prior to a winter beneath the snow seems superfluous. However, the higher mass may be necessary to survive the harsher microclimate in autumn before conditions ameliorate beneath the snow cover. Survival from April to May is higher in heavier animals (that do lose mass in autumn) than lighter animals (with mass in April equal to that of animals after loss of body mass). These lighter animals disappear from the population in autumn. With snow cover in place, A. swainsonii is able to increase mass in winter.

scholarly journals A poor substitute for the real thing: captive-reared monarch butterflies are weaker, paler and have less elongated wings than wild migrants

2020 ◽  
Vol 16 (4) ◽  
pp. 20190922 ◽  
Author(s):  
Andrew K. Davis ◽  
Farran M. Smith ◽  
Ashley M. Ballew
Keyword(s):  
Danaus Plexippus ◽  
Late Summer ◽  
Population Declines ◽  
Average Strength ◽  
Long Distance ◽  
Monarch Butterflies ◽  
Real Thing ◽  
In The Wild ◽  
Wild Group ◽  
Migration Propensity

For many animals and insects that are experiencing dramatic population declines, the only recourse for conservationists is captive rearing. To ensure success, reared individuals should be biologically indistinct from those in the wild. We tested if this is true with monarch butterflies, Danaus plexippus , which are increasingly being reared for release by citizens and commercial breeders. Since late-summer monarchs should be as migration capable as possible for surviving the arduous long-distance migration, we evaluated four migration-relevant traits across two groups of captive-reared monarchs ( n = 41 and 42) and one group of wild-caught migrants ( n = 41). Monarchs (descendants of wild individuals) were reared from eggs to adulthood either in a warm indoor room next to a window, or in an incubator that mimicked late-summer conditions. Using an apparatus consisting of a perch mounted to an electronic force gauge, we assessed ‘grip strength' of all groups, then used image analysis to measure forewing size, pigmentation and elongation. In three of the four traits, reared monarchs underperformed compared to wild ones, even those reared under conditions that should have produced migration-ready individuals. The average strength of reared monarchs combined was 56% less than the wild group, even when accounting for size. Their orange wing colour was paler (an indicator of poor condition and flight ability) and their forewings were less elongated (elongation is associated with migration propensity) than wild monarchs. The reason(s) behind these effects is unknown but could stem from the frequent disturbance and/or handling of reared monarchs, or the fact that rearing removes the element of natural selection from all stages. Regardless, these results explain prior tagging studies that showed reared monarchs have lower migratory success compared to wild.

scholarly journals From daily movements to population distributions: weather affects competitive ability in a guild of soaring birds

2013 ◽  
Vol 10 (88) ◽  
pp. 20130612 ◽  
Author(s):  
Emily L. C. Shepard ◽  
Sergio A. Lambertucci
Keyword(s):  
Competitive Ability ◽  
Meteorological Factors ◽  
Interspecific Interactions ◽  
Wing Loading ◽  
Spatial And Temporal Scales ◽  
Population Distributions ◽  
Common Resource ◽  
Soaring Flight ◽  
The Cost ◽  
Ephemeral Resources

The ability of many animals to access and exploit food is dependent on the ability to move. In the case of scavenging birds, which use soaring flight to locate and exploit ephemeral resources, the cost and speed of movement vary with meteorological factors. These factors are likely to modify the nature of interspecific interactions, as well as individual movement capacity, although the former are less well understood. We used aeronautical models to examine how soaring performance varies with weather within a guild of scavenging birds and the consequences this has for access to a common resource. Birds could be divided broadly into those with low wing loading that are more competitive in conditions with weak updraughts and low winds (black vultures and caracaras), and those with high wing loading that are well adapted for soaring in strong updraughts and moderate to high winds (Andean condors). Spatial trends in meteorological factors seem to confine scavengers with high wing loading to the mountains where they out-compete other birds; a trend that is borne out in worldwide distributions of the largest species. However, model predictions and carcass observations suggest that the competitive ability of these and other birds varies with meteorological conditions in areas where distributions overlap. This challenges the view that scavenging guilds are structured by fixed patterns of dominance and suggests that competitive ability varies across spatial and temporal scales, which may ultimately be a mechanism promoting diversity among aerial scavengers.

Longitudinal clines in the frequency distribution of ‘super-clones’ in an aphid crop pest

2015 ◽  
Vol 105 (6) ◽  
pp. 694-703 ◽  
Author(s):  
A. Gilabert ◽  
C.-A. Dedryver ◽  
S. Stoeckel ◽  
M. Plantegenest ◽  
J.-C. Simon
Keyword(s):  
Frequency Distribution ◽  
Rhopalosiphum Padi ◽  
Late Summer ◽  
Cereal Aphid ◽  
Main Mode ◽  
Frequency Distributions ◽  
Cropping Season ◽  
Northern Half ◽  
And Migration ◽  
Open Question

AbstractParthenogenesis is the main mode of reproduction of aphids. Their populations are therefore composed of clones whose frequency distribution varies in space and time. Previous population genetic studies on aphids have highlighted the existence of highly abundant clones (‘super-clones’), distributed over large geographic areas and persisting over time. Whether the abundance of ‘super-clones’ results from their ecological success or from stochastic forces, such as drift and migration, is an open question. Here, we looked for the existence of clines in clonal frequency along a climatic gradient in the cereal aphid Rhopalosiphum padi (Linnaeus, 1758) and examined the possible influence of geographical distance and environmental variables in the buildup and maintenance of such clonal clines. We investigated the spatial distribution of the commonest genotypes of R. padi by sampling populations along an east–west transect in maize fields in the northern half of France in both spring and late summer. Individual aphids were genotyped at several polymorphic loci, allowing the assessment of frequency distributions of multilocus genotypes (MLGs) across the cropping season. We found several MLGs showing longitudinal clines in their frequency distribution in both spring and summer. In particular, two dominant asexual genotypes of R. padi showed inverted geographical clines, which could suggest divergent adaptations to environmental conditions. We concluded that while the distribution of some ‘super-clones’ of R. padi seems most likely driven by the action of migration and genetic drift, selection could be also involved in the establishment of longitudinal clines of others.

scholarly journals Evidence for facultative migratory flight behavior in Helicoverpa armigera (Noctuidae: Lepidoptera) in India

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245665
Author(s):  
Patil Jyothi ◽  
Prabhuraj Aralimarad ◽  
Vijaya Wali ◽  
Shivansh Dave ◽  
M. Bheemanna ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Significant Proportion ◽  
Danaus Plexippus ◽  
Flight Behavior ◽  
Wing Loading ◽  
Long Distance ◽  
Migratory Flight ◽  
Helicoverpa Armígera ◽  
Single Night ◽  
Polyphagous Insect

Despite its deleterious impact on farming and agriculture, the physiology and energetics of insect migration is poorly understood due to our inability to track their individual movements in the field. Many insects, e.g. monarch butterflies, Danaus plexippus (L.), are facultative migrants. Hence, it is important to establish whether specific insect populations in particular areas migrate. The polyphagous insect, Helicoverpa armigera (Hübner), is especially interesting in this regard due to its impact on a variety of crops. Here, we used a laboratory-based flight mill assay to show that Helicoverpa armigera populations clearly demonstrate facultative migration in South India. Based on various flight parameters, we categorized male and female moths as long, medium or short distance fliers. A significant proportion of moths exhibited long-distance flight behavior covering more than 10 km in a single night, averaging about 8 flight hours constituting 61% flight time in the test period. The maximum and average flight speeds of these long fliers were greater than in the other categories. Flight activity across sexes also varied; male moths exhibited better performance than female moths. Wing morphometric parameters including forewing length, wing loading, and wing aspect ratio were key in influencing long-distance flight. Whereas forewing length positively correlated with flight distance and duration, wing loading was negatively correlated.

The Biology and Behaviour of the European Pine Shoot Moth Rhyacionia buoliana (Schiff.), in Southern Ontario II. Egg, Larva, and Pupa

1963 ◽  
Vol 95 (8) ◽  
pp. 844-863 ◽  
Author(s):  
P. J. Pointing
Keyword(s):  
Small Groups ◽  
Ground Surface ◽  
Late Summer ◽  
Feeding Period ◽  
Tree Crown ◽  
Mortality Factors ◽  
Short Supply ◽  
Southern Ontario ◽  
Web Construction ◽  
Third Instar Larvae

AbstractThis is the second of two papers on this subject. The eggs of R. buoliana are usually found singly or in small groups on the hark or needle sheaths of new shoots, except under conditions of severe infestation where new foliage is in short supply. The first two instars feed on needles from within webs. Third-instar larvae mine one or more buds and cease feeding in late summer before the advent of unfavourable temperatures. Low temperature, lethal to overwintering third-instar larvae, is one of the most important and readily measured mortality factors, Larvae spin webs and moult before they resume feeding in April or May. Migration, usually upward in the tree crown, and web construction continue throughout the spring feeding period. Larvae within two feet of the ground surface on trees less than eight feet tall complete their development earlier than larvae at higher levels. Parasitism, based on previous extensive surveys, has very likely been underestimated.

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