scholarly journals Seasonal Patterns of Fat Deposits in Relation to Migratory Strategy in Facultative Migrants

2021 ◽  
Vol 9 ◽  
Author(s):  
Jamie M. Cornelius ◽  
Thomas P. Hahn ◽  
Ashley R. Robart ◽  
Ben J. Vernasco ◽  
Dorothy L. Zahor ◽  
...  
Keyword(s):  
Wing Loading ◽  
Long Distance ◽  
Flight Duration ◽  
House Finches ◽  
Fat Deposits ◽  
Migratory Season ◽  
Partial Migrant ◽  
Migration Strategies ◽  
Migratory Strategy ◽  
Red Crossbills

Physiological preparations for migration generally reflect migratory strategy. Migrant birds fuel long-distance flight primarily with lipids, but carrying excess fuel is costly; thus, the amount of fat deposited prior to departure often reflects the anticipated flight duration or distance between refueling bouts. Seasonal pre-migratory deposition of fat is well documented in regular seasonal migrants, but is less described for more facultative species. We analyze fat deposits of free-living birds across several taxa of facultative migrants in the songbird subfamily Carduelinae, including house finches (Haemorhous mexicanus), American goldfinches (Spinus tristis), pine siskins (Spinus pinus) and four different North American ecotypes of red crossbills (Loxia curvirostra), to evaluate seasonal fat deposition during facultative migratory periods. Our data suggest that the extent of seasonal fat deposits corresponds with migratory tendency in these facultative taxa. Specifically, nomadic red crossbills with a seasonally predictable annual movement demonstrated relatively large seasonal fat deposits coincident with the migratory periods. In contrast, pine siskins, thought to be more variable in timing and initiation of nomadic movements, had smaller peaks in fat deposits during the migratory season, and the partial migrant American goldfinch and the resident house finch showed no peaks coincident with migratory periods. Within the red crossbills, those ecotypes that are closely associated with pine habitats showed larger peaks in fat deposits coincident with autumn migratory periods and had higher wing loading, whereas those ecotypes associated with spruces, Douglas-fir and hemlocks showed larger peaks coincident with spring migratory periods and lower wing loading. We conclude that population averages of fat deposits do reflect facultative migration strategies in these species, as well as the winter thermogenic challenges at the study locations. A difference in seasonal fattening and wing loading among red crossbill ecotypes is consistent with the possibility that they differ in their migratory biology, and we discuss these differences in light of crossbill reproductive schedules and phenologies of different conifer species.

scholarly journals A Revised and Improved Version of the Northern Wheatear (Oenanthe oenanthe) Transcriptome

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 151
Author(s):  
Roberto Carlos Frias-Soler ◽  
Lilian Villarín Pildaín ◽  
Michael Wink ◽  
Franz Bairlein
Keyword(s):  
Quality Parameters ◽  
Northern Wheatear ◽  
Long Distance ◽  
Assembly Quality ◽  
Oenanthe Oenanthe ◽  
Mrna Sequencing ◽  
Sequencing Coverage ◽  
Muscle Tissues ◽  
Migratory Season ◽  
Migratory Phenotype

This work presents an updated and more complete version of the transcriptome of a long-distance migrant, the Northern Wheatear (Oenanthe oenanthe). The improved transcriptome was produced from the independent mRNA sequencing of adipose tissue, brain, intestines, liver, skin, and muscle tissues sampled during the autumnal migratory season. This new transcriptome has better sequencing coverage and is more representative of the species’ migratory phenotype. We assembled 20,248 transcripts grouped into 16,430 genes, from which 78% were successfully annotated. All the standard assembly quality parameters were improved in the second transcriptome version.

scholarly journals High Temperatures Decrease the Flight Capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 394
Author(s):  
Carlos A. Antolinez ◽  
Tobias Moyneur ◽  
Xavier Martini ◽  
Monique J. Rivera
Keyword(s):  
Relative Humidity ◽  
High Temperatures ◽  
Insect Pest ◽  
The United States ◽  
Diaphorina Citri ◽  
Long Distance ◽  
Flight Duration ◽  
Custom Made ◽  
Flight Capacity ◽  
Low Humidity

Diaphorina citri Kuwayama (Hemiptera: Liviidae), commonly known as Asian citrus psyllid (ACP), is an invasive insect pest and the vector of the bacterium causing Huanglongbing (HLB), a lethal disease of citrus. In the United States, ACP has been established in all citrus-producing zones, all of which have different environmental conditions. The spread of ACP and, more importantly, HLB, has progressed differently depending on the state, with more rapid spread in Florida and Texas than in California. Climatic variations between the regions are likely a strong factor in the difference in the rate of spread. Despite this, it is unknown how the flight capacity of D. citri is influenced by high temperatures (>30 °C) and subsequently, low humidity experienced in California but not in Texas or Florida. In this study, by using a custom-made, temperature-controlled flight mill arena, we assessed the effect of high temperatures on the flight capacity and flight propensity of D. citri under low (20–40%) and high (76–90%) relative humidity conditions. We found that temperature and humidity influence the propensity to engage in short or long-distance flight events. Psyllids exposed to temperatures above 43 °C only performed short flights (˂60 s), and a high relative humidity significantly decrease the proportion of long flights (≥60 s) at 26 and 40 °C. The flight capacity for insects who engaged in short and long flights was significantly affected by temperature but not by humidity. For long flyers, temperature (in the 26–43 °C range) was negatively correlated with distance flown and flight duration. The most favorable temperature for long dispersion was 26 °C, with suboptimal temperatures in the range of 32–37 °C and the least favorable temperatures at 40 and 43 °C. In conclusion, D. citri is able to fly in a broad range of temperatures and efficiently fly in high and low humidity. However, temperatures above 40 °C, similar to those experienced in semi-arid environments like Southern California or Arizona, are detrimental for its flight capacity.

scholarly journals Driving Factors in the Colonization of Oceania: Developing Island-Level Statistical Models to Test Competing Hypotheses

2015 ◽  
Vol 80 (2) ◽  
pp. 397-407 ◽  
Author(s):  
Adrian V. Bell ◽  
Thomas E. Currie ◽  
Geoffrey Irwin ◽  
Christopher Bradbury
Keyword(s):  
Model Selection ◽  
Statistical Models ◽  
Long Distance ◽  
Statistical Framework ◽  
Rigorous Framework ◽  
Migration Strategies ◽  
Level Model ◽  
Colonization Patterns ◽  
Selection Framework ◽  
Distance Travel

Migration is a key driver of human cultural and genetic evolution, with recent theoretical advances calling for work to accurately identify factors behind early colonization patterns. However, inferring prehistoric migration strategies is a controversial field of inquiry that largely relies on interpreting settlement chronologies and constructing plausible narratives around environmental factors. Model selection approaches, along with new statistical models that match the dynamic nature of colonization, offers a more rigorous framework to test competing theories. We demonstrate the utility of this approach by developing an Island-Level Model of Colonization adapted from epidemiology in a Bayesian model-selection framework. Using model selection techniques, we assess competing colonization theories of Near and Remote Oceania, showing that models of exploration angles and risk performed considerably better than models using inter-island distance, suggesting early seafarers were already adept at long-distance travel. These results are robust after artificially increasing the uncertainty around settlement times. We show how decades of thinking on colonization strategies can be brought together and assessed in one statistical framework, providing us with greater interpretive power to understand a fundamental feature of our past.

Changes in migration phenology and biometrical traits of Reed, Marsh and Sedge Warblers

2012 ◽  
Vol 7 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Szilvia Kovács ◽  
Péter Fehérvári ◽  
Krisztina Nagy ◽  
Andrea Harnos ◽  
Tibor Csörgő
Keyword(s):  
Body Mass ◽  
Population Level ◽  
Long Distance ◽  
Stopover Site ◽  
Sedge Warbler ◽  
Global Environmental ◽  
Migration Phenology ◽  
Spring Arrival ◽  
Migration Strategies ◽  
Migrant Birds

AbstractGlobal environmental processes like climate change could severely affect population level migratory behaviour of long range migrant birds. We analyzed changes in migration phenology and biometrics of three closely-related long-distance migrant Acrocephalus species. We used the records of 12 063 Sedge, 12 913 Reed, and 5 409 Marsh Warblers caught and ringed between 1989–2009, at a Hungarian stopover site. Quantile regressions were used to analyse the changes in spring and autumn migration phenology. Median spring arrival date of Sedge and Reed Warblers shifted 6.5 and 7.5 days earlier, respectively. Autumn arrival of all species shifted one (Reed and Marsh Warblers) or two (Sedge Warbler) weeks later. Mean body mass of adult Reed and Marsh Warblers decreased in spring (by 0.3 and 0.2 grams, respectively) and in autumn (by 0.8 and 0.2 grams, respectively) while body mass of adult Sedge Warblers decreased only in autumn (by 0.4 grams). Mean wing length of all species increased significantly (range of change: 0.6–1 mm). Despite the fact that the studied species are closely related, all three have remarkably different migration strategies. However, similar patterns can be observed in the studied parameters, indicating that global processes may have general effects on these species, albeit through markedly different mechanisms.

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.

scholarly journals Convergent patterns of long-distance nocturnal migration in noctuid moths and passerine birds

2011 ◽  
Vol 278 (1721) ◽  
pp. 3074-3080 ◽  
Author(s):  
Thomas Alerstam ◽  
Jason W. Chapman ◽  
Johan Bäckman ◽  
Alan D. Smith ◽  
Håkan Karlsson ◽  
...  
Keyword(s):  
Passerine Birds ◽  
Long Distance ◽  
Flight Behaviour ◽  
Preferred Direction ◽  
Migration Strategies ◽  
Migrant Birds ◽  
Nocturnal Migration ◽  
Self Powered ◽  
Migratory Strategies ◽  
Air Streams

Vast numbers of insects and passerines achieve long-distance migrations between summer and winter locations by undertaking high-altitude nocturnal flights. Insects such as noctuid moths fly relatively slowly in relation to the surrounding air, with airspeeds approximately one-third of that of passerines. Thus, it has been widely assumed that windborne insect migrants will have comparatively little control over their migration speed and direction compared with migrant birds. We used radar to carry out the first comparative analyses of the flight behaviour and migratory strategies of insects and birds under nearly equivalent natural conditions. Contrary to expectations, noctuid moths attained almost identical ground speeds and travel directions compared with passerines, despite their very different flight powers and sensory capacities. Moths achieved fast travel speeds in seasonally appropriate migration directions by exploiting favourably directed winds and selecting flight altitudes that coincided with the fastest air streams. By contrast, passerines were less selective of wind conditions, relying on self-powered flight in their seasonally preferred direction, often with little or no tailwind assistance. Our results demonstrate that noctuid moths and passerines show contrasting risk-prone and risk-averse migratory strategies in relation to wind. Comparative studies of the flight behaviours of distantly related taxa are critically important for understanding the evolution of animal migration strategies.

scholarly journals The non-breeding distribution of Dupont's Lark Chersophilus duponti in Spain

2006 ◽  
Vol 16 (4) ◽  
pp. 317-323 ◽  
Author(s):  
FRANCISCO SUÁREZ ◽  
JESÚS T. GARCÍA ◽  
FRANCISCO J. SAMPIETRO ◽  
VICENTE GARZA
Keyword(s):  
Short Distance ◽  
Weather Conditions ◽  
Breeding Period ◽  
Long Distance ◽  
Breeding Sites ◽  
Large Numbers ◽  
Breeding Distribution ◽  
Partial Migrant ◽  
Dupont’S Lark ◽  
Specific Conservation

In this paper, we analyse the non-breeding distribution of Dupont's Lark, one of Europe's most threatened and least known passerines, using breeding and wintering censuses, published and unpublished records of individuals outside their breeding areas, and data on radio-tagged individuals and field observations. Results suggest that most breeding Dupont's Larks remain around the breeding sites during the non-breeding season, including those populations from areas with harsh winter weather conditions. The probability of winter presence of Dupont's Larks in breeding areas was significantly correlated with population size, but the altitude of the locality studied did not influence winter presence. Records outside breeding areas indicate that part of the population moves some distance after breeding, occupying lower sites and principally those with agrarian substrates. We also found several records far from well-known breeding areas during the breeding period. Our results suggest that Dupont's Lark seems to be a partial migrant, wintering in breeding areas in large numbers (probably the adult fraction of the population) but with some part of the populations moving to other areas. The movements are short-distance in most cases, although medium- and long-distance dispersive movements were also detected. We discuss the implications of these results for the design of specific conservation measures for the species.

scholarly journals Quantifying flight aptitude variation in wild A. gambiae s.l. in order to identify long-distance migrants

2020 ◽  
Author(s):  
Roy Faiman ◽  
Alpha Seydou YARO ◽  
Moussa Diallo ◽  
Adama Dao ◽  
Djibril Samake ◽  
...  
Keyword(s):  
Sensu Stricto ◽  
Flight Activity ◽  
Malaria Vectors ◽  
Anopheles Coluzzii ◽  
Wing Size ◽  
Wet Season ◽  
Long Distance ◽  
Flight Duration ◽  
Tethered Flight ◽  
Gravid Females

Abstract Background In the West African Sahel, mosquito reproduction is halted during the 5-7 month-long dry season, due to the absence of surface waters required for larval development. However, recent studies have suggested that both Anopheles gambiae sensu stricto (s.s.) and Anopheles arabiensis repopulate this region via migration from distant locations where larval sites are perennial. Anopheles coluzzii engages in more regional migration, presumably within the Sahel, following shifting resources correlating with the ever-changing patterns of Sahelian rainfall. Understanding mosquito migration is key to controlling malaria—a disease that continues to claim more than 400,000 lives annually, especially those of African children. Using tethered flight data of wild mosquitoes, the distribution of flight parameters were evaluated as indicators of long-range migrants versus appetitive flyers, and the species specific seasonal differences and gonotrophic states compared between two flight activity modalities. Morphometrical differences were evaluated in the wings of mosquitoes exhibiting high flight activity (HFA) vs. low flight activity (LFA).Methods A novel tethered-flight assay was used to characterize flight in the three primary malaria vectors- An. arabiensis, An. coluzzii and An. gambiae s.s. The flights of tethered wild mosquitoes were audio-recorded from 21:00h to 05:00h in the following morning and three flight aptitude indices were examined: total flight duration, longest flight bout, and the number of flight bouts during the assay.Results The distributions of all flight indices were strongly skewed to the right, indicating that the population consisted of a majority of low-flight activity (LFA) mosquitoes and a minority of high-flight activity (HFA) mosquitoes. The median total flight was 586 seconds and the maximum value was 16,110 seconds (~4.5 h). In accordance with recent results, flight aptitude peaked in the wet season, and was higher in gravid females than in non-blood-fed females. Flight aptitude was also found to be higher in An. coluzzii compared to An. arabiensis, with intermediate values in An. gambiae s.s., but displaying no statistical difference. Evaluating differences in wing size and shape between LFA individuals and HFA ones, the wing size of HFA An. coluzzii was larger than that of LFAs during the wet season—its length was wider than predicted by allometry alone, indicating a change in wing shape. No statistically significant differences were found in the wing size/shape of An. gambiae s.s. or An. arabiensis.Conclusions The partial agreement between the tethered flight results and recent results based on aerial sampling of these species suggest a degree of discrimination between appetitive flyers and long-distance migrants although identifying HFAs as long-distance migrants is not recommended without further investigation.

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