Geolocators reveal variation and sex‐specific differences in the migratory strategies of a long‐distance migrant

Ibis ◽  
2021 ◽  
Author(s):  
Fraser Bell ◽  
Stuart Bearhop ◽  
Martins Briedis ◽  
Myriam El Harouchi ◽  
Sophie C Bell ◽  
...  
Keyword(s):  
Long Distance ◽  
Migratory Strategies

scholarly journals Partial altitudinal migration of the Near Threatened satyr tragopan Tragopan satyra in the Bhutan Himalayas: implications for conservation in mountainous environments

Oryx ◽  
2016 ◽  
Vol 51 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Nawang Norbu ◽  
Ugyen ◽  
Martin C. Wikelski ◽  
David S. Wilcove
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Full Range ◽  
Single Species ◽  
Anthropogenic Pressure ◽  
Forest Types ◽  
Long Distance ◽  
Altitudinal Migration ◽  
Breeding Grounds ◽  
Migratory Strategies

AbstractRelative to long-distance migrants, altitudinal migrants have been understudied, perhaps because of a perception that their migrations are less complex and therefore easier to protect. Nonetheless, altitudinal migrants may be at risk as they are subject to ongoing anthropogenic pressure from land use and climate change. We used global positioning system/accelerometer telemetry to track the partial altitudinal migration of the satyr tragopan Tragopan satyra in central Bhutan. The birds displayed a surprising diversity of migratory strategies: some individuals did not migrate, others crossed multiple mountains to their winter ranges, others descended particular mountains, and others ascended higher up into the mountains in winter. In all cases migration between summer breeding and winter non-breeding grounds was accomplished largely by walking, not by flying. Females migrated in a south-easterly direction whereas males migrated in random directions. During winter, migrants occupied south-east facing slopes whereas residents remained on south-west facing slopes. Migratory and resident tragopans utilized a range of forest types, with migratory individuals preferring cool broadleaved forests during winter. These complex patterns of migration suggest that conservation measures should extend across multiple mountains, protect the full range of forest types and encompass multiple landscape configurations to protect aspect diversity. Given the diversity of migratory strategies employed by this single species it seems clear that more research on altitudinal migrants is needed to understand what must be done to ensure their future in an era of widespread land-use and climate change.

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 Unravelling the life history of Amazonian fishes through otolith microchemistry

2016 ◽  
Vol 3 (6) ◽  
pp. 160206 ◽  
Author(s):  
Theodore W. Hermann ◽  
Donald J. Stewart ◽  
Karin E. Limburg ◽  
Leandro Castello
Keyword(s):  
Life History ◽  
Effective Means ◽  
Cost Effective ◽  
Otolith Microchemistry ◽  
Simultaneous Increase ◽  
Long Distance ◽  
Environmental Threats ◽  
Nursery Habitats ◽  
History Of ◽  
Migratory Strategies

Amazonian fishes employ diverse migratory strategies, but the details of these behaviours remain poorly studied despite numerous environmental threats and heavy commercial exploitation of many species. Otolith microchemistry offers a practical, cost-effective means of studying fish life history in such a system. This study employed a multi-method, multi-elemental approach to elucidate the migrations of five Amazonian fishes: two ‘sedentary’ species ( Arapaima sp. and Plagioscion squamosissimus ), one ‘floodplain migrant’ ( Prochilodus nigricans ) and two long-distance migratory catfishes ( Brachyplatystoma rousseauxii and B. filamentosum ). The Sr : Ca and Zn : Ca patterns in Arapaima were consistent with its previously observed sedentary life history, whereas Sr : Ca and Mn : Ca indicated that Plagioscion may migrate among multiple, chemically distinct environments during different life-history stages. Mn : Ca was found to be potentially useful as a marker for identifying Prochilodus 's transition from its nursery habitats into black water. Sr : Ca and Ba : Ca suggested that B. rousseauxii resided in the Amazon estuary for the first 1.5–2 years of life, shown by the simultaneous increase/decrease of otolith Sr : Ca/Ba : Ca, respectively. Our results further suggested that B. filamentosum did not enter the estuary during its life history. These results introduce what should be a productive line of research desperately needed to better understand the migrations of these unique and imperilled fishes.

scholarly journals Flexibility in migratory strategy contrasts with reliance on restricted staging and overwintering grounds for Sabine’s gulls from the Canadian High Arctic

2021 ◽  
Vol 8 (1) ◽  
pp. 84-97
Author(s):  
Sarah Elizabeth Gutowsky ◽  
Shanti E Davis ◽  
Mark Maftei ◽  
Mark L Mallory
Keyword(s):  
Environmental Variability ◽  
Current System ◽  
High Arctic ◽  
Long Distance ◽  
Stopover Site ◽  
California Current System ◽  
Xema Sabini ◽  
Wintering Areas ◽  
Migratory Strategies ◽  
Migratory Strategy

Abstract Sabine’s gulls (Xema sabini) undertake the longest migration of any gull, a trans-equatorial journey between Arctic breeding and southern hemisphere wintering areas. For such long-distance migrants, quantifying within- and between-individual variation in migratory strategy is key towards understanding resilience to environmental variability encountered over migration. We tracked 22 birds on 32 migrations from the Canadian Arctic to evaluate strategies and quantify flexibility among individuals and years. All birds undertook extended stopovers in a geographically-restricted staging area halfway through migration in the California Current System in both directions. Individuals were otherwise flexible in most aspects of migration but were repeatable in arrival date and duration of the southbound staging phase. Routes taken during southbound migration and overlap in overwintering areas were significantly larger within the same year than among years. Overall, birds showed high individual flexibility in migratory strategies but made similar decisions to one another in the same years. Every year, all birds showed repeatable, consistent reliance on the staging grounds as a key stopover site in both directions. This suggests Sabine’s gulls adjust to environmental change in many aspects of their migration but may be vulnerable to climate change and other anthropogenic influences during critical stages of the journey.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

Popliteal entrapment syndrome and age

VASA ◽  
2012 ◽  
Vol 41 (4) ◽  
pp. 262-268 ◽  
Author(s):  
Schweizer ◽  
Hügli ◽  
Koella ◽  
Jeanneret
Keyword(s):  
Risk Factors ◽  
Leg Pain ◽  
Walking Distance ◽  
Therapeutic Approaches ◽  
Long Distance ◽  
Entrapment Syndrome ◽  
Long Distance Running ◽  
Popliteal Entrapment ◽  
Popliteal Entrapment Syndrome ◽  
Atherosclerotic Risk Factors

On the occasion of diagnosing a popliteal entrapment syndrome in a 59-year old man with no cardiovascular risk factors, who developed acute ischemic leg pain during long distance running, we give an overview on this entity with emphasis on patients’age. The different types of the popliteal artery compression syndrome are summarized. The diagnostic and therapeutic approaches are discussed. The most important clinical sign of a popliteal entrapment syndrome is the lack of atherosclerotic risk factors in patients with limited walking distance. Not only in young athletes but also in patients more than 50 years old the popliteal entrapment syndrome has to be taken into account.

Attachment Styles, Physical Proximity, and Relational Satisfaction

2014 ◽  
Vol 4 (2) ◽  
pp. 106-112
Author(s):  
Anita Shrivastava ◽  
Andrea Burianova
Keyword(s):  
Attachment Styles ◽  
Romantic Relationship ◽  
Distinct Type ◽  
Relational Satisfaction ◽  
Long Distance ◽  
Avoidant Attachment ◽  
Geographic Separation ◽  
Relationship Of ◽  
Attachment Dimensions

This study aimed to explore the relationships between attachment styles, proximity, and relational satisfaction. This was achieved by assessing a distinct type of long distance romantic relationship of flying crews, compared with proximal (non-flying crew) romantic relationships. The responses of 139 expatriate professionals revealed significant associations between proximity and anxious and avoidant attachment dimensions. The role of the avoidant dimension in comparison with that of the anxious dimension was found to be a significant predictor of relational satisfaction. This study contributes significantly toward addressing the role of proximity and attachment in relational satisfaction in a new context of geographic separation.

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