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185 records – page 1 of 19.

Accumulated state of the Yukon River watershed: part I critical review of literature.

https://arctichealth.org/en/permalink/ahliterature121234
Source
Integr Environ Assess Manag. 2013 Jul;9(3):426-38
Publication Type
Article
Date
Jul-2013
Author
Monique G Dubé
Breda Muldoon
Julie Wilson
Karonhiakta'tie Bryan Maracle
Author Affiliation
Canadian Rivers Institute, University of New Brunswick, Alberta, Canada. Dub.mon@hotmail.com
Source
Integr Environ Assess Manag. 2013 Jul;9(3):426-38
Date
Jul-2013
Language
English
Publication Type
Article
Keywords
Alaska - epidemiology
Animal Migration
Animals
British Columbia - epidemiology
Climate change
Environment
Environmental Monitoring - methods
Fish Diseases - epidemiology - microbiology - parasitology
Fishes - physiology
Fresh Water - analysis - microbiology - parasitology
Humans
Neoplasms - chemically induced - epidemiology
Seasons
Water Movements
Water Pollutants, Chemical - analysis - metabolism - toxicity
Water Quality
Yukon Territory - epidemiology
Abstract
A consistent methodology for assessing the accumulating effects of natural and manmade change on riverine systems has not been developed for a whole host of reasons including a lack of data, disagreement over core elements to consider, and complexity. Accumulated state assessments of aquatic systems is an integral component of watershed cumulative effects assessment. The Yukon River is the largest free flowing river in the world and is the fourth largest drainage basin in North America, draining 855,000 km(2) in Canada and the United States. Because of its remote location, it is considered pristine but little is known about its cumulative state. This review identified 7 "hot spot" areas in the Yukon River Basin including Lake Laberge, Yukon River at Dawson City, the Charley and Yukon River confluence, Porcupine and Yukon River confluence, Yukon River at the Dalton Highway Bridge, Tolovana River near Tolovana, and Tanana River at Fairbanks. Climate change, natural stressors, and anthropogenic stresses have resulted in accumulating changes including measurable levels of contaminants in surface waters and fish tissues, fish and human disease, changes in surface hydrology, as well as shifts in biogeochemical loads. This article is the first integrated accumulated state assessment for the Yukon River basin based on a literature review. It is the first part of a 2-part series. The second article (Dubé et al. 2013a, this issue) is a quantitative accumulated state assessment of the Yukon River Basin where hot spots and hot moments are assessed outside of a "normal" range of variability.
PubMed ID
22927161 View in PubMed
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Activity of the pituitary-gonadal axis is increased prior to the onset of spawning migration of chum salmon.

https://arctichealth.org/en/permalink/ahliterature90768
Source
J Exp Biol. 2009 Jan;212(Pt 1):56-70
Publication Type
Article
Date
Jan-2009
Author
Onuma Takeshi A
Sato Shunpei
Katsumata Hiroshi
Makino Keita
Hu Weiwei
Jodo Aya
Davis Nancy D
Dickey Jon T
Ban Masatoshi
Ando Hironori
Fukuwaka Masa-Aki
Azumaya Tomonori
Swanson Penny
Urano Akihisa
Author Affiliation
Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan. takeshikiai@msn.com
Source
J Exp Biol. 2009 Jan;212(Pt 1):56-70
Date
Jan-2009
Language
English
Publication Type
Article
Keywords
Age Factors
Analysis of Variance
Animal Migration - physiology
Animals
DNA Primers - genetics
DNA, Mitochondrial - genetics
Follicle Stimulating Hormone, beta Subunit - metabolism
Gonadal Steroid Hormones - blood
Gonads - metabolism - physiology
Haplotypes - genetics
Microarray Analysis
Oncorhynchus keta - physiology
Pacific Ocean
Pituitary Gland - metabolism - physiology
RNA, Messenger - metabolism
Radioimmunoassay
Reverse Transcriptase Polymerase Chain Reaction
Seasons
Sexual Behavior, Animal - physiology
Abstract
The activity of the pituitary-gonadal axis (PG axis) in pre-migratory and homing chum salmon was examined because endocrine mechanisms underlying the onset of spawning migration remain unknown. Pre-migratory fish were caught in the central Bering Sea in June, July and September 2001, 2002 and 2003, and in the Gulf of Alaska in February 2006. They were classified into immature and maturing adults on the basis of gonadal development. The maturing adults commenced spawning migration to coastal areas by the end of summer, because almost all fish in the Bering Sea were immature in September. In the pituitaries of maturing adults, the copy numbers of FSHbeta mRNA and the FSH content were 2.5- to 100-fold those of the immature fish. Similarly, the amounts of LHbeta mRNA and LH content in the maturing adults were 100- to 1000-fold those of immature fish. The plasma levels of testosterone, 11-ketotestosterone and estradiol were higher than 10 nmol l(-1) in maturing adults, but lower than 1.0 nmol l(-1) in immature fish. The increase in the activity of the PG-axis components had already initiated in the maturing adults while they were still in the Gulf of Alaska in winter. In the homing adults, the pituitary contents and the plasma levels of gonadotropins and plasma sex steroid hormones peaked during upstream migration from the coast to the natal hatchery. The present results thus indicate that the seasonal increase in the activity of the PG axis is an important endocrine event that is inseparable from initiation of spawning migration of chum salmon.
PubMed ID
19088211 View in PubMed
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[Adaptive features of the ecology and annual cycle of the willow warbler (Phylloscopus trochilus L.) at the northern boundary of the Siberian part of the range].

https://arctichealth.org/en/permalink/ahliterature261514
Source
Izv Akad Nauk Ser Biol. 2014 Nov-Dec;(6):605-15
Publication Type
Article
Author
V N Ryzhanovskii
Source
Izv Akad Nauk Ser Biol. 2014 Nov-Dec;(6):605-15
Language
Russian
Publication Type
Article
Keywords
Adaptation, Physiological
Animal Migration
Animals
Climate change
Cold Climate
Feathers - anatomy & histology - physiology
Female
Flight, Animal - physiology
Male
Molting - physiology
Passeriformes - growth & development - physiology
Population Dynamics
Seasons
Siberia
Abstract
The ecology of the willow warbler in the north of Western Siberia is considered, and the adaptations that enable the spread of this species to the Subarctic are analyzed. It is established that one of the key factors that caused the change in the range of this species is the northward distribution of shrubs and, hence, the biomass of insects (available food items of these birds).
PubMed ID
25739309 View in PubMed
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Adaptive strategies in nocturnally migrating insects and songbirds: contrasting responses to wind.

https://arctichealth.org/en/permalink/ahliterature278633
Source
J Anim Ecol. 2016 Jan;85(1):115-24
Publication Type
Article
Date
Jan-2016
Author
Jason W Chapman
Cecilia Nilsson
Ka S Lim
Johan Bäckman
Don R Reynolds
Thomas Alerstam
Source
J Anim Ecol. 2016 Jan;85(1):115-24
Date
Jan-2016
Language
English
Publication Type
Article
Keywords
Adaptation, Physiological
Animal Migration
Animals
Flight, Animal
Moths - physiology
Radar
Seasons
Songbirds - physiology
Sweden
Wind
Abstract
Animals that use flight as their mode of transportation must cope with the fact that their migration and orientation performance is strongly affected by the flow of the medium they are moving in, that is by the winds. Different strategies can be used to mitigate the negative effects and benefit from the positive effects of a moving flow. The strategies an animal can use will be constrained by the relationship between the speed of the flow and the speed of the animal's own propulsion in relation to the surrounding air. Here we analyse entomological and ornithological radar data from north-western Europe to investigate how two different nocturnal migrant taxa, the noctuid moth Autographa gamma and songbirds, deal with wind by analysing variation in resulting flight directions in relation to the wind-dependent angle between the animal's heading and track direction. Our results, from fixed locations along the migratory journey, reveal different global strategies used by moths and songbirds during their migratory journeys. As expected, nocturnally migrating moths experienced a greater degree of wind drift than nocturnally migrating songbirds, but both groups were more affected by wind in autumn than in spring. The songbirds' strategies involve elements of both drift and compensation, providing some benefits from wind in combination with destination and time control. In contrast, moths expose themselves to a significantly higher degree of drift in order to obtain strong wind assistance, surpassing the songbirds in mean ground speed, at the cost of a comparatively lower spatiotemporal migratory precision. Moths and songbirds show contrasting but adaptive responses to migrating through a moving flow, which are fine-tuned to the respective flight capabilities of each group in relation to the wind currents they travel within.
PubMed ID
26147535 View in PubMed
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[Advantages and limitations of interspecies associations in northern migratory sandpipers (Charadrii, Aves)].

https://arctichealth.org/en/permalink/ahliterature261289
Source
Zh Obshch Biol. 2014 May-Jun;75(3):204-13
Publication Type
Article
Author
V V Gavrilov
Source
Zh Obshch Biol. 2014 May-Jun;75(3):204-13
Language
Russian
Publication Type
Article
Keywords
Animal Migration - physiology
Animals
Birds - physiology
Ecosystem
Female
Male
Nesting Behavior - physiology
Siberia
Abstract
Investigations were carried out at two stations of Ornithological Unit, IBPN FEB RAS, located in Nizhnekolymsk District, Yakutia, starting from May 15-20 in 1984, 1985, 1987, 1988, and 1990; at the northern coast of Pukhovoy Bay, Southern Island of Novaya Zemlya starting from June 1 in 1994; at Cape Beliy Nos, the Yugorsky Peninsula, starting from June 1 in 1995-1997. Classic associations are detected in interspecies flocks of sandpipers between the following species: the Pacific golden plover and the curlew sandpiper, the pectoral sandpiper and the long-billed dowitcher, the pectoral sandpiper and the dunlin, the grey plover and the dunlin. However, total amount of birds that form associations is not large. In species of group "A" (the grey plover, the Pacific golden plover, the pectoral sandpiper), no difference has been observed in migratory birds behavior within inter- or conspecific flocks. Species of group "B" (the dunlin, the curlew sandpiper, the long-billed dowitcher), on the contrary, change their behavior sharply depending on whether they belong to an association or not. Species of group "A" do not get any advantages when forming an association. Unlike them, species of group "B" profit from associating: a part of time spent in foraging substantially increases; more time is spent on rest and less time is spent on reconnaissance and vigilance (readiness for actions); safety of birds is enhanced. On the other hand, in species of group "B" there are also disadvantages related with associating: i.e., interspecies competition for food; foraging in suboptimal habitats which, in turn, may lead to notable increase of time spent by birds in foraging. An assumption is put forward that in species of group "B" advantages and limitations of associating cancel each other to a certain extent, and this explains rather small number of birds forming associations.
PubMed ID
25771678 View in PubMed
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An exception to the rule: carry-over effects do not accumulate in a long-distance migratory bird.

https://arctichealth.org/en/permalink/ahliterature257806
Source
PLoS One. 2014;9(2):e86588
Publication Type
Article
Date
2014
Author
Nathan R Senner
Wesley M Hochachka
James W Fox
Vsevolod Afanasyev
Author Affiliation
Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America.
Source
PLoS One. 2014;9(2):e86588
Date
2014
Language
English
Publication Type
Article
Keywords
Alaska
Animal Migration
Animals
Charadriiformes - physiology
Geography
Population Dynamics
Seasons
Time Factors
Abstract
Recent years have seen a growing consensus that events during one part of an animal's annual cycle can detrimentally affect its future fitness. Notably, migratory species have been shown to commonly display such carry-over effects, facing severe time constraints and physiological stresses that can influence events across seasons. However, to date, no study has examined a full annual cycle to determine when these carry-over effects arise and how long they persist within and across years. Understanding when carry-over effects are created and how they persist is critical to identifying those periods and geographic locations that constrain the annual cycle of a population and determining how selection is acting upon individuals throughout the entire year. Using three consecutive years of migration tracks and four consecutive years of breeding success data, we tested whether carry-over effects in the form of timing deviations during one migratory segment of the annual cycle represent fitness costs that persist or accumulate across the annual cycle for a long-distance migratory bird, the Hudsonian godwit, Limosa haemastica. We found that individual godwits could migrate progressively later than population mean over the course of an entire migration period, especially southbound migration, but that these deviations did not accumulate across the entire year and were not consistently detected among individuals across years. Furthermore, neither the accumulation of lateness during previous portions of the annual cycle nor arrival date at the breeding grounds resulted in individuals suffering reductions in their breeding success or survival. Given their extreme life history, such a lack of carry-over effects suggests that strong selection exists on godwits at each stage of the annual cycle and that carry-over effects may not be able to persist in such a system, but also emphasizes that high-quality stopover and wintering sites are critical to the maintenance of long-distance migratory populations.
Notes
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PubMed ID
24523862 View in PubMed
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An experimental field evaluation of winter carryover effects in semi-anadromous brown trout (Salmo trutta).

https://arctichealth.org/en/permalink/ahliterature275036
Source
J Exp Zool A Ecol Genet Physiol. 2015 Nov;323(9):645-54
Publication Type
Article
Date
Nov-2015
Author
Jonathan D Midwood
Martin H Larsen
Mikkel Boel
Kim Aarestrup
Steven J Cooke
Source
J Exp Zool A Ecol Genet Physiol. 2015 Nov;323(9):645-54
Date
Nov-2015
Language
English
Publication Type
Article
Keywords
Animal Migration - physiology
Animals
Denmark
Hydrocortisone - pharmacology
Rivers
Seasons
Stress, Physiological
Survival Analysis
Trout - growth & development - physiology
Abstract
For semi-anadromous brown trout, the decision whether or not to smoltify and migrate to the sea is believed to be made at the end of the preceding summer in response to both local environmental conditions and individual physiological status. Stressors experienced during the fall may therefore influence their propensity to migrate as well as carry over into the winter resulting in mortality when fish face challenging environmental conditions. To evaluate this possibility, we artificially elevated cortisol levels in juvenile trout (via intracoelomic injection of cortisol in the fall) and used passive integrated transponder tags to compare their overwinter and spring survival, growth, and migration success relative to a control group. Results suggest that overwinter mortality is high for individuals in this population regardless of treatment. However, survival rates were 2.5 times lower for cortisol-treated fish and they experienced significantly greater loss in mass. In addition, less than half as many cortisol-treated individuals made it downstream to a stationary antenna over the winter and also during the spring migration compared to the control treatment. These results suggest that a fall stressor can reduce overwinter survival of juvenile brown trout, negatively impact growth of individuals that survive, and ultimately result in a reduction in the number of migratory trout. Carryover effects such as those documented here reveal the cryptic manner in which natural and anthropogenic stressors can influence fish populations. J. Exp. Zool. 323A: 645-654, 2015. © 2015 Wiley Periodicals, Inc.
PubMed ID
26381608 View in PubMed
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Animal navigation: northern exposure.

https://arctichealth.org/en/permalink/ahliterature83289
Source
Curr Biol. 2005 Sep 6;15(17):R653-5
Publication Type
Article
Date
Sep-6-2005
Author
Gould James L
Author Affiliation
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1004, USA.
Source
Curr Biol. 2005 Sep 6;15(17):R653-5
Date
Sep-6-2005
Language
English
Publication Type
Article
Keywords
Animal Migration - physiology
Animals
Arctic Regions
Geography
Magnetics
Orientation - physiology
Sparrows - physiology
Abstract
A recent study has found that sparrows moved gradually east above the Arctic Circle completely altered their migration strategy after encountering the massive natural change in declination near the magnetic pole. This should not happen--or should it?
PubMed ID
16139193 View in PubMed
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Are Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. migratory relicts?

https://arctichealth.org/en/permalink/ahliterature95583
Source
Tsitol Genet. 2007 Jul-Aug;41(4):36-40
Publication Type
Article
Author
Parnikoza I Yu
Maidanuk D N
Kozeretska I A
Author Affiliation
Taras Shevchenko Kyiv National University, Volodimirska Street, 64, 01033, Kyiv, Ukraine.
Source
Tsitol Genet. 2007 Jul-Aug;41(4):36-40
Language
English
Publication Type
Article
Keywords
Acclimatization - genetics
Animal Migration
Animals
Antarctic Regions
Birds
Caryophyllaceae - genetics - growth & development
Cold Climate
Greenhouse Effect
Poaceae - genetics - growth & development
Abstract
It remains unclear why there are only two vascular plant species in Antarctica, Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae). Despite progressing climate warming, there is also just one alien plant species found in the region, introduced by humans and spreading mainly in disturbed habitats. In the present article we try to interpret the data concerning the history of the biota and glaciations of the continent, proceeding from the assumption that both plants migrated to Antarctica during the Oligocene-Pliocene, when it was less isolated and the climate was more favorable for their naturalization. Genetic evidence was also taken into consideration. Our data allow suggesting secondary dispersal in the region, due to transfer by birds with regard of climate changes. With this in mind, we believe that D. antarctica and C. quitensis are migratory relicts.
PubMed ID
18030724 View in PubMed
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Are migrant and resident elk (Cervus elaphus) exposed to similar forage and predation risk on their sympatric winter range?

https://arctichealth.org/en/permalink/ahliterature144394
Source
Oecologia. 2010 Sep;164(1):265-75
Publication Type
Article
Date
Sep-2010
Author
Barry G Robinson
Mark Hebblewhite
Evelyn H Merrill
Author Affiliation
Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada. bgrobins@ualberta.ca
Source
Oecologia. 2010 Sep;164(1):265-75
Date
Sep-2010
Language
English
Publication Type
Article
Keywords
Alberta
Animal Migration
Animals
Deer - psychology
Ecosystem
Humans
Predatory Behavior
Seasons
Wolves - psychology
Abstract
Partially migratory populations, where one portion of a population conducts seasonal migrations (migrants) while the other remains on a single range (residents), are common in ungulates. Studies that assess trade-offs between migratory strategies typically compare the amount of predation risk and forage resources migrants and residents are exposed to only while on separate ranges and assume both groups intermix completely while on sympatric ranges. Here we provide one of the first tests of this assumption by comparing the amount of overlap between home ranges of GPS-collared migrant and resident elk and fine-scale exposure to wolf predation risk and forage biomass at telemetry locations on a sympatric winter range in west-central Alberta, Canada. Overlap between migrant and resident home ranges increased throughout the winter, and both groups were generally intermixed and exposed to equal forage biomass. During the day, both migrants and residents avoided predation risk by remaining in areas far from timber with high human activity, which wolves avoided. However, at night wolves moved onto the grasslands close to humans and away from timber. Resident elk were consistently closer to areas of human activity and further from timber than migrants, possibly because of a habituation to humans. As a result, resident elk were exposed to higher night-time predation risk than migrants. Our study does not support the assumption that migrant and resident elk are exposed to equal predation risk on their sympatric range when human presence alters predation risk dynamics and habituation to humans is unequal between migratory strategies.
PubMed ID
20372929 View in PubMed
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185 records – page 1 of 19.