scholarly journals No general shift in spring migration phenology by eastern North American birds since 1970

2021 ◽  
Author(s):  
André Desrochers ◽  
Andra Florea ◽  
Pierre-Alexandre Dumas
Keyword(s):  
Short Distance ◽  
Species Abundance ◽  
Open Water ◽  
Early Spring ◽  
Spring Migration ◽  
The Arctic ◽  
Long Distance ◽  
Arrival Dates ◽  
Migration Phenology ◽  
First Arrival

We studied the phenology of spring bird migration from eBird and ÉPOQ checklist programs South of 49°N in the province of Quebec, Canada, between 1970 and 2020. 152 species were grouped into Arctic, long-distance, and short-distance migrants. Among those species, 75 significantly changed their migration dates, after accounting for temporal variability in observation effort, species abundance, and latitude. But in contrast to most studies on the subject, we found no general advance in spring migration dates, with 36 species advancing and 39 species delaying their migration. Several early-migrant species associated to open water advanced their spring migration, possibly due to decreasing early-spring ice cover in the Great Lakes and the St-Lawrence river since 1970. Arctic breeders and short-distance migrants advanced their first arrival dates more than long-distance migrants not breeding in the arctic. However, there was no difference among migrant groups when median arrival dates were considered. We conclude that general claims about advances in spring migration dates in eastern North America are misleading due to large taxonomic variation.

scholarly journals Changes in spring arrival dates of Central European bird species over the past 100 years

2020 ◽  
Vol 66 (3) ◽  
Author(s):  
László Bozó ◽  
Tibor Csörgő
Keyword(s):  
Short Distance ◽  
Recent Observation ◽  
Bird Species ◽  
Spring Migration ◽  
Observation Data ◽  
Long Distance ◽  
Endogenous Rhythms ◽  
The Past ◽  
Arrival Dates ◽  
Spring Arrival

Over the past decades, spring temperatures have increased in temperate regions, which resulted in birds arriving earlier in spring. Nonetheless, the timing of some species’ spring migration relies on endogenous rhythms that are not affected by climate change. In this study, we analysed changes in the spring arrival dates of 36 bird species over two periods in 22 towns and villages in Southeast Hungary and West Romania. The first period covered the national spring migration counts between 1894 and 1926, while the second period took place between 2005 and 2019 and is based on our recent observation data. Our results show, that the average spring arrival dates of most long-distance migrant species have not changed significantly over the past 100 years. In contrast, in cases of medium and short-distance migrants, most species arrive earlier recently than in the past. This may be caused by the fact, that the migration habit of long-distance migrants is characterized by strong genetic determinants, so they can not react as quickly to the warmer spring weather in Europe as the medium and short-distance migrants. However, in cases of some long-distance migrants, the timing of spring migration changed due to the drying of wintering grounds.

scholarly journals Climate change effects on migration phenology may mismatch brood parasitic cuckoos and their hosts

2009 ◽  
Vol 5 (4) ◽  
pp. 539-541 ◽  
Author(s):  
Nicola Saino ◽  
Diego Rubolini ◽  
Esa Lehikoinen ◽  
Leonid V. Sokolov ◽  
Andrea Bonisoli-Alquati ◽  
...  
Keyword(s):  
Climate Change ◽  
Short Distance ◽  
Life Cycles ◽  
Trophic Levels ◽  
Negative Consequences ◽  
Long Distance ◽  
Climate Change Effects ◽  
Parasitism Rates ◽  
Migration Phenology ◽  
Spring Arrival

Phenological responses to climate change vary among taxa and across trophic levels. This can lead to a mismatch between the life cycles of ecologically interrelated populations (e.g. predators and prey), with negative consequences for population dynamics of some of the interacting species. Here we provide, to our knowledge, the first evidence that climate change might disrupt the association between the life cycles of the common cuckoo ( Cuculus canorus ), a migratory brood parasitic bird, and its hosts. We investigated changes in timing of spring arrival of the cuckoo and its hosts throughout Europe over six decades, and found that short-distance, but not long-distance, migratory hosts have advanced their arrival more than the cuckoo. Hence, cuckoos may keep track of phenological changes of long-distance, but not short-distance migrant hosts, with potential consequences for breeding of both cuckoo and hosts. The mismatch to some of the important hosts may contribute to the decline of cuckoo populations and explain some of the observed local changes in parasitism rates of migratory hosts.

scholarly journals Bird number dynamics during the post-breeding period at the Tömörd Bird Ringing Station, western Hungary

The Ring ◽  
2017 ◽  
Vol 39 (1) ◽  
pp. 23-82
Author(s):  
József Gyurácz ◽  
Péter Bánhidi ◽  
József Góczán ◽  
Péter Illés ◽  
Sándor Kalmár ◽  
...  
Keyword(s):  
Temporal Pattern ◽  
Short Distance ◽  
Breeding Period ◽  
Migratory Species ◽  
Long Distance ◽  
Increasing Trend ◽  
Number Dynamics ◽  
Migration Phenology ◽  
Breeding Migration ◽  
Median Date

Abstract The fieldwork, i.e. catching and ringing birds using mist-nets, was conducted at Tömörd Bird Ringing Station in western Hungary during the post-breeding migration seasons in 1998-2016. Altogether, 106,480 individuals of 133 species were ringed at the station. The aim of this paper was to publish basic information on passerine migration at this site. Migration phenology was described through annual and daily capture frequencies. Furthermore, we provide the median date of the passage, the date of the earliest or latest capture, the peak migration season within the study period, and the countries where the birds monitored at the site were ringed or recovered abroad. To compare the catching dynamics for the fifty species with total captures greater than 200, a reference period was defined: from 5 Aug. to 5 Nov. 2001-2016. Some non-passerines that are more easily caught with mist-nets or that are caught occasionally were listed as well. The two superdominant species, the European Robin and the Eurasian Blackcap, with 14,377 and 13,926 total captures, made up 27% of all ringed individuals. Among the fifty species analysed, there were ten species with a decreasing trend, five species with an increasing trend and thirty-five species with a stable (or uncertain) trend in their numbers from 2001 to 2016. The temporal pattern of migration of long-distance migrants was different from that of the medium- and short-distance migratory species.

scholarly journals Approaching Freshet beneath Landfast Ice in Kugmallit Bay on the Canadian Arctic Shelf: Evidence from Sensor and Ground Truth Data

ARCTIC ◽  
2009 ◽  
Vol 61 (1) ◽  
pp. 76 ◽  
Author(s):  
Tony R. Walker ◽  
Jon Grant ◽  
Peter Jarvis
Keyword(s):  
Arctic Ocean ◽  
Ground Truth ◽  
Open Water ◽  
Early Spring ◽  
The Arctic ◽  
Ground Truth Data ◽  
The North ◽  
Landfast Ice ◽  
North American Arctic ◽  
Mackenzie River

The Mackenzie River is the largest river in the North American Arctic. Its huge freshwater and sediment load impacts the Canadian Beaufort Shelf, transporting large quantities of sediment and associated organic carbon into the Arctic Ocean. The majority of this sediment transport occurs during the freshet peak flow season (May to June). Mackenzie River-Arctic Ocean coupling has been widely studied during open water seasons, but has rarely been investigated in shallow water under landfast ice in Kugmallit Bay with field-based surveys, except for those using remote sensing. We observed and measured sedimentation rates (51 g m-2 d-1) and the concentrations of chlorophyll a (mean 2.2 ?g L-1) and suspended particulate matter (8.5 mg L-1) and determined the sediment characteristics during early spring, before the breakup of landfast ice in Kugmallit Bay. We then compared these results with comparable data collected from the same site the previous summer. Comparison of organic quality in seston and trapped material demonstrated substantial seasonal differences. The subtle changes in biological and oceanographic variables beneath landfast ice that we measured using sensors and field sampling techniques suggest the onset of a spring melt occurring hundreds of kilometres farther south in the Mackenzie Basin.

scholarly journals SEISMOGRAF REFRAKSI DENGAN SUMBER GELOMBANG WEIGH DROP

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Muhammad Zuhdi
Keyword(s):  
Short Distance ◽  
Arrival Time ◽  
Horizontal Distance ◽  
Long Distance ◽  
Incoming Wave ◽  
Wave Source ◽  
Direct Wave ◽  
Ground Source ◽  
First Arrival ◽  
Wave Arrival

Abstrak : Telah dibuat seimograf refraksi dengan sumber gelombang weigh drop berupa bola besi yang dijatuhkan 2 meter dari landasan. Sumber gelombang ini mampu memberikan sinyal pada geophone hingga jarak 150meter. Prinsip kerja seismograf refraksi adalah mengukur waktu tiba gelombang tercepat (fisrt arrival time) dari sumber menuju geophone. Untuk jarak pendek, gelombang tercepat adalah gelombang langsung, sedangkan untuk jarak selebihnya gelombang tercepat adalah gelombang refraksi. Waktu tiba gelombang tercepat diukur dengan instrumen elektronik dengan ketelitian hingga 0,1 milli sekon. Hasil ujicoba menunjukkan bahwa seismogram mampu mendeteksi perlapisan hingga kedalaman 5 meter dengan jarak horizontal mencapai 150 meter.Kata kunci : Seismograf, refraksi, weigh dropAbstract : Refraction seismograph is have been made with wave source of weigh drop made of iron ball from altitude 2 metre from the ground. Source of this wave can give geophone signal till 150 metre apart. Principal ofrefraction seismograph is to measure first arrival of incoming wave to geophone. For short distance, first arrival wave is direct wave, while for the medium and long distance first arrival wave is refraction wave. Arrival time is measured with electronic instrument with errors till 0,1 millisecond. Result of instrument trial indicate that seismogram can detect some layers till 5 metre deep with horizontal distance till 150 metre.Key words : Seismograph, refraction, weigh drop

scholarly journals Mechanistic movement models identify continuously updated autumn migration cues in Arctic caribou

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Matthew D. Cameron ◽  
Joseph M. Eisaguirre ◽  
Greg A. Breed ◽  
Kyle Joly ◽  
Knut Kielland
Keyword(s):  
Environmental Conditions ◽  
Rangifer Tarandus ◽  
Continuous Process ◽  
Population Level ◽  
Spring Migration ◽  
The Arctic ◽  
Autumn Migration ◽  
Long Distance ◽  
Movement Model ◽  
Migratory Patterns

Abstract Background Migrations in temperate systems typically have two migratory phases, spring and autumn, and many migratory ungulates track the pulse of spring vegetation growth during a synchronized spring migration. In contrast, autumn migrations are generally less synchronous and the cues driving them remain understudied. Our goal was to identify the cues that migrants use in deciding when to initiate migration and how this is updated while en route. Methods We analyzed autumn migrations of Arctic barren-ground caribou (Rangifer tarandus) as a series of persistent and directional movements and assessed the influence of a suite of environmental factors. We fitted a dynamic-parameter movement model at the individual-level and estimated annual population-level parameters for weather covariates on 389 individual-seasons across 9 years. Results Our results revealed strong, consistent effects of decreasing temperature and increasing snow depth on migratory movements, indicating that caribou continuously update their migratory decision based on dynamic environmental conditions. This suggests that individuals pace migration along gradients of these environmental variables. Whereas temperature and snow appeared to be the most consistent cues for migration, we also found interannual variability in the effect of wind, NDVI, and barometric pressure. The dispersed distribution of individuals in autumn resulted in diverse environmental conditions experienced by individual caribou and thus pronounced variability in migratory patterns. Conclusions By analyzing autumn migration as a continuous process across the entire migration period, we found that caribou migration was largely related to temperature and snow conditions experienced throughout the journey. This mechanism of pacing autumn migration based on indicators of the approaching winter is analogous to the more widely researched mechanism of spring migration, when many migrants pace migration with a resource wave. Such a similarity in mechanisms highlights the different environmental stimuli to which migrants have adapted their movements throughout their annual cycle. These insights have implications for how long-distance migratory patterns may change as the Arctic climate continues to warm.

scholarly journals Weather at the winter and stopover areas determines spring migration onset, progress, and advancements in Afro-Palearctic migrant birds

2020 ◽  
Vol 117 (29) ◽  
pp. 17056-17062 ◽  
Author(s):  
Birgen Haest ◽  
Ommo Hüppop ◽  
Franz Bairlein
Keyword(s):  
Climate Change ◽  
Migratory Birds ◽  
Spring Migration ◽  
Long Distance ◽  
Spring Phenology ◽  
Migration Timing ◽  
Climate Change Effects ◽  
Breeding Grounds ◽  
Migration Phenology ◽  
Exogenous Factors

Climate change causes changes in the timing of life cycle events across all trophic groups. Spring phenology has mostly advanced, but large, unexplained, variations are present between and within species. Each spring, migratory birds travel tens to tens of thousands of kilometers from their wintering to their breeding grounds. For most populations, large uncertainties remain on their exact locations outside the breeding area, and the time spent there or during migration. Assessing climate (change) effects on avian migration phenology has consequently been difficult due to spatial and temporal uncertainties in the weather potentially affecting migration timing. Here, we show for six trans-Saharan long-distance migrants that weather at the wintering and stopover grounds almost entirely (∼80%) explains interannual variation in spring migration phenology. Importantly, our spatiotemporal approach also allows for the systematic exclusion of influences at other locations and times. While increased spring temperatures did contribute strongly to the observed spring migration advancements over the 55-y study period, improvements in wind conditions, especially in the Maghreb and Mediterranean, have allowed even stronger advancements. Flexibility in spring migration timing of long-distance migrants to exogenous factors has been consistently underestimated due to mismatches in space, scale, time, and weather variable type.

Quatic Foraging in Garter Snakes: a Comparison of Specialists and Generalists

Behaviour ◽  
1983 ◽  
Vol 86 (1-2) ◽  
pp. 1-30 ◽  
Author(s):  
Hugh Drummond
Keyword(s):  
Short Distance ◽  
Water Surface ◽  
Search Time ◽  
Open Water ◽  
Garter Snakes ◽  
Nerodia Sipedon ◽  
Long Distance ◽  
Underwater Vision ◽  
Visual Accommodation ◽  
Made In

AbstractTo examine the assumption, underlying much ecological theory, that a "Jack-of-all-trades is master of none", a comparison was made of the aquatic predation of four colubrid snakes, two aquatic specialists (Thamnophis couchi, T. melanogaster) and two terrestrial-aquatic generalists (T. sirtalis, and T. elegans). Observations were made in the field, then juvenile snakes were compared under controlled laboratory conditions. The specialists and generalists had qualitatively different foraging repertoires. The specialists made lengthy dives, crawled slowly on the underwater substrate and made long-distance underwater responses to prey: orientation, approach, pursuit, and frontal attack. The generalists dived briefly, with rapid serpentine locomotion, or searched "terrestrially" by wandering along the shoreline and snatching prey from the water surface. Underwater, the generalists' only prey-directed response was sudden short-distance attack, and they appeared to rely on chance encounters with prey. There were significant differences between the two pairs. In comparison with the generalists, the specialists 1) captured more fish, 2) spent more time on aquatic search, 3) spent more aquatic search time diving, 4) spent more diving time on the underwater substrate, 5) made more attacks in every category of search in open water, and 6) attacked underwater from a greater distance. Significant differences were not found in attack frequencies in those search categories where underwater vision is probably unimportant (aerial attacks and attacks in underwater crevices), nor in aerial attack distances. The specialists' behavioral superiority in respect of their specialization supports the "Jack-of-all-trades" assumption. The observations suggest that this superiority is associated with superior underwater visual acuity (which may be due to superior visual accommodation). The generalists' principal underwater searching technique (serpentine diving) appears to be energetically costly, and may only be profitable when aquatic prey are especially vulnerable. Nerodia sipedon, member of a genus that is closely related to Thamnophis but more aquatic, had a foraging repertoire qualitatively similar to that of the generalists. The similarity may be associated with N. sipedon's nocturnal habits and presumed reliance on non-visual prey cues.

POLAR LOW DETECTION USING SOLAB SIOWS ARCTIC PORTAL

2017 ◽  
Author(s):  
Olga Mashtaler ◽  
Olga Mashtaler ◽  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Elizaveta Zabolotskikh ◽  
...  
Keyword(s):  
Model Development ◽  
Sharp Decrease ◽  
Open Water ◽  
The Arctic ◽  
Wind Fields ◽  
Polar Lows ◽  
Statistical Regularities ◽  
Meteorological Observations ◽  
Strong Winds ◽  
Synthetic Aperture Radars

The relevance of the polar lows (PLs) research is justified by their great destructive power and creation of threat to the safety of navigation in the high latitudes and along the Northern Sea Route. The most dangerous effects on maritime activities are strong winds, waves and icing. In addition, the study of the PLs acquires relevance due to the sharp decrease of the sea ice area in the Arctic in recent years and the emergence of areas of open water, suitable for the appearance and development of PLs. However, despite the importance of PLs, they are apparently not sufficiently studied. As there are no meteorological observations in the areas of their appearance, the main source of information about them are satellite observations. By using images on the SOLab SIOWS Arctic Portal from multiple satellites operating in the IR and visible ranges (e.g., MODIS and AVHRR), and using near-water wind fields from high resolution synthetic aperture radars (Sentine-1, ASAR) and low resolution scatterometers (ASCAT), we identify polar lows in various parts of the Arctic, revealing statistical regularities in the appearance of PLs, their distribution and intensity. Collected database of Pls and their characteristics will be used for further PLs forecasting model development.

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