Barometric Pressure-Patterns and Spring Migration

The Auk ◽  
1948 ◽  
Vol 65 (1) ◽  
pp. 147-147 ◽  
2019 ◽  
Vol 100 (5) ◽  
pp. 1501-1511 ◽  
Author(s):  
Piper L Roby ◽  
Mark W Gumbert ◽  
Michael J Lacki

Abstract The endangered Indiana bat (Myotis sodalis) congregates in large hibernation groups in winter and travels after spring emergence to form summer maternity colonies, but information on migration behavior in this species remains limited to mostly band recovery observations. We tracked female Indiana bats in spring migration toward summer grounds using aerial radiotelemetry. Adult female Indiana bats were radiotagged in spring from 2009 through 2017, with 15 individuals successfully tracked to summer grounds and an additional 11 bats located in summer grounds via aerial telemetry after migration was complete. This resulted in the location of 17 previously unknown summer grounds for female Indiana bats, including adding Georgia, Alabama, and Mississippi to the summer maternity range. Two of the colonies identified in this study were south of the previously known southernmost colony in Tennessee, expanding the summer maternity range for the species by 178 km. Time-stamped location fixes along the migration path provided information about nightly and overall distances traveled, duration of travel, migration speed, and weather-related influences on bat behavior. Bats traveled 164.6 ± 26.2 km (± SE) on average from hibernacula to summer grounds and were migrating for an average of 7.3 ± 1.4 calendar nights. Bats alternated between foraging and traveling throughout each night of their migration route. Nightly migration rate was 9.9 ± 0.8 km/h and bats were active on the landscape for an average of 6.1 ± 0.4 h/night. Lower nighttime temperatures and lower barometric pressure correlated with use of layover areas during a migration night. Understanding bat behavior during migration can provide pertinent information for land managers to consider in efforts to conserve potential migration corridors, foraging areas, and roosting habitats of species in decline.


1996 ◽  
Vol 2 (1) ◽  
pp. 247-251 ◽  
Author(s):  
Ingunn M. Tombre ◽  
Kjell E. Erikstad ◽  
Geir W. Gabrielsen ◽  
Karl-Birger Strann ◽  
Jeffrey M. Black

2021 ◽  
Vol 97 ◽  
pp. 103342
Author(s):  
Justine Cianci ◽  
Ashley G. Boyle ◽  
Darko Stefanovski ◽  
Amy S. Biddle

Author(s):  
Jorge García-Macía ◽  
Javier Vidal-Mateo ◽  
Javier De La Puente ◽  
Ana Bermejo ◽  
Rainer Raab ◽  
...  

AbstractRed Kite shows a great variability in its migration strategies: most individuals in north-eastern Europe are migrants, but there is also a growing number of sedentary individuals. Here, we tagged 49 Red Kites wintering in Spain with GPS/satellite transmitters between 2013 and 2020 to study the autumn and spring migration between the breeding or summering areas in Central Europe and the wintering quarters in Spain. In first place, differences between immatures and adults were found for spring migration. Adults began the spring migration towards the northeast in February–March while the immature individuals began to migrate significantly later and showing a wider date range (February-June). Adults also takes significantly less days to arrive at their destinations (12 ± 5 days) and cover more distance per day (134.2 ± 37.1 km/day) than immatures (19 ± 11 days and 98.9 ± 21.2 km/day). In second place, we also found differences between spring and autumn migration (excluding immatures). Spring migrations were clearly faster and with less stopovers days than autumn migrations. Autumn migration began between mid-October and late November and two different behaviours were observed: most birds made a quick migration direct to the wintering areas with only some days of stopovers, but others prolonged the migration with long stops along the route. These results highlight a great variation in the migratory movements of Red Kite, not only according to age but also between individuals and seasons.


2021 ◽  
Vol 10 (7) ◽  
pp. 437
Author(s):  
Hongxia Qi ◽  
Yunjia Wang ◽  
Jingxue Bi ◽  
Hongji Cao ◽  
Shenglei Xu

Floor positioning is an important aspect of indoor positioning technology, which is closely related to location-based services (LBSs). Currently, floor positioning technologies are mainly based on radio signals and barometric pressure. The former are impacted by the multipath effect, rely on infrastructure support, and are limited by different spatial structures. For the latter, the air pressure changes with the temperature and humidity, the deployment cost of the reference station is high, and different terminal models need to be calibrated in advance. In view of these issues, here, we propose a novel floor positioning method based on human activity recognition (HAR), using smartphone built-in sensor data to classify pedestrian activities. We obtain the degree of the floor change according to the activity category of every step and determine whether the pedestrian completes floor switching through condition and threshold analysis. Then, we combine the previous floor or the high-precision initial floor with the floor change degree to calculate the pedestrians’ real-time floor position. A multi-floor office building was chosen as the experimental site and verified through the process of alternating multiple types of activities. The results show that the pedestrian floor position change recognition and location accuracy of this method were as high as 100%, and that this method has good robustness and high universality. It is more stable than methods based on wireless signals. Compared with one existing HAR-based method and air pressure, the method in this paper allows pedestrians to undertake long-term static or round-trip activities during the process of going up and down the stairs. In addition, the proposed method has good fault tolerance for the misjudgment of pedestrian actions.


2020 ◽  
Vol 7 (1) ◽  
pp. 19-26
Author(s):  
Clayton D Delancey ◽  
Kamal Islam ◽  
Gunnar R Kramer ◽  
Garrett J MacDonald ◽  
Alexander R Sharp ◽  
...  

AbstractCerulean Warblers (Setophaga cerulea) are among the fastest declining Nearctic-Neotropical migrant wood-warblers (Parulidae) in North America. Despite ongoing conservation efforts, little is known about their non-breeding distribution. In June 2016-2018, we deployed geolocators (n = 30) on adult male Cerulean Warblers in Indiana, USA, to track annual movements of individuals. Recovered geolocators (n = 4) showed that Cerulean Warblers occurred broadly throughout northern South America. Autumn migration lasted 44-71 days (n = 4), whereas spring migration lasted 37-41 days (n = 3). The average migration distance was 5268 km. During autumn migration, Cerulean Warblers made 1-4 stopovers (i.e., ≥2 days; n = 4) and 1-2 stopovers during spring migration (n = 3). When crossing the Gulf of Mexico during autumn migration, two birds stopped over after crossing, but not beforehand. Two others navigated through the Caribbean rather than crossing the Gulf of Mexico. During spring migration, one individual stopped after crossing, one individual stopped before crossing, and one individual stopped before and after crossing the Gulf of Mexico. No birds migrated through the Caribbean Islands during spring migration. These results represent novel information describing annual movements of individual Cerulean Warblers and will inform conservation efforts for this declining species.


2010 ◽  
Vol 299 (5) ◽  
pp. H1439-H1450 ◽  
Author(s):  
Jennifer M. Hughes ◽  
Melissa A. Riddle ◽  
Michael L. Paffett ◽  
Laura V. Gonzalez Bosc ◽  
Benjimen R. Walker

The systemic vasculature exhibits attenuated vasoconstriction following hypobaric chronic hypoxia (CH) that is associated with endothelium-dependent vascular smooth muscle (VSM) cell hyperpolarization. We hypothesized that increased activity of endothelial cell (EC) large-conductance, calcium-activated potassium (BKCa) channels contributes to this response. Gracilis resistance arteries from hypobaric CH (barometric pressure = 380 mmHg for 48 h) rats demonstrated reduced myogenic reactivity and hyperpolarized VSM membrane potential ( Em) compared with controls under normoxic ex vivo conditions. These differences were eliminated by endothelial disruption. In the presence of cyclooxygenase and nitric oxide synthase inhibition, combined intraluminal administration of the intermediate and small-conductance, calcium-activated K+ channel blockers TRAM-34 and apamin was without effect on myogenic responsiveness and VSM Em in both groups; however, these variables were normalized in CH arteries by intraluminal administration of the BKCa inhibitor iberiotoxin (IBTX). Basal EC Em was hyperpolarized in arteries from CH rats compared with controls and was restored by IBTX, but not by TRAM-34/apamin. K+ channel blockers were without effect on EC basal Em in controls. Similarly, IBTX blocked acetylcholine-induced dilation in arteries from CH rats, but was without effect in controls, whereas TRAM-34/apamin eliminated dilation in controls. Acetylcholine-induced EC hyperpolarization and calcium responses were inhibited by IBTX in CH arteries and by TRAM-34/apamin in controls. Patch-clamp experiments on freshly isolated ECs demonstrated greater K+ current in cells from CH rats that was normalized by IBTX. IBTX was without effect on K+ current in controls. We conclude that hypobaric CH induces increased endothelial BKCa channel activity that contributes to reduced myogenic responsiveness and EC and VSM cell hyperpolarization.


1989 ◽  
Vol 35 (120) ◽  
pp. 209-213 ◽  
Author(s):  
S.C. Colbeck

Abstract Strong winds can disrupt the thermal regime in seasonal snow because of the variation in surface pressure associated with surface features like dunes and ripples. Topographical features of shorter wavelengths produce stronger surface flows, but the flow decays rapidly with depth. Longer-wavelength features produce weaker surface flows but the flow decays more slowly with depth. The flow may only be strong enough to disrupt the temperature field for features of wavelengths on the scale of meters or tens of meters at wind speeds of 10 m/s or more. Other possible causes of windpumping have been examined but they do not appear to be as significant. Rapid pressure perturbations due to turbulence produce very little displacement of the air because of the high frequency and low amplitude. Barometric pressure changes cause compression and expansion of the air in the pore space, but the rate is too low to have much effect.


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