scholarly journals Correlates of alternative migratory strategies in western bluebirds

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
C. A. Dale ◽  
J. J. Nocera ◽  
S. E. Franks ◽  
T. K. Kyser ◽  
L. M. Ratcliffe
Keyword(s):  
Western Bluebirds ◽  
Migratory Strategies

scholarly journals Delayed dispersal in western bluebirds: teasing apart the importance of resources and parents

2014 ◽  
Vol 25 (4) ◽  
pp. 843-851 ◽  
Author(s):  
J. L. Dickinson ◽  
E. D. Ferree ◽  
C. A. Stern ◽  
R. Swift ◽  
B. Zuckerberg
Keyword(s):  
Delayed Dispersal ◽  
Western Bluebirds

Nocturnal observations on the emergence and flight behaviour of Helicoverpa armigera (Lepidoptera: Noctuidae) in the post-rainy season in central India

1992 ◽  
Vol 82 (2) ◽  
pp. 243-256 ◽  
Author(s):  
J.R. Riley ◽  
N.J. Armes ◽  
D.R. Reynolds ◽  
A.D. Smith
Keyword(s):  
Helicoverpa Armigera ◽  
Central India ◽  
Pigeon Pea ◽  
Mate Finding ◽  
Flight Behaviour ◽  
Infra Red ◽  
Helicoverpa Armígera ◽  
Migratory Strategies ◽  
Lepidoptera Noctuidae ◽  
Oviposition Sites

AbstractA range of techniques was used to quantify the nocturnal flight behaviour of Helicoverpa armigera (Hübner) in pigeon pea (Cajanus cajan) crops near Hyderabad, in central India. These included visual observations in the field, the use of field cages and a vehicle-mounted net, optical and video imaging in the infra-red, and radar. Moth emergence from the soil was observed to start at dusk and recruitment continued steadily throughout the first half of the night. Little activity was observed in moths on the night of emergence, except for weak flying or crawling to daytime refuges. Flight activity of one-day old moths started about 20 min after sunset, peaked 15 min later and within about an hour of sunset had declined to a low level which persisted for the rest of the night. Flight of reproductively mature moths was most frequent about 1 h after sunset and at this time mainly comprised females searching for oviposition sites and nectar sources. By about 2 h after sunset, flight had decreased markedly, but there was a slight increase in activity in the second half of the night caused by males undertaking mate-finding flights. Under the conditions studied, the majority of H. armigera dispersed below 10 m, and there were no mass ascents to higher altitudes like those observed at outbreak sites of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae). The contrasting migratory strategies of H. armigera and S. exempta are briefly discussed.

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

Autumn Migration of Diurnal Raptors Across Kenting National Park, Taiwan, Along the East-Asian Oceanic Flyway

2021 ◽  
Author(s):  
Chao-Chieh Chen ◽  
Jing-Guo Lin ◽  
Yu-Jung Cheng ◽  
Ta-Chih Chen ◽  
Jo-Szu Tsai ◽  
...  
Keyword(s):  
National Park ◽  
East Asian ◽  
Large Numbers ◽  
Early Afternoon ◽  
Southern Taiwan ◽  
Migratory Strategies ◽  
Kenting National Park ◽  
Paired T Test ◽  
Southward Migration ◽  
Observation Period

ABSTRACT Diurnal raptors were counted during their southward migration in autumn of 2019 at Kenting National Park, southern Taiwan, an important hawkwatch site along the East-Asian Oceanic Flyway. Observations were conducted from 1 September to 31 October 2019 in the morning hours, but the observation period was extended to 1400 H whenever large numbers of raptors passed the site before noon. A total of 329,559 individuals of 14 migratory raptor species was recorded. The Chinese Sparrowhawk (Accipiter soloensis) and Gray-faced Buzzard (Butastur indicus) made up 78.3% (257,971 birds) and 21.6% (71,045 birds) of the total, respectively. The number of Chinese Sparrowhawks increased significantly when we extended the survey duration from 1200 H to 1400 H (paired t-test, t = 2.44, P = 0.04), but the number of Gray-faced Buzzards did not (t = 1.94, P = 0.09). Thus, Chinese Sparrowhawks may continue passing the site en route to the Philippine Islands in the afternoon hours, whereas Gray-faced Buzzards usually stop migrating in early afternoon, at least under certain conditions. How prevailing wind conditions along the East-Asian Oceanic Flyway in autumn shape the different migratory strategies of these two hawk species requires further study.

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