scholarly journals MIGRATORY RESTLESSNESS IN CAGED BOBOLINKS (DOLICHONYX ORYZIVORUS, A TRANSEQUATORIAL MIGRANT)

1962 ◽  
Vol 123 (3) ◽  
pp. 542-554 ◽  
Author(s):  
WILLIAM L. ENGELS
Keyword(s):  
Migratory Restlessness ◽  
Dolichonyx Oryzivorus

scholarly journals Diet of the Bobolink (Dolichonyx oryzivorus) in rice fields on its wintering grounds in Argentina

2019 ◽  
Vol 27 (1) ◽  
pp. 10-16
Author(s):  
Rodrigo E. Lorenzón ◽  
Carolina E. Antoniazzi ◽  
Franco N. Fabre ◽  
Virginia M. Quiroga ◽  
Silvia A. Regner ◽  
...  
Keyword(s):  
Stomach Contents ◽  
Rice Fields ◽  
Cultivated Plants ◽  
Relative Importance ◽  
Santa Fe ◽  
Wintering Grounds ◽  
Dolichonyx Oryzivorus ◽  
Winter Diet ◽  
Number Of Seeds ◽  
Plant Components

AbstractWinter diet of Bobolinks (Dolichonyx oryzivorus), a bird considered a pest of rice fields, is known to consist primarily of seeds. However, it is not yet possible to establish the extent to which non-rice plants and animal components contribute to its diet. To contribute to these issues, we studied the diet of the Bobolink found in rice fields on its wintering grounds in Santa Fe, Argentina, to provide information on (i) the composition of the diet and (ii) the relative importance of plant and animal components in the diet and of the different prey categories. We captured Bobolinks with mist nets and obtained samples of stomach contents by warm water and emetic-based regurgitation to determine the composition of the diet (n = 46 samples) and the importance of the different prey (n = 25 samples), mainly during March, just prior to northbound migration. We confirmed that the Bobolink’s diet in this region during this period is predominantly herbivorous (97%) and rice-based (55%), although it also consumes a large number of seeds of non-cultivated plants that represented 42% of the diet. Invertebrates, although of less importance than plant components (3%), had been consumed by 97% of captured individuais. Our results document the importance of non-cultivated plants and animal prey in the diet of Bobolinks in addition to rice.

scholarly journals Migratory restlessness and stopover duration in Wood sandpiper Tringa glareola

2021 ◽  
pp. 1-17
Author(s):  
Lorenzo Vanni ◽  
Giulia Cerritelli ◽  
Alessandro Turchi ◽  
Dimitri Giunchi
Keyword(s):  
Migratory Restlessness ◽  
Stopover Duration

scholarly journals Methods in field chronobiology

2017 ◽  
Vol 372 (1734) ◽  
pp. 20160247 ◽  
Author(s):  
Davide M. Dominoni ◽  
Susanne Åkesson ◽  
Raymond Klaassen ◽  
Kamiel Spoelstra ◽  
Martin Bulla
Keyword(s):  
Technological Development ◽  
Monitoring Systems ◽  
Migratory Restlessness ◽  
Biological Organization ◽  
Rapid Improvement ◽  
Free Living ◽  
The Future ◽  
In The Wild ◽  
Temporal Aspect ◽  
Different Levels

Chronobiological research has seen a continuous development of novel approaches and techniques to measure rhythmicity at different levels of biological organization from locomotor activity (e.g. migratory restlessness) to physiology (e.g. temperature and hormone rhythms, and relatively recently also in genes, proteins and metabolites). However, the methodological advancements in this field have been mostly and sometimes exclusively used only in indoor laboratory settings. In parallel, there has been an unprecedented and rapid improvement in our ability to track animals and their behaviour in the wild. However, while the spatial analysis of tracking data is widespread, its temporal aspect is largely unexplored. Here, we review the tools that are available or have potential to record rhythms in the wild animals with emphasis on currently overlooked approaches and monitoring systems. We then demonstrate, in three question-driven case studies, how the integration of traditional and newer approaches can help answer novel chronobiological questions in free-living animals. Finally, we highlight unresolved issues in field chronobiology that may benefit from technological development in the future. As most of the studies in the field are descriptive, the future challenge lies in applying the diverse technologies to experimental set-ups in the wild. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.

scholarly journals Migratory orientation in a narrow avian hybrid zone

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3201 ◽  
Author(s):  
David P.L. Toews ◽  
Kira E. Delmore ◽  
Matthew M. Osmond ◽  
Philip D. Taylor ◽  
Darren E. Irwin
Keyword(s):  
Hybrid Zone ◽  
Genetic Background ◽  
Migratory Restlessness ◽  
Long Distance ◽  
Mountain Valley ◽  
Migratory Orientation ◽  
Isotopic Studies ◽  
Migratory Routes ◽  
Species Specific ◽  
Migratory Divide

Background Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Rocky Mountains of Canada there is a narrow hybrid zone between Audubon’s and myrtle warblers that is likely maintained by selection against hybrids. Band recoveries and isotopic studies indicate that this hybrid zone broadly corresponds to the location of a possible migratory divide, with Audubon’s warblers migrating south-southwest and myrtle warblers migrating southeast. We tested a key prediction of the migratory divide hypothesis: that genetic background would be predictive of migratory orientation among warblers in the center of the hybrid zone. Methods We recorded fall migratory orientation of wild-caught migrating warblers in the center of the hybrid zone as measured by video-based monitoring of migratory restlessness in circular orientation chambers. We then tested whether there was a relationship between migratory orientation and genetic background, as measured using a set of species-specific diagnostic genetic markers. Results We did not detect a significant association between orientation and genetic background. There was large variation among individuals in orientation direction. Mean orientation was towards the NE, surprising for birds on fall migration, but aligned with the mountain valley in which the study took place. Conclusions Only one other study has directly analyzed migratory orientation among naturally-produced hybrids in a migratory divide. While the other study showed an association between genetic background and orientation, we did not observe such an association in yellow-rumped warblers. We discuss possible reasons, including the possibility of a lack of a strong migratory divide in this hybrid zone and/or methodological limitations that may have prevented accurate measurements of long-distance migratory orientation.

scholarly journals Increasing photoperiod stimulates the initiation of spring migratory behaviour and physiology in a facultative migrant, the pine siskin

2018 ◽  
Vol 5 (8) ◽  
pp. 180876 ◽  
Author(s):  
Ashley R. Robart ◽  
Mali M. K. McGuire ◽  
Heather E. Watts
Keyword(s):  
Experimental Test ◽  
Spring Migration ◽  
Fat Deposition ◽  
Day Length ◽  
Environmental Cues ◽  
Migratory Restlessness ◽  
Migratory Behaviour ◽  
Behavioural Changes ◽  
Short Day

The transition to a migratory state involves coordinated changes in physiology and behaviour. In species with regular, predictable (obligate) migrations, increasing day length triggers the expression of a spring migratory state and androgens play an important role in stimulating its development. By contrast, we know little about the environmental cues and endocrine mechanisms that regulate migration in species with less predictable (facultative) migrations. Here, we tested whether photoperiod stimulates a migratory state in a facultative nomadic migrant, the pine siskin ( Spinus pinus ). We exposed wintering birds to either a naturally increasing or short-day photoperiod and measured physiological and behavioural changes indicative of a migratory state. We also examined changes in circulating hormones that may play a role in the migratory transition. Natural-day, but not short-day, birds displayed physiological preparations for migration, including increases in fat deposition, and showed increased levels of migratory restlessness. We found no evidence for a role of corticosterone in the migratory transition, but testosterone may be important. This study is the first experimental test of the role of photoperiod in regulating facultative migration and demonstrates that the predictive cue used by many obligate migrants to time spring migration is also important in a facultative migrant.

scholarly journals RESPONSES OF NESTING BOBOLINKS (DOLICHONYX ORYZIVORUS) TO HABITAT EDGES

The Auk ◽  
2004 ◽  
Vol 121 (3) ◽  
pp. 767 ◽  
Author(s):  
Eric K. Bollinger ◽  
Thomas A. Gavin
Keyword(s):  
Dolichonyx Oryzivorus

Migratory behaviour of captive white-crowned sparrows, Zonotrichia leucophrys gambelii, differs during autumn and spring migration

Behaviour ◽  
2006 ◽  
Vol 143 (10) ◽  
pp. 1219-1240 ◽  
Author(s):  
Marilyn Ramenofsky ◽  
Renée Agatsuma
Keyword(s):  
Life History ◽  
High Intensity ◽  
Primary Source ◽  
Migratory Restlessness ◽  
Long Distance ◽  
Free Living ◽  
Zonotrichia Leucophrys ◽  
Life History Stages ◽  
In Captivity ◽  
Zonotrichia Leucophrys Gambelii

AbstractGambel's white-crown sparrow (Zonotorichia leucophrys gambelii) is a long-distance, over-land migrant. In captivity birds display many characteristics of the autumn and spring migratory life history stages that include hyperphagia, fattening and high intensity nocturnal activity termed migratory restlessness or Zugunruhe. We recorded the behaviour of captive birds while simultaneously collecting 24 h locomotor activity. These data were used to define the behaviour displayed by captive birds during autumn and spring in order to compare the two migratory stages and to draw inferences for free-living birds. The predominant behaviour during day and nighttime was rest. Feeding occurred only during daylight hours but at a greater frequency in autumn than spring. Birds generally used their feet as the primary source of locomotion during the day termed 'jump'. During the night, two distinct behaviours, 'beak-up flight' and 'beak-up' involving high intensity wing motions were observed and considered components of migratory restlessness. The frequency of the 'beak-up flight' was greatest during spring and associated with the enhanced tempo of vernal migration. In both stages, migratory restlessness was preceded by a quiescent phase, the occurrence of which differed and related to time available for foraging and length of the night. Given these findings, we hypothesize that diel behaviours displayed by autumn and spring migrants in captivity highlight distinctions between the two life history stages.

Suppression of Autumnal Migratory Unrest in Dark-Eyed Juncos Held During Summer on, Near, or Far From their Previous Wintering Sites

The Auk ◽  
1987 ◽  
Vol 104 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Ellen D. Ketterson ◽  
Val Nolan
Keyword(s):  
Home Range ◽  
Small Group ◽  
Site Fidelity ◽  
General Information ◽  
Previous Experience ◽  
Migratory Restlessness ◽  
Home Ranges ◽  
Junco Hyemalis ◽  
Far North ◽  
General Region

Abstract In previous experiments, Dark-eyed Juncos (Junco hyemalis) were captured on a winter home range to which they had shown year-to-year site fidelity and held there until just before the autumn. They failed to show normal autumn migratory restlessness and fattening, which suggested that previous experience at the migratory destination suppressed readiness to migrate. We asked what the suppressing cues might be. Possibilities included very local features peculiar to the individual's winter home range (e.g. its trees) and cues common to the general region (e.g. geophysical or celestial information); features of the latter sort might give information about latitude. To test these possibilities we monitored autumn restlessness and fattening of new groups of juncos that were held before migration where some could perceive landmarks of their familiar winter home range and others only more general information about their location. In autumn those held at, near, and far south of their winter home ranges again failed to become restless or fat. A small group held far north of their winter home ranges became somewhat restless, significantly more so than the others. These may have perceived that they had not reached their usual winter latitude, but alternative explanations are possible.

Fuel accumulation advances nocturnal departure: a migratory restlessness study on northern wheatears at stopover

2016 ◽  
Vol 117 ◽  
pp. 9-14 ◽  
Author(s):  
Cas Eikenaar ◽  
Florian Müller ◽  
Steffen Kämpfer ◽  
Heiko Schmaljohann
Keyword(s):  
Migratory Restlessness ◽  
Fuel Accumulation ◽  
Nocturnal Departure
Sign in / Sign up

Export Citation Format

Share Document