Spatial distribution and habitat use of reed warblers Acrocephalus scirpaceus during the autumn migration

Behaviour ◽  
2014 ◽  
Vol 151 (6) ◽  
pp. 799-817 ◽  
Author(s):  
Miren Andueza ◽  
Juan Arizaga ◽  
Emilio Barba ◽  
Ibon Tamayo-Uria
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Breeding Site ◽  
Autumn Migration ◽  
First Year ◽  
Home Ranges ◽  
Spatial Behaviour ◽  
Stopover Site ◽  
Stopover Sites ◽  
Acrocephalus Scirpaceus

Spatial behaviour and habitat selection at stopover sites have a strong influence on the foraging and fuelling performance of migrating birds and hence are important aspects of stopover ecology. The aim of this study was to analyse the spatial behaviour and habitat use of reed warblers Acrocephalus scirpaceus during the autumn migration. We used radio tracking data from reed warblers surveyed at a stopover site in northern Iberia and assigned to three different groups: (1) local adult birds which were still at their breeding site, (2) migrating first-year birds (originating from beyond Iberian peninsula) and (3) migrating adult birds. Overall, migrating first-year birds tended to have larger home ranges than both local and migrating adults and to move more widely in the study area. They also showed lower fat deposition rates than adults. The proportion of habitats in home ranges (reed-beds and tidal flats being the most abundant habitats) was similar amongst groups. The spatial distribution and habitat use of organisms have been theorised to follow an ideal-free or ideal-despotic distribution. However, according to our results, other complex underlying mechanisms may play an important role in shaping the spatial behaviour of birds at stopover sites.

scholarly journals Increased Stopover Duration and Low Body Condition of the Pied Flycatcher (Ficedula hypoleuca) at an Autumn Stopover Site

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2208
Author(s):  
Bernice Goffin ◽  
Marcial Felgueiras ◽  
Anouschka R. Hof
Keyword(s):  
Environmental Change ◽  
Body Condition ◽  
Environmental Conditions ◽  
Ficedula Hypoleuca ◽  
Autumn Migration ◽  
Long Distance ◽  
Stopover Site ◽  
Stopover Duration ◽  
Stopover Sites ◽  
Over Time

Many long-distance migratory bird species are in decline, of which environmental changes, such as climate change and land-use changes, are thought to be important drivers. The effects of environmental change on the migration of these birds have often been studied during spring migration. Fewer studies have explored the impacts of environmental change on autumn migration, especially at stopover sites. However, stopover sites are important, as the quality of these sites is expected to change over time. We investigated impacts of local environmental conditions on the migration strategy and body condition of the Pied Flycatcher (Ficedula hypoleuca) at an autumn migration stopover site using long-term ringing data (1996–2018) and local environmental conditions. We found that although the arrival and departure dates of birds at the stopover site remained unchanged, the body condition (fat score) of the individuals caught decreased, and the stopover duration increased. This suggests that conditions at the stopover site during the autumn migration period have deteriorated over time. This study emphasizes the importance of suitable stopover sites for migratory birds and stresses that changes in environmental conditions during the autumn migration period may be contributing to the current decline in long-distance migratory passerines.

scholarly journals Philopatry to Stopover Site and Body Condition of Transient Reed Warblers During Autumn Migration Through Israel

The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 441-444 ◽  
Author(s):  
Kobi Merom ◽  
Yoram Yom-Tov ◽  
Robin McClery
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Wing Length ◽  
First Year ◽  
Sahara Desert ◽  
Stopover Site ◽  
Acrocephalus Scirpaceus ◽  
The Mean ◽  
High Degree ◽  
Mass Increase

Abstract Philopatry to stopover site and changes in body condition of migrating Reed Warblers Acrocephalus scirpaceus were studied in Bet Shean Valley, Israel, where warblers were netted throughout the year. Although the majority of birds were seen only once, the proportion of transients seen twice or more in different years is comparable to the figure for summer residents returning between years, indicating a high degree of philopatry among transients. Transients get heavier with longer duration of stay, up to about 15 days, after which body mass increase appears to level off at about 3 g. Change in body condition, taken to be body mass divided by wing length, also was noted, albeit of less significance. The mean date of arrival in the autumn of birds in their first year was about 20 days later than that of older birds. Reed Warblers use their time effectively to replenish their body mass and improve their condition before starting the dangerous crossing of the Sahara Desert.

scholarly journals Consistent habitat preference underpins the geographically divergent autumn migration of individual Mongolian common shelducks

2019 ◽  
Vol 66 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Fanjuan Meng ◽  
Xin Wang ◽  
Nyambayar Batbayar ◽  
Tseveenmyadag Natsagdorj ◽  
Batmunkh Davaasuren ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Land Cover ◽  
Resource Selection ◽  
Population Level ◽  
Autumn Migration ◽  
Migration Routes ◽  
Stopover Site ◽  
Cross Prediction ◽  
Stopover Sites ◽  
Common Shelduck

Abstract While many avian populations follow narrow, well-defined “migratory corridors,” individuals from other populations undertake highly divergent individual migration routes, using widely dispersed stopover sites en route between breeding and wintering areas, although the reasons for these differences are rarely investigated. We combined individual GPS-tracked migration data from Mongolian-breeding common shelduck Tadorna tadorna and remote sensing datasets, to investigate habitat selection at inland stopover sites used by these birds during dispersed autumn migration, to explain their divergent migration patterns. We used generalized linear mixed models to investigate population-level resource selection, and generalized linear models to investigate stopover-site-level resource selection. The population-level model showed that water recurrence had the strongest positive effect on determining birds’ occupancy at staging sites, while cultivated land and grassland land cover type had strongest negative effects; effects of other land cover types were negative but weaker, particularly effects of water seasonality and presence of a human footprint, which were positive but weak or non-significant, respectively. Although stopover-site-level models showed variable resource selection patterns, the variance partitioning and cross-prediction AUC scores corroborated high inter-individual consistency in habitat selection at inland stopover sites during the dispersed autumn migration. These results suggest that the geographically widespread distribution (and generally rarity) of suitable habitats explained the spatially divergent autumn migrations of Mongolian breeding common shelduck, rather than the species showing flexible autumn staging habitat occupancy.

scholarly journals Low Initial Refueling Rate at Stopover Sites: A Methodological Effect?

The Auk ◽  
2001 ◽  
Vol 118 (3) ◽  
pp. 698-708 ◽  
Author(s):  
Regine Schwilch ◽  
Lukas Jenni
Keyword(s):  
Body Mass ◽  
Field Studies ◽  
Stopover Site ◽  
Body Mass Change ◽  
Stopover Sites ◽  
Acrocephalus Scirpaceus ◽  
Body Mass Changes ◽  
Capture Recapture ◽  
Migrating Birds ◽  
Plasma Metabolite

Abstract For various reasons, migrating birds may not refuel and gain mass immediately after they have arrived at a stopover site. That led to the concept of a search-settling time after arrival with a low or negative initial refueling rate, but its existence has not been clearly demonstrated in field studies. Body-mass changes resulting from capture–recapture data can be misleading if used for the estimation of a natural low initial refueling rate because (1) it is usually unknown whether the day of first capture is also the first day of stopover, and (2) handling at first capture may have an adverse effect on subsequent body-mass development. To circumvent those problems we increased probability of catching birds shortly after arrival by inducing landfall by tape-luring, and we estimated body-mass change without previous handling effects from concentration of two metabolites in blood plasma. In the Eurasian Reed-Warbler (Acrocephalus scirpaceus) studied at a stopover site in Switzerland, there was no difference in plasma-metabolite concentrations between a group of mostly newly arrived individuals and a group with few newly arrived birds. Similarly, there was no difference in those parameters between birds that had been handled before and birds at first capture. However, the analysis of capture–recapture data from two other Swiss stopover sites with longer handling times indicated that mean body mass of Eurasian Reed-Warblers and European Robins (Erithacus rubecula) dropped after capture and reached initial values only after one to several days. We concluded that mass loss after capture depended mainly on lost foraging time and that natural low initial refueling rate after arrival at a stopover site is not detectable under the conditions of this study.

Wing lengths of Clamorous Reed Warblers Acrocephalus stentoreus in Israel

Ring ◽  
2004 ◽  
Vol 26 (2) ◽  
pp. 89-92
Author(s):  
John Morgan
Keyword(s):  
Wing Length ◽  
First Year ◽  
Comparable Data ◽  
Reed Warbler ◽  
Data Set ◽  
Acrocephalus Scirpaceus ◽  
Different Seasons ◽  
A Site ◽  
Made In ◽  
New Discovery

Wing lengths of Clamorous Reed Warblers Acrocephalus stentoreus in Israel Wing length measurements taken from first-year, pre- and post-moulting (annual, complete) Clamorous Reed Warblers were recorded at a site in northern Israel. The resulting data set was examined using a time-series of residuals (CUSUM). Results from this analysis can explain the reported heterogeneity found in a comparable data set by Merom et al. (1999). Further observations made in their paper are rebutted: (1) an implied assumption that Reed Warbler (Acrocephalus scirpaceus) spring migration in Israel ends by 1 May is contrary to other publications; (2) the late autumn occurence in N Israel of longer-winged 1st cal. yr. Reed Warblers, unconvincingly explained as either delayed migration by larger individuals or post fledging feather growth, is most likely due to birds from different provenances origins moving at different seasons; (3) growth during adulthood in Reed Warbler is not a new discovery, though presented as such.

scholarly journals Sex, age, molt strategy, and migration distance explain the phenology of songbirds at a stopover along the East Asian flyway

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Jonas Wobker ◽  
Wieland Heim ◽  
Heiko Schmaljohann
Keyword(s):  
East Asian ◽  
Russian Far East ◽  
First Year ◽  
Large Set ◽  
Differential Migration ◽  
Breeding Area ◽  
Migration Distance ◽  
Stopover Site ◽  
Evolutionary Response ◽  
Migrant Birds

Abstract Sex- and age-specific differences in the timing of migration are widespread among animals. In birds, common patterns are protandry, the earlier arrival of males in spring, and age-differential migration during autumn. However, knowledge of these differences stems mainly from the Palearctic-African and Nearctic-Neotropical flyways, while detailed information about the phenology of migrant birds from the East Asian flyway is far scarcer. To help fill parts of this gap, we analyzed how migration distance, sex, age, and molt strategy affect the spring and autumn phenologies of 36 migrant songbirds (altogether 18,427 individuals) at a stopover site in the Russian Far East. Sex-differential migration was more pronounced in spring than in autumn, with half of the studied species (6 out of 12) showing a protandrous migration pattern. Age-differences in migration were rare in spring but found in nearly half of the studied species (11 out of 25) in autumn. These age effects were associated with the birds’ molt strategy and the mean latitudinal distances from the assumed breeding area to the study site. Adults performing a complete molt before the onset of autumn migration passed the study site later than first-year birds undergoing only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. These sex-, age-, and molt-specific migration patterns agree with those found along other flyways and seem to be common features of land bird migration strategies. Significance statement The timing of animal migration is shaped by the availability of resources and the organization of annual cycles. In migrant birds, sex- and age-differential migration is a common phenomenon. For the rarely studied East Asian flyway, we show for the first time and based on a large set of migrant songbirds that earlier migration of males is a common pattern there in spring. Further, the timing and extent of molt explained age-differential migration during autumn. Adults molting their complete plumage at the breeding area before migration showed delayed phenology in comparison to first-year birds, which perform only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. Since our results agree with the general patterns from the other migration flyways, similar drivers for differential migration may act across different flyway systems, provoking a similar evolutionary response.

The spatial dynamics of White-browed Babbler groups in a fragmented agricultural landscape

2002 ◽  
Vol 8 (4) ◽  
pp. 271 ◽  
Author(s):  
Peter G. Cale
Keyword(s):  
Home Range ◽  
Breeding Season ◽  
Group Dynamics ◽  
Agricultural Landscape ◽  
Local Population ◽  
Breeding Site ◽  
Home Ranges ◽  
Effective Population ◽  
Study Sites ◽  
Group Movements

White-browed Babbler Pomatostomus superciliosus groups occupying linear strips of vegetation had breeding territories that were smaller in area and had longer linear dimensions than those occupying patches. A group's non-breeding home range was larger than its breeding territory. Groups occupying linear/patch home ranges expanded the linear extent and area of their home ranges more than those within other home range configurations. Some groups moved during the non-breeding season and this was more likely to occur if the group occupied a remnant with a low abundance of invertebrates during summer. Some groups that moved returned prior to the next breeding season, but the majority were never seen again. New groups moved into the study sites and established in vacant home ranges. This suggests that those groups that left the study sites may have established new home ranges elsewhere. Breeding site fidelity was lower in groups that had failed in previous breeding attempts. Therefore, group movements were influenced by the feeding and breeding quality of the habitat. However, the configuration of the local population also influenced group movements with those groups on the edge of a local population being more likely to move than those in the interior. New groups were formed by two processes; group dispersal, where groups generally filled a vacant home range, and group budding, which involved the splitting of a large group. Group dispersal maintained group densities while group budding increased the density of groups in a local population. These two processes were common, producing localized fluctuations in the density of groups. Since babbler groups contain only one breeding pair, changes in group density represent changes in effective population size. Therefore, group dynamics may be important to the persistence of local populations of White-browed Babblers, especially in landscapes that have suffered from habitat loss and fragmentation.

Snowmobile Effects on Movements of White-tailed Deer: A Case-study

1979 ◽  
Vol 6 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Ronald G. Eckstein ◽  
Thomas F. O'Brien ◽  
Orrin J. Rongstad ◽  
John G. Bollinger
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Odocoileus Virginianus ◽  
Activity Patterns ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges

The effects of snowmobile traffic on the winter home-ranges, movements, and activity patterns, of White-tailed Deer (Odocoileus virginianus), were studied during two winters in northern Wisconsin. There were no significant differences in home-range size and habitat use of the Deer in areas with and without snowmobiling. However, snowmobiling caused some Deer to leave the immediate vicinity of the snowmobile trail. Deer were most affected when they were within 61 m of the snowmobile trail.

Malaria infection status of European Robins seems to associate with timing of autumn migration but not with actual condition

Parasitology ◽  
2019 ◽  
Vol 146 (6) ◽  
pp. 814-820
Author(s):  
Nóra Ágh ◽  
Imre Sándor Piross ◽  
Gábor Majoros ◽  
Tibor Csörgő ◽  
Eszter Szöllősi
Keyword(s):  
Avian Malaria ◽  
Arrival Time ◽  
Parasite Prevalence ◽  
Malaria Prevalence ◽  
Blood Parasites ◽  
Autumn Migration ◽  
Actual Condition ◽  
Infection Status ◽  
Stopover Site ◽  
Age Related

AbstractAvian malaria parasites can negatively affect many aspects of the life of the passerines. Though these parasites may strongly affect the health and thus migration patterns of the birds also during autumn, previous studies on avian malaria focused mainly on the spring migration and the breeding periods of the birds. We investigated whether the prevalence of blood parasites varies in relation to biometrical traits, body condition and arrival time in the European Robin (Erithacus rubecula) during autumn migration. We found no sex or age related differences in avian malaria prevalence and no relationship between infection status and body size or actual condition of the birds was found either. However, the timing of autumn migration differed marginally between infected and non-infected juveniles, so that parasitized individuals arrived later at the Hungarian stopover site. This is either because avian malaria infections adversely affect the migration timing or migration speed of the birds, or because later arriving individuals come from more distant populations with possibly higher blood parasite prevalence. The possible delay that parasites cause in the arrival time of the birds during autumn migration could affect the whole migratory strategy and the breeding success of the birds in the next season.

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