Data from: First records of complete annual cycles in water rails Rallus aquaticus show evidence of itinerant breeding and a complex migration system
Cite this dataset
Lislevand, Terje; Hahn, Steffen; Rislaa, Sven; Briedis, Martins (2020). Data from: First records of complete annual cycles in water rails Rallus aquaticus show evidence of itinerant breeding and a complex migration system [Dataset]. Dryad. https://doi.org/10.5061/dryad.bnzs7h48k
Abstract
In water rails Rallus aquaticus, northern and eastern populations are migratory while southern and western populations are sedentary. Few details are known about the annual cycle of this elusive species. We studied movements and breeding in water rails from southernmost Norway where the species occurs year-round. Colour-ringed wintering birds occurred only occasionally at the study site in summer, and vice versa. Geolocator tracks revealed that wintering birds (n = 10) migrated eastwards in spring to breed on both sides of the Baltic Sea, whereas a single breeding bird from the study site wintered in north Italy. Ambient light records of geolocator birds further indicated that all but one incubated 2–4 clutches per season. By combining information on incubation and movement, we found evidence for itinerant breeding in three individual birds: After a first breeding attempt (one did not incubate), all moved 129–721 km to breed again. This behaviour is rarely recorded in birds and was unexpected because the water rail is described as monogamous with both parents caring for eggs and chicks. The study greatly improves our knowledge about the annual cycle and reproduction in water rails. However, more studies are warranted to evaluate the generality of our findings and causes of breeding itinerancy.
Methods
The table includes data on the migration (timing of departure/arrival, estimated stationary periods and estimated coordinates of stationary sites) and timing of incubation (first to fourth clutch; one individual did not show any signs of incubating eggs) for 11 individual water rails. This information was estimated from light-level data collected by geolocators and processed in R package ‘TwGeos’ and using the ‘invChanges’ function from the R package ‘GeoLight’, ver. 2.0.1. For more details about methods, please see Lislevand et al. 2020: doi: 10.1111/jav.02595.
Usage notes
Cells without information are filled with "na", except for the incubation data where there is only a single line of information per nest (at the same line as info for site a). Description of columns:
| Column header | Description |
| Ring # | Ring number (Stavanger Museum, Norway) |
| Bird ID | Letters A-K followed by year of tracking (2014 or 2015) to separate individuals |
| Sex | M = male; F = female |
| Age | 2y = second calendar year; 3y = third calendar year; 3y+ = third calendar year or older |
| Mass | body mass in g |
| Wing | wing length in mm |
| Site | different letters to separate stationary sites (unique within individuals but not between) |
| arrival | Timing of arrival at the site |
| departure | Timing of departure from the site |
| Stationary duration | Duration of the stationary period |
| Movement duration | Duration of the movement period (time between stationary periods) |
| Long, median | Longitude, median calculated from data |
| Lon.2.5% | Longitude, lower limit of 95% CI |
| Lon.97.5% | Longitude, upper limit of 95% CI |
| Lat, median | Latitude, median calculated from data |
| Lat.2.5% | Longitude, lower limit of 95% CI |
| Lat.97.5% | Longitude, upper limit of 95% CI |
| GC distance from breeding site | Great circle distance from breeding site in km. |
| GC distance from previous site | Great circle distance from previous site in km. |
| Total GC migration distance | Total great circle distance travelled, in km |
| Incubation onset I | First date of recorded incubation, first nest |
| Incubation finish I | Last date of recorded incubation, first nest |
| Incubation onset II | First date of recorded incubation, second nest |
| Incubation finish II | Last date of recorded incubation, second nest |
| Incubation onset III | First date of recorded incubation, third nest |
| Incubation finish III | Last date of recorded incubation, third nest |
| Incubation onset IV | First date of recorded incubation, fourth nest |
| Incubation finish IV | Last date of recorded incubation, fourth nest |
Funding
Latvian Council of Science, Award: lzp-2019/1-0242