Skip to main content
Dryad logo

Data from: First records of complete annual cycles in water rails Rallus aquaticus show evidence of itinerant breeding and a complex migration system

Citation

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, Dryad, Dataset, 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

Latvijas Zinātnes Padome, Award: lzp-2019/1-0242