Abstract In many songbirds, the space use of breeders is well studied but poorly understood for non-breeders. In common ravens, some studies of non-breeders indicate high vagrancy with large individual differences in home range size, whereas others show that up to 40% of marked non-breeders can be regularly observed at the same anthropogenic food source over months to years. The aim of this study was to provide new insights on ravens’ behavior during dispersal in the Eastern Alps. We deployed Global Positioning System (GPS) loggers on 10 individuals to gather accurate spatial and temporal information on their movements to quantify: 1) the dimension of the birds’ space use (home range size with seasonal effects and daily/long-term travel distances), 2) how long they stayed in a dispersal stage of wandering as opposed to settling temporarily, and 3) their destination of movements. We recorded movements of up to 40 km per hour, more than 160 km within 1 day and more than 11,000 km within 20 months, indicating high vagrancy. Switching frequently between temporarily settling and travelling large distances in short time intervals leads to extensive home ranges, which also explains and combines the different findings in the literature. The destinations are rich anthropogenic food sources, where the birds spent on average 75% of their time. We discuss how ravens may find these “feeding hot spots” and which factors may influence their decision to stay/leave a site. The strong dependence on anthropogenic resources found in this population may have implications for site management and conservation issues.
GPS tracking of non-breeding ravens reveals the importance of anthropogenic food sources during their dispersal in the Eastern Alps
Matthias-Claudio Loretto,R. Schuster,T. Bugnyar
Published 2016 in Current Zoology
ABSTRACT
PUBLICATION RECORD
- Publication year
2016
- Venue
Current Zoology
- Publication date
2016-03-25
- Fields of study
Biology, Geography, Medicine, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- anthropogenic food sources
Human-associated feeding sites that provide food for the tracked ravens.
Aliases: human food sources, anthropogenic feeding sites
- dispersal stage
The phase of movement in which birds range away from natal areas before becoming more settled.
Aliases: dispersal period
- gps loggers
Satellite tracking devices attached to individual ravens to record their movements over time.
Aliases: GPS tracker, GPS tracking device
- home range size
The area encompassed by the regular movements of an individual bird.
Aliases: home-range size
- non-breeding ravens
Ravens monitored during the dispersal period rather than while engaged in nesting or parental care.
Aliases: nonbreeding ravens
- space use
The spatial extent and pattern of areas used by an individual bird during tracking.
Aliases: spatial use
- temporary settling
Short-term staying at a site during dispersal before resuming movement.
Aliases: temporary settlement, stopover
- time allocation
The division of tracked birds' time among the places they visit during dispersal.
Aliases: time spent
- travel distances
Distances covered by tracked birds over daily and longer time intervals.
Aliases: movement distance, displacement distance
- vagrancy
A highly mobile movement pattern marked by frequent long-distance displacement between sites.
Aliases: vagrant movement
- wandering
Unsettled movement between sites during dispersal without long-term residence at one location.
Aliases: roaming
REFERENCES
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