Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May 18;69(3):244-254.
doi: 10.1093/cz/zoac039. eCollection 2023 Jun.

The variability of juvenile dispersal in an opportunistic raptor

Jorge García-Macía  1 , Gabriel López-Poveda  1 , Javier De La Puente  2 , Ana Bermejo-Bermejo  2 , Manuel Galán  3 , Ernesto Álvarez  3 , Sara Morollón  1 , Vicente Urios  1
Affiliations

The variability of juvenile dispersal in an opportunistic raptor

Jorge García-Macía et al. Curr Zool. .

Abstract

The juvenile dispersal of raptors is a crucial stage that stretches from parental independence to the establishment of the first breeding area. Between 2012 and 2020, 44 juvenile red kites Milvus milvus from the Spanish breeding population were tagged using GPS telemetry to study their dispersal. Juveniles left the parental breeding area at the end of their first summer and performed wandering movements throughout the Iberian Peninsula, returning to the parental breeding area the following year, repeating the same pattern until they settled in their first breeding area. We analyzed the mean distance from the nest, the maximum reached distances, and the traveled distances (daily and hourly) during the first 2 years of dispersal and compared them. Despite the high individual variability, variables describing the dispersal movements of juveniles showed a decreasing trend during the second dispersal year: 80% of individuals reached a shorter maximum distance in the second year, 70% decreased their mean distance to the nest, 65% decreased their hourly traveled distances, and 50% decreased their daily traveled distances. On the other hand, the red kites usually combined wandering movements with the establishment of temporary settlement areas (TSA). The average duration of settlement in the TSAs was 75 ± 40 days (up to 182 days) and was located at 182 ± 168 km from the nest. In those areas, juveniles used 781.0 ± 1895.0 km2 (KDE 95%). Some of the TSAs were used by several individuals, which suggests that these areas might be good targets for conservation in future management plans.

Keywords: GPS telemetry; landfills; movement ecology; natal dispersal; red kite; spatial ecology.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Comparison between first and second dispersal periods according to the mean distance to nest (km), maximum distance to nest (km), daily traveled distance (km/day) and hourly traveled distance (km/h).
Figure 2.
Figure 2.
Example of two individuals’ tracks (Yelmo and Millau) which reduced their dispersal movements between the first and second years of dispersal. TSAs areas are represented by a white pentagon, while natal nest is represented by a yellow star.
Figure 3.
Figure 3.
Locations of all the TSAs where tagged red kites settled during their juvenile dispersal.
Figure 4.
Figure 4.
Distribution of the TSAs shared by more than one individual.
Figure 5
Figure 5
Histograms of the mean distances from the nest (A), and duration settlement (B) of TSAs identified for the juvenile red kites.
Figure 6.
Figure 6.
Kernel Density Estimators (95%, 75% and 50%) for a TSA of Millau in the province of Badajoz during its first year of dispersal. This area is representative because forest, agricultural, urban, river, and montane patches are found inside the home range of this red kite.
See this image and copyright information in PMC

References

    1. Aebischer A, Scherler P, 2021. Der Rotmilan: Ein Greifvogel im Aufwind. Germany: Haupt Verlag
    1. Balbontín J, Ferrer M, 2009. Movements of juvenile Bonelli’s eagles Aquila fasciata during dispersal. Bird Study 56(1): 86–95.
    1. Bird Life International. 2021. Red Kite (Milvus milvus)—BirdLife species factsheet. BirdLife International. Available at: http://datazone.birdlife.org/species/factsheet/red-kite-milvus-milvus/refs
    1. Bustamante J, 1993. Post-fledging dependence period and development of flight and hunting behaviour in the red kite Milvus milvus. Bird Study 40(3): 181–188.
    1. Cadahía L, López-López P, Urios V, Negro JJ, 2010. Satellite telemetry reveals individual variation in juvenile Bonelli’s eagle dispersal areas. Eur J Wildl Res 56(6): 923–930.