Online Resource 2
Appendix S2 Details of the radiotracking methods of three territorial Bonelli’s eagles
Two female and one male adults pertaining to three different territories (two of these formed part of the sample of 11 used for calculating the responses –T1 and T6– plus another located 30 km to the south of T3; see Fig. 1 in the main text) were radiotagged. A type TW-3 (Biotrack Ltd©) VHF transmitter was attached to the back of each of these individuals using a Teflon harness (Kenward 2001; see Consejería de Medio Ambiente 2006, 2008 for more details on the capture and marking process). The fixes were made in the same period for which the predation impact was calculated, the Bonelli’s eagle breeding season (February-May). Each eagle was individually radiotracked alternately from sunrise to midday or from midday to dusk in 10-18 non-consecutive daily sessions. A minimum of a one-hour interval was taken into account between consecutive locations.
A total of 224 valid radiotracking fixes were obtained for the 100 days of the breeding season, 78.1% of which were within the theoretical territory radius of 2.2 km, while 93.3% were within the theoretical radius of 4.4 km (Table S1). These results show that the theoretical radii included the great majority of the movements, i.e. activity, of the eagle, consequently supporting further use of them in our calculation of the predator responses.
References
Consejería de Medio Ambiente (2006) Programa de Actuaciones para la Conservación del Águila Perdicera en Andalucía (I). Technical report, Egmasa-CMA, Junta de Andalucía, Jaén
Consejería de Medio Ambiente (2008) Programa de Actuaciones para la Conservación del Águila Perdicera en Andalucía (II). Technical report, Egmasa-CMA, Junta de Andalucía, Jaén
Kenward R (2001) A Manual for Wildlife Radio Tagging. Academic Press, London
Table S1 Number of radiotracking fixes obtained for the three territorial birds within the two theoretical territory radii. The birds were numbered in correspondence with their territories (see Fig. 1 in the main text). The theoretical territory of individual E1 was corrected using a 2 km displacement to the NW given the presence of unsuitable habitat in the SE of the original territory. This corrected territory of E1 was also used during the calculation of the responses
E1 / 35 (70.0%) / 46 (92.0%) / 50
E1 corrected / 41 (82.0%) / 49 (98.0%) / 50
E6 / 35 (87.5%) / 40 (100%) / 40
E12 / 99 (73.9%) / 120 (89.6%) / 134
Total / 175 (78.1%) / 209 (93.3%) / 224
1