1. Ptilochronology as a non-invasive tool for evaluating nutritional condition in a wild population of Griffon Vultures (Gyps fulvus) in La Rioja, Spain
Alvaro Camina
Apartado de Correos 339, Majadahonda, Madrid, SPAIN
Reuven Yosef
International Birding & Research Center in Eilat, P. O. Box 774, Eilat 88000, ISRAEL

2. Chelo Atencia & Saturnino Moreno
* Ignacio Gamez Carmona
Centro de Recuperacion de fauna silvestre la fombera, gobierno de La Rioja
* Marti Surroca
Centro de Recuperacion Forn del Vidre C/Juan Ricart Miralles Vinaros
* Jose Rafael Garrido
Dept. Biodiversidad Animal, CES Marcelo Spinola-Univ. of Wales, Umbrete
Chelo Atencia & Saturnino Moreno
Centro de Recuperacion El Boticario FAADN Malaga

3. PTILOCHRONOLOGY (the study of feather time)
Michener, H., & J. R. Michener Bars in flight feathers. Condor 60:
Grubb, T. C. Jr Ptilochronology: feather growth bars as indicators of nutritional status.
Auk 106:

5. Graceful Warbler
Prinia gracilis
Eilat, Israel
24 h
growth
Fault bars
Optimal,
consistent growth
Irregular
Sub-optimal

9. Griffon Vultures La Rioja, Spain
4 caged adults (3-4 yrs)
16 free-living adults
11 free-living sub-adults
63 fledglings
mean width of 10 growth bars centered on 2/3 of the distance from the proximal end of the feather
total length
number of fault bars

10. Nutritional condition of Griffon Vultures in Spain
0+0
(N=4)
(N=14)
(N=25)

11. Nutritional condition of Griffon Vultures in Spain
Nestlings significantly better nutritional condition than free-living adults (Wilcoxon signed rank test z = , P = 0.02)
BUT not different from caged adults (z = , P = 0.14).
Simple regression analyses
no relationship between juvenile growth and faults bars
(y = x , r2 = 0.004)
which is in contrast to adults
(y = x , r2 = 0.374).

12. CONCLUSIONS
Free-living adults are the most adversely affected
Parents buffer young from fluctuating food availability by supplying food even if not enough for themselves
Ptilochronology can help evaluate the nutritional condition of wild populations of Griffon Vultures