Discussion
We hypothesize that buzzards are taking advantage of the mating season
of the crayfish when they are more visible, when the water level is a
little bit lower, since the cameras where active the whole year and we
only recorded this behaviour during this period. Crayfishes may suppose
an important energy source during this part of the year, when the young
buzzards are flying, since we detected the consumption of this
crustacean by Eurasian otters (Lutra lutra ) and American mink
(Neogale vison ), (that consume them almost year-round) but
especially by red fox (Vulpes vulpes ) that overlapped the
consumption period with buzzards (Figure 4).
Conclusion
We describe a new food source and foraging behaviour by a generalist
raptor, the common buzzard (Buteo buteo ), contributing to the
knowledge of the prey spectrum this species is capable of prey upon in
its distribution range.
Figure captions
Figure 1: Study area in Western Iberia (A), in Salamanca province white
line (B) and location of the camera trap in the middle of a riparian
forest close to the Tormes river (C).
Figure 2: A) Foraging behaviour observed, with the common buzzard
patrolling the riverbank looking for prey, including American
crayfishes. B) Successful catch of an American crayfish.
Figure 3: Full predation sequence, where the buzzard captures the
crayfish in the water and moves to a log to eat it.
Figure 4: American mink (A) and red fox (B) catching crayfishes during
the same period as the buzzards.
Reference list
Boletín Oficial del Estado. Real Decreto 630/2013, de 2 de agosto, por
el que se regula el Catálogo español de especies exóticas invasoras. BOE
2013, 185, 56764–56786.
Bullock, J. (2006). Barn Owl killed and eaten by Common Buzzards.
British Birds. 99(11): 578
Bustamante, J. (1985). Alimentación del Ratonero Común (Buteo
buteo , L. 1758) en el norte de España. Doñana Acta Vertebrata, 12 (1): 51-62.
Courter, J. R. (2017). Provisioning behavior of male and female eastern
screech-owls during the post-brooding period. The American Midland
Naturalist , 177 (1), 69-74.
Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the
Western Palearctic. Volume 2: Hawks to Bustards. Oxford University
Press, Oxford, UK.
J. Cruz, M., Rebelo, R., & G. Crespo, E. (2006). Effects of an
introduced crayfish, Procambarus clarkii, on the distribution of
south‐western Iberian amphibians in their breeding habitats.Ecography , 29 (3), 329-338.
Elósegui, J. (1974). Informe preliminar sobre alimentación de aves
rapaces en Navarra y provincias limítrofes. Ardeola , 19 (2):
249-256.
Fisher, C. Y. (2020). Effects of urbanization and habitat on the
diet and reproduction of Red-shouldered Hawks in central California (Master’s thesis, San Jose State University).
Gil-Sánchez, J.M., Alba-Tercedor, J. The Decline of the Endangered
Populations of the Native Freshwater Crayfish (Austropotamobius
pallipes ) in Southern Spain: It is Possible to Avoid Extinction?.Hydrobiologia 559 , 113–122 (2006).
https://doi.org/10.1007/s10750-005-1024-5
Johnston, D. W. (2000). Foods of birds of prey in Virginia. Part I.
Stomach analyses. Banisteria , 15 , 3-15.
Livezey, K. B. (2007). Barred owl habitat and prey: a review and
synthesis of the literature. Journal of Raptor Research ,41 (3), 177-201.
Madge, G. (1992). Buzzard with live common eel. British Birds. 85(4):
187.
Mañosa, S., Cordero, P. J. (1992). Seasonal and sexual variation in the
diet of the Common Buzzard in northeastern Spain . J. Raptor
Res., 26 (4): 235-238.
Oficialdegui, Francisco J., Marta I. Sánchez, and Miguel Clavero. ”One
century away from home: how the red swamp crayfish took over the world.”Reviews in Fish Biology and Fisheries 30.1 (2020): 121-135.
Orta, J., P. F. D. Boesman, J. S. Marks, and E. F. J. Garcia (2022).
Common Buzzard (Buteo buteo), version 1.1. In Birds of the World (P. G.
Rodewald, S. M. Billerman, and P. Pyle, Editors). Cornell Lab of
Ornithology, Ithaca, NY, USA.
https://doi.org/10.2173/bow.combuz1.01.1
Tablado, Z., Tella, J. L., Sánchez‐Zapata, J. A., & Hiraldo, F. (2010).
The paradox of the long‐term positive effects of a North American
crayfish on a European community of predators. Conservation
biology , 24 (5), 1230-1238.
Valverde, J. A. (1967). Estructura de una comunidad mediterránea de
vertebrados terrestres. Monografías de Ciencia Moderna, 76. Consejo
Superior de Investigaciones Científicas. Spain.
Vilà, M., Basnou, C., Pyšek, P., Josefsson, M., Genovesi, P., Gollasch,
S., … & DAISIE partners. (2010). How well do we understand the
impacts of alien species on ecosystem services? A pan‐European,
cross‐taxa assessment. Frontiers in Ecology and the Environment ,8 (3), 135-144.
Funding Information
None
Conflict of Interest statement
The authors declare no conflict of interest.
Data Availability statement.
All data are contained within this manuscript and its associated tables.
Acknowledgements
To all the people that, at some point, helped with fieldwork during the
main study. In memoriam Daniel Saldaña, “Saldi”, who would have
loved to know about this behaviour.
Figures
Figure 1