Effects of capture and video-recording on the behavior and breeding success of Great Tits in urban and forest habitats

Behavioral research often involves capturing and video-recording birds, but these procedures may have undesired effects on the behavior of birds that have rarely been quantified. In addition, birds in urban and more natural areas may differ in their sensitivity to disturbance. We examined the possible effects of both capturing, weighing and measuring, and taking a blood sample, and the presence of video-cameras on the behavior of male and female Great Tits (Parus major) breeding in urban and forest habitats. Using a 2 9 2 block design, we compared the behavior and breeding success of parents that either were or were not captured on their nests a few days before behavioral observations, and of parents that either were or were not habituated to the presence of a concealed video-recorder mounted on nest boxes. We found no significant effects of habituation to the camera on bird behavior, but males captured in their nest boxes were more vigilant and hesitated longer before entering nest boxes, and also had slightly lower provisioning rates than males that had not been captured. Captured females also tended to be more vigilant than females that had not been captured, but their provisioning rates were not affected. Capturing males also influenced the behavior of their non-captured mates, but capturing females had no effect on the behavior of their non-captured mates. We found no difference in the effects of capture on Great Tits in urban and forest habitats, and our treatments also had no effect on the mass, size, and survival of nestlings until fledging. Our results suggest that, for Great Tits, being captured results in sex-dependent behavioral effects that can last for at least several days. As such, we suggest that the possibility of similar effects in other species of birds should be considered in behavioral studies where birds must be captured, and recommend either that behavioral data be collected before capturing birds or that all birds in a study should be captured and handled in a standardized way. RESUMEN. Efecto de la captura y la toma de videos en la conducta y exito reproductivo de Parus major en h abitats urbanos y naturales Los estudios de conducta muchas veces incluyen la captura y la toma de video de aves. Pero estos procedimientos pudieran tener efectos, no deseados, en la conducta de las aves que raras veces es cuantificado. Adem as las aves en h abitats urbanos y areas m as naturales pudieran diferir en su susceptibilidad al disturbio. Examinamos el posible efecto de la captura, pesaje, toma de medidas y de muestras de sangre y la presencia de c amaras de video en la conducta de hembras y machos de Parus major, reproduci endose en h abitats urbanos y naturales. Utilizando un dise~ no de “bloque” 2 9 2, comparamos la conducta y el exito reproductivo de individuos que eran capturados o no capturados en sus nidos d ıas antes de llevarse a cabo observaciones de conducta, y de individuos que estaban o no estaban habituados a la presencia de c amaras de video escondidas, pero montadas, en cajas de anidamiento. Encontramos que no hubo efecto significativo en la conducta de las aves habituadas a la c amara. Sin embargo los machos capturados en la caja donde anidaban fueron m as cuidadosos y precavidos para entrar en sus cajas. Adem as se redujo, ligeramente, el n umero de viajes para llevar comida al nido, en comparaci on con machos que no fueron capturados. Las hembras capturadas tambi en fueron m as precavidas que las no capturadas, pero su tasa de llevar alimentos a los pichones no fue afectada. La captura de los machos tambi en influy o en la conducta de su pareja, que no fue capturada, aunque no hubo efecto en la conducta, de la pareja, en hembras capturadas. No encontramos diferencias en el efecto de la captura de estas aves en ambientes urbanos y forestados. Nuestra manipulaci on no tuvo efecto en la masa, tama~ no y sobrevivencia de los pichones hasta el momento de dejar el nido. Los resultados sugieren que el efecto de la captura, en la conducta de Parus major, depende del sexo del ave y que dicha conducta puede durar por varios d ıas. A tales efectos advertimos que existe la posibilidad de efectos similares en otras especies Corresponding author. Email: seressg@almos.uni-pannon.hu © 2017 Association of Field Ornithologists 1 J. Field Ornithol. 0(0):1–14, 2017 DOI: 10.1111/jofo.12205