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ABSTRACT. Although cameras have been used for many years to collect data at birds' nests, recent advances in digital technology have led to increased storage capacity, faster and easier review of data, and reduced power consumption. The development of sophisticated triggering mechanisms, such as video motion detection, herald a new era of portable, energy-efficient systems that require less frequent maintenance. We used a digital infrared camera system to monitor predation events at the nests of ground-nesting Lapwings (Vanellus vanellus; N = 40) and tree-nesting Spotted Flycatchers (Muscicapa striata; N = 17). Eight predator species were recorded taking eggs or chicks at Lapwing (N = 10) and Spotted Flycatcher (N = 7) nests, including red fox (Vulpes vulpes), badger (Meles meles), sheep (Ovis aries), and Carrion Crow (Corvus corone) at Lapwing nests and Eurasian Jay (Garrulus glandarius), European Buzzard (Buteo buteo), Great-spotted Woodpecker (Dendrocopus major), and domestic cat (Felis catus) at flycatcher nests. We tested three system configurations in an attempt to minimize power requirements and maximize predation-event recording capability. We found that the use of a passive-infrared sensor to awaken the system from standby mode did not compromise reliability and reduced power consumption. With this system, a 38-Ah battery operated the system for 120 h with no maintenance at a cost per unit of about $800 (US; or £400 UK Sterling). Further modifications would permit adaptation of the system for a wide range of scientific and nest surveillance operations. SINOPSIS. Nuevo instrumento para monitorear nidos a remoto, utilizando tecnología de camara digitalAunque las cámaras han sido utilizadas por mucho tiempo para tomar datos en nidos de aves, avances recientes en la tecnología digital, ha permitido incrementar la capacidad de almacenaje de información, el revisar fácil y rápidamente los datos y reducir el consumo de energía. El desarrollo de mecanismos sofisticados de disparo (triggering), tales como la detección de movimiento con video, marca una nueva era en equipo portátil de alta eficiencia energética que requiere poco mantenimiento. Utilizamos un sistema de cámara infraroja digital para monitorear eventos de depredación en nidos de Vanellus vanellus; N = 40) e individuos de Muscicapa striata; N = 17). Se pudo constatar la depredación de huevos de Vanellus (N = 10) y de Muscicapa (N = 7) por ocho especies de depredadores. Entre estos a Vulpes vulpes, Meles meles, Ovis aries y Corvus corone sobre nidos de Vanellus. También a Garrulus glandarius, Buteo buteo, Dendrocopus major y a gatos (Felis catus) en nidos de Muscicapa. Tres configuraciones de sistemas se pusieron a pruebas para tratar de minimizar los requerimientos de energía y maximizar la capacidad de grabación de los eventos de depredación. Encontramos que el uso de un sensor infrarojo pasivo, que encendiera el sistema de un modo de espera ("standby"), no comprometio la confiabilidad del aparato y redujo el consumo de energía. Con este sistema una...

Color bands and radio tags are widely used to facilitate individual recognition and relocation of precocial chicks in studies of prefledging survival. However, the accuracy of data collected and subsequent estimates of survival rates rely on the assumption that such techniques do not affect the parameters under study. We compared the body condition and survival of color‐banded and radio‐tagged Lapwing (Vanellus vanellus) chicks with noncolor‐banded and nonradio‐tagged individuals using a 10‐year dataset (N= 3174 chicks, with 205 color banded and 700 radio tagged). Color bands did not adversely affect chicks. However, radio‐tagged chicks and their untagged broodmates were handled more frequently because these broods were more readily encountered than those without a tagged member. Chicks disturbed and handled more frequently had lower body condition indices and higher mortality rates. Simulations of the impact of tagging and handling on breeding productivity under two scenarios indicated a 26% reduction in productivity in situations where nest and chick survival rates were low (as in our study), but only a 7% reduction in productivity for a simulated population with the higher levels of nest and chick survival associated with a stable population. The frequent disturbance associated with radio‐tracking and recapturing chicks, rather than the attachment of a tag or physical handling of chicks, may affect body condition. Frequent handling and disturbance may affect body condition by reducing foraging time, increasing stress levels, or increasing predation risk. Because our results suggested that the negative impact of handling could last up to a week, we recommend that investigators avoid disturbance of shorebird chicks more frequently than every 8 d.