Comparing local ecological knowledge and camera traps to estimate the abundance of mammals and game birds in the Eastern Amazon

• The use of signs and tracks can detect ungulate species as efficiently as camera traps. • Common species such as deer and agouti are detected efficiently by both methods. • Body mass and sociability have little influence on the detection of mammals and birds by local hunters. • Signals can contribute to monitoring species with large home ranges and vagility, such as the White-lipped Peccary. • The use of signals requires greater sampling effort to reduce variation in detection rates. The choice of appropriate methods to observe population changes of species of interest in environmental monitoring is crucial to ensure the success of long-term programs. Including methods based on local ecological knowledge (LEK) can contribute to the sustainability of monitoring programs in several aspects. We assessed the congruence between detection rates obtained from camera traps and sightings and traces detected through LEK in two protected areas of Eastern Amazonia, comparing detection probabilities and testing the influence of three ecological traits. Only three species showed congruence between the indices, with 10 of the 20 being detected efficiently by both methods, mainly ungulates. The trophic guild was the most important ecological trait influencing species detectability. Our results indicate the effectiveness of LEK in detecting focal species, but limitations in identifying population trends. We recommend collaborative research strategies and the inclusion of the knowledge and experience of local populations in monitoring and conservation programs in the Amazon and other tropical systems, which are the regions richest in biological diversity and sociocultural richness.