The forest between the lowlands and highlands contains the highest dendrobatid diversity of all forest types. The lower range (300 m) may contain lowland species, around 500 m these species frequently drop out and are replaced by highland specialists. For example, Epipedobates pongoensis ranges to about 400 m elevation - from here up it is replaced by E. bassleri. This narrow zone between 350 and 550 meters is known as the transition zone and is responsible for exceedingly high faunal diversity in small areas. The Cainarachi valley and Panguana (Rio Pachitea drainage) are both classic dendrobatid transition zones. One can see a wide range of habitats within premontane areas. The Aguaytia shelf near Pucallpa is a flat yet cool and moist area home to many species of Epipedobates. The rugged Cordillera Oriental near Tarapoto contains swift streams, with high morph endemism and habitat heterogeneity. These streams are home to many species of Atelopus, hylids, and centrolenids. Premontane forest is normally 24-27 C in the day with a slight drop at night. In Northern Peru, the months of January, July, and August have a marked decrease in rainfall.
Most premontane habitat is relatively wet and contains bromeliads, though they are often concentrated in specific areas such as ridgelines or alongside streams. Heliconia and Xanthosoma can be found in great abundance, which are used by species such as Dendrobates imitator and D. lamasi for breeding.
The bamboo forest near Tingo Maria (650 m) is one of the strangest sights we've seen. Here, D. lamasi can be found breeding in clusters of enormous bamboo. These dense clusters exclude most other vegetation, and walking through this sparse, dry habitat feels much like a temperate forest in the middle of the summer.
