Clark's nutcrackers (Nucifraga columbiana) are sensitive to distance, but not lighting when caching in the presence of a conspecific.

We examined the caching behavior of the Clark's nutcracker (Nucifraga columbiana), a relatively asocial corvid bird, during social and non-social conditions with conspecifics. Past work by Dally et al., (2004, 2005a) has found that the related but more social scrub jay (Aphelocoma californica) caches food in locations that are far away or that are more dimly illuminated when in the presence of an observer.

An investigation of quantity discrimination in Clark's nutcrackers (Nucifraga columbiana).

We examined quantity discrimination in the Clark's nutcracker (Nucifraga columbiana), a corvid bird with a strong dependence upon caching and recovering nuts. We presented 2 sets of nuts simultaneously, in 21 different conditions, to see if the nutcrackers could choose the larger of the 2 quantities. The nutcrackers displayed a strong ability to discriminate quantities of nuts.

Tests of inferential reasoning by exclusion in Clark's nutcrackers (Nucifraga columbiana).

We examined inferential reasoning by exclusion in the Clark's nutcracker (Nucifraga columbiana) using two-way object-choice procedures. While other social scatter-hoarding corvids appear capable of engaging in inferential reasoning, it remains unclear if the relatively less social nutcracker is able to do so. In an initial experiment, food was hidden in one of two opaque containers.

Clark's nutcrackers (Nucifraga columbiana) use gestures to identify the location of hidden food.

Heterospecific cues, such as gaze direction and body position, may be an important source of information that an animal can use to infer the location of resources like food. The use of heterospecific cues has been largely investigated using primates, dogs, and other mammals; less is known about whether birds can also use heterospecific gestures. We tested six Clark's nutcrackers in a two-way object-choice task using touch, point, and gaze cues to investigate whether these birds can use human gestures to find food.