The hole board test is useful for modeling anxiety in animals, in this test an anxiolytic-like state may be reflected by an increase in head –dipping behaviors [ 30, 31].
Through this study, we aimed to determine whether a group of chimpanzees modified probing tools in order to extract viscous foods (akin to 'fluid dip') from a novel 'artificial termite mound' in their enclosure and, if so, to identify under what circumstances they modified tools for fluid dipping behaviors.
Head-dip behavior did not differ between NAB and LAB mice (Figure 2b).
Altered adaptive responses were also found in a hole-board test in which head-dip behavior was increased and advanced.
In addition, the test session was videotaped for later analysis of the head-dip behavior by an experienced observer using the Eventlog 1.0 (EMCO Software).
NAB mice essentially displayed an intermediate anxiety-like phenotype compared with the extreme lines, although their head dip behavior was similar to that of the LAB line.
We note that the members shown in light green shading show the first prototypical behavior while members negatively correlated with this set show the dip behavior (Casp12 for example).
Although we have previously reported the behavior of this population of chimpanzees and their interaction with this artificial termite mound as 'termite fishing' [e.g. Lonsdorf et al., 2009], given that the mound was baited with liquid foods, we consider that the probing behaviors recorded during this study should be more accurately described as 'fluid dip' behaviors [c.f.
It found that the head-dipping behavior of the animals is directly related to their emotional state [26].
In the hole-board test, a significant decrease in head-dipping behavior was observed in both the ethanol alone and ethanol plus stress groups at 6 h after the discontinuation of ethanol treatment.
The behaviors included percentage time spent in the open areas, total numbers of transitions between the two open areas, stretch-attend postures, head-dipping behavior, and percentage time spent in freezing behavior.
