Relaxed

• Neutral expression of relaxed animal
• Eyes open and calm
• Facial muscles appear relaxed
• Positive welfare indicator

Sleepy Face

• Relaxed face with eyes half closed and mouth slightly open
• Facial muscles appear relaxed
• Positive welfare indicator

Alert Stare

• Stare with eyes open, mouth closed
• Head held upright and may visually scan surrounding environment
• Vigilant
• Negative welfare indicator if persistent

Slit Stare

• Stare with eyelids half closed, eyes slits and lowered brow
• Submissive
• In response to being approached by an aggressive marmosets

Open-mouth in Play

• Mouth open with teeth bared, or not, but eyes and face relaxed
• Playful/friendly
• Positive welfare indicator

Frown

• Stare with open eyes and lowered brow
• Aggressive
• To cause approaching marmoset to retreat

Bared Teeth Grin/Scream

• Mouth open, teeth bared (teeth visible and corners of mouth drawn back)
• Submissive/fearful
• In response to being approached by an aggressor, being ‘chastised’
• Negative welfare indicator

Open-mouth in Surprise/Fear

• Stare with eyes and mouth open
• Fearful
• Negative welfare indicator if persistent

Tufts Flattened

• Tufts/ears flatten against the head
• Usually in fear (or in aggressive situation indicating submission), although it occasionally occurs in play so context is important
• In response to aggression it is submissive

Tufts Flick Stare

• Marmoset flicks tufts/ears backwards and then forwards
• Occurs in aggressive contexts but in some others, so context is important

Tufts Held Forwards

• Tufts/ears held forwards and the face may redden
• Aggressive
• May be given before attacking another marmoset