October 30, 2015
Thanks to Shelby Yu for this guest student blog post. Shelby describes how Tufted Titmice alter their calling and feeding behavior in the face of inanimate objects, like, maybe your Halloween decorations!
His large, black eyes are fixed on the sunflower seeds scattered on a wooden platform. Tilting his grey head, a Tufted Titmouse lets out a clear repeated whistle peter-peter-peter. He spreads his wings, and like a gymnast, leaps off the branch causing a rustle of leaves. Landing swiftly on the feeder, he impatiently scans his surroundings again. Right before he snags his first seed, he sees—out of the corner of his eye—a grotesque face that resembles his greatest nightmare, the neighborhood ginger cat. The titmouse hesitates, dips his tufted crest, spreads his wings and flies off.
As FeederWatchers, we know that one thing that scares birds away from our feeders is a predator. But did you know that the Halloween decorations in your yard might also affect your feeder birds? New research suggests that birds see even inanimate objects as threats and behave differently depending on whether or not that threat is facing them.
Professor Todd Freeberg and his team of researchers at the University of Tennessee Forest Resources, Research and Education Center investigated how social factors like group size and a predator’s position affect bird behavior. Using stuffed cats and people wearing animal masks, they set out to see if Tufted Titmice acted differently when the masked person or stuffed animal was facing toward, or away, from a feeder.
Tufted Titmice typically travel in flocks and make nasal, scratchy alarm calls that sound like tsee-day when they see a predator nearby. They use varying frequencies to communicate different messages to their group. For example, if titmice call in long-strings of day notes, they are being aggressive and the flock may attack the predator. It is also known that titmice take fewer seeds and visit feeders less frequently when a predator is present. Freeberg and his team (2014) wanted to find out whether these behaviors were affected by the direction the predator was facing.
They found that when a masked person was facing the feeding station, the titmice took fewer seeds, waited longer before taking their first seed, visited the feeder more frequently without taking seeds, and were less aggressive toward one another. Regardless of whether the mask was facing the feeder or not, the titmice did not call differently. The researchers believe that calls were unaffected because the titmice could see the masked person as they flew near the feeding station and were therefore aware of the predator’s presence.
The research team’s second study (2015) showed that the behavior of the titmice flock was also influenced by whether the titmice had experience with real cats. This time using stuffed cats to represent predators, the cats were either faced toward, or away, from the seed. The researchers found that titmice avoided the feeder more when the stuffed animal was facing the food. Additionally, titmice that were accustomed to predators produced longer calls than those who were not, possibly to warn the flock about their surroundings.
If you have Halloween decorations near your feeders, listen and observe whether or not you see any difference in the behavior of your feathered trick-or-treaters!
References: Book, D. L., and Todd M. Freeberg. Titmouse Calling and Foraging Are Affected by Head and Body Orientation of Cat Predator Models and Possible Experience with Real Cats. Animal Cognition Anim Cogn 18.5 (2015): 1155-164.
Freeberg, Todd M., Tatjana Krama, Jolanta Vrublevska, Indriķis Krams, and Cecilia Kullberg. Tufted Titmouse (Baeolophus Bicolor) Calling and Risk-sensitive Foraging in the Face of Threat. Animal Cognition Anim Cogn 17.6 (2014): 1341-352.