Close encounters: Behavioral responses of migrating songbirds to the perceived risk of predation

Migrating birds face competing pressures to travel as quickly and efficiently as possible while minimizing the risk of predation en route. Despite the potential importance, antipredator behaviors in migrating songbirds have been little studied relative to time and energy tradeoffs, even as humans have introduced novel predators including free-roaming domestic cats (Felis catus) across the globe. Birds confronted with predators during stopover can employ antipredator behaviors to reduce their immediate mortality risk, but doing so may slow refueling or impose other costs that influence migration. We captured migrating Gray Catbirds (Dumetella carolinensis) and exposed them to either a live cat, model hawk, or non-predator control in an aviary experiment to assess their behavioral responses. Birds moved lower after exposure to a model hawk, but showed no significant behavioral changes in response to a cat. After release, we monitored activity levels of a subset of tagged individuals via t..., All pre- and post-test behavioral observations were recorded by C.E. Nemes using Gray Catbirds captured during fall migration. Methods for data collection and processing are described in the associated paper.
For the activity analysis, a subset of catbirds were nano-tagged by C.E. Nemes. Detections of tagged individuals at local receivers were downloaded from the Motus Wildlife Telemetry System website (www.motus.org) using the Motus R package and de-trended signal strength values were calculated as described in the paper. Motus detection data are freely accessible but must be cited, which is not compatible with Dryad's CC0 policy. Hence, we have archived detection data for the activity analysis at Zenodo., , # Data from: Close encounters: Behavioral responses of migrating songbirds to the perceived risk of predation

[https://doi.org/10.5061/dryad.s1rn8pkjg](https://doi.org/10.5061/dryad.s1rn8pkjg)

## Description of the data and file structure

Behavioral experiment: Spreadsheet containing behaviors of individual Gray Catbirds recorded for 5 minutes pre-exposure and 5 minutes post-exposure to treatment condition. Details of data collection methods are described in the corresponding paper.

Activity analysis: Detections of a subset of nano-tagged Gray Catbirds at local receivers were downloaded from the Motus Wildlife Telemetry System website ([www.motus.org](http://www.motus.org)) using the Motus R package and summarized.

### Files and variables

#### File: nemes\_et\_al\_close\_encounters\_experiment\_data.csv

**Description:** Behaviors of individual Gray Catbirds on stopover recorded for 5 minutes pre-exposure and 5 minutes post-exposure to treatment condition. Details of data collecti...