Enhanced conspicuousness of prey in warmer water mitigates the constraint of turbidity for predators

Changes in environmental conditions impact predator-prey interactions by altering behaviour through sensory and non-sensory (e.g., metabolic or cognitive) pathways. Elevated water temperature and turbidity are known to alter activity levels and anti-predator responses in prey fish, and are increasing globally as a result of anthropogenic activities. Less is known about how temperature and turbidity impact predators’ ability to detect prey directly, or indirectly via changes to prey behaviour. We quantified the detectability of Trinidadian guppies (Poecilia reticulata) free-swimming in a large arena from the perspective of a stationary visual predator (simulated as an underwater camera). We used a fully factorial experimental design testing the independent and combined effects of increased temperature and turbidity. We found that both stressors had a strong influence on the appearance of prey (objectively quantified as the mean magnitude of the optical flow in the videos). As expected, t..., , , Data files included:

#### **1. Final_data.csv**

This data file includes all averaged variables used in the statistical analysis described in the Methods section

* VideoFile: Unique trial identifier. Video files are not included in this repository. Available on request by contacting the first author CZ directly on [e-mail] or [e-mail].

- MeanMagnitude MaxMagnitude: mean and max average magnitude of optical flow for each trial

* Trail_N: Unique Trial Number 1-96

- Guppy_tub: Number of holding tanks of origin 1-4

* Guppy_group : number of group tested each day 1-6

- Guppy_N : number of individual guppies within each group

* Rep_Testing : Repeated testing 1-4

- Min_from_Midnight: minutes passed from midnight when trial commenced

* SqrMean SqrMax : Square root transformations of mean and max magnitude

- Treatment : categorical variable

* Temp : categorical variable, H = Hot, W = Warm

- Turb : categorical variable, C = Clear, T = Turbid

* Proportion_Ye...,