Altitudinal differences in foraging decisions under predation risk in great tits
Cite this dataset
Crouchet, Thomas; Heeb, Philipp; Chaine, Alexis (2024). Altitudinal differences in foraging decisions under predation risk in great tits [Dataset]. Dryad. https://doi.org/10.5061/dryad.mkkwh7162
Abstract
Foraging decisions under risk of predation are crucial for survival as predation risk can contribute to a reduction of food intake over time leading to a trade-off between starvation and predation. Environmental variation can provoke changes in food accessibility or predation risk that will in turn affect foraging decisions. Specifically, less predictable or harsher environments, such as those found at high elevation, should lead to more risk-prone foraging in order to prevent risk of starvation, but empirical confirmation of this hypothesis is lacking. In the current study, we used video playbacks combined with an automatic feeder to measure continuous foraging choices between control and predator videos by wild great tits originating from high and low elevations and tested under controlled conditions. Great tits discriminated between two conditions representing differences in predation risk and visited the feeder less frequently when a predator was shown. Moreover, we found that birds from low elevation populations were more risk-averse and visited the feeder significantly less when a predator video playback was broadcasted compared to high elevation individuals. This elevation related contrast was also dependent on the season, body mass and fat reserves of individuals, and was more marked in females. Furthermore, adults visited the feeder less in the presence of a predator compared to yearlings. These results are consistent with predictions from life history theory and starvation-predation trade-off hypotheses and could have implications for individual movements and population dynamics in changing environments.
README: Altitudinal differences in foraging decisions under predation risk in great tits
These datasets are used to investigate altitudinal differences in foraging decisions under predation risk in great tits.
Three successive datasets were used to that aim:
df.PredAbundance
Measurement of predator abundance per elevation using camera trap
Presentation of variables:
- Elevation: elevation above see level in meters of the location of the camera trap
- ElevationClasses: elevation sorted by category: 100-600; 600-1000; 1000-1500
- PredatorType: type of predator identified on cameratrap, either avian (AvianPred) or mammal (MammalPred)
- CamTrap: identity of the camera trap used.
- IndividualCount: number of predators identified
- Year: year of measure of the predator abundance (either 2016 or 2017)
df.PredElevation
Measurement of the number of visits to a feeder depending on video playbacks for various great tits
Presentation of variables:
- ID: Bird identity number composed of 7 characters
- Elevation: Elevation of origin of each individual based on the site of capture, either High or Low
- Site: Site of capture of each individual (AT, AU, MJ, VI)
- Sex: Sex of each individual, either male (M) or female (F)
- Age: Age of each individual, either adult or yearling. Information was not measured for one individual due to difficulty to age it (labelled as NA).
- TarsusS: scaled value of tarsus measured at capture (initially in g)
- Weight.inS: scaled value of weight at capture (initially in g). Information was not measured for three individuals due to technical issues (labelled as NA).
- Weight.outS: scaled value of weight at release (initially in g)
- FatS: scaled value of fat reserves at capture (4 level scale, see main text for details). Information was missing for four individuals (labelled as NA).
- ExploS: scaled value of exploration score measured at first release in aviaries (number of movements during a 3-min period). Information was not measured for two individuals due to time constraints (labelled as NA).
- Season: Season of capture of each individual, either Fall or Winter
- Batch: Batch of capture of each individual (8 levels)
- V_blackbird: Number of visits per day during control video playbacks
- V_sparrowhawk: Number of visits per day during predator video playbacks
The weight at capture and the
df.PredPeriod (supplementary materials)
Measurement of the number of visits to a feeder depending on video playbacks and period of the day for various great tits
Presentation of variables:
- ID: Bird identity number composed of 7 characters
- V_blackbird: Number of visits per period during control video playbacks
- V_sparrowhawk: Number of visits per period during predator video playbacks
- Period: Separation of the experiment in 6 1-hour period (from 1 to 6)
Funding
Ministry of Higher Education and Research
Human Frontiers Science Program
Agence Nationale pour la Recherche
Laboratoire d'Excellence TULIP