Extreme temperatures can intensify predator-prey interactions

Abstract
Extreme temperatures and heatwave events present challenging conditions for wildlife and are increasing in frequency and intensity in many regions due to climate change. High daily temperatures increase physiological stress and cause mortality in susceptible individuals (e.g. from poor health or exposure) but may also drive behavioural changes as individuals seek to thermoregulate (e.g. seeking shelter or water). As daily high temperatures accumulate into heatwave events, the ability of wildlife to tolerate conditions can diminish and exacerbate stress. Although climate change is well known to decouple species interactions, here we examined how extreme conditions may intensify interactions between predators and prey. In particular, we explored whether predators can exploit the thermoregulatory requirements of prey as they increasingly require access to water. We presented evidence from the use of artificial waterpoints by dingoes, Canis dingo, and eastern grey kangaroos, Macropus giganteus, on a wildlife property in Australia's semiarid drylands, asking whether high temperatures and heatwaves alter species behaviour and interactions between them. Both species increasingly accessed waterpoints as daily maximum temperatures increased; however, the degree of co-occurrence at waterpoints increased significantly as the temperatures became extreme and resulted in heatwaves. Not only did waterpoints become increasingly important for both species during heatwaves, but dingo hunting attempts on kangaroos at these times were significantly higher than expected based on the number of days when heat anomalies occurred. Additionally, dingoes relaxed their predisposition to hunt kangaroos in poor body condition, making kangaroo hunting opportunistic during these times. Our findings emphasize the potential for climate change to exacerbate predator–prey interactions, which may have an impact on species persistence if prey is unable to adapt to predators that exploit their thermoregulatory demands.
GENERAL INFORMATION
1. Corresponding Author Information Name:
Loic Q. Juillard
2. Date of data collection (single date, range, approximate date): November 2019 - April 2021
3. Geographic location of data collection: South-western Queensland, Australia.
4. Information about funding sources that supported the collection of the data: Detroit Zoological Foundation (donations), Australia Zoo (in-kind)
Sharing/Access information
1. Links to publications that cite or use the data: To be updated post paper publication
2. Links to other publicly accessible locations of the data: NA
3. Links/relationships to ancillary data sets: NA
4. Was data derived from another source? NA
5. Recommended citation for this dataset: Cite the paper.
DATA & FILE OVERVIEW
1\. File List:
PredictedMourachan_BOM_Daily_Temp_1913_2021.xlsx - Predicted daily temperature of the Mourachan property based on BOM temperature data for the St George town from 1913 to 2021.
Kangaroo_dingo_events_Heatwave_indices.xlsx - Kangaroo and dingo events at waterpoints split by camera and time of event, event durations as well as temperature and heatwave index data also present.
All_Heatwave_Indices_Tested.xlsx - All heatwave indices (with daily values) created from the MMM found for the field site (32.102 degrees C)
Calculating_Heatwave_Indices.R - R script used to calculate heatwave indices found in spreadsheet All_Heatwave_Indices_Tested.xlsx using mean daily temperature and MMM of 32.102 degrees C.
METHODOLOGICAL INFORMATION
1\. Description of methods used for collection/generation of data: All animal-based data were collected from camera trapping, temperature data for the Mourachan property were collected using iButton temperature sensors. Past temperature data and heatwave conditions were collected using iButton data along with long-term BOM data for the nearest town (St George).
2\. Methods for processing the data:Read the full paper for details.
3\. Instrument- or software-specific information needed to interpret the data: N/A
4\. Standards and calibration information, if appropriate: NA
5\. Environmental/experimental conditions: NA
6\. Describe any quality-assurance procedures performed on the data: NA
7\. People involved with sample collection, processing, analysis and/or submission: All authors
DATA-SPECIFIC INFORMATION FOR: PredictedMourachan_BOM_Daily_Temp_1913_2021.xlsx
1. Number of variables: 7
2. Number of cases/rows: 35668
3. Variable List:
Date: Day/Month/Year
Mourachan_maximum_daily_temperature_C: Max daily temp for Mourachan
Mourachan_minimum_daily_temperature_C: Min daily temp for Mourachan
Mourachan_average_daily_temperature_C: Mean daily temp for Mourachan
StGeorge_maximum_daily_temperature_C: Max daily temp for St George (BOM)
StGeorge_minimum_daily_temperature_C: Min daily temp for St George (BOM)
StGeorge_average_daily_temperature_C: Mean daily temp for St George (BOM)
DATA-SPECIFIC INFORMATION FOR: Kangaroo_dingo_events_Heatwave_indices.xlsx
1. Number of variables: 18
2. Number of cases/rows: 28946
3. Variable List:
Date: Day/Month/Year for each kangaroo and dingo events
Dam: Name of waterpoints where cameras were present
DateTime: Date and time of events observed
Time: Time of events observed
nTime: nTime of events observed
timeSinceLastVisit_mins: Number of minutes between current and previous event
Roo_Duration: Length of events where kangaroos were observed (minutes)
Dingo_Duration: Length of events where dingoes were observed (minutes)
Dingo_pres_abs: Whether dingoes were present on a specific event (1 = yes)
Kangaroo_pres_abs: Whether kangaroos were present on a specific event (1 = yes)
Species: Species name
Daily_max_ibutton_temp: Daily maximum temperature for the Mourachan property
Mean_Daily_Adjusted_Temperature: Daily mean temperautre for the Mourachan property
MMM_1971-2000: the Maximum Monthly Mean used by this study (32.102C) found from a 1971-2000 baseline
Hin_0_degree_threshold__13_day_window: Heatwave metric made and used for this study (negative values represent days where temperature was below the MMM, while positive values exceeded the MMM and represent the intensity of heatwave conditions)
DATA-SPECIFIC INFORMATION FOR: All_Heatwave_Indices_Tested.xlsx
1. Number of variables: 26
2. Number of cases/rows: 5153.
Variable List:
Date: List of days from start to end of the study period
Mean_temperature: Mean daily temperature in degrees Celsius
0_degree_threshold__1_day_window (onward): heatwave indices showing the threshold used as well as rolling average (day window) used.
0_degree_threshold__13_day_window: heatwave index used in the research article