Skip to main content
Dryad logo

Data from: Crocodile social environments dictated by male philopatry

Citation

Baker, Cameron et al. (2021), Data from: Crocodile social environments dictated by male philopatry , Dryad, Dataset, https://doi.org/10.5061/dryad.mw6m905vw

Abstract

Examining the social behaviors of solitary species can be challenging due to the rarity in which interactions occur and the large and often inaccessible areas which these animals inhabit. As shared space-use is a prerequisite for the expression of social behaviors, we can gain insights into the social environments of solitary species by examining the degree of spatial overlap between individuals. Over a 10-year period, we examined how spatial overlap amongst 105 estuarine crocodiles Crocodylus porosus was influenced by season, sex and movement tactic. We discovered that crocodiles displayed highly consistent spatial overlaps with conspecifics between months and across years. Furthermore, male crocodiles that exhibited a greater degree of site fidelity displayed more stable social environments, while females and males that were less site-attached had more dynamic social environments with spatial overlaps between conspecifics peaking during the mating season. Our results demonstrate how long-term tracking of multiple individuals within the same population can be used to quantify the spatial structure and social environment of cryptic and solitary species.

Usage Notes

Baker_et_al_acoustic_telmetry_dataset.csv - The raw acoustic telemetry detections of the 174 estuarine crocodile (Crocodylus porosus) that have been tagged in the Wenlock and Ducie river since 2008. The data has been processed to remove all tag detections from outside of the period they were implanted within an inidividual and has been reformated for analysis using the 'ReadInputData' function for the VTrack R package. 

Baker_et_al_acoustic_hydrophone_location.csv - The location (latitude and longitiude) of each of the acoustic hydrophone stations that have been used as part of the Wenlock and Ducie river acoustic telemetry array. Included with the dataset is also the distance (km) that each hydrophone station is from the mouth of Port Musgrave in both eulidean (sDISTANCE) and distance along the river system via least cost paths (rDISTANCE). 

Baker_et_al_crocodile_movement_tactics.csv - The identity of each tagged crocodile, along with their assigned movement tactic and total body length (m). 

Baker_et_al_study_site_raster.asc - A 50 x 50 m raster of the Wenlock and Ducie river systems for the extent of the acoustic hydrophone array as of 2019. 

Baker_et_al_study_site_cost_raster.rds - A 50 x 50 m raster of the Wenlock and Ducie river systems for the extent of the acoustic hydrophone array as of 2019. This raster is used to genterate the least cost utilisation distributions of crocodiles. The rivers and their tributaries have been assigned a value of 1, and non-crocodile movement habitat have been assigned a value of 1000, indicating that it is 1000 times more difficult to move through non-habitiat than habitat for least cost trajectory analyses.

Baker_et_al_line_file - A folder containing the eight individual files which create the spatial lines file of the Wenlock and Ducie river systems for the extent of the acoustic hydrophone array as of 2019.

Funding

Australian Research Council, Award: LP140100222