Data from: Africa’s overlooked top predator: towards a better understanding of martial eagle feeding ecology in the Maasai Mara, Kenya
Data files
Mar 07, 2024 version files 25.52 KB
-
groundtruthedkills.csv
8.99 KB
-
martialeagleweights.csv
384 B
-
NBdates.csv
905 B
-
README.md
6.71 KB
-
reportedkills.csv
3.61 KB
-
trainingdata.csv
4.91 KB
Abstract
Raptors exert top-down influences on ecosystems via their effects on prey population dynamics and community composition. Most raptors are sympatric with other predators, thus complicating our understanding of their relative influence in these systems. Estimates of kill rates and prey biomass recycling have been used as predation metrics that allow quantitative comparison among species and assessment of the relative role of single species within complex food webs. Few studies have produced findings of kill rates or prey biomass recycling for raptors. We used a supervised machine learning algorithm to behaviourally classify high resolution accelerometer informed GPS locations of tagged adult non-breeding martial eagles Polemaetus bellicosus in the Maasai Mara region of Kenya to estimate kill rates and prey biomass recycling. Eagle locations classified as feeding were clustered using distance and time thresholds to identify kills and calculate kill rates. Identified kill sites were quickly ground-truthed to confirm kills and identify prey species. We estimated kill rates for martial eagles at 0.59 kills/day for males and 0.38 kills/day for females, and we estimated biomass recycling per ground-truthed kill at 1796 g for males and 3860 g for females. From our sample of identified ground-truthed kills, “gamebirds” was the most frequently recorded prey category for male eagles and “small ungulates” was the most frequently recorded prey category for female eagles. These results position martial eagles close to sympatric mammalian top predators in trophic pyramids and provide evidence for their classification as a top predator.
README: Africa’s overlooked top predator: Towards a better understanding of martial eagle feeding ecology in the Maasai Mara, Kenya
https://doi.org/10.5061/dryad.v15dv423j
This dataset contains raw data that were collected and used for the manuscript entitled "Africa’s overlooked top predator: Towards a better understanding of martial eagle feeding ecology in the Maasai Mara, Kenya".
Description of the data and file structure
There are 5 CSV files in this dataset.
martialeagleweights.csv - The file contains the weight of each martial eagle used in this study to estimate sex-specific martial eagle weights.
reportedkills.csv - The file contains each kill that was reported to us with the correct time and location requirements.
groundtruthedkills.csv - This file contains the information on each of the algorithm identified kills that our team ground-truthed in the field.
NBdates.csv - This files contains the start and end dates for the non-breeding season periods for each martial eagle used in this study.
trainingdata.csv - This file contains the observer recorded behaviorally classified transmitter data that we used to train our behavioral classification model.
How these data were collected and used is described in detail in the manuscript. We have not made the raw transmitter data used in this study public in Dryad as it contains sensitive information on an endangered species, but it is available upon request, and we can provide access via Movebank (Movebank study ID: 170240210).
#########################################################################
DATA-SPECIFIC INFORMATION FOR: martialeagleweights.csv
1. Number of variables: 3
2. Number of cases/rows: 21
3. Variable List:
* martial_eagle: martial eagle individual ID as per Movebank
* sex: sex of the martial eagle (male/female)
* weight_grams: weight of the martial eagle in grams
4. Missing data codes: None
5. Specialized formats or other abbreviations used: None
#########################################################################
DATA-SPECIFIC INFORMATION FOR: reportedkills.csv
1. Number of variables: 13
2. Number of cases/rows: 31
3. Variable List:
* kill_ID: ID number given to each reported kill
* observer: individual that reported the kill
* date: date the reported kill was observed (mm/dd/yyyy)
* time: approximate time the reported kill was observed (hh:mm or morning/midday/afternoon/evening)
* martial_eagle: martial eagle individual ID that made the reported kill as per Movebank
* sex: sex of the martial eagle that made the reported kill (male/female)
* kill_species: common name of kill species identified by the observer
* age_kill_species: age of kill species identified by the observer or through photos
* location_description: rough location of the reported kill described by the observer
* latitude: estimated latitude in decimal degrees where observer reported the kill rounded to 1 decimal point as the study species is endangered
* longitude: estimated longitude in decimal degrees where observer reported the kill rounded to 1 decimal point as the study species is endangered
* pictures_taken: confirmation on whether the observer took pictures of the reported kill (yes/no)
* kill_detected: confirmation on whether the algorithm detected the reported kill (yes/no)
4. Missing data codes: None
5. Specialized formats or other abbreviations used: None
#########################################################################
DATA-SPECIFIC INFORMATION FOR: groundtruthedkills.csv
1. Number of variables: 12
2. Number of cases/rows: 96
3. Variable List:
* kill_ID: ID number given to each ground-truthed kill
* observer: individual that ground-truthed the kill
* ground-truth_date: date the kill was ground-truthed (mm/dd/yyyy)
* ground-truth_time: time the kill was ground truthed (hh:mm)
* kill_start_date: date the kill began and was identified by the algorithm (mm/dd/yyyy)
* martial_eagle: martial eagle individual ID as per Movebank
* sex: sex of the martial eagle that made the kill (male/female)
* kill_confirmed: confirmation on whether the observer confirmed that a kill took place (yes/no)
* kill_species: common name of kill species identified by the observer
* age_kill_species: age of kill species identified by the observer
* latitude: latitude in decimal degrees where observer ground-truthed the kill rounded to 1 decimal point as the study species is endangered
* longitude: longitude in decimal degrees where observer ground-truthed the kill rounded to 1 decimal point as the study species is endangered
4. Missing data codes: None
5. Specialized formats or other abbreviations used: None
#########################################################################
DATA-SPECIFIC INFORMATION FOR: NBdates.csv
1. Number of variables: 8
2. Number of cases/rows: 16
3. Variable List:
* martial_eagle: martial eagle individual ID as per Movebank
* sex: sex of the martial eagle (male/female)
* NB_1_start: start date of the first non breeding period for the individual martial eagle (mm/dd/yyyy)
* NB_1_end: end date of the first non breeding period for the individual martial eagle (mm/dd/yyyy)
* NB_2_start: start date of the second non breeding period for the individual martial eagle (mm/dd/yyyy)
* NB_2_end: end date of the second non breeding period for the individual martial eagle (mm/dd/yyyy)
* NB_3_start: start date of the third non breeding period for the individual martial eagle (mm/dd/yyyy)
* NB_3_end: end date of the third non breeding period for the individual martial eagle (mm/dd/yyyy)
4. Missing data codes: None
5. Specialized formats or other abbreviations used: None
#########################################################################
DATA-SPECIFIC INFORMATION FOR: trainingdata.csv
1. Number of variables: 6
2. Number of cases/rows: 73
3. Variable List:
* individual: martial eagle individual ID as per Movebank that was observed for the given behavioral bout
* behavior: behavior assigned to the bout as assigned by the observer in the field (feed/flight/other)
* bout: ID number given to each bout of observed behavioral training data
* start: start date and time of the observed behavioral bout (mm/dd/yyyy hh:mm)
* end: end date and time of the observed behavioral bout (mm/dd/yyyy hh:mm)
* comments: misc. notes on the observed behavioral bout
4. Missing data codes: None
5. Specialized formats or other abbreviations used: None
#########################################################################