Dataset DOI: 10.5061/dryad.b2rbnzsrw

Description of the data and file structure

This dataset presents the data on the behavioral response of the Mexican pigmy rattlesnake Crotalus ravus to the approach of simulated predators (an overflying bird, an attacking bird, and a fox) and a human and its behavior towards a prey (mouse). All observed behaviors are included and consisted of escape, rattle, bite, freezing the body, lateral compression of the body, elevating the head, and hiding the head near or below its body. 21 snakes were tried in all tests.

Data was recorded on focal snakes. Trials with an approaching human took place in the field before capture. In the other predator trials, a stuffed fox and a silhouette of a bird approached the snake in a direct line from a distance of 300 cm, using pulleys. In the trial of the overflying bird the bird silhouette approached the snake in a horizontal line at a height of 3 m, and the attacking bird approached the snake in a dive with a 45º angle, starting at a height of 3 m at 3 m distance. In the trial with the prey, the snake was placed in a corner of an enclosure of 1.5 x 1.5 m and then a mouse was released in the opposite corner.

For each trial, the data shows behaviors presented, their frequency, the chronological order in which behaviors were displayed, and the distance from the predator or prey (i.e., the approach distance). When the snake escaped the flight distance is given. In cases of the behavioral responses body compression and rattle duration is also given. The first response is given with the reaction distance, also the first essential behavior shown is given. Essential behaviors are: escape, rattle or bite. These were so called because these important behaviors may avoid or result in an ophidian accident.

Files and variables

File: Antipredation_behavior_Crotalus_ravus.xlsx

GENERAL INFORMATION

Data from: Unpredictable aggressive defence of the venomous snake, Crotalus ravus, towards predators and humans

Behavioral data of Crotalus ravus, collected in June to October of 2011, in Maxtleca de Galeana, Estado de Mexico, Mexico (coordinates 19°1’62’’, 99°33’49’’, 2494 m asl).

DATA & FILE OVERVIEW

File List: one excel file with several data sheets

Sheet 1: data

Raw data obtained in the antipredation and predation tests on the rattlesnake Crotalus ravus.

Variables are:

ID: Individual identification number

Sex: Male or female

Test: The test in which the behavior was recorded. Antipredation behavior tests were human, bird attack, bird overflying, and fox, predation test was mouse.

Number in order of behaviors performed: The order in which the behaviors were performed; 1 = first behavior presented, 2 = 2nd behavior presented, etc.

Approach distance: The distance between the snake and the potential predator or prey at the moment the behavior was presented in cm.

Behavior: The behavior presented by the snake, consisting of bite, rattle, escape, freezing of the body, lateral compression, elevating head, and hiding head near or below its body.

Duration: Duration of the behavior in seconds. Only given for rattle, compression, and hide head. (NA = not applicable; i.e., the behavior was not displayed).

Flight distance: Distance between the location of the snake before and after flight in cm. Only given when the snake escaped. (NA = not applicable; i.e., the behavior was not displayed).

Notes: notes on the behavior of the snake in the predator test, stating whether the snake bit and killed the mouse, and whether it ate the mouse. Cells are empty when there are no notes given.

Sheet 2: Presence of the behavior

Data shows whether the behaviors was present, in which frequency, and whetehr it was the first behavior presented in each of the tests for each individual.

Variables are:

ID: Individual identification number

Sex: Male or female

Test: The test performed human, bird attack, bird overflying, fox, and mouse.

Behavior: The behavior bite, rattle, escape, freezing, compression, elevating head, and hiding head.

Present: The behavior was present (1) or not present (0) during the test with this individual.

Frequency: The frequency of the behavior during the test with this individual.

First behavior: This variable shows whether the behavior was the first behavior presented by the snake (1) or not (0).

First essential behavior: The first behavior presented when only including bite, rattle and escape. First behavior is indicated by 1, others are 0.

Temperature: Air temperature during the test. (In a few cases temperature was not recorded, indicated by NA).
 
Sheet 3: First behavior

Data shows the first behavior presented in each test per individual.

Vaiables are:

ID: Individual identification number

Sex: Male or female

Test: The test performed human, bird attack, bird overflying, fox, and mouse.

First behavior: The first behavior displayed by the snake.

First essential behavior: The first behavior displayed by the snake when only considering bite, rattle and escape.

Temperature: Air temperature during the test (°C).  (In a few cases temperature was not recorded, indicated by NA).

Sheet 4: Reaction distance 

Data shows the distance between predator or prey animal and the snake at the moment the snake showed its first behavioral response.

Vaiables are:

ID: Individual identification number

Sex: Male or female

Test: The test performed human, bird attack, bird overflying, fox, and mouse.

Approach distance: The distance between predator or prey animal and the snake at the moment the snake presented its first behavior in cm.

First behavior: Type of behavior first shown by the snake.