DOI: 10.5061/dryad.b2rbnzsrw
title: Data from: Unpredictable aggressive defense of the venomous snake, Crotalus ravus, towards predators and humans

description: This dataset shows 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. 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, so called because these important
 behaviors may avoid or result in an ophidian accident.
description: Data was recorded on focal snakes during the approach of a
 potential predator or in the presence of a prey. Human trials took place
 in the field before capture, a human approached the snake at approximately
 2 km/h. 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, whereas 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. Sample size is 21 snakes.
description: # Data from: Unpredictable aggressive defense of the venomous
 snake, Crotalus ravus, towards predators and humans Dataset DOI:
 [10.5061/dryad.b2rbnzsrw](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.