---
title: "What the sources say about the Timber Rattlesnake | AnimalTracks.wiki"
description: "47 claims from the Timber Rattlesnake profile, each beside the words of the source that backs it."
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---

# What the sources say about the Timber Rattlesnake (*Crotalus horridus*)

> 47 claims from the Timber Rattlesnake profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Timber Rattlesnake](https://animaltracks.wiki/animals/timber-rattlesnake/)

## Timber rattlesnake. Smithsonian's National Zoo.

https://nationalzoo.si.edu/animals/timber-rattlesnake

| The page says | The source says |
| :--- | :--- |
| Forested hills, swamps and river floodplains across the eastern United States | Timber rattlesnakes live in a variety of habitats, including mountainous or hilly forests, hardwood or pine forests, swamps and river floodplains (note: stats.habitat) |
| Mice, shrews, chipmunks and squirrels, plus birds, lizards and amphibians | primarily eat small- to medium-sized rodents, such as mice, shrews, chipmunks and squirrels. They also eat birds, lizards and amphibians. (note: stats.diet) |
| The timber rattlesnake is a large, heavy-bodied pit viper that hunts by waiting. | Like other members of the pit viper family, the timber rattlesnake has a large, heavy-bodied appearance. (note: also large heavy-bodied) |
| strikes, bites and injects venom | quickly striking, biting and injecting venom into passing prey |
| Its meals are mainly small to medium rodents like mice, shrews, chipmunks and squirrels, with birds, lizards and amphibians as extras. | primarily eat small- to medium-sized rodents, such as mice, shrews, chipmunks and squirrels. They also eat birds, lizards and amphibians. |
| Adults typically reach 2.5 to 5 feet (0.76 to 1.5 meters), and there are reports of snakes up to 7 feet (2 meters). | Adults typically reach lengths of 2.5-5 feet (.76-1.5 meters), but there are reports of timber rattlesnakes growing up to 7 feet (2 meters) long. |
| The rattle is made of loosely attached keratin segments, the same substance as human hair and fingernails. | Loose sections of the tail made of keratin (the same substance as human hair and fingernails) form the characteristic rattles or "buttons" at the tip of the timber rattlesnake's tail. (note: DEC: loosely attached segments made of keratin) |
| A young snake has just one button | Young rattlesnakes resemble adults, except that they have only one button on their tail |
| When threatened, the snake props itself up and shakes the rattle, and the segments press together with a rapid, crisp sound. | When threatened, it props itself up and shakes its rattle, which presses the buttons together producing a rapid, crisp rattling sound. |
| That sound is a warning before a strike. | The sound serves as a warning before the snake strikes. |
| The National Zoo calls it more docile than other members of its family, and likelier to stay motionless when found. | the timber rattlesnake is more docile than other members of its family and is more likely to stay coiled or stretched out, motionless when encountered in the wild |
| Timber rattlesnakes range across the eastern half of the United States, from eastern Kansas and Texas to Georgia, the Carolinas and New England, and from New York to northern Florida. | Their range extends from eastern Kansas, Texas, Iowa and central Wisconsin to Georgia, the Carolinas, West Virginia, western Virginia, Pennsylvania and New England. Timber rattlesnakes can be found as far north as New York and as far south as northern Florida. |
| They hibernate in crevices on or just under the ground | In the winter, they hibernate in crevices found on the ground or slightly underneath. |
| The IUCN rated the species Least Concern in 2007 | As of a 2007 analysis, timber rattlesnakes are listed as a species of least concern (note: 2007 assessment) |
| New Jersey saw a 50 to 66 percent population decline | in New Jersey the timber rattlesnake experienced a 50-66% population decline |
| the species is regionally extinct in Canada | This species is regionally extinct in Canada |
| Adults typically measure between 2.5 and 5 feet long (0.76 to 1.5 meters), according to the National Zoo, though some have been reported at up to 7 feet (2 meters). | Adults typically reach lengths of 2.5-5 feet (.76-1.5 meters), but there are reports of timber rattlesnakes growing up to 7 feet (2 meters) long. (note: FAQ) |
| A timber rattlesnake that feels threatened raises its body and shakes its tail, knocking the keratin buttons of the rattle into each other. | When threatened, it props itself up and shakes its rattle, which presses the buttons together (note: FAQ) |
| It sits in the brush, waits for prey to pass, then strikes, bites and injects venom. | capture prey by waiting patiently in the brush, and then quickly striking, biting and injecting venom into passing prey |
| and in some places they gather in dens under rocks. | In other parts of their range, they congregate in dens underneath rocks |
| The National Zoo describes the sound as a warning before the snake strikes. | The sound serves as a warning before the snake strikes. (note: FAQ) |
| From Kansas to Florida, and gone from Canada | This species is regionally extinct in Canada (note: heading) |
| A warning first, then venom | The sound serves as a warning before the snake strikes. (note: heading) |
| To warn. | The sound serves as a warning before the snake strikes. (note: FAQ) |

## Crotalus horridus. Animal Diversity Web.

https://animaldiversity.org/accounts/Crotalus_horridus/

| The page says | The source says |
| :--- | :--- |
| The big eastern pit viper that senses heat, waits in ambush and rattles a warning first | timber rattlers are pit vipers. This means they have heat sensitive pit organs (note: tagline; ambush and warning below) |
| Heat-sensing pits between nostril and eye that detect very slight changes in temperature | heat sensitive pit organs located between the nostrils and the eyes. They are sensitive to radiant energy and can distinguish very slight changes in temperature. (note: stats.superpower) |
| It swallows its prey whole once the venom has killed it. | The prey is killed when bitten because the snake injects venom. Timber rattlesnakes wait until the animal is dead then swallows prey whole. |
| Timber rattlers are pit vipers, with heat-sensitive pit organs between the nostrils and the eyes that can tell very slight changes in temperature apart. | timber rattlers are pit vipers. This means they have heat sensitive pit organs located between the nostrils and the eyes. They are sensitive to radiant energy and can distinguish very slight changes in temperature. (note: blockquote) |
| A snake that senses heat | heat sensitive pit organs (note: heading) |
| Heat sensor | heat sensitive pit organs (note: blockquote lead) |

## AnAge entry for Crotalus horridus. Human Ageing Genomic Resources, AnAge.

https://genomics.senescence.info/species/entry.php?species=Crotalus_horridus

| The page says | The source says |
| :--- | :--- |
| AnAge lists an average adult weight of 1,000 grams, about a kilogram. | Adult weight 1,000 g (note: listed under 'Life history traits (averages)') |
| AnAge's maximum longevity figure is 30.2 years, for a snake in captivity. | Maximum longevity 30.2 years (captivity) |
| weightKg: 1 | Adult weight 1,000 g (note: battleStats; Light class) |

## Timber Rattlesnake. New York State Department of Environmental Conservation.

https://www.dec.ny.gov/animals/7147.html

| The page says | The source says |
| :--- | :--- |
| In New York, where the record is 60 inches, it is the largest venomous snake. | the timber rattlesnake is the largest venomous snake in New York. The record length in New York is 60 inches. |
| New York's DEC says an adult's average lifespan may be 15 to 20 years | once they reach maturity, the average life span may be between 15 and 20 years (note: current DEC page replaces AnAge's 16-22, which cites an older DEC text [0440]) |
| a new segment is added each time the snake sheds its skin | A new segment is added to the base of the rattle each time the snake sheds. |
| Segments also break off, and a full rattle is rarely seen. | Snakes with a complete rattle are rarely seen-segments regularly break off during the year. |
| some wild ones are known to have lived beyond 50 years | individuals being documented to have lived for more than 50 years in the wild (note: FAQ) |
| a snake that survives to maturity may live 15 to 20 years on average | once they reach maturity, the average life span may be between 15 and 20 years (note: FAQ) |
| Juvenile deaths run very high | Juvenile mortality is very high |
| some wild snakes have been recorded past 50 | individuals being documented to have lived for more than 50 years in the wild |
| Many die young. | Juvenile mortality is very high (note: FAQ) |

## Rokyta, Wray & Margres (2013). The genesis of an exceptionally lethal venom in the timber rattlesnake (Crotalus horridus) revealed through comparative venom-gland transcriptomics. BMC Genomics.

https://doi.org/10.1186/1471-2164-14-394

| The page says | The source says |
| :--- | :--- |
| Some rattlesnake venoms have shifted exceptionally fast. | some rattlesnakes have undergone exceptionally rapid, dramatic shifts in the composition, lethality, and pharmacological effects of their venoms |
| Timber rattlesnake venom generally causes bleeding (it is hemorrhagic), but populations along the southern edge of the range carry highly lethal, neurotoxic venom instead. | generally has hemorrhagic venom, but populations along the southern edge of their range express highly lethal, neurotoxic venom (note: Discussion) |
| A 2013 study of one snake from northern Florida found its venom glands made almost none of the two major classes of bleeding toxins. | almost complete loss of expression of the two major classes of diverse hemorrhagic toxins (note: one animal sequenced: 'we sequenced the venom-gland transcriptome of an animal from this population'; population from northern Florida) |
| The venom itself varies. | Such shifts have occurred within species (note: also 'generally has hemorrhagic venom, but populations along the southern edge') |

## Hammerson (2007). Crotalus horridus. The IUCN Red List of Threatened Species 2007: e.T64318A12765920.

https://doi.org/10.2305/iucn.uk.2007.rlts.t64318a12765920.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). (note: conservationStatus; assessed 2007; category read via GBIF copy of the Red List) |