There are no native populations of crocodiles or alligators living in the wild of New Jersey. These large reptiles are not naturally found in the state’s waterways because environmental constraints prevent their long-term survival and breeding. Any rare appearance of a crocodilian in New Jersey results from human activity, typically the illegal release of an exotic pet.
Why New Jersey’s Climate Forbids Native Crocodilians
Crocodilians are ectotherms, or “cold-blooded,” meaning they rely on external heat sources to regulate their internal body temperature. They cannot generate sufficient body heat to maintain consistent warmth in a cold environment. Their preferred body temperature range is narrow, typically between 86 and 91 degrees Fahrenheit (30 to 33 degrees Celsius).
This reliance restricts their natural habitat to warm and tropical regions. Most crocodilians cannot survive in areas where the average temperature of the coldest month falls below 50 to 59 degrees Fahrenheit (10 to 15 degrees Celsius). New Jersey’s consistent, freezing winter conditions, which often see water bodies freeze over, make it impossible for these reptiles to thrive or breed year-round.
While the American Alligator has an adaptation that allows it to survive short periods of freezing conditions, New Jersey’s sustained winter cold is prohibitive. American Alligators, the most cold-tolerant of the group, can enter a state of dormancy. However, they cannot withstand the long-term, deep-cold temperatures required to maintain a viable population. The cumulative effect of the cold prevents the necessary growth, feeding, and reproductive activities required for permanent establishment.
Addressing the Alligator Confusion
Many people confuse the terms “crocodile” and “alligator,” which belong to two distinct families within the order Crocodylia. The American Alligator is native to the southeastern United States, with its natural range generally not extending farther north than North Carolina. The American Crocodile is more restricted, found only in the extreme southern tip of Florida.
The two can be distinguished by examining the snout shape and tooth arrangement. Alligators possess a broad, rounded, U-shaped snout. When their mouth is closed, the upper jaw overlaps the lower, concealing most of the lower teeth. Crocodiles, in contrast, have a longer, more pointed, V-shaped snout.
A primary identifying feature of a crocodile is that its upper and lower jaws are roughly the same width, causing some teeth to interlock and remain visible even when the mouth is shut. This includes the large fourth tooth on the lower jaw, which is clearly exposed on the outside of the upper jawline.
The Reality of Non-Native Sightings
The only way a crocodilian appears in New Jersey is through the exotic pet trade. Alligators are sometimes illegally kept as pets after being purchased when small, until they grow too large or unmanageable. Releasing these animals into the wild is irresponsible and a violation of state law.
New Jersey state regulations require a permit for the possession of any exotic mammal, bird, reptile, or amphibian not specifically exempted. The liberation of any exotic or non-native species into the state’s environment is strictly prohibited. This is done to protect both the public and the state’s native ecosystems from invasive species.
These illegal releases are the source of occasional, isolated sightings that make headlines, such as the four-foot alligator captured in Piscataway or one found in an Atlantic City hotel pool. These animals are typically captured by wildlife officials and either relocated to an appropriate sanctuary or zoo, or humanely euthanized, since they cannot survive the coming cold weather and pose a risk to the public.