“I Used To See Reptiles and/or Amphibians Often, But No Longer Do! Why Is This?”

One of the common questions we are asked both in person at events and outreach, and online is “I used to see, or have reptiles or amphibians often, but now no longer do”, or to some variation or extent of this topic. Why is this? Are populations still doing alright? Are they threatened or endangered?

Part of this question might stem from our human tendency to try to find explanations or deeper meanings and analysis to the things we don’t fully know or understand. However, without knowing more specific details or information about each local area or population, it can be hard to say or generalize what factors may or may not be taking place when it comes to wild, or native populations of reptiles and amphibians. However, there can be several possible reasons why there may be local declines or changes to herptile populations.

1. Lack of Observation: Many species of reptiles and amphibians are secretive and cryptic animals which seldom make noise or which might not always be readily detectable. We oftentimes tend to be much more observant of the natural world around us during our childhood, but become increasingly busier as our lives and lifestyles change. In many cases, herps may still be there; we have just become less observant of them over time or are not actively looking for them.

2. Changes in Local Populations: Another reason why we might not always observe herptiles with the frequency that we used to might have to do with natural population changes or fluxes, whether due to changes or modifications in habitat, food, or other resource availability over time. The reasons for these population shifts are not yet always readily known or understood, and continue to be in need of further scientific study and analysis.

3. Increased Human Influence or Chemical/Pesticide Usage: A third possible factor could have to do with increased human expansion and development, and/or chemical and pesticide usage. Increased road mortality, overcollection, and even outright persecution can all certainly take their toll on many native herp populations. However, without knowing more specific details or information about the localized area, or without further study, it can be difficult to say for sure whether these issues are the case or are at play. Some species are sensitive to human activity and influence, and can quickly decline or disappear in the face of human expansion, while other species can still be common and ubiquitous, being able to persist and thrive even in heavily urbanized areas.

4. Differences in Yearly Weather Patterns and Phenology: A fourth reason for possible declines or fluctuations in native herptile populations might have to do with yearly differences in weather patterns and phenology. For instance, if there happens to be generally a cold or snowy spring, this can push back herp breeding activity and emergence, or cause everything to simply happen later than expected. Likewise, if we get an unusually warm, summer-like spring in general, this can expedite the phenology and breeding periods and cause everything to happen much earlier than anticipated. Some species, such as wood frogs, tend to also have relatively short breeding or emergence windows of only a couple weeks before they finish calling and reproducing for the year and begin to disperse to their summer habits and habitats.

In these cases, they are likely still present; we just may have missed their peak activity and breeding season.