Amphibians in the Landscape

Amphibians are often overlooked in the grand scheme of landscaping; however, in Pennsylvania there are more than 30 species of amphibians, many of which become active this time of year in our gardens, neighborhoods, and parks.  Amphibians are fascinatingly complex creatures, sensitive to many of the changes we make in the landscape regularly. In the world of sustainable landscaping, we are stewards of the land, and as such, we should protect and encourage habitat for these unique animals.

Double lives

Eastern Newt

The “Eastern” or “Red Spotted” Newt is a common amphibian in specific habitats of the Pennsylvania landscape.

In Pennsylvania, the Amphibian class consists of what we more commonly recognize as frogs, toads, salamanders, and newts. It is the duality of these creatures’ lives that makes them such a unique class. Amphibian literally translates to “both lives” or “two lives” in Latin, referring to the animal’s life spent partially in water and partially on land.  Amphibian eggs are laid in water and when they hatch, they resemble fish- legless and breathing through gills. As they grow, they develop legs and live predominantly on land.

The skin on their backs

Through metamorphosis, adult amphibians develop thin skin that must remain moist. Some amphibians produce a slimy secretion to keep the skin moist; others must keep it wet through contact with water. This thin skin allows oxygen to enter through the skin and go directly into an amphibian’s bloodstream. It also enables amphibians to breathe underwater, although they can use their lungs to breathe on land. They also absorb water through their skin instead of drinking it through their mouths.

Because of their ability to absorb air and water through their skin, amphibians are sensitive to pesticide and fertilizer pollutants. Some of these chemicals may kill the animal directly, while others cause issues with reproduction or even birth defects.

5 things you can do to protect amphibians

  1. Stop or minimize pesticide use– Ideally, we want to eliminate all pesticide use to reduce the chance of our amphibian friends absorbing it through their skin. Sometimes extreme problems do require remedy, though. If the problem cannot be solved by improving cultural conditions, then look for organic or biological solutions. Whether you choose the organic route or the chemical route, always follow label instructions.
  2. Reduce fertilizer- Synthetic fertilizers can be just as damaging to amphibians as some pesticides. Consider whether you really need fertilizer before applying it to lawns, beds, or trees. If you are not sure, get a soil test done. In most lawn and garden scenarios, a light application of rich compost improves the soil condition and provides a slow release of nutrients. Most large trees are self sufficient at picking up nutrients and may only require help if extreme changes to the land have occurred nearby.
  3. Stop mowing around ponds and along streams– If you are fortunate enough to have a body of water on your property (natural pond, stream, or man-made pond) amphibians are sure to find it and make use these wet conditions. However, amphibians are commonly preyed upon by birds, so if they don’t have sufficient cover, they may be less likely to stick around. Habitat loss is a significant factor in amphibian decline.
  4. Allow water to remain on parts of property– Frogs, toads, and salamanders require standing water in the spring to lay their eggs. Fish will eat these eggs, so amphibians prefer to occupy water without fish. These locations may include marshes, swamps, and “vernal pools”- ponds that exist in the spring, but dry up in the summer. If you have a property with any of these features, avoid filling or draining it and embrace it as a unique asset to your property.
  5. Protect canopy trees and plant additional trees– Similar to reptiles, amphibians do not create their own body heat, so they are sensitive to changes in weather temperatures. Keeping water temperatures cool by shading water with trees is very helpful. Additionally, some amphibians, like Spring Peepers can actually climb trees for protection and food.
  6. EXTRA– Continue learning more about amphibians and their habitat. The lack of knowledge in regard to these creatures is considered one of the biggest threats to their populations.

Remember, sustainable landscaping is a holistic approach to the landscape and the actions we take are connected to more than we might imagine. Making thoughtful decisions on how to manage the land will not only benefit the plants and animals we intend to help, but will also forge a deeper connection within ourselves to our environment.

If you are interested in studying amphibians up close, consider participating in the Pennsylvania Amphibian and Reptile Survey (PARS). This state-wide survey asks volunteers of all experience levels to collect information and photos of local amphibians and reptiles. You can sign up on the PARS website to become a volunteer or get started at the upcoming workshop at Bowman’s Hill Wildflower Preserve in New Hope, PA on March 29th, 2014. Pre-registration for the workshop is recommended.

Please look for future “Field Notes” on amphibians who call this area home. If you would like to read more now, these online resources may be helpful:

Review of Status in Pennsylvania, Pennsylvania Biological Survey

Physiological Description of Amphibians in bullet points, Sam Houston State University

Negative impact of fertilizers and pesticides on amphibians, Oregon State University

Why do amphibians have thin moist skin, Paw Nation

Characteristics of Amphibians, Buffalo Zoo