It's widely known backyard folklore that a few pennies tossed in a bird bath will help keep the basin clean. But is it true that copper keeps a bird bath clean, and how can backyard birders be sure they are treating their birdbath appropriately?
Copper is a natural element (chemical symbol Cu), a soft, malleable metal with a lustrous red-orange color. Copper can be mined directly and does not require separating from an ore before basic uses. It is one of the first metals to have been mined and used for tools, household objects and decorations, and in fact, copper has been used for roughly the past 10,000 years. It is widely used in its pure form, as well as combined with other metals to create alloys, such as brass (with zinc), bronze (with tin, aluminum or silicon) and numerous nickel and silver alloys.
This metal is biostatic, which means that many types of algae, bacteria, and fungi will not adhere to it or grow on it. This makes copper very easy to clean and valuable for antibacterial uses because it can, to a limited extent and depending on overall conditions, self-sterilize. This unusual and valuable property has led to copper being used for doorknobs and handles in many hospitals and similar facilities.
Copper is widely found hammered, extruded, molded or melted into a variety of objects. The most common uses of copper include bowls, vases, urns, utensils, and other kitchen items, wiring, pipes, coins, jewelry, and roofing.
Effect on Birds and Bird Baths
Because of copper's biostatic properties, algae is less likely to grow in a bird bath that is either made of copper or has copper elements in its design. While algae will be repelled, however, it is important to note that copper will not completely eliminate algae and bacteria growth in a bird bath. All bird baths, even those made of pure copper, must still be cleaned regularly to remove all unwanted growths.
There is some concern about the potential for copper toxicity if birds are exposed to excess copper in their water. This condition creates vomiting, low blood pressure, jaundice and other symptoms in humans. Its effects on wildlife have not been widely studied, but there are no known complications for birds drinking or bathing in water exposed to copper. It should also be noted that extreme amounts of copper ingestion are necessary for toxicity to occur, and simply using a copper basin or having bits of copper submerged in the water are unlikely to be dangerous. Only when copper becomes oxidized and interacts with extremely acidic water is it most hazardous, conditions that are highly unlikely when using copper in a bird bath. For the safest option, any copper added to a birdbath should be fully submerged in the water to avoid any complications, while fully copper bird baths should be regularly cleaned to ensure their safety.
It must be noted that fish and marine wildlife have a much greater sensitivity to levels of copper in the water. Backyard birders who have aquatic features in their yard that nurture fish or amphibians should avoid adding any copper to those features.
Sources of Copper
There are many ways backyard birders can add small amounts of copper to their bird baths to take advantage of the metal's algae-repellant properties. Fully copper birdbaths are available in beautiful hammered or molded designs, and these baths can be stunning accents to a yard or garden. They are often more expensive than other bird baths, however, and birders on a budget may prefer to simply add small bits of copper to their existing bird baths. Popular and effective choices include:
- Pennies (US-minted before 1982; pennies after that date are mostly zinc, and zinc is much more toxic) or other copper coins
- Pipes, either vintage copper pipes or new copper pipes, fittings or joints purchased from home improvement stores
- Coils of wire bound together to create a larger block; avoid small bits of wire that would be too easy for birds to ingest accidentally
- Bullets or copper bullet casings, but avoid any lead-based ammunition that is highly toxic even in small quantities
- Pendants, chains, rings or other jewelry pieces so long as they are fully copper without other potentially dangerous metals
Any very small pieces of copper, such as individual chain links, BB ammunition or very small screws, washers or similar items should be avoided. Larger birds such as jays, crows, and other corvids may be attracted to the shiny, sparkly copper bits, and the birds can carry them away. These items can pose a choking hazard to birds and may also be dangerous if brought to nests.
Caring for a Copper Bird Bath
Regardless of whether a birdbath is made of copper, has a copper fountain leading to a larger basin or just has pieces of copper added to the basin to reduce algae growth, it still needs proper care. All birdbaths should be cleaned regularly, including wiping down rims and edges to remove any accumulated feces, dirt or other debris. Water should often be changed, especially during the hottest summer days, and steps should be taken to keep a birdbath full, so there is always fresh water available to birds.
Because copper bird baths can be more lightweight than expected, it is important to position the birdbath safely to avoid falls or tips that can damage or dent the metal. Putting a copper birdbath in a luxurious flowerbed will not only add a luxurious gleam to the setting but will also help water the flowers as eager birds splash in the basin. Avoid putting any metal bird bath, including a copper one, in full sunlight, however, as the metal will conduct heat more efficiently and become very hot to touch. While birds' feet are not as sensitive to heat, hotter water is less useful to keep birds cool and will evaporate more quickly.
Copper can be both a beautiful accent to a bird bath as well as a practical one as it helps repel algae and keep the bird bath cleaner. Why not add this stunning metal to your bird bath today?