Why keeping bird seed feeders dry is now considered best practice

Extensive research has been carried out over many years looking at disease transmission in garden birds, with a recent review of this research by the RSPB and BTO highlighting a number of key issues with bird feeders.

We’ve already covered most of these issues in detail, including the particular risk that bird tables and other types of feeders with a flat surface present – which is essentially because contaminated dropped food sits on the surface for another bird to pick up.

But what we’ll cover here is the increased risk of disease transmission, and notably Trichomonosis in finches, when feeders are wet or even just damp. This not only applies to flat surfaces but also the ports and perches of hanging tube feeders. Also covered are the risks from food becoming damp in feeders.

(If you’re not familiar with Trichomonosis, then read our detailed blog here.) Outside of a host bird, the parasite Trichomonas gallinae which causes Trichomonosis, and mainly in finches, can live for much longer in a wet environment than it can a dry one. This therefore means that the longer the parasite remains alive, the greater the risk of transmission to more birds.

A bird infected by Trichomonosis is generally unable to swallow food, so as it tries to eat it will drop food coated in saliva which contains the parasite. If this food lands on a dry surface, then it’s only the saliva which will help keep the parasite alive until it dries up. But on an already wet surface like the exposed perch of a feeder, the parasite is likely to live much longer. A further factor will be if the perch and port isn’t clean and has caked-up waste and food on and around it, as this will also hold more moisture.  

For any feeder with a flat surface which isn’t covered to keep it dry, then in wet weather conditions the risk of the parasite living longer will be considerably increased. The flat surface anyway also increases the risk of dropped contaminated food being present, as at least on a hanging tube feeder only a small percentage will end up on the perch rather than being dropped on the ground.

Trichomonosis isn’t the only disease which affects our garden birds, with others like Salmonella and E. coli potentially allowing the respective bacteria to breed in damp food in feeders which starts to deteriorate and go mouldy. Therefore, keeping food dry and fresh in feeders is also important.

We have two products which will help keep seed feeders and the food in them dry:

The first is the Droll Yankee Rain Away, which has a 63.5 mm diameter hole that will fit Ring-Pull Click, Ring-Pull Plastic, Lifetime and Bird Lovers Feeders.

The second is actually a Squirrel Baffle but will serve equally well as a rain guard. An advantage of this product is that it’s universal because it doesn’t go around the feeder, but instead the feeder hooks on underneath it – so any seed hanging feeder will work with it.  

Mesh peanut feeders will also benefit with the Squirrel Baffle fitted, as will hanging fat ball and suet block feeders – though it’s not so important to keep these dry, as the nature of the product anyway repels water to a large extent.

Dish-style feeders which have a dome top like the Robin Feeder will also keep food dry, but it’s important to note that this type of feeder requires very frequent cleaning if used for seed and seed mixes. This is firstly because a bird infected with Trichomonosis may drop food directly into the dish, and secondly husks and other waste may accumulate in the dish rather than falling to the ground as they would a hanging tube feeder.

What we’ve covered here is one of many requirements now needed for safely feeding garden birds. For information on the other aspects read our guide here.

This is also a useful guide about the risks of bird tables and other feeders with flat surfaces.