By Jon Friedman
(This updated and expanded article was originally published in a 2012 newsletter.)
We sometimes hear from customers who ask if hummingbirds can empty a full feeder overnight. We explain to them that hummers are asleep all night, not out foraging. What they are experiencing is nectar-eating bats. There are three species of bats that are known to frequent, and usually empty, nectar feeders in a single night. These bats are somewhat common in selected regions of the southwest, particularly in areas that border Mexico. Two of the species, the Mexican Long-nosed and the Mexican Long-tongued Bats, are frequent visitors to backyard feeding stations in our region.
One is considered critically endangered and the other is considered seriously threatened. This means that continued habitat fragmentation and habitat loss are major reasons for their declining numbers. Critically endangered means that in the next several years, perhaps in as few as ten, extinction may be what they are facing. There are also several other explanations which may contribute to their perilous demise. But, whatever we can do to help support bat communities, we should do. Nectar eating bats do not use bat houses but feeding them with nectar feeders makes their lives a little easier. For insectivore bats (bats that consume insects as the staple in their diet) providing housing is a big help in conserving their numbers.
From late July till close to the end of the year, nectar eating bats are present in some regions of the border states. While they may be present in smaller numbers at other times of the year, at the height of their season, they consume as much as 90 ounces of nectar each night from my backyard feeders. I, and many others, am more than happy to accommodate these bats. They are very important to our environment and the desert landscape. As they are the major pollinators and propagators of many of the plants that symbolize the Sonoran Desert, their eventual extinction will have a terrible effect on the total ecology of the region. So, we gladly give them all the nectar they can slurp.
They cannot hover as long or as well as a hummingbird, but they can hover long enough to get their long tongues into the feeder for a quick slurp. The larger the food ports, the easier it is for the bats to access the nectar. Feeders that have very small food ports don’t discourage them, it just makes it harder for them to use efficiently. Smaller food ports usually mean more of a sticky mess. So, to keep the feeders relatively clean, but more so for their ease of use, I prefer and encourage others to use larger capacity feeders that feature larger food ports.
There is no single best feeder to use in attracting and feeding bats. I have found larger capacity pan-type feeders (flat bottomed with the reservoir of nectar below the food ports) less prone to becoming a sticky mess. Most pan-type oriole feeders are designed with larger than standard nectar food ports and do not leak, drip or spill nectar. The bats’ large gauge tongues easily get coated with nectar. While they will find and use any nectar feeder, I discovered years ago that the Dr. J.B.’s line of larger capacity gravity-fed nectar feeders might actually be the best. They come in several sizes, up to 80 ounces, and are equipped with standard hummingbird food ports that can be taken out for nighttime use, thereby giving the bats larger ports and easier access.
If you have other nectar feeders you want to convert into bat feeders, this can be easily accomplished with little effort. Pan-type feeders always make it easiest for bats to use without making a huge mess. Pan-type feeders provide complete top access without them having to navigate around a bottle at the top of the feeder. Enlarge the food ports by using a ¼” or 3/8” drill bit to provide the easiest and cleanest access. Be sure to file or scrape any remaining sharp material under the food port after using the drill. We don’t want any bats cutting their tongues. I have done this successfully with Aspects’ 16-ounce Excel and 12-ounce Ultra models.
While hummingbirds, orioles, bats, butterflies and bees all share the same natural nectar sources in the wild, it is very important to be sure your hummingbirds are fed real nectar. They have fragile bodies and unique, very high metabolisms. The other pollinators can metabolize sugar water fairly efficiently. Hummers always function at peak levels when they utilize nectar, whether in the wild or at our feeders. So, either high quality nectar or plain sugar water in a 5 or 6 to 1 ratio will prove very appealing to nectar eating bats.
For further information, read our articles on bats or feel free to contact us.