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Hummingbirds Ingest Leftover Barbecue Ash

Dear Bird Folks,

I’m sure you get your share of strange questions, but I swear I’m not making this up. The other day we saw a hummingbird in our yard, but instead of feeding from the flowers or from our feeder, it flew over to the barbecue grill and started eating the old ashes from the night before. At first we thought it must be eating something else, but no, it was clearly consuming ashes. What is going on?

– Carolyn, Orleans, MA


It’s okay, Carolyn,

Don’t ever feel bad about asking me strange questions. They are what keep us going. In fact, at closing time we often vote on the strangest question of the day, and believe me, your ash-eating hummingbird wouldn’t even make the top ten. I could share a few of the past strange question winners with you, but I don’t think it would be appropriate. Oh, who am I kidding? When have I ever worried about being appropriate? Here’s today’s winner (and yes, this is true): A guy asked if we sold mealworms for bluebirds. I said, “ Yes, we have both live and dead mealworms,” to which he replied, “What’s the difference?”

Finding out what many birds eat is a fairly straightforward process. We can easily observe geese eating grass, crows chowing down on fresh road kill, or chickadees enjoying delicious, locally purchased birdseed. But figuring out what hummingbirds eat is not so simple. Oh sure, researchers can see the birds stick their tiny beaks into flowers, but they can’t tell what the birds are actually extracting. Some have argued the birds were eating pollen, while others thought they were feeding on nectar. To test the nectar theory they caught a few hummingbirds, put them in a flight cage and gave them all the nectar they wanted. The birds instantly drank the nectar and the excited researchers yelled, “Aha! Nectar wins!” Well, nectar won for a few days, until the birds started to become sick from a lack of important nutrients. So it was back to the drawing board.

The next step was to capture some more hummers and examine their stomach contents. (Don’t ask how.) What the investigators found surprised them. Inside the birds was zero nectar, very little pollen and until last week, no Twinkies. Instead, the birds’ stomachs were packed with insects. The researchers quickly jumped to the conclusion that the birds were sucking bugs out of the flowers and had no interest in either pollen or nectar. But wait, they all saw the birds drinking nectar. Why wasn’t there any nectar in the birds’ stomachs? It turns out hummingbirds have a special digestive process and nectar is siphoned off before it reaches the stomach. Thus, it was concluded that the bulk of a hummingbird’s diet is insects, which are then washed down with a nectar chaser. It was also decided that the birds had little use for pollen. Hummingbirds left most of the pollen for the bees…and for the freaks in the health food stores.

Now that the researchers had solved the hummingbird mystery, they could move on to other more puzzling scientific topics like: How come Twinkies never go bad? And what is the difference between live and dead mealworms? But soon after the experts had figured out what hummingbirds ate, people (like you, Carolyn) reported seeing them eating ashes. At first they thought the birds must have been picking tiny insects from the ashes. But after further review, it turns out the birds were really and truly eating ash, particularly wood ash. Why? Ashes actually have some nutritional value (if the health food store freaks only knew). Ashes supply the birds with a number of important minerals, especially calcium. The majority of ash-eating hummingbirds are females, which need to replace the nutrients they lose during egg production. That’s why they are seen nibbling around our backyard grills. (If the birds want an easier way to get ashes, they should just make a batch of microwave popcorn. That always comes out burnt.) Egg production may be a drain on the females, but there is something else that depletes important nutrients from all hummingbirds and that’s their constant need to pee. Because of their high liquid intake, hummingbirds may expel as much 150% of their body mass each day and that expulsion is in the form of urine. (Hmm, maybe the rain in the rainforest isn’t just rain after all.) And in case you are wondering, the daily amount of urine expelled by us humans is only about 2% of our body mass. I have no idea who came up with that low number, but whoever it was never made a road trip with my kids. We did more stopping than driving.

Seeing hummingbirds eat ashes is indeed strange, Carolyn, but ashes are not the only strange things they eat. Observers have also seen hummers ingest seawater, sand and even good old dirt. But we should not confuse hummingbirds eating dirt with allowing them to eat from dirty feeders. (Can you sense a lecture coming?) This summer’s heat has caused the food in our hummingbird feeders to spoil quickly, so it’s important to change and clean them regularly. Feeders with black mold on them are bad for the birds. It only takes a few days for sugar water to spoil. If you don’t have the time to clean your feeders and want to give your birds something that doesn’t spoil so quickly, offer them Twinkies. They never go bad.