Birds eat all kinds of foods, some of which are very appealing to our own palates, particularly things like fruits, berries, nuts, corn, and perhaps even fish, crabs, mollusks, and crustaceans. However, sushi lovers aside, most of us prefer the latter types of food in an at least partially cooked format. Then there are those birds that eat things that almost everyone finds downright repulsive.
It’s doubtful that you even know a few people who salivate at raw meat of any kind or have an appetite for insects or slimy invertebrates, let alone carrion. Sure there are plenty of people in this word that eat roadkill and other things firmly planted in the category of weird, but generally speaking we can chalk this up to cultural differences or isolated oddities of the world.
One thing that some birds are known to eat that we humans simply don’t consume, at least not for food, is wax. Wax in the general sense and naturally occurring refers to a class of organic compounds that are insoluble in water, solid and brittle when cold, solid but malleable at room temperature, and melt to a low-viscosity liquid at temperatures higher. Wax consists of long chain fatty acids and is very difficult for most organisms to digest. Apart from its limited appearance in things like chewing gum or to wrap some types of cheese, wax is not something we eat, but something for which we have found all sorts of creative practical applications. Birds can always be counted on to defy basic logic or provide exceptions to general rules, and eating wax is no exception.
Actually, there are several groups of birds that eat on purpose and can metabolize wax. Many seabirds, for example, such as petrels and razorbills, obtain energy indirectly from the wax found in the crustaceans they eat. Then there are a handful of land birds, like certain species of warblers and swallows, that gorge themselves on waxy berries. The digestive tracts of these rare birds are characterized by higher concentrations of gallbladder secretions, higher concentrations of bile salts in the intestines, and a relatively slower rate of passage of lipids acquired from food. There is also some evidence that these birds are ruminators, like cows, in that the partially digested waxy compounds somehow return to the gizzard from the small intestine for a second or third round of digestion.
Incredible as it sounds, none of these birds are eating wax directly, they are simply forced to consume it because it is an unavoidable part of the foods they prefer. Enter the Honeyguides (Indicatoridae), a family of 17 species found only in Africa and ranked in the same order as Woodpeckers (Piciformes). Quite unspectacular in appearance and basically the size of a songbird, these birds are mostly insectivorous, but are famous for their curious behavior of eating the pure wax from combs. Also, these strange birds enlist the help of honey-loving animals such as honey badgers and even humans by calling their attention to the location of a hive so that their assistant will open the hive to take the honey and leave the comb behind. waxy and bee larvae to honey guide. .
