By Doug Ottinger – Do chickens have tonsils? Can chickens get rabies? How do ducks mate? Do questions about these facts about chickens ever keep you up awake at night? If so, this article will hopefully answer these questions and give you some bits of trivia and facts about chickens and ducks to share.
Let’s look at some lesser-known facts about chickens.
Chickens have tonsils, but they are not found where yours and mine are found. Chickens and most other birds have two small, whitish-colored, finger-like projections, at the cecum, or beginning of the large intestine. Called cecal tonsils, they are part of the lymphatic system and serve as germ traps just as tonsils found in humans. There are several other areas of tonsillar tissue in various areas of the chicken’s gastrointestinal tract, but the two main units are the ones found at the cecum.
Chickens, as well as other birds, normally have very high blood-sugar levels. In lab studies, White Leghorn roosters were found to have blood-sugar readings well-in-excess of 200, after 24 hours of fasting. This would signal severe diabetes in a human, but chickens normally maintain non-fasting blood sugar levels in the 300 to 400 range. Temporary spikes of over 500 are not unknown. Chickens can get diabetes, but it is not common. The pancreas in humans, as well as chickens, makes two hormones, insulin, and glucagon. Insulin lowers blood sugar and glucagon raises blood sugar. Constant glucagon production is the main agent responsible for higher blood sugar in birds. Because of a bird’s constant activity and high metabolic rate, higher blood-sugar levels are needed.
Can chickens, or other birds, contract rabies? The first lab experiments on this were done back in 1884. Numerous studies have been conducted since then. It was found that birds did not get rabies, but the exact reasons remained unknown for many years. The rabies virus can attach to one of the specialized protein receptors in the brain cells of most mammals, including humans, causing degeneration and death of the cells. Chickens and other birds have the same specialized protein receptor in their brain cells, but it has some slight structural differences, making it impossible for the rabies virus to attach.
Are chickens musically-inclined? Chickens seem to have definite preferences for music. Some owners of backyard chickens have observed and commented on this fact for years, but now there are scientific studies to back up what they already observed and knew! In one study, baby chicks, incubated in a sound-proof incubator, were placed in a brooder, with two identical objects. Both objects had speakers attached. One played melodious, or consonant music and the other played clashing, or dissonant music. The majority of chicks immediately chose to bond with the object playing the melodious sounds.
In another study, chickens laid more eggs in nests that played classical music, versus nests that played none. Classical music and polkas seem to be the music that chickens prefer. Just don’t make it too loud, though! Studies indicate that chickens become upset with constant sounds of eighty decibels, or higher (the equivalent sound levels of a dishwasher or garbage disposal).
Okay, so chickens like music. Does it put them in a romantic mood?
That is one study I have never seen! But since we’ve moved on to this, let’s look at some anatomical facts about chickens and chicken mating. Most male birds, including chickens, do not have a penis, or phallus (as it is sometimes referred to, in birds). In chicken mating, the rooster simply jumps on top of the hen. She moves her tail to one side and everts her cloaca. He quickly positions his everted cloaca down to meet hers, and once contact is made, ejaculation takes place and seminal fluid is transferred, in what ornithologists refer to as the cloacal kiss.
Which leads us to some amazing facts about ducks.
In ducks, copulation is significantly different. Male ducks, or drakes (along with male geese, swans, and ostriches), are among the few male birds with an actual penis, or phallus. The phallus is contained inside the cloaca and is everted at the time of mating. However, the duck is one of the most unusual. The duck’s penis is coiled into a pointed mass, resembling a corkscrew. Depending on species, this organ can be anywhere from one-fourth the length of the drake (mallard ducks), or longer than the drake itself (Argentinian Pond Ducks). Ducks often mate in the water, but will also mate on land. In both cases, the drake gets on top of the hen, just as roosters do. For many years, we knew very little about the actual anatomical action of the mating. Thanks to modern technology and high-speed digital photography, researchers have been able to observe, record and measure the copulation. The duck penis everts, makes internal contact with the female and retracts, usually in less than one second total time. Among the more amazing facts about ducks; the female duck is one of the few birds that has a true vaginal tract. It twists and turns and has pockets, which means only the most virile drakes can penetrate and fertilize the eggs.
Another amazing fact about ducks is that they sleep with only one hemisphere of their brain shut down. The other half is awake and watching for predators. Studies have been, and are currently being done on this issue, in hopes of learning more about human insomnia.
We’ve addressed facts about chickens, and facts about ducks, now how about some egg facts?
Egg shells are not solid. The average chicken egg contains about nine-thousand pores. These exist for the transfer of oxygen and waste gases, to aid in the development of the baby chick. The shell of a normal chicken egg has four distinct layers of calcium. For many years, we believed that the shell pigment of brown eggs, protoporphyrin, was only on the exterior of the eggshell. In fact, I said this in a recent article. Updated research has found that bits and pieces of this pigment are found in every layer of calcium in the shell! The solid application of brown color, however, is just on the exterior.
Which end is laid first? Roughly two-thirds of eggs are laid pointed end first. About one-third are laid blunt-end first. How can this be? All eggs are formed the same way in the oviduct and move along, blunt-end first. However, shortly before laying, the eggs rotate in most hens, to a pointed-end-first position, but not always.
An egg contains four separate layers of white, or albumen. Those little white, twisted things that you see, when you break an egg open, are called chalazae. They are considered one of the albumen layers and are safe to eat. These twisted membranes attach to the yolk and each end of the egg, keeping the yolk in the center, where it belongs.
With some slight variations in individual eggs, the shell makes up about ten percent of an egg’s total weight, albumen about sixty percent, and the yolk roughly thirty percent.
What unusual facts about chickens, or other fowl, have you come across? Join in the conversation below.