OUTDOOR CORNER: CALLS OF THE WILD: SPRING KICKS IN REPRODUCTIVE INSTINCTS

Shadows or no shadows, Groundhog Day has come and gone. Whether or not we'll have six more weeks of winter or an early spring is debatable. However, nature affords us one certainty; the emergence of a groundhog (woodchuck) from its hibernation burrow is a sure sign that the mating season has begun.

For the hundreds of animal species that breed in Missouri, the mandate of spring is the same: to replicate themselves. The wonder lies in the diversity of the process, the myriad ways in which our animals accomplish that mandate, often in spite of daunting obstacles. Each species has its own method of courtship and breeding, a ritualized strategy for survival so deeply embedded in the genes that no individual has to figure out how it ought to proceed.

Why does one animal choose a particular mate over others? How does one advertise his or her availability? And how does one accept or reject explicit overtures? Such questions surround the courtship of animals.

Courtship behavior, or courting, as it refers to humans, occurs before mating. For many bird species, song appears to serve as the inducement to mating. Others depend primarily on visual signals, as our late February breeders the Spotted and Tiger Salamanders. Still others use a combination of sight and sound: Canada Geese and American Woodcocks, also late winter breeders, are in this category.

Undoubtably, one of Missouri's most endearing February courtship displays is that of the Spotted Salamander where they may number in the hundreds in a single pond. During their aquatic courtship, two or more salamanders go through a series of movements known as "liebesspiel" or "love play." This takes place at night in shallow water where the males walk and swim around, gently nudging the females. A male may swing his head form side to side near a female, or nudge her at the base of her tail. Eventually, the female will move forward and pick up a packet of sperm left by one of the males -- evidence that making all the right moves can really count.

Often courtship displays accent striking features of an animal's physical characteristics or appearance. The strutting male Ruffed Grouse performs a grand show of sight and sound by strutting and running to attract mates. Drumming is usually performed on a log where the accelerating and decelerating sound is produced by rapid forward and upward strokes of the wings. Relentless in their pursuit, male Ruffed Grouse also strut back and forth in front of females, tail fanned, neck ruff feathers and crest erect.

The conspicuous, labored flight displays of the male Red-winged Blackbird exaggerate his red shoulder patches. Males will perch elevated on cattails with tails fanned, wings drooped, feathers fluffed, colored patches raised and leaning forward with their head pointing down, singing for a prospective mate. Interestingly, studies have revealed that female Red-winged Blackbirds choose males with the largest and brightest patches.

On the other hand, some male birds do not advertise with physical attributes; they demonstrate skills. One of the most complex and impressive courtship behaviors that occurs this time of year is the flight display of the American Woodcock. Males begin advertising their availability to females when they are still on the wintering ground through aerial maneuvers above the female that end in flight resembling that of a falling leaf. The male will alight on the ground and walk stiff-legged to the female. On the breeding grounds, this fantastic spectacle can often be witnessed at dusk, or by the light of a full moon.

As mentioned earlier, Canada Geese begin searching for mates in February. A courting male Canada Goose holding his head one inch off the ground, bill open, tongue raised, hissing loudly, quills shaking will approach a female. If the female proves receptive to his provocative advancements, she will permit him to pass his neck around hers. Consequently, a long-term pair bond between the two will ensue.

The assessment, or sizing up, of a male by a female is made possible if a male can convince a female that he is a good choice. Some scientists have suggested that courtship feeding may be important in this respect. In many birds, for example, males may provide food for the female during courtship which is crucial to the successful development of her eggs. Food is a resource which often limits a female's capacity to make eggs.

During courtship females may choose whether or not to mate with a male on the basis of his ability to provide food. In the endangered Least Tern, a male will exhibit his ability as a parental provider by displaying a fish in his bill, whereupon he will be chased upwards by one to six other birds. After this harassment, if he manages to retain possession of the fish, he will glide down and present the food item to the receptive female. Pairs often break up during the courtship feeding period and it is possible that females are assessing their mates and rejecting poor partners.

In some cases, courtship behavior can function for more than ensuring that an individual selects the best available mate. May courtship signals are designed for species identification, since a male an female will both benefit by mating with a member of the same species. Some of the clearest examples of this role of courtship come from studies of frog calls. When several species of frogs live in the same pond, each has a distinct mating call given by the male, and females are attracted only to calls of their own species. In our native Cricket Frog, studies have shown that the female's hearing system is tuned in to the specific frequencies of the male's metallic "gick, gick, gick" call.

Males must usually display to females to obtain them as mates and courtship can be regarded as a contest between male salesmanship and female sales scrutiny. Given a choice of potential mates, females should choose the most fit, but often the only evidence they have of a male's fitness is his courtship behavior. Any of this sound familiar?

Amy Salveter is a natural history regional biologist for the Missouri Department of Conservation.