Reproductive biology

Short-beaked echidnas are sexually mature at five to seven years of age. Courtship and breeding occur during the Australian winter through spring, June to September. At the beginning of the courtship period, male echidnas abandon their solitary life style in search of a female. A group of males following a single female is called an echidna train. Courtship lasts between one and four weeks, with up to 10 males accompanying, prodding, and following a female until she is receptive. Males then compete, by shoving each other head on head, to dig a trench beside the female. When only one male remains, he completes the mating trench that prevents him from rolling over as he lifts the female and places his tail under hers, cloaca on cloaca. Copulation, which lasts between 30 and 120 minutes, is the only time that the penis is outside the body. A female mates only once during the reproductive season. After mating, males and females return to a solitary life style.

During the 22-day gestation the mammary glands of the female begin to swell and form a longitudinal pouch on the belly. In a sitting position, the female extends her cloaca and lays a single egg directly into the pouch. The 0.6 in (15 mm)

Long-beaked echidnas (Zaglossus bruijni) are believed to be solitary animals. (Photo by Tom McHugh/Photo Researchers, Inc. Reproduced by permission.)
The long-beaked echidna (Zaglossus bruijni) has tooth-like projections on its tongue. (Photo by Pavel German. Reproduced by permission.)

egg, about the diameter of 10-cent coin, has a soft, leathery shell. After 10.5 days of incubation, the young echidna, called a "puggle" hatches. Weighing only 0.0105 oz (300 mg), it takes 10 puggles to weigh as much as a 10-cent coin. There are no teats or nipples for the puggle to attach to. It clings to the hairs on the mother's belly with minuscule but well developed front limbs. Milk is suckled from the milk patches, areolae with specialized hairs, located anteriorly and on either side of the pouch. The puggle remains in the pouch for about 50 days and increases its body mass 85,000%. When too large to carry, the female leaves the young in a secure nursery burrow and returns for two hours every five days to suckle it. At weaning, seven months of age, the young weigh 1.7-3.3 lb (800-1,500g), depending on the size of the mother. There is no mother/offspring relationship after weaning. Young leave the natal area at about one year of age and travel up to 25 mi (40 km) to establish a home range. Most sexually mature females produce only one young every three to five years.

There have been no observations on the reproductive ecology of long-beaked echidnas. Their urogenital systems are identical to Tachyglossus and their reproductive biology is believed to be similar. No one has ever seen a pouch or burrow young Zaglossus in the wild and there are no specimens of young in world museum collections.

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