Observations on freeliving, lactating echidnas, Tachyglossus aculeatus (Monotremata: Tachyglossidae), and sucklings.

Abstract

The diameters of home ranges of a lactating Tachyglossus aculeatus multiaculeatus and of two T. a. aculeatus were 425 m, 600 m and 800 m respectively. The nurseries of two of these animals were discovered; one consisted of a short burrow underneath the mound of a termite Nasutitermes exitiosus, the other was a burrow system in a mound of earth and garden refuse. The body weight of the young found under the termite mound increased from 206 g to 566 gin 54 clays, exhibiting an estimated total milk intake of 998 ml, ie. a weight increment of 0.36 g ml-1 milk consumed. The body weight of the other young increased from 1.058 kg to 1.210 kg over a period of 41 clays; milk intake was 581 ml, a weight increment of 0.26 g ml-1 milk consumed. Intervals between sucklings for this young were 5-10 days. During these intervals the female travelled minimum distances of over 2 km. At one of the sucklings a minimum of 190 g milk was ingested. The temperature of the nursery varied from 14 to 23°C. The young of the third female was not discovered, but since her milk, as far as total solids, whey proteins, iron content and fatty acid complement were concerned, was normal for at least 18 days after initial capture, it was concluded she was suckling a young one. In addition to the above, two other suckling T. aculeatus were found. One (body weight 474 g) was living in a burrow but was not visited by its mother during a period of observation lasting 16 days. For most of that time it was torpid; the temperature of the burrow varying from 7.2 to 14.0°C. The other suckling was discovered in an artificial mound of pinewood shavings and chips. Since this nursery was ruined the animal was taken into captivity; it was infested with ticks (Aponomma concolor) at various stages of engorgement.