-Mother-young behavior was studied in a population of free-ranging white-tailed deer (Odocoileus virginianus) in southern Texas. Fawns remained hidden and inactive for the first three or four weeks of their lives except when visited by their mothers, and siblings were maintained separately during this period. After four weeks of age, fawns remained active with their mothers for longer periods and began to appear in larger multi-family groups. The amount of nursing, both in frequency and duration, dropped sharply three to four weeks postpartum. Nursing infrequently was observed after fawns were ten weeks old. The behavior of white-tailed deer (Odocoileus virginianus) has attracted considerable attention in recent years (Hawkins and Klimstra, 1970; Moore and Marchinton, 1974; Hirth, 1977; Nelson and Mech, 1981), as biologists have tried to link the behavior of this species with a variety of ecological factors in different parts of its range. However, the mother-young relationship seldom was reported on in free-ranging animals (Michael, 1966; Jackson et al., 1972; Ozoga et al., 1982) because of the cryptic behavior of fawns and the dense cover in which they often are located. This paper describes the doe-fawn relationship in its first six months, during which fawns undergo a transition from the isolation of a strictly hiding phase, to a following phase, to gradual integration into the adult social structure. Types of doe-fawn interactions and their rates are detailed throughout this critical developmental period. Field work was conducted on the Welder Wildlife Refuge near Sinton, Texas. The refuge is in southern Texas, approximately 80 km northeast of Corpus Christi and 5 km from the Gulf of Mexico. Deer on this refuge were free-ranging; the population was not hunted. The density of deer was estimated at 0.5 per ha (Evans, 1975). Habitat at the Welder Refuge was a mixture of open grasslands and large areas of dense brush, known as chaparral. A more complete description of the soils and vegetation is provided by Box and Chamrad (1966). METHODS.-Observations using 7x binoculars and a 20x telescope were made from platforms atop 10 m high utility poles. The study area was flat, and the observation platforms made excellent vantage points enabling me to see great distances in open areas and down into the chaparral in brushy areas. My presence in these towers was seldom detected by deer. The study period lasted from May 1971 to mid-January 1972, by which time fawns were integrated into larger social units. Fawns in this study were not marked, and their ages were estimated. No fawns were seen being born or in the neonatal period immediately following birth, but observations began when some were clearly only one or two days old. Interaction rates, calculated for all doe-fawn pairs (maternal and nonmaternal) within a social group (Table 1), were expressed as interactions per pair-hour to correct for groups with different numbers of does and fawns (Hirth, 1977). Pair-hours are the numbers of different doe-fawn pair combinations in a group multiplied by the number of hours the group was under observation. The nonparametric Kruskal-Wallis test was used to evaluate differences in interaction rates over time, and the Dunn method, also nonparametric, was used to test pairwise comparisons between individual months (Hollander and Wolfe, 1973). This content downloaded from 207.46.13.112 on Mon, 03 Oct 2016 05:01:13 UTC All use subject to http://about.jstor.org/terms The Southwestern Naturalist TABLE 1.-Rates of interaction between adult does and fawns (interactions/ hr). Observation time was calculated as doe-fawn pairs multiplied by time under observation. Common superscripts within rows indicate no significant difference between rates (P>0.05).