This is additional observation records of 1970 of a breeding pair of Jungle Crow Corvus macrorhynchos and chiefly supplements the lack of 1969 observations in early incubation period. 1. In 1970, probably the same pair remained in the same territory of 1969. On March 27, the female was found incubating, unexpectedly in a Ligustrum about several meters from the ground, not high up in the big gingko tree as in the previous year. 2. In early incubation period (2nd-3rd days), the incubation rate of the female was 68-70%, with average 20 minutes sessions and 7-8 (longest minutes 16, 22) minutes recessions. In a case of middle incubation period (14th day), the rate increased to 75%, with 15-42 (av. 29.3) minutes cessions and 5-10 (av. 7) recessions. In later period (19-20th days), in short evening observations, the incubation rate further increased to 76-86%, with 15-32 (av. 19) minutes sessions and av. 2-3 minutes recessions. 3. The trespass intrusion over territorial border of wandering, apparently young, pairs or solitary crows were frequent, especially during early incubation period. These were not so strongly defended (often only watched by male), but those intruded over territory within about 400m from nest site were positively chased away by male with cooperation of female, and once, when the female was away from the nest, a crow succeeded to thrust himself deep to the center of territory attracted by old (1969's) nest in gingko tree, but was violently attacked by female and chased away by male (see Kuroda, Misc. Rep. Yam. Inst. Nos. 37/38: 548). 4. The territory trespass of wandering crows was most frequent during the morning and in total 9 cases of 21 birds on March 28 and 6 cases of 11 birds on March 29 were recorded during 7.30-12.08 a. m. (278min.) and 6.45-9.07 a. m. (137min.): therefore 1.98 times and 2.64 times per hour respectively. But at noon, March 29, 12.40-15.42 p. m. (182min.), there was only one case of trespassing. 5. On April 9 (14th day of incubation), there were still 4 cases, 6 birds of trespassings, during 5.05-7.01 a. m. (116min.), 2.04 times per hour, but no case was observed on May 1 (14 days after hatching) between 8.45 a. m. -12.02 p. m. (197min.) and only 2 cases on May 2, 4.45-6.29 a. m. (104min.) (1.15 times/h). 6. However, the female's defensive impulse is raised toward later incubation to nestling periods. Thus, the female would suddenly fly out of the nest, with attacking notes, to chase the intruders away, and on April 9 even flew to distant (750m. from nest) territory border. Moreover, she was observed on May 1 and 2, to chase smaller birds, the bulbul Hypsipetes amaurotis and blue-winged magpie Cynopica cyana from last year's nesting tree adjacent to her nest tree of this year. 7. On the other hand, the male, who often positively defended by pursuing trepassers, even by aerial fighting in some cases, during early incubation period when the female closely sat in nest without noticing the trespassers, got conservative in defense as the female's defensive attitude was strengthened toward later incubation period, and now he only assisted her or watched her with warning notes. He was even indifferent to trespassers if he was busy in his job of food searching. Thus, the territorial defense of the pair was well balanced to be effective according to the breeding stage, territorial maintenance and food securance in correlation with the sexual division of labor. 8. In incubation period, especially early in the morning, the male works hard for food search widely, but usually within about 400m. from the nest, to prepare stored food on buildings, under eaves of houses, or in trees (hidden by plucked leaves) and under stone (hidden by fallen leaves).
1. As appears in Tables 1-2, the number of species and individual birds sighted in the census generally shows a decreasing tendency as the census was progressing from Seocheon area where the forest is suffering a severe damage by pine needle gall-midges, through Kochang area where forests are suffering an average affliction, to Muan area which suffered a severe forest damage but it now much recovered from the affliction. In each of these areas, more species and individuals of birds are sighted in a red pine forest than in a black pine forest. In general, more species of birds are sighted in October than in November because of the arrival of transients, while in November large flocks of a few species of winter visitors arrive in the census areas for wintering showing a high population density. 2. Typically dominant species in the census areas are the 6 species of permanent residents-Great tit, Jay, Turtle dove, Crow tit, Yellow-throated bunting and Greenfinch; the 3 species of winter visitors-Siskin, Brambling and Golderest; and several species of transients such as Dusky thrush, Tristram's bunting and Chestnut bunting. These dominant species of birds have a feeding activity closely related to pine needle gall-midges. A survey of insectivorous birds previously conducted by Ko et al. in 1969 reports that the majority of these bird species feed on pine needle gall-midges also. 3. Jay is dominant in red pine forests and Greenfinch is dominant in black pine forests. 4. Early morning plot censuses usually sight more species and individual birds than plot census carried out later in the morning.