In most classifications of the past century, the rails (Rallidae) have been placed in the Gruiformes with the cranes and their allies, including the Sunbittern, bustards, Limpkin, sungrebes, trumpeters, seriemas, and the Kagu. In a few classifications the rails have been assigned to an Order Ralliformes; in other classifications some taxa now usually placed in the Charadriiformes have been assigned to the Gruiformes, as relatives of the Rallidae. DNA-DNA hybridization data support other evidence that the rails are closer to the typical gruiforms than to any other group, but that they have no close relatives within the Gruiformes.
A specimen of the young flightless Okinawa Rail Rallus okinawae, endemic to Okinawa Island, the Ryukyus, was studied anatomically for the first time. This bird was obtained accidentally, and had been preserved frozen at the Educational Committee of Higashison, Okinawa, until it was sent to Abiko Bird Museum for preservation where the carcass was offered to me for anatomical study. As expected, it showed marked degeneration of pectoralo (shallow sternal keel)-humeral (short and thin) structure and well developed femoro-tibial muscles compared with a typical rail, Rallus aquaticus, as well as other species. Some anatomical details are given based on relative data of Rallina eurizonoides, capable of flight, but an insular endemic species. The Okinawa Rail is entirely terrestrial, but roosts on inclined dead trees, climbing often to a great height. This habit has apparently been developed as a fugitive reaction from terrestrial predators, especially the poisonous snake Trimeresurus flavoviridis. The Okinawa Rail seems to be further threatened by the introduced weasel Mustela itatsi and mongoose Herpestes mungo, both of which are spreading to the rail's habitat.
Calls and songs of the Okinawa Rail Rallus okinawae YAMASHINA et MANO were recorded with video camera and tape recorder in "Yanbaru", northern Okinawa Island. Vocalizations were described and analysed by sonograph and wave form; (1) Kyo call (Call I), (2) Gu call (Call II), (3) Krr calls (Solo-song I), (4) Kek duet and (5) Kek call (Solo-song II). Two birds were observed to duet without facing each other. Duetting was initiated by one bird assumed to be a male, while the other followed suit. Vocal calls then occurred either in unison or antiphonally. Each individual exhibited a distinct pattern of varied tones and interval of calls. Solo-song II resembled a duet, but each was distinct in wave form.
Roosting behavior of the Okinawa Rail Rallus okinawae was investigated by driving along the forest roads at night using powerful spotlights to locate the birds. The birds were commonly found to climb trees to roost on branches. This behavior was observed throughout the year, but declined somewhat in winter. Their preferred roosting trees were mainly chinquapin, camphor or pine that were either dead or alive. The height of the roosting trees averaged 10.6m, while the branches were 6.7m. The diameter of roosting tree trunks averaged 29.2cm, while the diameter of the branches averaged 12.7cm. The rails were found on trunks leaning at angles 30° to 80° (average 67.2°), which the birds could climb easily. Similarly, the angle of roosting branches varied from horizontal to 70° (average 27.7°). Data collected during this study suggest that roosting in the tree by Okinawa Rail may be predator avoidance behavior. The rail distributed only the northern part of Okinawa Island, where Itajii Castanopsis siebold forest predominated. Conservation of the rail's diminishing remaining habitat is necessary to preserve the species. Development of techniques for captive breeding the Okinawa Rail are recommended.
The distribution and size of roosts of crows Corvus macrorhynchos and Corvus corone were examined in the northwestern part of Chiba Prefecture from January 1990 to February 1990, and from October 1990 to February 1991. Five roosts were found in the study area, with a mean distance between neighboring roosts of 15.2km. The total number of crows gathering at the Konoyama roost was estimated to be about 2, 000-2, 600. The catchment area of the crows at the Konoyama roost was 70km2. It was observed that they flew directly from foraging locations to their roosts.
Oral administration of nitrofurantoin (200mg/kg body weight daily for 5 days) caused reduction in testis weight, seminiferous tubular diameter, and secondary spermatocyte and spermatid populations in the yellow-throated sparrow (Petronia xanthocollis, Burton). Spermatozoa bacame less abundant, but Leydig cell nuclear area, 3β-HSDH activity and sialic acid content of the testis remained unaltered after treatment. Single intraperitoneal injection of cadmium chloride (0.05mg/kg body weight) failed to produce any perceptible effect on the testis of the yellow-throated sparrow. It is suggested that nitrofurantoin has an antispermatogenetic effect in the yellowthroated sparrow. But cadmium chloride, at least with the dose administered, has no effect on the testis of this avian species. Moreover, both the chemosterilants have no effect on gonadotrophic activity or testicular steroidogenic activity in the yellow-throated sparrow.
The effects of water deprivation on the adrenal glands were studied in two avian species, the pigeon and the house sparrow. Dehydration failed to produce any change in the histology of the adrenal gland of the house sparrow, while, in the pigeon, medullary lobes were constricted and myeloid tissues increased. Biochemical observations showed that dehydration resulted in the decrease of both norepinephrine (34%) and epinephrine (50%) from the adrenal medulla of the house sparrow, whereas, in the pigeon, only epinephrine (45%) decreased following water deprivation. Water deprivation caused an increase of glandular corticosterone both in the pigeon (375.7%) and in the house sparrow (336.7%). The present observations illustrate that participation of corticosterone in dehydration is possibly universal in birds. By contrast, the differential responsiveness of the catechol hormones in these two species was noted. However, the adrenomedullary catecholamine response during water deprivation was independent of the NE: E ratio of both species. To explain this, the reno-physiological status and concentration of other hormones in these birds needs to be considered.
Observations were made of breeding Black Woodpeckers Dryocopus martius at two sites in Hokkaido; a conifer forest in Shikaoi (43°18'N, 143°7'E, 810m alt.) in 1987 and a deciduous broad-leaved forest in Chitose (42°45'N, 141°17'E, 260m alt.) in 1988. In 1987, eggs were laid between May 11-13, hatching on May 27 or 28. Three young fledged on June 29 1987, and on June 21 1988 respectively. Based on breeding records from the present study, and other sources in Hokkaido, young fledged in mid-June in southeastern areas, and in late June in other areas. The combined sex ratio for 26 broods was 1:1. Both the male and female incubated eggs and brooded nestlings during the day, up until the first week of the nestling period. Only the male incubated eggs and brooded nestlings at night during the corresponding period. Frequency of feeding increased from 10 times per day in the early nestling period, to 20 times per day in the middle of the nestling period. Feeding then began to decrease 4 to 5 days before fledging. Frequency of carrying faeces also began to decrese 4 to 5 days before fledging. Both males and females perched on trees near the nesting tree when flying to and from the nest. Frequency of perching after feeding began to increase before fledging. Freguency of drumming also increased just before fledging. Diet consisted mostly of ants, Formica sanguinea, Lasius niger, Camponotus obscuripes and C. herculeanus sachalinensis.
The Bonin Islands Honeyeater Apalopteron familiare is a passerine species endemic to the Ogasawara (Bonin) Islands, 1, 000km south of the Japanese mainland. The male Bonin Islands Honeyeater has been thought to sing rarely, even in the breeding season. To determine whether or not males were poor singers, I examined the diurnal rhythm of singing activity and the distribution of singing males in Hahajima in early June 1991. Two supposedly paired males showed a remarkable diurnal rhythm of singing activity. They sang actively between 0400h and 0430h in the morning, but then virtually ceased to sing, singing only sporadically in the daytime. Between 91 and 94 songs were delivered between 0400h and 0430h, accounting for 93.8% (91/97) and 71.2% (94/132) of the total songs in one day. Singing males were well recorded in the Okimura village between 0400h and 0500h, but rarely recorded between 0500h and 0700h in the mornings of June 3 to 8. Singing males were infrequently recorded in the daytime, even though they were widely distributed on Hahajima.