A description is given of a field experiment from winter through fall in which excess artificial food was provided in some areas with Peromyscus maniculatus, but not in others. Population size and production of young increases, and adult but not juvenile survival improves slightly with additional food; hence the hypothesis that no differences in breeding and survival :would exist between experimental and control areas is rejected in part. The numbers of adult males in experimental and control situations are similar, suggesting that the male portion of the breeding population may, as hypothesized by Sadleir (1965) and Healey (1967), be held relatively constant during breeding by behavioral mechanisms. Attention is drawn to the different numerical responses of males and females, and the possibilty of different regulating mechanisms for the sexes.

24 treefall gaps accumulated over a 10 year period along an altitudinal transect covering 4.6 ha on Mt. Hauhungatahi, Tongariro National Park, New Zealand were described quantitatively in terms of the area of damage ('expanded gap'), the canopy opening ('light-gap') and the size of the root mound. Tree mortality and branch loss following cyclone Bola, 1988, were recorded. In each gap saplings were ranked by species according to their vigour. Pre-gap and post-gap vertical and horizontal branch growth rates were calculated. Effects in the subalpine forest (> 1050 m) were compared with those in the montane zone.Tree mortality was highly episodic, associated with major storms, and patchy. Falling canopy trees destroyed, on average, 1.3 additional trees (> 10 cm diameter at 1 m). About half the trees were uprooted and the remainder broken off. Uprooted angiosperm (canopy) trees frequently resprouted from their bases, gymnosperms rarely. Expanded gap area averaged 56 m 2 in the sub-alpine forest and 88 m 2 in the montane zone. Median expanded gap areas were about twice those of light gaps. Gap size frequency distribution was highly skewed. The largest gap was formed by a single Dacrydium cupressinum which destroyed six other trees creating a gap of ca. 0.03 ha.Expanded gaps, light gaps, and root mounds comprised 4.5, 2.8 and 0.l % of the forest area in the sub-alpine zone, and 3.8, 2.5 and 0.06 % in the montane forest. These values represent 10 years of accumulation, and imply light gap 'return times' of 360 years for the sub-alpine and 400 years for the montane forest. These periods are in agreement with the known longevities of the canopy and emergent trees.Vertical shoot growth rate was about twice that in the horizontal plane, and both increased following gap formation. The relative increase was greatest in the subalpine forest. Using the measured growth rates it is estimated that gaps of median dimensions are filled by lateral extension growth in 31 -44 yr. Saplings require longer to reach the mean canopy height and consequently require large (multiple tree) gaps or sequential gap events.

The Hihi or Stitchbird Notiomystis cincta breeding system is highly variable and includes monogamy, polyandry, polygyny and polygynandry. Males have large testes (4.2% of body mass), very large numbers (1460 × 106) of sperm in their seminal glomera and an unusually enlarged cloacal protuberance. These features are also found in other species with highly variable mating systems where males are under intense sperm competition. Hihi copulate in two different positions: face to face and, more conventionally, with the male on the female's back. Face‐to‐face copulation is unique among birds and appears to be a form of forced copulation. The presence of enlarged cloacas in both sexes could aid the transfer of sperm. Both male and female Hihi appear to benefit from a mixed reproductive strategy where a female Hihi can solicit copulations from males other than her partner and male Hihi can perform extra‐pair copulations both with willing females or by forced copulation.

No abstract

Annual nests of the German wasp Vespula germanica were collected in Manawatu between January and May, 1969-1988, and analysed as a single cohort Most nests were from urban locations, and subterranean nests were selected preferentially. The study is a baseline measure of a German wasp population in the absence of common wasps. Given the rapid spread of common wasps this circumstance may never be repeated on mainland New Zealand.Manawatu colonies reach peak numbers between mid and late April. Drones are most numerous in mid April and queens in late April to early May. Nests taken in the same locality on the same day vary demographically; large nests generally hold higher proportions of reproductives than small nests.Manawatu nests are generally larger and have more combs than those in England. The area and number of combs increases steadily from January to May. Complementary seasonal changes in the total area of pupal cells, and of empty cells plus cells with eggs, support the view that colonies achieve maximum size in mid to late April. The total area of larval cells remains fairly stable from January to May, as does the larva: worker ratio between mid February and early May.