New Zealand Natural Sciences Journal

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https://ir.canterbury.ac.nz/handle/10092/12522

New Zealand Natural Sciences is produced at the University of Canterbury, New Zealand, and contains papers documenting research in the earth, life, and environmental sciences of relevance to New Zealand or Antarctica. It continues in sequence from its predecessor, Mauri Ora, which was first published in 1973. Financial and technical support from the School of Biological Sciences is gratefully acknowledged. www.nznaturalsciences.org.nz/

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Open Access
Segmentation, autotomy and regeneration of lost posterior segments in Harmothoe imbricata (L.) (Polychaeta: Polynoidae)
(New Zealand Natural Sciences, 1973) Daly, J. M.
In regulär monthly samples from a population of Harmothoe imbricata, between 8 and 35% of the individuals were found to be regenerating lost posterior Segments. Breakage always occurred cleanly at an intersegmental boundary and the body wall at this point is specialized for autotomy. The septa are inserted just anterior to the plane of autotomy in each segment. The septa are displaced from the transverse plane in H. imbricata by the insertions of two oblique muscles which have become functionally intersegmental. Neither starva- tion nor removal of the brain influences the rate at which posterior segments are regenerated after experimental ablation.
Open Access
The avifauna of the Lake Ellesmere area, Canterbury
(New Zealand Natural Sciences, 1973) Tunnicliffe, G. A.
The avifauna of the Lake Ellesmere area is described. A brief description of the area is given; past literature is reviewed; a checklist of birds, compiled from a variety of sources, is presented. For each species and subspecies (129 are listed), notes are given on Status and the generalised Vegetation zones or other habitat categories where it has been sighted or been found to breed. In one census area, lake level has a pronounced affect on which species are present.
Open Access
An animal counter using a camera and trigger system
(New Zealand Natural Sciences, 1973) Carryer, T. J.
A light beam System for triggering a camera, suitable for counting and identifying animals using a 'run', is described.
Open Access
Movements and social behaviour of the opossum, Trichosurus vulpecula KERR, in a mixed scrub, bush and pasture habitat
(New Zealand Natural Sciences, 1973) Jolly, J. N.
The movements of Australian brush-tailed opossums, Trichosurus vulpecula, were studied in a mixed bush, scrub, and pasture habitat on Banks Peninsula by live-trapping and spotlighting over a period of six months from February to July 1971. Thirty-four opossums were marked. Estimates of the size of ranges in the pasture (0.8 ha males; 0.3 ha females) were smaller than those found elsewhere, probably because of the restricted habitat. Range sizes of animals resident in the bush were considerably altered by their movements" to seasonal food sources in the pasture. Male opossums did not hold territories as described in some studies. In this mixed habitat opossums may move between scrub, bush and pasture to obtain food and shelter.
Open Access
Helminth parasites of the long-finned eel, Anguilla dieffenbachii, and the short-finned eel, A. australis
(New Zealand Natural Sciences, 1973) Rid, L. E.
Fifty-four long-finned eels (Angullla dieffenbachii) and forty-seven short-finned e e l s (A. australis) were taken from the Waimakariri and Okuku rivers, and Lake Ellesmere, and examined for helminth parasites. The following trematodes: Stegodexamene anguillae, Telogaster opisthorchis, Lecitochirium sp. and a bivesiculid; and the following nematodes: Spirocamallanus anguillae, Cucullanus anguillae, Paraquimperia novaezelandiae, and Anguillicola australiensis, were recovered. The incidence of parasites differed in the two species, dominants being Stegodexamene in the short-finned, and Spirocamallanus in the long-finned eel. Food preferences, avoidance reactions of trematodes to neroatodes, and host ränge of Spirocamallanus, are suggested to explain this difference. Incidence and number of helminths increased with increasing host length. Differences in incidence and intensity of individual helminth species in each eel species were observed. Each parasite species showed a preference for one gut region.
Open Access
Editorial
(New Zealand Natural Sciences, 1973) Bennington, S.L.
Open Access
Activity and daily breathing patterns of the gecko, Hoplodactylus pacificus Gray
(New Zealand Natural Sciences, 1973) McIvor, I.
Actograph studies were used to demonstrate the daily pattern of activity of Hoplodactylus paclficus, the common New Zealand gecko. An endogenous activity pattern is shown to be synchronised with sunset, with maximum activity occurring in the four hours following sunset. This nocturnal activity is restricted by temperature; activity decreasing with falling temperature to an imperceptible level below 10°C. A peak in breath rate coincides with the onset of the activity period, suggesting an endogenous correlation of breath rate with activity pattern.
Open Access
Sub-fossil avian remains from two limestone caves in North Taranaki
(New Zealand Natural Sciences, 1973) Paulin, C. D.
Sub-fossil avian remains from two cave Systems of Mahoenui Valley, Taranaki, New Zealand, are listed, with reference to the occurrence of present day birds of the area.
Restricted
Breeding biology and population dynamics of the weddell seal, Leptonychotes weddelli: a review
(New Zealand Natural Sciences, 1973) Fenwick, G. D.
A brief review of the breeding biology of the Weddell seal, Leptonychotes weddelli is presented, with a discussion of factors which regulate the sizes of the populations. In early spring breeding colonies form on sea-ice as pregnant females haul out in areas of perennial cracking. The period between hauling out and birth of the pup, a time of fasting for the female, apparently increases in length with latitude and is generally later at higher latitudes. Development of the Single pup i s rapid; i t doubles i t s weight in 10 days and reaches 114 kg weight before weaning at 6 to 7 weeks of age. Twinning is rare. The lanugo of the pup provides insulation in the absence of blubber and allows the pup to survive at temperatures well below freezing. Mortality of pups, highest in the first week of life, is largely determined by climatic and physical factors. The pup's diving and swimming proficiency develops fairly rapidly but appears to necessitate a transitional crustacean diet following weaning. Weaning at high latitudes is thought to be timed to coincide with the summer phytoplankton bloom. The parent-offspring bond, initially strong, is broken about 50 days after birth and pups are forced, through strong competition with adults for food, to retreat towards the pack-ice. In breeding colonies seals are spaced wider than at other times on the sea-ice because of territorial behaviour. Both sexes defend aquatic territories while breeding but there is little fighting. Populations of Leptonychotes exist as discrete units. Food is probably the ultimate factor limiting population size but other important factors are the availability of breathing holes and the ability to maintain these. Intra-specific and intra-sexual strife are also significant. Ice stability can have large effects on pupping success. Predation may be important in some areas but is poorly documented.
Open Access
Positive feedback mechanisms and plant disease
(New Zealand Natural Sciences, 1973) Walker, J. R. L.
A novel biochemical concept of a positive feedback System is suggested based on the reactions occurring in apple fruit infected with Penicillium expansum or plants suffering from boron deficiency.
Open Access
Notes on the burrow system of a colony of Rattus norvegicus (Berkenhout, 1767) near Christchurch
(New Zealand Natural Sciences, 1973) Gibson, R. N.
The burrow System of a small colony of Rattus norvegicus on the western bank of the Avon river mouth, Christchurch, was excavated, mapped and described in May 1972. Fifteen rats (3 adult and 4 juvenile females; 7 juvenile males; 1 unsexed individual) were caught between 21 and 27 April in break-back traps set near the colony from 21 April to 5 May. The burrows penetrated an inter-tidal Salicornia bed, the river bank and a grassy area, and were between 0.1 and 0.3 m below the surface. There were two Systems, one with three, and the other with seven openings; the larger System (10.3 m of burrows) contained eight Chambers, two with nests and two with dried grass only. No rat faeces or food Stores were found in the burrows.
Open Access
Reproduction of the house mouse, Mus musculus L. in the Christchurch area
(New Zealand Natural Sciences, 1973) Gibson, R. N.
Some population characteristics of the mouse, Mus musculus, collected by fumigation and trapping from suburban and pastoral areas and grain stores near Christchurch from 6 March to 18 July 1970 are described. Significantly more females (83) than males (59) were caught (P < 0.05); female predominance was greater in samples of heavier (> 16.5 g) and older (> 20 weeks) mice. Both sexes became fecund at about 8 weeks old and 10.6 - 12.5 g body weight. An index of testis size (length and width) was correlated with fecundity in both laboratory and wild male mice, although values differed. Corpora lutea in the ovaries of females indicated fecundity. A significantly greater (P < 0.02) proportion of females heavier than 18.5 g were pregnant (71%) than was so in lighter females (21%). There was no increase in average proportion pregnant with increasing age. On average, 36% of females were fecund during the collection period and each produced 3.34 litters (total 19.2 embryos) in that time. Extrapolating from the sex ratio in 31 nestling mice (19 females; 12 males) 11.8 of the embryos would become daughters. Apart from the above, some of the main conclusions of this study are that the visibility of tubules in the cauda epididymis is the best indicator of male fecundity; the presence of corpora lutea in the ovaries indicates female fecundity; the breeding of wild mice in Christchurch may continue into the winter, the physical condition of females, as indicated by their weight, is more important than age in affecting fertility.
Open Access
The distribution of the blue duck, Hymenolaimus malacorhynchos, in the South Island: a preliminary study
(New Zealand Natural Sciences, 1973) Fordyce, R. E.
The past and present distribution of the blue duck, Hymenolaimus malacorhynchos, in the South Island, is briefly reviewed. The data presented here indicate that the blue duck is widely distributed throughout the mountainous areas of the Island. It is suggested that since early European times there has been a gradual disappearance of ducks from the lower reaches and gorges of many rivers, especially in more developed agricultural areas. Several possible causes of this decline are discussed. Man appears to have been the cause of the restriction in distribution by changing physical parameters of the environment, and by predation.
Open Access
Energetics of captive house mice (Mus musculus L.), fed two different foods
(New Zealand Natural Sciences, 1973) Winterbourn, M. J.
The energetics of captive house mice fed two separate foods, sheep nuts and dog biscuits, were studied and compared. Short term experiments on food consumption, assimilation, and metabolism were made and the results combined in the form of energy budgets for representative 12 and 25 g mice. Growth of three litters fed the experimental foods was also determined. Mice fed sheep nuts consumed more, assimilated a higher percentage of the food and grew to a greater size. As growth rates of young mice fed the two foods were similar it seems that sheepnut-fed mice were using more energy in respiration, probably due to higher levels of activity.
Open Access
A benthic study of the Avon spring stream, Christchurch
(New Zealand Natural Sciences, 1973) Marshall, J. W.
The Avon Stream arises from one helocrene and four rheocrene Springs. These have a constant flow into a small moderately fast stream with a bed of clay, mud and patches of weed. Oxygen, temperature, pH, cross sectional area and flow were measured in conjunction with biological sampling. Oxygen Saturation of the spring water was constant at 51% while downstream it showed a diel fluctuation. Animal density ranged from 100-500/0.1 m^2. Oligochaeta, Amphipoda and Mollusca were the most abundant faunal groups while Platyhelminthes were noticeably less common. A dilution technique for increasing counting accuracy is described. A biotope for the spring stream is proposed.
Open Access
A method for analysis of plant competition experiments
(New Zealand Natural Sciences, 1973) Langer, Hilary, J.
A method is outlined for estimating the competitive ability of one species over another, grown in pure and mixed culture, to fixed treatments factorially applied. An application of the method to assess the response of two grasses to increasing levels of Substrate phosphorus and nitrogen is described.
Open Access
The ecological niches of Leptospermum scoparium and L. ericoides (Angiospermae: Myrtaceae)
(New Zealand Natural Sciences, 1973) Burrows, C. J.
Open Access
Observations on nesting sites of the welcome swallow, Hirundo tahitica, on the eastern fringe of Lake Ellesmere, Christchurch
(New Zealand Natural Sciences, 1973) Hughes, O. R.
Records of nesting activity of a population of the welcome swallow, Hirundo tahitica, from December 1969 to October 1972, are presented. These data reveal an expanding population, and this is discussed with reference to possible influencing factors. Suggestions are made for more detailed study.
Open Access
Incidence of a trematode, Diploproctodaeum plicitum (Linton, 1928) in the pufferfish, Uranostoma richei (Fréminville, 1913)
(New Zealand Natural Sciences, 1973) Wilkinson, Christine E.
The trematode, Diploproctodaeum plicitum is drawn and synonyms are listed. Species of this genus have only been found, to date, in puffer- fishes. D. plicitum in Uranostoma richei is a new host record for this species of trematode. I. richei were collected from Lyttleton Harbour, Christchurch, to examine the incidence of D. plicitum infection. Twenty-eight per cent were infected, with no significant difference in rate between male and female hosts. Highest infection was in the anterior portion of the intestine, and in age groups 1+ to 4+. Mean length of D. plicitum was highest in the 2+ host age group, and declined in older fish. The possible causes of this maximum parasite length in young fish and subsequent decline, are discussed in terms of inferred patterns of infection.
Open Access
A comparison of nutrients in leaves and litter of red, silver and mountain beech
(New Zealand Natural Sciences, 1973) Heine, M.
A nutrient analysis was carried out of leaves and litter of Nothofagus fusca (red beech), N. menziesii (silver beech), and N. solandri var . cliffortioides (mountein beech). The nutrients assayed were nitrogen, potassium, sodium, magnesium and calcium. Although the small number of replicates did not allow Statistical Validation of the results, some trends could be seen. In general Nothofagus fusca had a higher mineral content, and N. solandri var. cliffortioides a lower nutrient content, than N. menziesii. Within a species, nutrient loss during leaf fall and decomposition, as a percentage of dry weight, varied between nutrients according to their solubility and their use by micro-organisms. Potassium, which is quite soluble, was lost rapidly, whereas calcium and magnesium, which are less soluble, were lost slowly. Sodium was always at a low level. Nitrogen initially was lost very rapidly but rose in concentration in later stages of decomposition. This was attributed to its incorporation into micro-organisms and humic structures.