Comparative Growth and Symbiotic Performance of Seedlings of Acacia spp. in Defined Pot Culture or as Natural Understorey Components of a Eucalypt Forest Ecosystem in S.W. Australia

Hansen, A. P. and Pate, J. S. 1987. Comparative growth and symbioticperformance of seedlings of Acacia spp. in defined pot cultureor as natural understorey components of a eucalypt forest ecosystemin S.W. Australia.—J. exp. Bot. 38: 13–25 Growth, nitrogen accumulation, nodulation and nitrogenase activity(C₂H₂ reduction activity) were monitored in a dense stand ofseedlings of Acacia pulchella R.Br. and A. alata R.Br. duringtwo growing seasons after fire at a jarrah (Eucalyptus marginataDonn ex Sm.) forest site at Illawarra, 35 km south-east of Perth.Nitrogen fixation, estimated by a previously calibrated C₂H₂reduction assay, was essentially restricted to the winter andspring months (July to October) and was estimated to contribute37% and 9% respectively of the total N accumulated by A. pulchelladuring the first and second seasons of growth. Comparable valuesfor A. alata were 29% and 2%. Comparisons with fully symbioticplants raised in a glasshouse in supposedly non-limiting growthconditions in minus nitrogen sand culture indicated that waterstress rather than high temperatures was responsible for lossof nodules, cessation of symbiotic activity and attenuationof growth during summer in the field. By 19 months glasshouseplants had gained 130–230 times the dry weight and accumulated110–160 times the total N of similarly aged, field grownplants. Growth, nodulation and N₂ fixation of symbiotically-dependentsand cultured plants of A. pulchella and A. alata respondedmarkedly to phosphate, and additions of water and nutrientsto 3-year plants of A. pulchella during a winter growing seasonin the field indicated that periods of reduced soil moistureand low availability of nutrients, particularly phosphorus,might limit symbiotic performance under natural conditions. Key words: Seasonal nitrogen fixation, Acacia spp     

Movements of female polar bears (<Emphasis Type="Italic">Ursus maritimus</Emphasis>) in the East Greenland pack ice

The movements of two adult female polar bears ( Ursus maritimus) in East Greenland and the Greenland Sea area were studied by use of satellite telemetry between the fall of 1994 and the summer of 1998. One female was tracked for 621 days, the other for 1,415 days. During this time the females used maternity dens on land. If denning periods on land were excluded, the two females used between 73% and 100% of the tracking time offshore where they were able to navigate in the dynamic pack ice and counteract the fast southward movement of the ice (up to 30 km/h) in the East Greenland Current. Mean monthly movement rates varied between 0.32 and 0.76km/h. Both bears had very large home ranges (242,000 and 468,000 km ²) within the dynamic pack ice of the Greenland Sea. The facts that the bears made extensive use of the offshore sea ice and that there is a marked reduction of the Greenland Sea ice call for a closer monitoring of the effects of this change on the East Greenland polar bear population.     

Movements and Home Sites of Timber Wolves in Algonquin Park

Ecological studies of timber wolves (Canis lupus) in a forestedenvironment have always been difficult to undertake in the past,particularly during the summer months, because of the lack ofa suitable technique. In 1960 Pimlott devised a technique whichemployed the use of broadcast wolf howls in locating wolvesin the field. This report reviews the success of this techniquein studying the movements of two packs of wolves, and theiruse of home sites in Algonquin Park, Ontario. Wolves responded by howling a total of 476 occasions or approximately13% of the occasions that broadcast howls were given. Humanimitations were more successful than tape-recordings in inducingresponses. Wolves responded at any time of day, but dusk wasthe most favorable period. They also responded more frequentlyin July and August than in May and June. Two types of home sites were found: the den site, occupied duringthe early life of the pups, and the rendezvous site, a placeoccupied by wolves during later development of pups. All ofhe home sites were adjacent to some immediate source of water.The movement of wolves appeared also to be concentrated alongthe water courses. The locations of the home sites and the evidence obtained fromhowling responses, tracks, and scats suggested that the summerrange comprised a minimum area of eight square miles. The samerange was utilized by a pack in 1961 and 1963.     

美洲斑潜蝇在不同温度下的飞行能力

利用昆虫飞行磨测试了美洲斑潜蝇Liriomyza sativae在18℃到36℃条件下的飞行能力。结果表明：在33℃下美洲斑潜蝇的飞行能力最强,个体最大飞行距离、最高飞行速度和最长飞行时间分别为8.22 km、1.10 km/h和253.50 min,其平均飞行距离为0.95 km。其飞行的适温范围是21～36℃,18℃为其飞行的下限温度。从18～33℃,随着温度的升高平均飞行距离（0.08～0.95 km）和平均飞行时间(6.57～47.94 min)也在增加,但到36℃又开始下降;雌虫比雄虫飞行能力强。在理论上,美洲斑潜蝇能靠自身飞行扩散0.08～0.95 km。     

Spatial distribution of digestive enzyme activities of Calanus finmarchicus and C.hyperboreus in Fram Strait/Greenland Sea

Digestive enzymes of copepodite V (CV) Calanus finmarchicusand C.hyperboreus from two different depths were compared duringMIZEX 1984 (June/July) at stations in the ice and open water.CV of both species from 500–200 m showed reduced enzymeactivity, indicating that they were in a resting stage. In moultingexperiments at the end of June using CV from 100–0 m moultingwas delayed and began only after 3 weeks in C.finmarchicus andafter 3 months in C.hyperboreus. These results suggest thatthe deep CV populations are the seed of the new overwinteringstock. In surface CV C.finmarchicus and C. hyperboreus enzymeactivities were generally much higher than in deep CV. In neitherspecies were enzyme activities correlated with chlorophyll concentrations.Activities in C.finmarchicus reflected overall phytoplanktondistribution and were highest in the marginal ice zone, whereasthey decreased under the ice except for polynya stations onthe East Greenland Shelf. In surface C.hyperboreus digestiveenzymes were not correlated with those of C.finmarchicus, pointingto different diets or regulatory mechanisms. Enzyme activitywas lowest in the marginal ice zone and increased under theice. High activities were found at polynya stations and otherclose pack ice. The utilization of ice algae by C.hyperboreuscould explain these discrepancies in digestive enzyme activitiesof both species.     

Foraging strategies as a function of season and rank among wild female chimpanzees (Pan troglodytes)

Among mammals, female reproduction is generally thought to befood limited, and dominance should theoretically afford high-rankingfemales with access to better food resources. Although the importanceof dominance rank among female chimpanzees (Pan troglodytes)has been debated in the past, mounting evidence suggests thatrank is very important among females (P. t. schweinfurthii)at Gombe National Park, Tanzania. In this study, we investigatedthe influence of season and dominance rank on female foragingstrategies. We found that high-ranking females spent less timeforaging and tended to have a narrower diet breadth and higherdiet quality than subordinate females. In this way, subordinatefemale foraging strategies were consistent with how femalesin general adapted to periods of food scarcity. The resultsof this study therefore suggest that low-ranking females mayface persistent "food scarcity" as a result of interferencefood competition. We also provide evidence that subordinatesmay forage less efficiently because they occupy lower qualityhabitats or avoid associating with dominant females in sharedareas.     

球形芽孢杆菌对致倦库蚊的后致死作用

研究了球形芽孢杆菌Bacillus sphaericus C3-41菌株对致倦库蚊Culex quinquefasciatus幼虫的毒力及其后致死作用。生物测定表明,该菌株对目标蚊幼虫具有很高的毒力,其丙酮粉剂对3～4龄幼虫48 h的半致死浓度(LC₅₀)为(6.92±0.22) μg/L。用不同亚致死浓度处理2～3龄致倦库蚊幼虫,存活幼虫在后期发育中存在明显的延续死亡和损伤现象,经LC₃₀、LC₅₀、LC₇₀、LC₉₀和LC₉₈剂量的C3.41粉剂处理的致倦库蚊羽化前的总死亡率分别为84%、91%、95%、97%和100%,同时存活的幼虫、蛹和成蚊的发育和行为也受到一定的影响。这种后致死作用随处理浓度的升高而增强,可能同球形芽孢杆菌毒素蛋白对处理期间蚊幼虫中肠上皮细胞造成的损伤相关。     

Observations of mortality associated with extended open-water swimming by polar bears in the Alaskan Beaufort Sea

During aerial surveys in September 1987–2003, a total of 315 live polar bears were observed with 12 (3.8%) animals in open water, defined for purposes of this analysis as marine waters >2 km north of the Alaska Beaufort Sea coastline or associated barrier islands. No polar bear carcasses were observed. During aerial surveys in early September, 2004, 55 polar bears (Ursus maritimus) were seen, 51 were alive and of those 10 (19.9%) were in open water. In addition, four polar bear carcasses were seen floating in open water and had, presumably, drowned. Average distance from land and pack ice edge for live polar bears swimming in open water in 2004 (n=10) were 8.3±3.0 and 177.4±5.1 km, respectively. We speculate that mortalities due to offshore swimming during late-ice (or mild ice) years may be an important and unaccounted source of natural mortality given energetic demands placed on individual bears engaged in long-distance swimming. We further suggest that drowning-related deaths of polar bears may increase in the future if the observed trend of regression of pack ice and/or longer open water periods continues.     

Annual distribution of hooded seals (Cystophora cristata) in the Greenland and Norwegian seas

 Nineteen hooded seals (Cystophora cristata) were tagged with satellite-linked platform terminal transmitters (PTT) on the sea ice near Jan Mayen. Fifteen were instrumented after completion of the moult in July 1992 (five males, ten females, at 71°N, 12°W), and four during breeding in March 1993 (four females, at 69°N, 20°W). Sixteen of the seals were tagged with Satellite-Linked Time-Depth-Recorders (SLTDR), yielding location, dive depth and dive duration data. The average (±SD) longevity of all PTTs was 199±84 days (n=19; range: 43–340 days), and they yielded 12,834 location fixes. Between tagging in July 1992 and pupping in March 1993, two seals remained in or near the ice off the east coast of Greenland for most of the tracking period. However, most of the seals made one or several trips away from the ice edge, mostly to distant waters. These excursions had an average (±SD) duration of 47±22 days (n=46; range: 4–99 days). Eight seals travelled to waters off the Faeroe Islands, three to the continental shelf break south of Bear Island, and three to the Irminger Sea southwest of Iceland. Eleven seals were tracked in the period between breeding (March/April) and moulting (July). Several of these spent extended periods at sea west of the British Isles, or in the Norwegian Sea. Received: 3 August 1994/Accepted: 4 July 1995     

SATELLITE-MONITORED MOVEMENTS AND DIVE BEHAVIOR OF A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) IN TAMPA BAY, FLORIDA

An adult, female bottlenose dolphin ( Tursiops trucncatus ) was radio tagged and monitored via satellite-based Argos receivers for 25 d from 28 June to 23 July 1990, in Tampa Bay, Florida. A total of 794 transmissions were obtained during 106 satellite passes. A mean of 3.9 (SE = 0.24) locations/day were determined by Service Argos and showed the animal remained in the bay, usually close to the southeastern shore. The dolphin moved at least 581 km at a minimum mean speed of 1.2 (SE = 0.1) km/h. Data from 63, 922 dives were recorded. The animal spent an average of 87.1 (SE = 0.6)% of the time submerged, with a mean dive duration of 25.8 (SE = 0.5) sec. Mean dive duration differed significantly between four periods of the day, as did the mean percent of time spent submerged. During the early morning the animal spent more time at the surface, averaged shorter dives, and was submerged less than other times of day. This is the first study to demonstrate die1 dive cycles in a bottlenose dolphin. Four months after tag loss, the dolphin was photographed with no evidence of necrosis or disfigurement of the dorsal fin. Satellite telemetry was demonstrated as an effective means of documenting the movements and dive behavior of a small inshore cetacean.     

THE PHYSIOLOGY AND FEEDING BEHAVIOUR OF TWO MARINE SCAVENGING GASTROPODS IN HONG KONG: THE SUBTIDAL BABYLONIA LUTOSA (LAMARCK) AND THE INTERTIDAL NASSARIUS FESTIVUS (POWYS)

Aspects of the physiology and feeding behaviour of the scavengingsnails, Babylonia lutosa and Nassarius festivus have been studiedand compared. N. festivus has a wider physiological tolerancethan B. lutosa; upper lethal temperatures being 31.5°C and28.5°C respectively and lower lethal salinities 15.5 and11.5. N. festivus was also more resistant to desiccation. N.festivus is adapted to an intertidal environment that is morevariable than the subtidal habitat of B. lutosa. The metabolicrate of adult N. festivus was two to three times higher thanthat of adult B. lutosa, the specific oxygen consumption rateof the former being 7.91±0.49x10^–6 mol of O₂.g^–1wet wt.hr^–1. This correlates with estimates of consumptionobtained for the two animals, B. lutosa eating, on average,6.57% of its wet tissue weight per day, N. festivus 15.33%.Standardization of the data for 2 g animals of both species,however, reveals no significant difference in terms of oxygenconsumption and thus the enhanced consumption by N. festivussimply reflects its smaller size. Both species are opportunisticfeeders and can survive long periods of starvation (>100days). The feeding strategies of the two are also different,N. festivus eating faster than B. lutosa, possibly because ofthe more ephemeral nature of carrion in the intertidal. Starvationaffected the feeding behaviour of N. festivus more than B. lutosaand N. festivus was able to perceive carrion from greater relativedistances than B. lutosa. (Received 27 February 1989; accepted 24 July 1989)     

Temperature- and size-dependent growth and movement of the North Pacific giant octopus (Enteroctopus dofleini) in the Bering Sea

Octopus growth and movement occurs during all life stages and have implications for survival, food web dynamics and reproduction. From 2009 to 2011, 1714 North Pacific giant octopus (Enteroctopus dofleini) were tagged and recaptured in the eastern Bering Sea with visible implant elastomers to better understand the ecology of this data-poor species. Over this period, 246 of the tagged individuals were recaptured. In autumn, when temperatures were warmest, E. dofleini had higher growth rates and moved more than in the colder winter months. For both short- and long-term recaptures, small octopus grew faster than large octopus. Movement of octopus over short- and long-term periods was low for very small and very large octopus and high for median-sized octopus, which is likely to be a function of maturity status and reproductive activities. Approximately 80% of recaptures moved less than 2?km from the initial tagging location for time periods up to a year, suggesting long-term site fidelity. As temperature and size may be tightly linked to growth and movement rates for E. dofleini in the eastern Bering Sea, predicted climate warming will likely alter ecological processes for the species and impact their distribution.     

THE BANDED MONGOOSE, MUNGOS MUNGO GMELIN

The banded mongoose is a social, diurnal, medium-sized carnivore classified in the family Viverridae. Packs of up to 32 animals were found to occupy a single, old termite mound for periods in excess of 2 months. Nine out of ten dens were in termite mounds, the other was in a gully. One den was excavated to show structure. The whole pack occupied the central chamber each night. One group of 32 consisted of 17 adults, 7 juveniles, and 8 babies too small to leave the den with the pack during the day. The animals were strictly diurnal, usually leaving the den about one hour after dawn; time of return was more variable, but was usually during the hour before dark. Senses of sight, smell and hearing were found to be very acute. During the day the packs covered large distances, foraging as they went. During the period of study, food (estimated by dung analysis) consisted almost entirely of Coleoptera (mainly dung beetles) and millipedes. The packs followed the trails of elephant and buffalo and obtained most of their food from their dung. Detailed behaviour is described. Mating was seen on three occasions and two males were seen to copulate with the same female. Family size was not determined, but eight young were seen to be suckled by three females indiscriminately. One mother looked after all eight young during the day when the pack was away. The animals used communal defaecating areas on and around the den, the faeces being scattered over the surface of the ground. Reactions to various animals, including predators, are described. When caught in the open the pack tended to bunch together acting as a single unit. If bushes were near they used them for shelter. Adaptations are discussed.     

Glucose metabolism in vivo in crossbred Holstein cattle feeding on different types of roughage during late pregnancy and early lactation

An experiment was carried out to study the glucose kinetics of crossbred Holstein cattle feeding on either hay or 5% urea treated rice straw during late pregnancy (21 days prepartum) and early lactation (30 days postpartum). In all 16 pregnant heifers (23–25 months of age) were selected for the experiments, including eight animals of two breed types, Holstein Friesian×Red Sindhi (50:50=50% HF) and Holstein Friesian×Red Sindhi (87.5:12.5=87.5% HF). They were divided into four groups of four animals each. Animals from the same breed type in each group were fed with either rice straw treated with 5% urea or pangola hay (Digitaria decumbens) as the source of roughage throughout the experiments. The glucose turnover rate in both types of crossbred Holstein cattle was determined using a continuous infusion of [U-¹⁴C] and 3-[³H]glucose during late pregnancy and early lactation. Total glucose entry and utilization rates increased significantly during lactation for all groups. Recycling of [C]glucose was, approximately, 20% in both crossbred cattle fed either hay or urea treated rice straw and was unaffected by the stage of late pregnancy or early lactation. Comparing 50 and 87.5% HF animals, arterial plasma glucose concentrations were slightly higher during pregnant periods but significantly higher in lactating periods in 50% HF animals. The ratio of specific radioactivity of arterial blood bicarbonate relative to that of arterial blood [¹⁴C]glucose in the lactating period, significantly decreased in 50% HF animals fed either urea treated rice straw or hay. An increase in udder blood flow during early lactation was significantly higher in 87.5% HF animals than in 50% HF animals. The uptake, arteriovenous differences and extraction ratio for glucose across the udder, significantly increased in the lactating period for all crossbred animals. Glucose uptake by the udder of 87.5% HF animals accounted for 65% of the total glucose turnover rate compared to a value of 46% in the lactating 50% HF animals. It can be concluded that both crossbred cattle fed either urea treated rice straw or hay exhibit the same body glucose turnover rate. The 87.5% HF animal has the genetic potential for a high milk yield and has high body and udder glucose metabolisms compared with 50% HF animals.     

Homing and group cohesion in Atlantic cod Gadus morhua revealed by tagging experiments

Homing behaviour and group cohesion in Atlantic cod Gadus morhua from the northern Gulf of St Lawrence were studied based on tagging-recapture data from two periods, the 1980s and a recent period from 1996 to 2008. Two or more tags from a single tagging experiment were frequently recovered together in subsequent years. The null hypothesis was tested that the frequency of matching tag recoveries occurred by chance only through random mixing of tagged G. morhua before their recapture by the commercial fishery. The alternative hypothesis was that non-random, positive association (group cohesion) existed among tagged individuals that persisted through time and during migrations. Results show that the G. morhua population exhibits a homing behaviour, with temporal stability across seasons and years: 50% of recaptured fish in the recent period were caught <34 km from their mark site, even 3 years after release. In the 1980s, G. morhua were located at <10 km from their release site 1 year after tagging during summer and at <16 km during spring and autumn combined. Despite the increasing distance between the mark and recapture sites over time, the difference was not significant. In addition, occurrences of two or more tagged fish from the same release event that were caught together indicated a non-random association among individual fish for periods of one to several years and through migrations over several hundred kilometres. Hence G. morhua showed group cohesion in addition to site fidelity. These two interacting behaviours may be fundamental for the rebuilding and conservation of depleted fish stocks.     

Evidence of artificial habitat use by a recovering marine predator in southern California

The giant sea bass Stereolepis gigas Ayres 1859 (GSB) is a critically endangered top marine predator in California. Since protection in 1982 and 1994, the population has appeared to increase, and individuals within a growing population may expand their ranges to new habitats to reduce intraspecific competition and increase foraging opportunities. In 2016–2018, two GSB tagged with acoustic transmitters were detected at artificial reefs for periods of up to 3 months during October–March, and one individual travelled 53 km from an offshore island to mainland California in 56 h. Artificial reefs may provide important foraging opportunities for these protected marine predators as they recover from exploitation.     

Seasonal variation and life history of the pelagic chaetognatha, Sagitta elegans Verrill, in Toyama Bay, southern Japan Sea

The seasonal variation and life history of the pelagic chaetognatha,Sagitta elegans Verrill, in Toyama Bay, southern Japan Sea,were investigated using a time series of 0–500 m verticalhauls with a Norpac net from 1 February 1990 to 30 January 1991.Nine species of one genus occurred in Toyama Bay throughoutthe year, including the cold-water species S.elegans. Therewas no remarkable variation in abundance throughout the year,although many individuals were collected in August. Juvenilesoccurred mostly in spring and summer, from late March to August.Adults (Stage 3) occurred in all seasons, except summer. Thebody length of adults ranged from 26 to 30 mm. There were twoprincipal spawning periods. One was in March-May and the otherwas in August. Life spans of both cohorts were 10–12 months.Copepods were major prey of S.elegans inhabiting Toyama Bay.The annual mean food-containing ratio (FRC) was 6.1%, but values>10% occurred in February, April, May, July and September.     

The rotifers of Warri River, Nigeria

The rotifer assemblage of the dendritic tidal Warri River wasinvestigated at four sampling points from July 1981 to July1982. Forty-one species of Rotifera were identified. Five ofthese — Anuraeopsis racenesi Berzins Keratella cochlearismacracantha Lauterbom, Monostyla lunaris Pawlowsky,M. stenroosiMeissner and Trichocerca similis grandis Hauer — are beingrecorded for the first time in West Africa. The Warri Riverrotifers are 65% cosmopolitan and 20% pantropical although therewas no species limited to African waters only. The dominantrotifers in the Warri River were Keratella tropica and K. cochleariswhich were found in the predominantly freshwater sampling stationat Udu Bridge to Warri and Orugbo Creek where low brackish watersalinities and conductivities are observed from December orJanuary to April each year. The preponderance and longitudinaldistribution of these two well-known cyclomorphic rotifers providesan opportunity to study their salinity tolerance and the effectof salinity and conductivity on their cyclomorphosis by samplingalong the length of the river from Udu Bridge to Forcados wherethe Warri River joins the Atlantic Ocean.     

Fine‐scale movements and use of space by spotted hyaena (Crocuta crocuta) on Ongava Game Reserve,Namibia

We deployed Global Positioning System (GPS) collars on spotted hyaena, Crocuta crocuta, on Ongava Game Reserve in northern Namibia. We analysed the movement profiles recorded from three periods of fine temporal scale (15 min interval) GPS data – dry season data from a sub‐adult female (36 days) and a lactating adult female (54 days), and wet season data from the same adult female (55 days). The hyaenas both had similar daily activity patterns – at rest between 12.00 and 18.00 hours, with a peak of activity in the 2‐h period around sunrise. They exhibited one or two active periods each night, travelling up to 30 km and being active for up to 10 h. Daily rest sites were widely distributed across the reserve, typically located on elevated ground and never revisited on consecutive days. In the dry season, both hyaenas made extensive use of the reserve, plus adjacent areas in Etosha National Park (sub‐adult home range 240 km², adult home range 366 km²). The wet season data for the adult female showed a significant reduction of space used (home range 232 km²). However, their utility distributions showed a nonuniform use of space, with multiple areas of high‐density utilization located away from open terrain.