Journal articles: 'Koala growth and behaviour'

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Hynes, Emily F., Geoff Shaw, Marilyn B. Renfree, and Kathrine A. Handasyde. "Contraception of prepubertal young can increase cost effectiveness of management of overabundant koala populations." Wildlife Research 46, no. 4 (2019): 317. http://dx.doi.org/10.1071/wr18109.

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Context With limited resources for wildlife management and conservation, it is vital that the effectiveness of management programs is maximised and costs reduced. Koala populations need to be reduced in locations where they are locally overabundant and over-browsing their food trees. Subcutaneous contraceptive implants containing levonorgestrel are currently used to control koala fertility to assist in reducing population densities. Dependent young are caught with their mothers, so are also available for contraception. Aims The overall aim was to investigate whether the effectiveness of koala contraception programs can be improved by administering levonorgestrel implants to female young along with their mothers. This was achieved by: (1) determining if implanting females before sexual maturation affects their fertility, growth and pouch development; and (2) developing a stage-structured population growth model to compare two management scenarios. Methods Juvenile female koalas (11–17 months old) were treated with either a control (n = 5) or 70 mg levonorgestrel implant (n = 5). Koalas were caught every 4 to 6 weeks for 15 months, then every 3 to 12 months for 5 years. Koalas were weighed and head length measured. Pouches were checked for young. Pouch development was assessed as a proxy for sexual maturation. A stage-based population model simulating koala population growth was developed to compare different management scenarios: no treatment; treatment of adults only; and treatment of adults plus their dependent young. Key results Levonorgestrel implants prevented births with no effect on growth, survival or timing of sexual maturation. Population growth simulations indicate that treating dependent young with their mothers results in earlier population reduction. Conclusions The treatment of prepubertal female koalas with levonorgestrel implants is a safe and effective method that increases the effectiveness of koala contraception programs. Implications Development of novel strategies may provide opportunities to increase the efficiency and cost-effectiveness of management programs with constrained resources.

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Matthews, Alison, Daniel Lunney, Shaan Gresser, and Wendy Maitz. "Tree use by koalas (Phascolarctos cinereus) after fire in remnant coastal forest." Wildlife Research 34, no. 2 (2007): 84. http://dx.doi.org/10.1071/wr06075.

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The aim of this study was to examine the effects of fire on resource use by a population of koalas in remnant coastal forest. Fifty-five koalas were monitored regularly by radio-tracking for up to 35 months. The attributes of each tree in which the koala was sighted were recorded, giving a total of 8390 records. Analyses were undertaken on a range of ecological information. Regeneration of the forest began immediately following the fires and within three months koalas were seen among the epicormic growth. From a total 4631 trees used by koalas, 3247 (70%) were burnt. Observations of koalas feeding included 53% in burnt trees. Koalas changed trees frequently; individual trees were used once only on 3555 occasions (42% of all observations). Of all the trees used, 95% were used by only one collared koala; no trees were used by more than three koalas. Swamp mahogany (Eucalyptus robusta) was the tree species most frequently used by koalas, particularly at night and by breeding females. Koalas preferred trees of larger diameter (>30 cm) and used significantly taller trees during summer. This study has shown that resource depletion from intense wildfire is short-term for koalas because they utilise burnt trees within months of the fire for both food and shelter.

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Lunney, Daniel, Eleanor Stalenberg, Truly Santika, and Jonathan R. Rhodes. "Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW." Wildlife Research 41, no. 1 (2014): 22. http://dx.doi.org/10.1071/wr13054.

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Context Reviews of climate change in Australia have identified that it is imposing additional stresses on biodiversity, which is already under threat from multiple human impacts. Aims The present study aimed to determine the contributions of several factors to the demise of the koala in the Eden region in south-eastern New South Wales and, in particular, to establish to what extent climate change may have exacerbated the decline. Methods The study built on several community-based koala surveys in the Eden region since 1986, verified through interviews with survey respondents. Historical records as far back as the late 19th century, wildlife databases and field-based surveys were used to independently validate the community survey data and form a reliable picture of changes in the Eden koala population. Analysis of the community survey data used a logistic model to assess the contribution of known threats to koalas, including habitat loss measured as changes in foliage projective cover, fire, increases in the human population and climate change in the form of changes in temperature and rainfall, to the regional decline of this species. Key results We found a marked, long-term shrinkage in the distribution of the koala across the Eden region. Our modelling demonstrated that a succession of multiple threats to koalas from land use (human population growth and habitat loss) and environmental change (temperature increase and drought) were significant contributors to this decline. Conclusions Climate change, particularly drought and rising temperatures, has been a hitherto hidden factor that has been a major driver of the decline of the koala in the Eden region. Implications Development of strategies to help fauna adapt to the changing climate is of paramount importance, particularly at a local scale.

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Cristescu, Romane, Valma Cahill, William B. Sherwin, Kathrine Handasyde, Kris Carlyon, Desley Whisson, Catherine A. Herbert, Britt Louise J. Carlsson, Alan N. Wilton, and Des W. Cooper. "Inbreeding and testicular abnormalities in a bottlenecked population of koalas (Phascolarctos cinereus)." Wildlife Research 36, no. 4 (2009): 299. http://dx.doi.org/10.1071/wr08010.

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Habitat destruction and fragmentation, interactions with introduced species or the relocation of animals to form new populations for conservation purposes may result in a multiplication of population bottlenecks. Examples are the translocations of koalas to French Island and its derivative Kangaroo Island population, with both populations established as insurance policies against koala extinction. In terms of population size, these conservation programs were success stories. However, the genetic story could be different. We conducted a genetic investigation of French and Kangaroo Island koalas by using 15 microsatellite markers, 11 of which are described here for the first time. The results confirm very low genetic diversity. French Island koalas have 3.8 alleles per locus and Kangaroo Island koalas 2.4. The present study found a 19% incidence of testicular abnormality in Kangaroo Island animals. Internal relatedness, an individual inbreeding coefficient, was not significantly different in koalas with testicular abnormalities from that in other males, suggesting the condition is not related to recent inbreeding. It could instead result from an unfortunate selection of founder individuals carrying alleles for testicular abnormalities, followed by a subsequent increase in these alleles’ frequencies through genetic drift and small population-related inefficiency of selection. Given the low diversity and possible high prevalence of deleterious alleles, the genetic viability of the population remains uncertain, despite its exponential growth so far. This stands as a warning to other introductions for conservation reasons.

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Cristescu, Romane, Valma Cahill, William B. Sherwin, Kathrine Handasyde, Kris Carlyon, Desley Whisson, Catherine A. Herbert, Britt Louise J. Carlsson, Alan N. Wilton, and Des W. Cooper. "Corrigendum to: Inbreeding and testicular abnormalities in a bottlenecked population of koalas (Phascolarctos cinereus)." Wildlife Research 39, no. 4 (2012): 374. http://dx.doi.org/10.1071/wr08010_co.

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Habitat destruction and fragmentation, interactions with introduced species or the relocation of animals to form new populations for conservation purposes may result in a multiplication of population bottlenecks. Examples are the translocations of koalas to French Island and its derivative Kangaroo Island population, with both populations established as insurance policies against koala extinction. In terms of population size, these conservation programs were success stories. However, the genetic story could be different. We conducted a genetic investigation of French and Kangaroo Island koalas by using 15 microsatellite markers, 11 of which are described here for the first time. The results confirm very low genetic diversity. French Island koalas have 3.8 alleles per locus and Kangaroo Island koalas 2.4. The present study found a 19% incidence of testicular abnormality in Kangaroo Island animals. Internal relatedness, an individual inbreeding coefficient, was not significantly different in koalas with testicular abnormalities from that in other males, suggesting the condition is not related to recent inbreeding. It could instead result from an unfortunate selection of founder individuals carrying alleles for testicular abnormalities, followed by a subsequent increase in these alleles' frequencies through genetic drift and small population-related inefficiency of selection. Given the low diversity and possible high prevalence of deleterious alleles, the genetic viability of the population remains uncertain, despite its exponential growth so far. This stands as a warning to other introductions for conservation reasons.

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Jurskis, Vic. "Ecological history of the koala and implications for management." Wildlife Research 44, no. 7 (2017): 471. http://dx.doi.org/10.1071/wr17032.

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Assessments of the conservation status of koalas and trends in their population have been based on mostly unstated false assumptions about their pre-European status and on notions that either they were naturally regulated by their predators, chiefly Aborigines and dingoes, or that they somehow ‘self-regulated’ their fecundity. Closer examination of their ecological history suggests that frequent mild burning by Aborigines maintained eucalypt forests having fewer, mostly healthy trees, fewer young trees, canopies comprising mostly hard and dry leaves with low nutrient content, and, consequently, very few koalas. European explorers did not see them because they were solitary animals occupying large home ranges. After burning was disrupted, koalas responded to increased food resources in dense new growth of eucalypts and in stressed trees continually turning over new foliage. An export skin industry flourished. When their food resources were depleted by clearing or ringbarking of new growth and/or death of declining stands during droughts, koalas crashed back to low levels. Koalas continue to irrupt and decline through much of their range according to changing land management. Wildlife managers should re-assess their status and their management from a clear historical and ecological perspective.

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Trueman, Stephen J., Tracey V. McMahon, Elektra L. Grant, David A. Walton, and Helen M. Wallace. "Designing food and habitat trees for urban koalas: graft compatibility, survival and height of tall eucalypt species grafted onto shorter rootstocks." Australian Journal of Botany 62, no. 3 (2014): 196. http://dx.doi.org/10.1071/bt14060.

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The Corymbia and Eucalyptus species eaten by koalas are generally large trees, but these are often unpopular with urban landowners and councils because of the dangers of limbs falling from a great height. We aimed to develop shorter koala food and habitat trees for urban areas by heterografting tall eucalypt species onto rootstocks of shorter species and comparing their survival and growth with homografted trees and control ungrafted trees. In total, 12 of 14 interspecific scion/rootstock combinations were grafted successfully in the nursery but graft compatibility and field survival depended on taxonomic relatedness. The six interspecific combinations that had multiple surviving trees at 5 years after planting were all between species within the same taxonomic section or between a species and its own interspecific hybrid. Almost all trees died from grafts between species in different taxonomic sections. In most cases, the height of surviving interspecific grafted trees did not differ from control intraspecific grafted trees or from ungrafted trees of their scion species. Grafting elicited a ‘thrive or not survive’ response that diminished its usefulness for producing shorter trees. However, one combination, E. moluccana/E. behriana, had field survival of 40% and reduced height (4.0 m vs 9.9 m). These could be valuable habitat trees for koalas and other fauna in urban areas.

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Hynes, Emily F., Chris D. Nave, Geoff Shaw, and Marilyn B. Renfree. "Effects of levonorgestrel on ovulation and oestrous behaviour in the female tammar wallaby." Reproduction, Fertility and Development 19, no. 2 (2007): 335. http://dx.doi.org/10.1071/rd06063.

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Subcutaneous hormone implants are a useful method for managing overabundant marsupials in restricted enclosures in Australia. Levonorgestrel induces long-term infertility in the kangaroo, tammar wallaby and koala, although the contraceptive mechanism of levonorgestrel is unknown for any marsupial. In the present study, it was investigated if insertion of a single levonorgestrel or control implant at the time of reactivation of the diapausing blastocyst affected the subsequent post-partum oestrus or the preceding follicular development. Twenty levonorgestrel-treated and 16 control animals were autopsied the day before birth and the accompanying post-partum oestrus (Day 25), and 10 levonorgestrel-treated and five of the nine control animals were autopsied 3–4 days (Days 29–30) after the expected birth and oestrus. Peripartum behaviour was observed and birth and mating times were recorded. Levonorgestrel treatment did not prevent follicular growth because there was no significant difference between treatment and control animals in the size of the dominant follicle at Day 25. None of the levonorgestrel-treated females autopsied at Days 29–30 had ovulated (n = 10), in contrast to controls, where four of the five that were autopsied had ovulated. Mating occurred in eight of nine control animals but in only three of 10 levonorgestrel-treated females. Males showed a more sustained period of interest in the three that were mated than in the controls, and mating took place significantly later after birth (36 v. 10 h; P = 0.038). Follicular growth and development was not blocked in any female but only one-third of the animals mated and none ovulated after levonorgestrel treatment. These results suggest that levonorgestrel inhibits the preovulatory surge of luteinising hormone.

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Gordon, G. "Estimation of the age of the Koala, Phascolarctos cinereus (Marsupialia: Phascolarctidae), from tooth wear and growth." Australian Mammalogy 14, no. 1 (1991): 5. http://dx.doi.org/10.1071/am91001.

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Wear of the premolar and molar teeth of the Koala, Phascolarctos cinereus, was studied at two localities, in central and southern Queensland respectively. Tooth wear was classified into 10 tooth wear classes (TWC). Mean ages were determined for TWCs 1- 6, ranging from 1.2 to 7.3 years. An age estimate is also given for TWC 7 (9 years), but is based on data from only one known age animal. Rate of tooth wear varied greatly between animals from the same area, but there was no difference in rate of wear between the two localities, at which diets differed (Eucalyptus tereticornis / E. microtheca versus E. populnea). TWC is useful for dividing samples of animals from P. cinereus populations into separate age classes and for giving an approximation to the age of particular animals. The correlation between age and head length of P. cinereus of known year class was examined. Head length differs between P. cinereus from year classes 0, I and 2, and may be used to place animals in this age range into a year class.

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Osawa, Ro, Tomohiko Fujisawa, and Tomotari Mitsuoka. "Characterization of Gram-negative Anaerobic Strains, Isolated from Koala Feces, which Exhibit Satellite Growth and Pleomorphism." Systematic and Applied Microbiology 15, no. 4 (December 1992): 628–35. http://dx.doi.org/10.1016/s0723-2020(11)80126-8.

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Martin, R. W. "Overbrowsing, and decline of a population of the koala, Phascolarctos cinereus, in Victoria. I. Food preference and food tree defoliation." Wildlife Research 12, no. 3 (1985): 355. http://dx.doi.org/10.1071/wr9850355.

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Tree usage by koalas as a measure of foliage preference was analysed for 2 yr in an open forest near Walkerville, Victoria, containing 3 Eucalyptus species. At the start of the study, there was significant defoliation of E. ovata. The koalas showed a significant preference for this species, which became increasingly defoliated as the study progressed. The preference for E. ovata decreased in the second year of the study, probably as a result of a decline in available foliage. It also changed seasonally, with koalas showing a stronger preference for E. ovata in autumn and winter than in spring and summer. The preference for E. radiata and E. obliqua was greater in summer, when these species were producing abundant new growth. It is suggested that the koalas select foliage so as to maximize their intake of crude protein.

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Tanaka, Mark M., Romane Cristescu, and Desmond W. Cooper. "Effective population size of koala populations under different population management regimes including contraception." Wildlife Research 36, no. 7 (2009): 601. http://dx.doi.org/10.1071/wr08160.

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Context. The management of wildlife populations aiming to control population size should also consider the preservation of genetic diversity. Some overabundant koala populations, for example, have low genetic variation. Different management strategies will affect population genetic variation differently. Aims. Here, we compare four strategies with respect to their effects on the effective population size, Ne , and therefore on genetic variation. Methods. The four strategies of interest are: (1) sterilisation or culling (which have the same effect on genetic variation); (2) random contraception of females with replacement; (3) random contraception of females without replacement; and (4) regular contraception, giving every female equal opportunity to reproduce. We develop mathematical models of these alternative schemes to evaluate their impact on Ne . We also consider the effect of changing population sizes by investigating a model with geometric population growth in which females are removed by sterilisation or culling. Key results. We find that sterilisation/culling at sexual maturity has the most detrimental effect on Ne , whereas regular contraception has no impact on Ne . Random contraception lies between these two extremes, leading to a moderate reduction in Ne . Removal of females from a growing population results in a higher Ne than the removal of females from a static population. Conclusions. Different strategies for controlling a population lead to different effective population sizes. Implications. To preserve genetic diversity in a wildlife population under control, the effective population size should be kept as large as possible. We suggest that a suitable approach in managing koala populations may be to prevent reproduction by all females older than a particular age.

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Martin, R. W. "Overbrowsing, and decline of a population of the koala, Phascolarctos cinereus, in Victoria. II. Population condition." Wildlife Research 12, no. 3 (1985): 367. http://dx.doi.org/10.1071/wr9850367.

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Juvenile and sub-adult koalas from a population at Walkerville, Victoria, which was severely defoliating its preferred food trees, had significantly lower growth rates than animals from a population on French Island, Victoria. Mature males from Walkerville were significantly smaller than French Island males in most age classes. There was no significant difference between the body weights of mature females of the 2 populations. Haematological tests on the females showed that nutritionally induced anaemia was significant in the Walkerville animals by Jan. 1981. Heavy tick loads probably exacerbated the effects of the food shortage on the animals' condition, but were not the cause of the anaemia. The low fertility rate of the Walkerville females appeared to be due to their poor nutritional state and to reproductive tract disease.

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Mella, Valentina S. A., Caitlin Orr, Lachlan Hall, Sabrina Velasco, and George Madani. "An insight into natural koala drinking behaviour." Ethology 126, no. 8 (May 2, 2020): 858–63. http://dx.doi.org/10.1111/eth.13032.

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Rundle-Thiele, Sharyn. "A reflection on motivating community action to protect an endangered species using marketing." European Journal of Marketing 56, no. 9 (November 16, 2022): 2558–72. http://dx.doi.org/10.1108/ejm-03-2022-0146.

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Purpose This paper aims to describe a case that has worked with community aiming to prevent koala deaths and injuries across known causes including dogs. Design/methodology/approach Over a 6½-year period, a project team has applied the Co-create–Build–Engage (CBETM) process initially delivering a proof-of-concept pilot programme for one threat faced by koalas, which was later scaled to citywide delivery. This approach is now being extended across 12 local government areas, and the author’s team is now working across all preventable threats faced by koalas’ regionwide. Leave It is now nested as one behaviour change project in a wider project delivered across Southeast Queensland, in partnership with Queensland Government, 12 local government areas, community groups and other organisations. Findings Underpinned by the pathway to impact and CBETM processes, this paper describes how the 3½-year Leave It project reduced koala deaths from dog attacks by 40% in the Redland City Council area. A reduction in koala deaths will contribute to a measurable increase in the local koala population across successive generations delivering lasting impact. Research limitations/implications This paper provides an overview of links between inputs, activities, outputs and outcomes to impact. Robust koala population data is needed to precisely measure impact over time. Practical implications One female koala joey saved equates to seven new koalas in the next generation and prevention of koala deaths can be achieved when people can be motivated to take action. Originality/value This paper reflects on 6½ years of experience applying marketing to deliver changes in people’s behaviour that protect koalas. A high-level overview of the strategic and operational marketing efforts that have been and continue to be applied is described.

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Jiang, Alex Zijian, Andrew Tribe, Clive J. C. Phillips, and Peter J. Murray. "Insights from Koala–Cattle Interaction Experiments: Koalas and Cattle May See Each Other as a Disturbance." Animals 12, no. 7 (March 30, 2022): 872. http://dx.doi.org/10.3390/ani12070872.

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Koalas are facing many threats and have now been officially listed as endangered. Recently, concerns were raised in anecdotal reports of koalas being killed by livestock, especially cattle. We investigated the significance of cattle as a threat to koala survival via two koala–cattle interaction experiments, from both the koala and cattle perspectives. In the first experiment, we recorded the ranging behaviour of free-ranging, radio-collared koalas prior to, during and after cattle grazed within their usual home range. Koalas decreased their distance travelled and the size of their home range when they shared space with cattle, compared with the period before cattle started grazing within their home range. In the second experiment, we recorded the reactions of cattle towards koalas that they encountered on the ground, using motorised animal models: a model koala mounted on a remote-controlled vehicle and a model dog mounted on the same vehicle, and the vehicle alone. The koala model elicited aggression and fear in cattle, similar to the dog model, whereas their reaction to the vehicle was significantly less aggressive. No actual attacks by the cattle were observed. The results provide experimental evidence that negative koala–livestock interactions occur and indicate that cattle and koalas may see each other as a disturbance.

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Phillips, Stephen. "It’s the blues Jim, but not as we know it: a response to FitzGibbon et al. (2016)." Australian Mammalogy 39, no. 1 (2017): 113. http://dx.doi.org/10.1071/am17007.

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A cautious approach to managing the impacts of disturbance on free-ranging koala (Phascolactos cinereus) populations is fundamental to effective management of this iconic species. The critique by FitzGibbon et al. (2017) of a pioneering study by Phillips (2016) on the impacts of noise on koalas argued that a departure from aspects of the methods, a disregard for disease issues, other koala mortality data and an onerous approach to mitigation of potential impact detracted from the merit of the work. In response and while acknowledging some departures in evaluation criteria, the primary outcomes arising from the study remain unchanged, concerns about unreported koala mortalities are premature, while mitigation measures proposed by Phillips (2016) have been misinterpreted. Unravelling the implications of anthropogenic disturbance on terrestrial wildlife communities is a rapidly expanding field of ecological study. The work in question provides novel descriptions of aversive behaviour by koalas, each of which remains testable in the context of disturbance ecology, thus laying the foundations for further research to be undertaken.

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Dexter, C. E., R. G. Appleby, J. Scott, J. P. Edgar, and D. N. Jones. "Individuals matter: predicting koala road crossing behaviour in south-east Queensland." Australian Mammalogy 40, no. 1 (2018): 67. http://dx.doi.org/10.1071/am16043.

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The ability to predict the frequency with which koalas (Phascolarctos cinereus) cross roads is an important step in developing mitigation strategies aimed at maintaining metapopulation viability for this species. In south-east Queensland, Australia, rapid urban development, including fragmentation and vehicle-related mortality, has contributed to a dramatic decline in local koala populations. Assessment of wildlife crossing structures that mitigates the impact of roads demonstrates these to be beneficial for many species. However, building enough structures to enable animals to move freely across impacted landscapes may be prohibitive in complex urban landscapes. The focus for this study was to consider the role of differing characteristics for species at risk. We examined the frequency of road crossings by individual koalas among six subpopulations in south-east Queensland. We explored the influence of potential predictor variables including: age, sex, and distance from roads. We established that road crossings were limited to a subset of individuals, with only 18 of 51 (~35%) koalas studied ever crossing a road. We found that koalas were disproportionately more likely to cross a road if they had initially been found within a distance of 100 m of that road. Males were more likely to cross roads than females, as were koalas aged less than five years. We suggest that successful wildlife road mitigation can be improved by better understanding the road-crossing behaviour of species such as the koala.

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Briscoe, Natalie J., Kathrine A. Handasyde, Stephen R. Griffiths, Warren P. Porter, Andrew Krockenberger, and Michael R. Kearney. "Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals." Biology Letters 10, no. 6 (June 2014): 20140235. http://dx.doi.org/10.1098/rsbl.2014.0235.

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How climate impacts organisms depends not only on their physiology, but also whether they can buffer themselves against climate variability via their behaviour. One of the way species can withstand hot temperatures is by seeking out cool microclimates, but only if their habitat provides such refugia. Here, we describe a novel thermoregulatory strategy in an arboreal mammal, the koala Phascolarctos cinereus. During hot weather, koalas enhanced conductive heat loss by seeking out and resting against tree trunks that were substantially cooler than ambient air temperature. Using a biophysical model of heat exchange, we show that this behaviour greatly reduces the amount of heat that must be lost via evaporative cooling, potentially increasing koala survival during extreme heat events. While it has long been known that internal temperatures of trees differ from ambient air temperatures, the relevance of this for arboreal and semi-arboreal mammals has not previously been explored. Our results highlight the important role of tree trunks as aboveground ‘heat sinks’, providing cool local microenvironments not only for koalas, but also for all tree-dwelling species.

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Johnston, Stephen. "Challenges associated with the development and transfer of assisted breeding technology in marsupials and monotremes: lessons from the koala, wombat and short-beaked echidna." Reproduction, Fertility and Development 31, no. 7 (2019): 1305. http://dx.doi.org/10.1071/rd18113.

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This reflective review describes how a research model, which was originally established for the successful AI of the koala (Phascolarctos cinereus), is currently being developed and extended to the wombat (Lasiorhinus latifrons and Vombatus ursinus) and short-beaked echidna (Tachyglossus aculeatus). The research model centres around the establishment of an AI program and involves: (1) semen collection, evaluation and preservation, requiring an understanding of male reproductive physiology and gamete biology; (2) timing of insemination, based on a knowledge of oestrous cycle and gestation physiology and oestrous behaviour; and (3) the appropriate placement of semen, which relies on an accurate description of female reproductive anatomy. Published and unpublished studies of assisted breeding technology (ABT) development in all three species of Australian mammals reported in this review (koala, wombat and short-beaked echidna) clearly demonstrate the importance of recognising species-specific variation in reproductive biology. Even in closely related species, such as the koala and wombat, subtle differences in reproductive physiology can hinder the transfer of ABT across species. Significant progress in marsupial and monotreme ABT will also require adequate access to captive wildlife colonies (zoos, university collections and private partners) in sufficient numbers in order to conduct quality science.

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Bentley, P. D., and T. D. Penman. "Is there an inherent conflict in managing fire for people and conservation?" International Journal of Wildland Fire 26, no. 6 (2017): 455. http://dx.doi.org/10.1071/wf16150.

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Wildfires are a natural disturbance in many ecosystems, creating challenges for land management agencies who need to simultaneously reduce risk to people and maintain ecological values. Here we use the PHOENIX RapidFire fire behaviour simulator to compare fuel treatment strategies that meet the twin objectives of reducing wildfire risk to human settlements and a fire sensitive endangered species, the koala (Phascolarctos cinereus) in south-eastern Australia. The local koala population is in decline and a conservation management plan is being prepared to exclude wildfire for a 10-year period to assist with population recovery. Twelve scenarios developed by the land management agencies were compared using four indicators: wildfire size; burn probability; impact from exposure to fire; and treatment cost. Compared with the current risk setting, three treatment scenarios were found to reduce wildfire size and burn probability concurrently to both people and koalas. These strategies worked by increasing the landscape area treated, which came with increased financial cost. However, the impact from exposure to fire for both property and koala habitat remains high. Additional complementary strategies beyond landscape fuel reductions are needed to reduce impact from exposure in the event of a wildfire.

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Jiang, Alex Zijian, Peter Murray, Clive Phillips, Andrew Tribe, and William Ellis. "Movement of Free-Ranging Koalas in Response to Male Vocalisation Playbacks." Animals 12, no. 3 (January 24, 2022): 287. http://dx.doi.org/10.3390/ani12030287.

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Effective conservation strategies rely on knowledge of seasonal and social drivers of animal behaviour. Koalas are generally solitary and their social arrangement appears to rely on vocal and chemical signalling. Male koala vocalisations, known as bellows, are believed to be closely related to their breeding behaviour. Previous research suggests that oestrous female koalas use bellows to locate unique males to mate with, and that males can similarly use bellows to evaluate the physical attributes of their peers. We tested the behavioural responses of 20 free ranging koalas to bellow recordings collected from small (<6 kg) and large (>8.5 kg) adult male koalas. Individual koala movement was reported by hourly-uploaded GPS coordinates. We report evidence of intra-male competition, with adult males approaching bellow playbacks, particularly those from small-sized males. In contrast, males under three years of age were averse to the playbacks. No patterns in the response of females were detected. Our results provide the strongest evidence yet that bellows are primarily a means by which males occupy and control space during the breeding season. Future studies are required to see if female response to bellows depends on their reproductive status.

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DeSantis, L. R. G., and C. Hedberg. "Stable isotope ecology of the koala (Phascolarctos cinereus)." Australian Journal of Zoology 64, no. 5 (2016): 353. http://dx.doi.org/10.1071/zo16057.

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Australia has undergone significant climate change, both today and in the past. Koalas, due to their restricted diet of predominantly eucalyptus leaves and limited drinking behaviour may serve as model organisms for assessing past climate change via stable isotopes of tooth enamel. Here, we assess whether stable carbon and oxygen isotopes from tooth enamel record known climate variables, including proxies of relative aridity (e.g. mean annual precipitation, mean annual maximum temperature, and relative humidity). The results demonstrate significant negative relationships between oxygen isotope values and both relative humidity and mean annual precipitation, proxies for relative aridity. The best model for predicting enamel oxygen isotope values incorporates mean annual precipitation and modelled oxygen isotope values of local precipitation. These data and the absence of any relationship between modelled oxygen isotope precipitation values, independently, suggest that koalas do not track local precipitation values but instead record relative aridity. The lack of significant relationships between carbon isotopes and climate variables suggests that koalas may instead be tracking the density of forests and/or their location in the canopy. Collectively, these data suggest that koalas are model organisms for assessing relative aridity over time – much like kangaroos.

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Dique, David S., Jim Thompson, Harriet J. Preece, Deidré L. de Villiers, and Frank N. Carrick. "Dispersal patterns in a regional koala population in south-east Queensland." Wildlife Research 30, no. 3 (2003): 281. http://dx.doi.org/10.1071/wr02043.

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Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

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Yndestad, Harald. "The code of the long-term biomass cycles in the Barents Sea." ICES Journal of Marine Science 60, no. 6 (January 1, 2003): 1251–64. http://dx.doi.org/10.1016/s1054-3139(03)00152-8.

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Abstract Barents Sea capelin (Mallotus villosus), Norwegian spring-spawning herring (Cluea harengus), and Northeast Arctic cod (Gadus morhua) have been associated with large fluctuations of biomass growth. The cause of these large fluctuations has been poorly understood and led to problems in biomass management. The identification of a deterministic cause would provide the possibility of forecasting future biomass fluctuations. In this investigation, the Kola Section sea temperature and the biomasses of capelin, herring, and cod have been analyzed by a wavelet transform to identify the source of the long-term cycles. The wavelet analysis shows that the Kola Section temperature has dominant cycles at the lunar-nodal tide cycles of 3×18.6=55.8, 18.5 and 18.6/3 = 6.2 years. The recruitment of Barents Sea capelin, Norwegian spring-spawning herring, and Northeast Arctic cod has adopted an optimal recruitment cycle close to the stationary 6.2 years Kola temperature cycle. Long-term biomass growth is correlated to the phase relation between the biomass eigen-frequency cycle and the Kola temperature cycles. The biomasses of capelin, herring and cod have long-term growth when the 6.2 and 18.6 years Kola temperature cycles are positive at the same time. There is a long-term biomass reduction when the temperature cycles are not positive at the same time, and a biomass collapse when the temperature cycles are negative at the same time. The deterministic property of the 18.6 years lunar-nodal tide provides a new way of long-term biomass forecasting over periods of 50–80 years or more.

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Schmid, LM, KL Schmid, and B. Brown. "Behavioural determination of visual function in the Koala (Phascolarctos cinereus)." Wildlife Research 18, no. 3 (1991): 367. http://dx.doi.org/10.1071/wr9910367.

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A behavioural estimate of the koala's dependence on vision was made using fabric hoods to degrade the vision of ten male koalas. Koalas were placed on the ground in a square enclosure, with a centrally placed 'tree'. With unobstructed vision, the koalas quickly travelled across the ground to the tree and climbed it. However, with severely reduced vision, the koalas would not search for or climb the tree. When their vision was obscured, the koalas tended to raise their forelegs when walking, taking high, reaching steps. The koala appears to require a certain minimum level of vision before climbing trees. Ocular chlamydial infection, which can cause a significant visual loss, may result in similar changes in behaviour and thus contribute to mortality.

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Ballantyne, K., A. Lisle, A. Mucci, and S. D. Johnston. "Seasonal oestrous cycle activity of captive female koalas in south-east Queensland." Australian Mammalogy 37, no. 2 (2015): 245. http://dx.doi.org/10.1071/am14018.

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This study investigated the seasonality of behavioural oestrus in a captive koala population in south-east Queensland. A total of 33 sexually mature koalas were examined over a 4-year period (2009–12) to determine the possible influence of temperature, photoperiod and rainfall on the incidence of expression of behavioural oestrus without the confounding effect of lactation or limiting food resource availability. Although signs of behavioural oestrus were detected throughout the year, an obvious seasonality was apparent, with significantly fewer females displaying behavioural oestrus in late autumn and winter (May–August) than September to April (P < 0.0001). While average monthly photoperiod (P < 0.0001) and average monthly temperature (P < 0.0001) were significantly related to oestrous behaviour, rainfall was not (P > 0.05). A better understanding of the seasonality of reproductive function in the female koala will facilitate the use of reproductive management-assisted breeding technology to enable improved genetic management in captive populations.

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Tobey, J. R., C. H. Andrus, L. Doyle, V. D. Thompson, and F. B. Bercovitch. "Maternal effort and joey growth in koalas (Phascolarctos cinereus)." Journal of Zoology 268, no. 4 (April 2006): 423–31. http://dx.doi.org/10.1111/j.1469-7998.2005.00041.x.

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Wilmer, JMW, A. Melzer, F. Carrick, and C. Moritz. "Low genetic diversity and inbreeding depression in Queensland Koalas." Wildlife Research 20, no. 2 (1993): 177. http://dx.doi.org/10.1071/wr9930177.

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The amount of genetic variation in two natural populations of Queensland koalas (Phascolarctos cinereus adustus) was assessed by analysis of mitochondrial DNA. Levels and any adverse effects of inbreeding (inbreeding depression) were estimated from the pedigree of a well-characterised captive colony. Genetic diversity of mitochondrial DNA was found to be exceedingly low both within and between the two populations, but the variation detected was found to be strongly structured geographically. Inbreeding levels in the captive colony were moderate to high yet the only apparent evidence of inbreeding depression was a male-biased sex ratio. There was no evidence for decreased juvenile survivorship or growth rate with inbreeding. Because of the limited data it would be premature to conclude that koalas are relatively resistant to the effects of inbreeding. However, we suggest the hypothesis that koalas have a history of small population size, resulting in reduced susceptibility to inbreeding depression.

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Ballantyne, K., S. T. Anderson, M. Pyne, V. Nicolson, A. Mucci, A. Lisle, and S. D. Johnston. "The use of a synthetic progesterone, levonorgestrel (LNG), to control the oestrous cycle in the koala." Reproduction, Fertility and Development 28, no. 10 (2016): 1526. http://dx.doi.org/10.1071/rd14387.

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This study investigated the efficacy of a synthetic progestogen, levonorgestrel (LNG), to control koala ovarian activity for the purposes of oestrous synchronisation. Captive koalas were administered either saline control or a 70-mg LNG implant on Day 2 of oestrus. Urogenital cytology, oestrous behaviour and plasma oestradiol-17β and LH concentrations were monitored over a 6-week period. After LNG implant removal females were monitored to determine if the return to oestrus was synchronised. LNG-treated koalas immediately ceased displaying oestrous behaviour, showed no evidence of cornified epithelial cells in smears of urogenital cytology and exhibited low plasma oestradiol-17β concentrations throughout the implantation period. In contrast, oestradiol-17β levels in control koalas showed evidence of continued cyclic activity associated with behavioural oestrus and increased cornified epithelial cells in urogenital smears on Days 33 to 35 after saline injection. After implant removal, LNG-treated koalas exhibited oestrus at 13, 14, 17 and 30 days after implant removal. Plasma LH concentrations varied throughout the study period with no significant time (P = 0.49) or treatment (P = 0.13) effect. Overall results from this study suggest that LNG implants in koalas can inhibit oestrous behaviour and reduce circulating oestradiol-17β levels before oestrus, most likely by preventing development of the pre-ovulatory follicle. However, there was no evidence of LH suppression by the LNG implants. Removal of LNG implants resulted in the synchronous return to oestrus in three of the four treated koalas. Further studies on a larger population are required to validate these findings.

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Logan, M. "Evidence for the occurrence of rumination-like behaviour, or merycism, in the koala (Phascolarctos cinereus, Goldfuss)." Journal of Zoology 255, no. 1 (September 2001): 83–87. http://dx.doi.org/10.1017/s0952836901001121.

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Ashman, Kita R., and Desley A. Whisson. "Developing guidelines for the use of traps to capture koalas." Australian Mammalogy 42, no. 3 (2020): 380. http://dx.doi.org/10.1071/am20018.

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Capture of wildlife is essential both for research and management, and minimising the amount of stress an animal experiences during capture is important. We examined the behavioural response of koalas to cage traps to improve protocols for trapping koalas. We used heat- and motion-sensing cameras to record the behaviour of koalas in traps, and the duration spent in traps. Behavioural responses were scored on a scale of 0 (no apparent response) to 3 (heightened response) from videos. We successfully trapped a koala in 19 of 21 attempts. For 12 occasions when traps were monitored with cameras, koalas spent 6.3–181.2min in traps and 8 of 12 koalas displayed heightened behavioural responses (score of ≥2). The frequency of response scores did not vary between males and females and was not influenced by trapped duration. We found that traps were effective for capturing koalas; however, to minimise overt behavioural responses by trapped koalas, trap-check intervals need to be as short as possible. We recommend the use of trap-trigger devices to alert personnel when a koala is trapped. The addition of such devices in trapping practices may reduce potential for adverse behavioural responses and improve the cost-efficacy of trapping.

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White, Neil A. "Ecology of the koala (Phascolarctos cinereus) in rural south-east Queensland, Australia." Wildlife Research 26, no. 6 (1999): 731. http://dx.doi.org/10.1071/wr98002.

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This study investigated home-range size, utilisation of tree species and patches, and the influence of spacing behaviour by females on social organisation. It was undertaken in south-east Queensland in an area dominated by agricultural activity (beef and dairy cattle and cropping). Extensive clearing in the study area resulted in patches of vegetation that varied in size from less that 1 ha to blocks of 50–100 ha. Eucalyptus tereticornis and E. crebra were the dominant species in these patches and koalas used both species. The average home-range size (delineated by the 95% probability polygon from a kernel estimator) was 34.4 ha and 15.0 ha for males and females respectively; that delineated by the 70% probability polygon was 12.5 ha and 5.0 ha for males and females respectively. Koalas were not reliant on corridor systems and sometimes moved further than 5 km in a season. Koalas have few non-food-related requirements, i.e. they do not need den sites, nest sites, display areas, etc. Furthermore, they do not utilise the understorey and their mobility between patches does not appear to be compromised by the absence of corridors of trees. It is suggested that, in comparison with other arboreal marsupials, it should be relatively easy to provide habitat for koalas within rural areas.

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Mitchell, Dave L., Mariela Soto-Berelov, and Simon D. Jones. "Regional Variation in Forest Canopy Height and Implications for Koala (Phascolarctos cinereus) Habitat Mapping and Forest Management." Forests 12, no. 11 (October 29, 2021): 1494. http://dx.doi.org/10.3390/f12111494.

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Previous research has shown that the Koala (Phascolarctos cinereus) prefers larger trees, potentially making this a key factor influencing koala habitat quality. Generally, tree height is considered at regional scales which may overlook variation at patch or local scales. In this study, we aimed to derive a set of parameters to assist in classifying koala habitat in terms of tree height, which can then be used as an overlay for existing habitat maps. To determine canopy height variation within a specific forest community across a broad area in eastern Australia, we used freely available Airborne Laser Scanning (ALS) data and adopted a straightforward approach by extracting maximum-height ALS returns within a total of 288 30 m × 30 m “virtual” ALS plots. Our findings show that while maximum tree heights generally fall within published regional-scale parameters (mean height 33.2 m), they vary significantly between subregions (mean height 28.8–39.0 m), within subregions (e.g., mean height 21.3–29.4 m), and at local scales, the tree heights vary in response to previous land-use (mean height 28.0–34.2 m). A canopy height dataset useful for habitat management needs to recognise and incorporate these variations. To examine how this information might be synthesised into a usable map, we used a wall-to-wall canopy height map derived from ALS to investigate spatial and nonspatial clustering techniques that capture canopy height variability at both intra-subregional (100s of hectares) and local (60 hectare) scales. We found that nonspatial K-medians clustering with three or four height classes is suited to intra-subregional extents because it allows for simultaneous assessment and comparison of multiple forest community polygons. Spatially constrained clustering algorithms are suited to individual polygons, and we recommend the use of the Redcap algorithm because it delineates contiguous height classes recognisable on a map. For habitat management, an overlay combining these height classification approaches as separate attributes would provide the greatest utility at a range of scales. In addition to koala habitat management, canopy height maps could also assist in managing other fauna; identifying forest disturbance, regenerating forest, and old-growth forest; and identifying errors in existing forest maps.

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Sutherland, William J. "Growth and foraging behaviour." Nature 330, no. 6143 (November 1987): 18–19. http://dx.doi.org/10.1038/330018a0.

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Savit, R., and R. K. P. Zia. "Quasiperiodic behaviour in growth oscillations." Journal of Physics A: Mathematical and General 20, no. 15 (October 21, 1987): L987—L992. http://dx.doi.org/10.1088/0305-4470/20/15/010.

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Masuda, Y., S. Kamisaka, and T. Hoson. "Growth behaviour of rice coleoptiles." Journal of Plant Physiology 152, no. 2-3 (January 1998): 180–88. http://dx.doi.org/10.1016/s0176-1617(98)80130-2.

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Ellis, W. A. H., A. Melzer, F. N. Carrick, and M. Hasegawa. "Tree use, diet and home range of the koala (Phascolarctos cinereus) at Blair Athol, central Queensland." Wildlife Research 29, no. 3 (2002): 303. http://dx.doi.org/10.1071/wr00111.

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Free-ranging koalas (Phascolarctos cinereus) were monitored by means of radio-relocation in the area of Blair Athol Coal Mine and surrounding properties. Daytime tree use, home range and diet of these koalas was determined in spring and autumn, as was the leaf moisture composition of potential fodder species. Koalas used on average 93 (male koalas) and 56 (female koalas) trees during the period of observation, occupying home ranges of 135 and 101 ha respectively. Mean sightings per tree were 1.19 for both males and females and home-range sizes were not significantly different between sexes or seasons. Koalas were observed returning to previously used daytime roosting trees infrequently (<12%). Although koalas were observed roosting in trees of the species that they ate, proportional species representation in the diet of these koalas during spring and autumn did not accurately reflect concurrent observations of their daytime tree-roosting behaviour. Koalas were observed to utilise non-fodder species for daytime roosting, and patterns of daytime tree use and diet selection varied between individuals inhabiting adjacent communities within the site. Leaf moisture of tree species represented in koala diets was greater in autumn than spring.

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Beauchamp, Miriam H., Fanny Dégeilh, Keith Yeates, Isabelle Gagnon, Ken Tang, Jocelyn Gravel, Antonia Stang, et al. "Kids’ Outcomes And Long-term Abilities (KOALA): protocol for a prospective, longitudinal cohort study of mild traumatic brain injury in children 6 months to 6 years of age." BMJ Open 10, no. 10 (October 2020): e040603. http://dx.doi.org/10.1136/bmjopen-2020-040603.

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IntroductionMild traumatic brain injury (mTBI) is highly prevalent, especially in children under 6 years. However, little research focuses on the consequences of mTBI early in development. The objective of the Kids’ Outcomes And Long-term Abilities (KOALA) study is to document the impact of early mTBI on children’s motor, cognitive, social and behavioural functioning, as well as on quality of life, stress, sleep and brain integrity.Methods and analysesKOALA is a prospective, multicentre, longitudinal cohort study of children aged 6 months to 6 years at the time of injury/recruitment. Children who sustain mTBI (n=150) or an orthopaedic injury (n=75) will be recruited from three paediatric emergency departments (PEDs), and compared with typically developing children (community controls, n=75). A comprehensive battery of prognostic and outcome measures will be collected in the PED, at 10 days, 1, 3 and 12 months postinjury. Biological measures, including measures of brain structure and function (magnetic resonance imaging, MRI), stress (hair cortisol), sleep (actigraphy) and genetics (saliva), will complement direct testing of function using developmental and neuropsychological measures and parent questionnaires. Group comparisons and predictive models will test the a priori hypotheses that, compared with children from the community or with orthopaedic injuries, children with mTBI will (1) display more postconcussive symptoms and exhibit poorer motor, cognitive, social and behavioural functioning; (2) show evidence of altered brain structure and function, poorer sleep and higher levels of stress hormones. A combination of child, injury, socioenvironmental and psychobiological factors are expected to predict behaviour and quality of life at 1, 3 and 12 months postinjury.Ethics and disseminationThe KOALA study is approved by the Sainte-Justine University Hospital, McGill University Health Centre and University of Calgary Conjoint Health Research Ethics Boards. Parents of participants will provide written consent. Dissemination will occur through peer-reviewed journals and an integrated knowledge translation plan.

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Phillips, Stephen. "Aversive behaviour by koalas (Phascolarctos cinereus) during the course of a music festival in northern New South Wales, Australia." Australian Mammalogy 38, no. 2 (2016): 158. http://dx.doi.org/10.1071/am15006.

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The effects of short-term disturbances that result in changes to movement patterns and/or behaviour of wildlife are poorly understood. In this study the movements of seven koalas were monitored before, during and after a five-day music festival. During the monitoring program koalas occupied home-range areas of 0.6–13 ha with one or more core areas of activity. Aversive behaviour in the form of evacuation of known ranging areas was demonstrated by three koalas that had core areas within 525 m of the approximate centre of the festival area, the associated responses comprising movements that were perpendicular to and away from staging areas where music was played. Responses contained within known ranging areas were observed in three other koalas whose core areas were located up to 600 m away. The type of response appeared related to the proximity of koala home ranges to music-staging areas, while the maximum distance associated with an aversive response was 725 m. Six of the radio-tracked koalas returned to their home-range areas following the conclusion of festival activities. While the specific stimulus eliciting aversive behaviour was not identified, responses in all instances were initiated during the musical phase of the festival event. The potential for short-term disturbances such as music festivals to significantly influence the ranging patterns of koalas warrants recognition of possible longer-term ecological consequences for planning and management purposes.

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Tekin, A., and J. W. Martin. "Fatigue crack growth behaviour of MA6000." Materials Science and Engineering 96 (December 1987): 41–49. http://dx.doi.org/10.1016/0025-5416(87)90538-6.

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Baur, Karin, Klemens Fellner, Mark Parsons, and Manuela Tschabold. "Growth behaviour of periodic tame friezes." Revista Matemática Iberoamericana 35, no. 2 (February 5, 2019): 575–606. http://dx.doi.org/10.4171/rmi/1063.

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JINGEN, Z., Z. JIANYUN, F. ZHONGXIN, and L. NIAN. "Growth behaviour of small fatigue cracks." International Journal of Fatigue 15, no. 2 (March 1993): 141–44. http://dx.doi.org/10.1016/0142-1123(93)90008-e.

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Itofuji, Haruki, and Ayumi Masutani. "Nucleation and growth behaviour of chunky graphite." International Journal of Cast Metals Research 14, no. 1 (July 2001): 1–14. http://dx.doi.org/10.1080/13640461.2001.11819419.

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Plewis, Ian. "Modelling Behaviour with Multivariate Multilevel Growth Curves." Methodology 1, no. 2 (January 2005): 71–80. http://dx.doi.org/10.1027/1614-1881.1.2.71.

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Abstract. Developmental data are often both longitudinal and multivariate and can be handled within a multilevel framework. This paper fits a range of multivariate multilevel models to both continuous and binary data to examine the ways in which a set of behavioural measures change together with age. These data were collected by researchers in Montreal, Canada. Methodologically, we find that within and between individual correlations vary only a little according to the ways in which the models are specified. Substantively, we find that measures of aggression and opposition are closely related but both are less closely related to a measure of hyperactivity. Models for the effects of socio-economic status on levels and changes are fitted, as are models that examine change conditional on an initial measure. The findings are compared with those previously obtained using a growth trajectories approach.

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Gehre, Florian, Jacob Otu, Kathryn DeRiemer, Paola Florez de Sessions, Martin L. Hibberd, Wim Mulders, Tumani Corrah, Bouke C. de Jong, and Martin Antonio. "Deciphering the Growth Behaviour of Mycobacterium africanum." PLoS Neglected Tropical Diseases 7, no. 5 (May 16, 2013): e2220. http://dx.doi.org/10.1371/journal.pntd.0002220.

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Stanley, Michael H. R., Luís A. N. Amaral, Sergey V. Buldyrev, Shlomo Havlin, Heiko Leschhorn, Philipp Maass, Michael A. Salinger, and H. Eugene Stanley. "Scaling behaviour in the growth of companies." Nature 379, no. 6568 (February 1996): 804–6. http://dx.doi.org/10.1038/379804a0.

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Bekedam, D. J., G. H. A. Visser, J. J. de Vries, and H. F. R. Prechtl. "Motor behaviour in the growth retarded fetus." Early Human Development 12, no. 2 (November 1985): 155–65. http://dx.doi.org/10.1016/0378-3782(85)90178-1.

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Benaqqa, Chahid, Jerome Chevalier, Malika Saädaoui, and Gilbert Fantozzi. "Slow crack growth behaviour of hydroxyapatite ceramics." Biomaterials 26, no. 31 (November 2005): 6106–12. http://dx.doi.org/10.1016/j.biomaterials.2005.03.031.

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Zhao, Xinbing. "About the stochastic behaviour in grain growth." Scripta Metallurgica et Materialia 33, no. 7 (October 1995): 1081–86. http://dx.doi.org/10.1016/0956-716x(95)00334-r.

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Journal articles on the topic 'Koala growth and behaviour'

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