Abstract. Grasslands are among the most endangered ecosystems, with <1% of Victorian grasslands remaining. Extinctions of many grassland fauna species have occurred since European settlement due to loss of suitable habitat, and dramatic range reductions continue for those that still exist. Fat-tailed dunnarts (Sminthopsis crassicaudata) are the only small ground-dwelling marsupial known to persist in Victorian grassland habitats. The last long-term targeted surveys for this species were conducted in Victoria in the 1970s. Incidental findings from more recent short-term targeted and non-targeted surveys in the same area suggest a decline. We performed direct targeted surveys for fat-tailed dunnarts at the 1970s survey site over a 12-month period in 2019 and found no evidence of fat-tailed dunnart presence. The species is classified as Near Threatened in the state and Least Concern internationally. Our work highlights the importance of targeted surveys to assess the stability of this species across Victoria, and the need for collection of long-term data to better identify population declines.
{"title":"Fat-tailed dunnarts (Sminthopsis crassicaudata) of the Werribee grasslands: a case study of a species in decline","authors":"Emily L. Scicluna, B. P. Gill, K. Robert","doi":"10.1071/ZO21014","DOIUrl":"https://doi.org/10.1071/ZO21014","url":null,"abstract":"Abstract. Grasslands are among the most endangered ecosystems, with <1% of Victorian grasslands remaining. Extinctions of many grassland fauna species have occurred since European settlement due to loss of suitable habitat, and dramatic range reductions continue for those that still exist. Fat-tailed dunnarts (Sminthopsis crassicaudata) are the only small ground-dwelling marsupial known to persist in Victorian grassland habitats. The last long-term targeted surveys for this species were conducted in Victoria in the 1970s. Incidental findings from more recent short-term targeted and non-targeted surveys in the same area suggest a decline. We performed direct targeted surveys for fat-tailed dunnarts at the 1970s survey site over a 12-month period in 2019 and found no evidence of fat-tailed dunnart presence. The species is classified as Near Threatened in the state and Least Concern internationally. Our work highlights the importance of targeted surveys to assess the stability of this species across Victoria, and the need for collection of long-term data to better identify population declines.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"62 1","pages":"27 - 32"},"PeriodicalIF":0.8,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73237431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reannan Honey, C. McLean, B. Murray, Michael N. Callan, J. Webb
ABSTRACT The loss of hollow-bearing trees is a key threat for many hollow-dependent taxa. Nesting boxes have been widely used to offset tree hollow loss, but they have high rates of attrition, and, often, low rates of usage by target species. To counter these problems, chainsaw carved hollows (artificial cavities cut into trees) have become a popular alternative, yet little research has been published on their effectiveness. We examined the usage of 150 chainsaw carved hollows by cavity-dependent fauna in the central west of New South Wales using observations from traditional inspection methods and remote cameras. Between October 2017 and April 2019, we detected 21 species of vertebrates (two reptile, one amphibian, 10 bird, and eight mammal species) inside chainsaw carved hollows, but the number of species detected was dependent on the chosen monitoring method. We detected six species inside hollows during physical inspections, whereas remote cameras detected 21 species entering hollows. Cameras detected eight species using hollows as breeding sites, whereas physical inspections detected just four species. Cameras detected two threatened mammals (squirrel glider (Petaurus norfolcensis) and greater glider (Petauroides volans)) raising young inside hollows, yet we failed to detect these species during physical inspections. For birds, the two methods yielded equivalent results for detection of breeding events. Overall, our study showed that few cavity-dependent species used chainsaw carved hollows as breeding sites. This highlights how artificial hollows are not a substitute for retaining naturally occurring hollows in large trees and revegetation programs.
{"title":"Choice of monitoring method can influence estimates of usage of artificial hollows by vertebrate fauna","authors":"Reannan Honey, C. McLean, B. Murray, Michael N. Callan, J. Webb","doi":"10.1071/ZO21012","DOIUrl":"https://doi.org/10.1071/ZO21012","url":null,"abstract":"ABSTRACT The loss of hollow-bearing trees is a key threat for many hollow-dependent taxa. Nesting boxes have been widely used to offset tree hollow loss, but they have high rates of attrition, and, often, low rates of usage by target species. To counter these problems, chainsaw carved hollows (artificial cavities cut into trees) have become a popular alternative, yet little research has been published on their effectiveness. We examined the usage of 150 chainsaw carved hollows by cavity-dependent fauna in the central west of New South Wales using observations from traditional inspection methods and remote cameras. Between October 2017 and April 2019, we detected 21 species of vertebrates (two reptile, one amphibian, 10 bird, and eight mammal species) inside chainsaw carved hollows, but the number of species detected was dependent on the chosen monitoring method. We detected six species inside hollows during physical inspections, whereas remote cameras detected 21 species entering hollows. Cameras detected eight species using hollows as breeding sites, whereas physical inspections detected just four species. Cameras detected two threatened mammals (squirrel glider (Petaurus norfolcensis) and greater glider (Petauroides volans)) raising young inside hollows, yet we failed to detect these species during physical inspections. For birds, the two methods yielded equivalent results for detection of breeding events. Overall, our study showed that few cavity-dependent species used chainsaw carved hollows as breeding sites. This highlights how artificial hollows are not a substitute for retaining naturally occurring hollows in large trees and revegetation programs.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"1983 1","pages":"18 - 25"},"PeriodicalIF":0.8,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90303513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Booth, A. Dunstan, Katharine Robertson, J. Tedeschi
ABSTRACT Egg inviability at oviposition is a possible explanation for the high rate of early-stage embryo death of eggs laid by green turtles at Raine Island, the largest green turtle nesting aggregation in the world. We tested this possibility by assessing egg viability of freshly laid eggs. We found that green turtle eggs laid at Raine Island have high viability at their time of laying, and that there was no relationship between egg viability and early-stage embryo death or hatching success within a clutch. Hence, the inviable egg at oviposition hypothesis cannot explain the high death rate of early-stage embryos that is characteristic of green turtle clutches laid at Raine Island.
{"title":"Egg viability of green turtles nesting on Raine Island, the world's largest nesting aggregation of green turtles","authors":"D. Booth, A. Dunstan, Katharine Robertson, J. Tedeschi","doi":"10.1071/ZO21024","DOIUrl":"https://doi.org/10.1071/ZO21024","url":null,"abstract":"ABSTRACT Egg inviability at oviposition is a possible explanation for the high rate of early-stage embryo death of eggs laid by green turtles at Raine Island, the largest green turtle nesting aggregation in the world. We tested this possibility by assessing egg viability of freshly laid eggs. We found that green turtle eggs laid at Raine Island have high viability at their time of laying, and that there was no relationship between egg viability and early-stage embryo death or hatching success within a clutch. Hence, the inviable egg at oviposition hypothesis cannot explain the high death rate of early-stage embryos that is characteristic of green turtle clutches laid at Raine Island.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"94 49 1","pages":"12 - 17"},"PeriodicalIF":0.8,"publicationDate":"2021-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83745409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. V. Van Dyke, M. Thompson, C. Burridge, M. Castelli, S. Clulow, D. Dissanayake, Caroline M. Dong, J. Doody, D. Edwards, T. Ezaz, C. Friesen, M. Gardner, A. Georges, M. Higgie, Peta Hill, C. Holleley, Daniel S. Hoops, C. Hoskin, Deirdre L. Merry, J. Riley, E. Wapstra, G. While, S. Whiteley, M. Whiting, Stephen M Zozaya, C. Whittington
Abstract Australian lizards are a diverse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable diversity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship; mechanisms involved in mating, egg production, and sperm competition; nesting and gestation; sex determination; and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.
{"title":"Australian lizards are outstanding models for reproductive biology research","authors":"J. V. Van Dyke, M. Thompson, C. Burridge, M. Castelli, S. Clulow, D. Dissanayake, Caroline M. Dong, J. Doody, D. Edwards, T. Ezaz, C. Friesen, M. Gardner, A. Georges, M. Higgie, Peta Hill, C. Holleley, Daniel S. Hoops, C. Hoskin, Deirdre L. Merry, J. Riley, E. Wapstra, G. While, S. Whiteley, M. Whiting, Stephen M Zozaya, C. Whittington","doi":"10.1071/ZO21017","DOIUrl":"https://doi.org/10.1071/ZO21017","url":null,"abstract":"Abstract Australian lizards are a diverse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable diversity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship; mechanisms involved in mating, egg production, and sperm competition; nesting and gestation; sex determination; and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"10 1","pages":"168 - 199"},"PeriodicalIF":0.8,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78510782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The permanent exclusion of flying-foxes from camps (camp dispersal) near human settlements is a management tool commonly used to mitigate human–wildlife conflict. We summarised information on the costs and outcomes of 48 camp dispersals in Australia. Our aim was to improve the information base on which camp management decisions are made. Camp dispersals were largely triggered by impacts on neighbouring residents (75%). A disproportionately high number occurred in 2013–14, associated with changes in Queensland flying-fox management policy following an increase in the number of urban camps. Repeat actions over months or years were typically required to exclude flying-foxes from camps (58%). In 88% of cases, replacement camps formed within 1 km and became sites of transferred conflict. Only 23% of dispersal attempts were successful in resolving conflict for communities, generally after extensive destruction of roost habitat. Costs were poorly documented, although no dispersal attempt costing less than AU$250 000 proved successful. We conclude that camp dispersal is a high-risk, high-cost tool for mitigating human–wildlife conflict, in situ management strategies and tools should be developed, evidence-based information on management options should be made available to stakeholders via a nationally curated resource library, and research is required on impacts of camp management practices on flying-foxes.
{"title":"Review of dispersal attempts at flying-fox camps in Australia","authors":"B. Roberts, M. Mo, M. Roache, P. Eby","doi":"10.1071/ZO20043","DOIUrl":"https://doi.org/10.1071/ZO20043","url":null,"abstract":"The permanent exclusion of flying-foxes from camps (camp dispersal) near human settlements is a management tool commonly used to mitigate human–wildlife conflict. We summarised information on the costs and outcomes of 48 camp dispersals in Australia. Our aim was to improve the information base on which camp management decisions are made. Camp dispersals were largely triggered by impacts on neighbouring residents (75%). A disproportionately high number occurred in 2013–14, associated with changes in Queensland flying-fox management policy following an increase in the number of urban camps. Repeat actions over months or years were typically required to exclude flying-foxes from camps (58%). In 88% of cases, replacement camps formed within 1 km and became sites of transferred conflict. Only 23% of dispersal attempts were successful in resolving conflict for communities, generally after extensive destruction of roost habitat. Costs were poorly documented, although no dispersal attempt costing less than AU$250 000 proved successful. We conclude that camp dispersal is a high-risk, high-cost tool for mitigating human–wildlife conflict, in situ management strategies and tools should be developed, evidence-based information on management options should be made available to stakeholders via a nationally curated resource library, and research is required on impacts of camp management practices on flying-foxes.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"9 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90646239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to advances in fish-finding equipment and vessel capabilities, commercial and recreational fishers are now regularly accessing deep waters off the edge of the continental shelf and catching fish species that are rarely encountered in shallower waters or that have not previously been caught. This study details the capture of two Japanese rubyfish (Erythrocles schlegelii) in deep, offshore waters on the south coast of Western Australia, and in waters further south than previously encountered. This study also provides the first age estimates from counts of growth (opaque) zones in sectioned sagittal otoliths. The estimated ages of 8 years for both individuals, one female and the other male, are much lower than what would have been expected based on age estimates for this species derived from scales undertaken in an earlier study. Understanding the biological characteristics of these deepwater fish species will assist in future management of these resources.
{"title":"A rare capture of two Japanese rubyfish (Erythrocles schlegelii) (Richardson, 1846) off southern Western Australia, including their otolith characteristics and age","authors":"P. Coulson, G. Moore","doi":"10.1071/zo21020","DOIUrl":"https://doi.org/10.1071/zo21020","url":null,"abstract":"Due to advances in fish-finding equipment and vessel capabilities, commercial and recreational fishers are now regularly accessing deep waters off the edge of the continental shelf and catching fish species that are rarely encountered in shallower waters or that have not previously been caught. This study details the capture of two Japanese rubyfish (Erythrocles schlegelii) in deep, offshore waters on the south coast of Western Australia, and in waters further south than previously encountered. This study also provides the first age estimates from counts of growth (opaque) zones in sectioned sagittal otoliths. The estimated ages of 8 years for both individuals, one female and the other male, are much lower than what would have been expected based on age estimates for this species derived from scales undertaken in an earlier study. Understanding the biological characteristics of these deepwater fish species will assist in future management of these resources.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"52 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78322024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The role of the foregut (crop and proventriculus) in mechanical processing of food has received little attention in insects. Using the Australian plague locust (Chortoicetes terminifera) and the black field cricket (Teleogryllus commodus) as models, the role of the crop in processing of wheat or rye grass was examined. Interior cuticular structures (spines) of the foregut were described using light and scanning electron microscopy, with locusts having sclerotised structures and crops of crickets being unsclerotised internally. Muscular bands on the exterior surface of the crop part of the foregut are similar in males of both species, but contractions and movements are more forceful in locusts. Passage rate from the foregut is much faster in locusts (<3 h) than in crickets (>3 h). Water within the crop is reduced compared with the water content of fresh grass within the foregut of locusts, but water is increased in cricket crops. Spines within the crops are small relative to the size of food particles in both species. Some spines of locusts contain metals. The slower passage rate from the crop of crickets may be limited by the proventriculus. Foregut structure and food processing facilitates the generalist diet of crickets, but may restrict locusts to consuming softer grasses.
{"title":"The role of the foregut in digestion in the cricket Teleogryllus commodus and the locust Chortoicetes terminifera","authors":"Shouheng Zhou, J. D. Woodman, Hua Chen, P. Cooper","doi":"10.1071/ZO20092","DOIUrl":"https://doi.org/10.1071/ZO20092","url":null,"abstract":"Abstract The role of the foregut (crop and proventriculus) in mechanical processing of food has received little attention in insects. Using the Australian plague locust (Chortoicetes terminifera) and the black field cricket (Teleogryllus commodus) as models, the role of the crop in processing of wheat or rye grass was examined. Interior cuticular structures (spines) of the foregut were described using light and scanning electron microscopy, with locusts having sclerotised structures and crops of crickets being unsclerotised internally. Muscular bands on the exterior surface of the crop part of the foregut are similar in males of both species, but contractions and movements are more forceful in locusts. Passage rate from the foregut is much faster in locusts (<3 h) than in crickets (>3 h). Water within the crop is reduced compared with the water content of fresh grass within the foregut of locusts, but water is increased in cricket crops. Spines within the crops are small relative to the size of food particles in both species. Some spines of locusts contain metals. The slower passage rate from the crop of crickets may be limited by the proventriculus. Foregut structure and food processing facilitates the generalist diet of crickets, but may restrict locusts to consuming softer grasses.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"14 1","pages":"212 - 221"},"PeriodicalIF":0.8,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83779563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Goldingay, David A. Newell, Darren McHugh, Liam J. Bolitho
Population monitoring is required to guide conservation programs. We conducted a capture–mark–recapture study of a population of the vulnerable green and golden bell frog (Litoria aurea) at the northern end of its range. Frogs were captured and marked over three breeding seasons (2015/16, 2016/17, 2017/18) in a large coastal lagoon. We aimed to: (1) produce annual estimates of population size to describe population trajectory, and (2) investigate monthly variation in abundance, capture probability, and temporary emigration to understand how these factors change at a finer temporal scale. Frog abundance varied across the three annual breeding seasons: 60–280 adult males, 120–190 adult females, and 90–420 subadults. We infer that the population is stable because adult abundance estimates were higher after 2015/16. Because our study sampled only half the available breeding habitat, the overall population may number 350–850 adults. Our modelling revealed >40 males but <20 females were detected in the sample area in our monthly samples. Estimates of temporary emigration were high (males: 0.54; females: 0.79), suggesting behaviour that made frogs unavailable for capture between months. Our results suggest that monitoring at greater than annual intervals should be adequate to monitor the future trend of this population.
{"title":"Population stability in an unmanaged population of the green and golden bell frog in northern New South Wales, Australia","authors":"R. Goldingay, David A. Newell, Darren McHugh, Liam J. Bolitho","doi":"10.1071/zo20101","DOIUrl":"https://doi.org/10.1071/zo20101","url":null,"abstract":"Population monitoring is required to guide conservation programs. We conducted a capture–mark–recapture study of a population of the vulnerable green and golden bell frog (Litoria aurea) at the northern end of its range. Frogs were captured and marked over three breeding seasons (2015/16, 2016/17, 2017/18) in a large coastal lagoon. We aimed to: (1) produce annual estimates of population size to describe population trajectory, and (2) investigate monthly variation in abundance, capture probability, and temporary emigration to understand how these factors change at a finer temporal scale. Frog abundance varied across the three annual breeding seasons: 60–280 adult males, 120–190 adult females, and 90–420 subadults. We infer that the population is stable because adult abundance estimates were higher after 2015/16. Because our study sampled only half the available breeding habitat, the overall population may number 350–850 adults. Our modelling revealed >40 males but <20 females were detected in the sample area in our monthly samples. Estimates of temporary emigration were high (males: 0.54; females: 0.79), suggesting behaviour that made frogs unavailable for capture between months. Our results suggest that monitoring at greater than annual intervals should be adequate to monitor the future trend of this population.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":"46 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87806847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}