Abstract. Extreme weather events (e.g. heatwaves and droughts) can expose animals to environmental conditions outside of their zones of physiological tolerance, and even resistance, and impact long-term viability of populations and species. We examined the thermal and hygric physiology of the critically endangered western ringtail possum (Pseudocheirus occidentalis), a member of a family of marsupial folivores (Pseudocheiridae) that appear particularly vulnerable to environmental extremes. Basal metabolic rate and other standard physiological variables measured at an ambient temperature of 30°C conformed to values for other marsupials. At lower temperatures, body temperature decreased slightly, and metabolic rate increased significantly at 5°C. At higher temperatures, possums experienced mild hyperthermia and increased evaporative heat loss by licking rather than panting. Their point of relative water economy (–8.7°C) was more favourable than other pseudocheirid possums and the koala (Phascolarctos cinereus). We predict that western ringtail possums should tolerate low ambient temperatures well and be more physiologically tolerant of hot and dry conditions than common (Pseudocheirus peregrinus) and particularly green (Pseudochirops archeri) ringtail possums, and koalas. Our physiological data can be incorporated into mechanistic species distribution models to test our hypothesis that western ringtail possums should physiologically tolerate the climate of habitat further inland than their current distribution, and withstand moderate impacts of climate change in the south-west of Western Australia.
{"title":"Physiological implications of climate change for a critically endangered Australian marsupial","authors":"C. Cooper, P. Withers, James M. Turner","doi":"10.1071/ZO20067","DOIUrl":"https://doi.org/10.1071/ZO20067","url":null,"abstract":"Abstract. Extreme weather events (e.g. heatwaves and droughts) can expose animals to environmental conditions outside of their zones of physiological tolerance, and even resistance, and impact long-term viability of populations and species. We examined the thermal and hygric physiology of the critically endangered western ringtail possum (Pseudocheirus occidentalis), a member of a family of marsupial folivores (Pseudocheiridae) that appear particularly vulnerable to environmental extremes. Basal metabolic rate and other standard physiological variables measured at an ambient temperature of 30°C conformed to values for other marsupials. At lower temperatures, body temperature decreased slightly, and metabolic rate increased significantly at 5°C. At higher temperatures, possums experienced mild hyperthermia and increased evaporative heat loss by licking rather than panting. Their point of relative water economy (–8.7°C) was more favourable than other pseudocheirid possums and the koala (Phascolarctos cinereus). We predict that western ringtail possums should tolerate low ambient temperatures well and be more physiologically tolerant of hot and dry conditions than common (Pseudocheirus peregrinus) and particularly green (Pseudochirops archeri) ringtail possums, and koalas. Our physiological data can be incorporated into mechanistic species distribution models to test our hypothesis that western ringtail possums should physiologically tolerate the climate of habitat further inland than their current distribution, and withstand moderate impacts of climate change in the south-west of Western Australia.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74697112","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}
Lisa N. Godinho, L. Lumsden, G. Coulson, S. R. Griffiths
Abstract. Bat boxes are often used as a conservation tool in human-disturbed landscapes across Australia; however, to assess their effectiveness we need to understand the factors influencing their occupancy by insectivorous bats. We investigated roost selection by Gould’s wattled bat (Chalinolobus gouldii) using 76 bat boxes, comprising six designs, across three sites in suburban Melbourne, Australia. We conducted monthly surveys for a year and recorded the physical characteristics of each box. Five species of bats were recorded but Gould’s wattled bats dominated box occupancy year-round at all three sites. Group sizes ranged from 1 to 58 individuals, with maternity colonies forming over summer. There was little consistency in the use of selection criteria by Gould’s wattled bats when choosing a bat box as a day roost, with considerable variability across sites and seasons, highlighting the flexibility in roost site selection by this widespread, adaptable species. Our findings show that bat boxes can be an effective tool for providing supplementary roosts for Gould’s wattled bats in urbanised landscapes. However, little is known about the impact on the whole bat community, especially disturbance-sensitive taxa, of artificially increasing roosting resources for common species.
{"title":"Flexible roost selection by Gould’s wattled bats (Chalinolobus gouldii) using bat boxes in an urban landscape","authors":"Lisa N. Godinho, L. Lumsden, G. Coulson, S. R. Griffiths","doi":"10.1071/ZO20022","DOIUrl":"https://doi.org/10.1071/ZO20022","url":null,"abstract":"Abstract. Bat boxes are often used as a conservation tool in human-disturbed landscapes across Australia; however, to assess their effectiveness we need to understand the factors influencing their occupancy by insectivorous bats. We investigated roost selection by Gould’s wattled bat (Chalinolobus gouldii) using 76 bat boxes, comprising six designs, across three sites in suburban Melbourne, Australia. We conducted monthly surveys for a year and recorded the physical characteristics of each box. Five species of bats were recorded but Gould’s wattled bats dominated box occupancy year-round at all three sites. Group sizes ranged from 1 to 58 individuals, with maternity colonies forming over summer. There was little consistency in the use of selection criteria by Gould’s wattled bats when choosing a bat box as a day roost, with considerable variability across sites and seasons, highlighting the flexibility in roost site selection by this widespread, adaptable species. Our findings show that bat boxes can be an effective tool for providing supplementary roosts for Gould’s wattled bats in urbanised landscapes. However, little is known about the impact on the whole bat community, especially disturbance-sensitive taxa, of artificially increasing roosting resources for common species.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77018372","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 abundance of feral pigs in Australia has been estimated previously and been a topic of some debate. This study aims to update a previous estimate of abundance (13.5 million, 95% CI: 3.5 million to 23.5 million) of feral pigs in Australia. Abundance estimates for the 1970s, 1980s, 1990s, 2000s and 2010s were collated from published literature. Mean abundances in the middle decades were estimated using the ratio method. The average abundance of feral pigs varied from 4.4 million (95% CI: 2.4 million to 6.3 million) in the 1980s, to 3.0 million (95% CI: 2.3 million to 3.7 million) in the 1990s, to 3.2 million (95% CI: 2.4 million to 4.0 million) in the 2000s. Mean density across all 142 studies was 1.03 pigs km–2. The average abundance of feral pigs in Australia during the 1980s to 2000s was much lower and more precise than estimated previously, so scientists and managers should update their use of abundance estimates. Density estimates are above, and below, estimates of threshold host densities for infectious exotic disease establishment.
{"title":"How many feral pigs in Australia? An update","authors":"J. Hone","doi":"10.1071/ZO20077","DOIUrl":"https://doi.org/10.1071/ZO20077","url":null,"abstract":"Abstract. The abundance of feral pigs in Australia has been estimated previously and been a topic of some debate. This study aims to update a previous estimate of abundance (13.5 million, 95% CI: 3.5 million to 23.5 million) of feral pigs in Australia. Abundance estimates for the 1970s, 1980s, 1990s, 2000s and 2010s were collated from published literature. Mean abundances in the middle decades were estimated using the ratio method. The average abundance of feral pigs varied from 4.4 million (95% CI: 2.4 million to 6.3 million) in the 1980s, to 3.0 million (95% CI: 2.3 million to 3.7 million) in the 1990s, to 3.2 million (95% CI: 2.4 million to 4.0 million) in the 2000s. Mean density across all 142 studies was 1.03 pigs km–2. The average abundance of feral pigs in Australia during the 1980s to 2000s was much lower and more precise than estimated previously, so scientists and managers should update their use of abundance estimates. Density estimates are above, and below, estimates of threshold host densities for infectious exotic disease establishment.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82729987","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 two iconic Tasmanian species, the Tasmanian devil (Sarcophilus harrisii) and the thylacine (Thylacinus cynocephalus), are of great interest to the general public and the media. The most likely extinct Tasmanian wolf or tiger, the thylacine, symbolises human responsibility for nature and species conservation and inspired the ‘National Threatened Species Day’, which commemorates the death of the last thylacine at Beaumaris Zoo in Hobart on 7 September 1936 to raise awareness of endangered plants and animals. Since the spread of the Devil Facial Tumour Disease critically endangered the survival of the largest remaining native carnivore (S. harrisii) today, this has generated both scientific interest and the interest of the general public. Google Trends has already been used as a tool for documenting and investigating the information needs and concerns of the population, as has been shown using the example of diseases. In this study, Google Trends data were used to examine the seasonality of the search term ‘thylacine sightings’ and the development of the frequency of different search terms in the period between 2004 and 2020. As a result, relative search intensities for ‘thylacine cloning’ and ‘cloning extinct species’ have shown a decrease over time. While Google Trends cannot clearly determine search motivation, search terms can be selected for the examinations that document more hope or a rational need for information or concern.
{"title":"Thylacine and Tasmanian devil: between hope and reality – a lesson to be learnt from Google Trends search data","authors":"M. Zieger, Steffen Springer","doi":"10.1071/ZO20073","DOIUrl":"https://doi.org/10.1071/ZO20073","url":null,"abstract":"Abstract. The two iconic Tasmanian species, the Tasmanian devil (Sarcophilus harrisii) and the thylacine (Thylacinus cynocephalus), are of great interest to the general public and the media. The most likely extinct Tasmanian wolf or tiger, the thylacine, symbolises human responsibility for nature and species conservation and inspired the ‘National Threatened Species Day’, which commemorates the death of the last thylacine at Beaumaris Zoo in Hobart on 7 September 1936 to raise awareness of endangered plants and animals. Since the spread of the Devil Facial Tumour Disease critically endangered the survival of the largest remaining native carnivore (S. harrisii) today, this has generated both scientific interest and the interest of the general public. Google Trends has already been used as a tool for documenting and investigating the information needs and concerns of the population, as has been shown using the example of diseases. In this study, Google Trends data were used to examine the seasonality of the search term ‘thylacine sightings’ and the development of the frequency of different search terms in the period between 2004 and 2020. As a result, relative search intensities for ‘thylacine cloning’ and ‘cloning extinct species’ have shown a decrease over time. While Google Trends cannot clearly determine search motivation, search terms can be selected for the examinations that document more hope or a rational need for information or concern.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85372408","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. Small insectivorous bats commonly use torpor while day-roosting, even in summer. However, reproductive female bats are believed to benefit from avoiding torpor because a constant, elevated body temperature maximises the rate of offspring growth, which could increase offspring survival. We used temperature-sensitive radio-transmitters to locate roosts and document the thermal biology of pregnant and lactating females of Nyctophilus geoffroyi (9 g) and N. gouldi (11 g) at a woodland in a cool temperate climate. Unlike males, reproductive female Nyctophilus spp. roosted as small groups (<25) within insulated tree cavities. Roost switching occurred every 3.7 ± 1.5 (N. geoffroyi) or 1.7 ± 0.8 days (N. gouldi), and radio-tagged individuals roosted together and apart on different days. Skin temperature during roosting was most often between 32 and 36°C, and torpor was used infrequently. Male Nyctophilus have been shown in previous studies to use torpor daily during summer. These contrasting torpor patterns likely reflect the warmed cavities occupied by maternity colonies and the thermally unstable shallow crevices occupied by individual males. Our results support the hypothesis that availability of thermally suitable roosts will influence thermoregulatory patterns of reproductive females and hence the growth rates and survival of their offspring. Thus, it is important to conserve woodland habitat with trees in a range of decay stages to provide opportunities for selection and movement among roost trees by reproductive female bats.
{"title":"Roost use and thermoregulation by female Australian long-eared bats (Nyctophilus geoffroyi and N. gouldi) during pregnancy and lactation1","authors":"C. Turbill, G. Körtner, F. Geiser","doi":"10.1071/ZO20036","DOIUrl":"https://doi.org/10.1071/ZO20036","url":null,"abstract":"Abstract. Small insectivorous bats commonly use torpor while day-roosting, even in summer. However, reproductive female bats are believed to benefit from avoiding torpor because a constant, elevated body temperature maximises the rate of offspring growth, which could increase offspring survival. We used temperature-sensitive radio-transmitters to locate roosts and document the thermal biology of pregnant and lactating females of Nyctophilus geoffroyi (9 g) and N. gouldi (11 g) at a woodland in a cool temperate climate. Unlike males, reproductive female Nyctophilus spp. roosted as small groups (<25) within insulated tree cavities. Roost switching occurred every 3.7 ± 1.5 (N. geoffroyi) or 1.7 ± 0.8 days (N. gouldi), and radio-tagged individuals roosted together and apart on different days. Skin temperature during roosting was most often between 32 and 36°C, and torpor was used infrequently. Male Nyctophilus have been shown in previous studies to use torpor daily during summer. These contrasting torpor patterns likely reflect the warmed cavities occupied by maternity colonies and the thermally unstable shallow crevices occupied by individual males. Our results support the hypothesis that availability of thermally suitable roosts will influence thermoregulatory patterns of reproductive females and hence the growth rates and survival of their offspring. Thus, it is important to conserve woodland habitat with trees in a range of decay stages to provide opportunities for selection and movement among roost trees by reproductive female bats.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88234461","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 morphology of the skin of living dipnoans can be compared with the arrangements present in the dermis and epidermis of the snout and mandible of fossil dipnoans, but the structures that may have been present in the fossils are significantly reduced in living lungfish. One advantage of assessing the living species is that soft tissues are intact. Fossil dipnoans have cosmine in the epidermis of the snout and mandible, and the dermis is supported by several layers of structured extracellular matrix. Cosmine includes dentine elements as well as pore canals. Among the pore canals are gaps in the cosmine layer that would have housed electroreceptors in the living fish. Below the cosmine is a layer of cancellous bone, separated from the dermal tissues within by a thin, almost continuous, ossified layer. Deep to this layer is a region that lacks any ossified structure, and below this the tubules that pass through the dermis terminate in irregular bulbs. Thin branches with an ossified coat arise from the tubules in the terminal layer and enter the cancellous bone below the cosmine and the pore canals, although they are not numerous. Living dipnoans have no ossified structures in the skin, and lymphatic vessels in the snout are reduced to the plexus below the epidermis, and the lymphatic loops that emerge from the plexus and enter the epidermis. These are numerous and occur in regular layers. In the living species, the lymphatic loops are close to electroreceptors. This may have been the case in fossil lungfish as well. Parallels in fossil and living dipnoans are present.
{"title":"Skin morphology in fossil and living dipnoans","authors":"A. Kemp","doi":"10.1071/ZO20021","DOIUrl":"https://doi.org/10.1071/ZO20021","url":null,"abstract":"Abstract. The morphology of the skin of living dipnoans can be compared with the arrangements present in the dermis and epidermis of the snout and mandible of fossil dipnoans, but the structures that may have been present in the fossils are significantly reduced in living lungfish. One advantage of assessing the living species is that soft tissues are intact. Fossil dipnoans have cosmine in the epidermis of the snout and mandible, and the dermis is supported by several layers of structured extracellular matrix. Cosmine includes dentine elements as well as pore canals. Among the pore canals are gaps in the cosmine layer that would have housed electroreceptors in the living fish. Below the cosmine is a layer of cancellous bone, separated from the dermal tissues within by a thin, almost continuous, ossified layer. Deep to this layer is a region that lacks any ossified structure, and below this the tubules that pass through the dermis terminate in irregular bulbs. Thin branches with an ossified coat arise from the tubules in the terminal layer and enter the cancellous bone below the cosmine and the pore canals, although they are not numerous. Living dipnoans have no ossified structures in the skin, and lymphatic vessels in the snout are reduced to the plexus below the epidermis, and the lymphatic loops that emerge from the plexus and enter the epidermis. These are numerous and occur in regular layers. In the living species, the lymphatic loops are close to electroreceptors. This may have been the case in fossil lungfish as well. Parallels in fossil and living dipnoans are present.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79898710","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 bumphead parrotfish, Bolbometopon muricatum, is an iconic and ecologically significant species that is vulnerable to extinction. Although the Great Barrier Reef provides extensive habitat for this species, the scarcity of juvenile fish in this region may suggest that these populations rely on colonisation by adults from further north, rather than local larval recruitment. Consequently, B. muricatum populations exhibit the strongest latitudinal gradient of any parrotfish on the Great Barrier Reef. Here, we review all records of B. muricatum from the southern Great Barrier Reef and report a new observation of a juvenile at Heron Reef. This is the southernmost report of a juvenile for this species. Given its size (standard length, 25–30 cm), this individual is likely to have settled as a larval recruit in the relative vicinity of Heron Reef, rather than migrating from a more northern site on the Great Barrier Reef or beyond.
{"title":"Southernmost observation of a juvenile bumphead parrotfish, Bolbometopon muricatum (Valenciennes, 1840)","authors":"S. Martin, K. Brown, O. Hoegh‐Guldberg","doi":"10.1071/ZO20029","DOIUrl":"https://doi.org/10.1071/ZO20029","url":null,"abstract":"Abstract. The bumphead parrotfish, Bolbometopon muricatum, is an iconic and ecologically significant species that is vulnerable to extinction. Although the Great Barrier Reef provides extensive habitat for this species, the scarcity of juvenile fish in this region may suggest that these populations rely on colonisation by adults from further north, rather than local larval recruitment. Consequently, B. muricatum populations exhibit the strongest latitudinal gradient of any parrotfish on the Great Barrier Reef. Here, we review all records of B. muricatum from the southern Great Barrier Reef and report a new observation of a juvenile at Heron Reef. This is the southernmost report of a juvenile for this species. Given its size (standard length, 25–30 cm), this individual is likely to have settled as a larval recruit in the relative vicinity of Heron Reef, rather than migrating from a more northern site on the Great Barrier Reef or beyond.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81315221","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}
M. Walker, S. R. Griffiths, Christopher S. Jones, K. Robert
Abstract. Although variation in meal size is known to have an impact on digestive energetics, there is limited information on how it influences metabolic rate and energy assimilation in insectivorous bats. We investigated the influence of meal size, representing 10% or 20% of an individual’s weight, on the digestive energetics of Gould’s wattled bat, Chalinolobus gouldii (n = 61 bats). Using open-flow respirometry, we recorded a median resting metabolic rate of 2.0 mL g–1 h–1 (n = 51, range = 0.4–4.8) at an air temperature of 32°C. Median postprandial metabolic rate peaked at 6.5 (range = 3.4–11.6, n = 4) and 8.2 (range = 3.8–10.6, n = 7), representing 3.3- and 4.1-fold increases from resting metabolic rate for the two meal sizes. Using bomb calorimetry, we calculated the calorific value of the two meal sizes, and the calories lost during digestion. Following gut passage times of 120 min (range = 103–172, n = 15) and 124 min (range = 106–147, n = 12), C. gouldii assimilated 88.0% (range = 84.6–93.8, n = 5) and 93.3% (range = 84.0–99.4, n = 10) of the kilojoules available from the 10% and 20% meal sizes, respectively. When fed ad libitum, C. gouldii consumed a mean of 23.2% of their body weight during a single sitting (n = 18, range = 6.3–34.1%). Overall, digestive energetics were not significantly different between 10% or 20% meal sizes. The ability to ingest small and large meals, without compromising the rate or efficiency of calorie intake, indicates that free-ranging C. gouldii are likely limited by food available in the environment, rather than the ability to assimilate energy.
{"title":"The influence of meal size on the digestive energetics of Gould’s wattled bat, Chalinolobus gouldii","authors":"M. Walker, S. R. Griffiths, Christopher S. Jones, K. Robert","doi":"10.1071/ZO20028","DOIUrl":"https://doi.org/10.1071/ZO20028","url":null,"abstract":"Abstract. Although variation in meal size is known to have an impact on digestive energetics, there is limited information on how it influences metabolic rate and energy assimilation in insectivorous bats. We investigated the influence of meal size, representing 10% or 20% of an individual’s weight, on the digestive energetics of Gould’s wattled bat, Chalinolobus gouldii (n = 61 bats). Using open-flow respirometry, we recorded a median resting metabolic rate of 2.0 mL g–1 h–1 (n = 51, range = 0.4–4.8) at an air temperature of 32°C. Median postprandial metabolic rate peaked at 6.5 (range = 3.4–11.6, n = 4) and 8.2 (range = 3.8–10.6, n = 7), representing 3.3- and 4.1-fold increases from resting metabolic rate for the two meal sizes. Using bomb calorimetry, we calculated the calorific value of the two meal sizes, and the calories lost during digestion. Following gut passage times of 120 min (range = 103–172, n = 15) and 124 min (range = 106–147, n = 12), C. gouldii assimilated 88.0% (range = 84.6–93.8, n = 5) and 93.3% (range = 84.0–99.4, n = 10) of the kilojoules available from the 10% and 20% meal sizes, respectively. When fed ad libitum, C. gouldii consumed a mean of 23.2% of their body weight during a single sitting (n = 18, range = 6.3–34.1%). Overall, digestive energetics were not significantly different between 10% or 20% meal sizes. The ability to ingest small and large meals, without compromising the rate or efficiency of calorie intake, indicates that free-ranging C. gouldii are likely limited by food available in the environment, rather than the ability to assimilate energy.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83885420","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}
F. Geiser, A. Bondarenco, Shannon E. Currie, Anna C. Doty, G. Körtner, Bradley S. Law, Chris R. Pavey, A. Riek, Clare Stawski, C. Turbill, C. K. R. Willis, R. Brigham
Abstract. We aim to summarise what is known about torpor use and patterns in Australian and New Zealand (ANZ) bats from temperate, tropical/subtropical and arid/semiarid regions and to identify whether and how they differ. ANZ bats comprise ∼90 species from 10 families. Members of at least nine of these are known to use torpor, but detailed knowledge is currently restricted to the pteropodids, molossids, mystacinids, and vespertilionids. In temperate areas, several species can hibernate (use a sequence of multiday torpor bouts) in trees or caves mostly during winter and continue to use short bouts of torpor for the rest of the year, including while reproducing. Subtropical vespertilionids also use multiday torpor in winter and brief bouts of torpor in summer, which permit a reduction in foraging, probably in part to avoid predators. Like temperate-zone vespertilionids they show little or no seasonal change in thermal energetics during torpor, and observed changes in torpor patterns in the wild appear largely due to temperature effects. In contrast, subtropical blossom-bats (pteropodids) exhibit more pronounced daily torpor in summer than winter related to nectar availability, and this involves a seasonal change in physiology. Even in tropical areas, vespertilionids express short bouts of torpor lasting ∼5 h in winter; summer data are not available. In the arid zone, molossids and vespertilionids use torpor throughout the year, including during desert heat waves. Given the same thermal conditions, torpor bouts in desert bats are longer in summer than in winter, probably to minimise water loss. Thus, torpor in ANZ bats is used by members of all or most families over the entire region, its regional and seasonal expression is often not pronounced or as expected, and it plays a key role in energy and water balance and other crucial biological functions that enhance long-term survival by individuals.
{"title":"Hibernation and daily torpor in Australian and New Zealand bats: does the climate zone matter?1","authors":"F. Geiser, A. Bondarenco, Shannon E. Currie, Anna C. Doty, G. Körtner, Bradley S. Law, Chris R. Pavey, A. Riek, Clare Stawski, C. Turbill, C. K. R. Willis, R. Brigham","doi":"10.1071/ZO20025","DOIUrl":"https://doi.org/10.1071/ZO20025","url":null,"abstract":"Abstract. We aim to summarise what is known about torpor use and patterns in Australian and New Zealand (ANZ) bats from temperate, tropical/subtropical and arid/semiarid regions and to identify whether and how they differ. ANZ bats comprise ∼90 species from 10 families. Members of at least nine of these are known to use torpor, but detailed knowledge is currently restricted to the pteropodids, molossids, mystacinids, and vespertilionids. In temperate areas, several species can hibernate (use a sequence of multiday torpor bouts) in trees or caves mostly during winter and continue to use short bouts of torpor for the rest of the year, including while reproducing. Subtropical vespertilionids also use multiday torpor in winter and brief bouts of torpor in summer, which permit a reduction in foraging, probably in part to avoid predators. Like temperate-zone vespertilionids they show little or no seasonal change in thermal energetics during torpor, and observed changes in torpor patterns in the wild appear largely due to temperature effects. In contrast, subtropical blossom-bats (pteropodids) exhibit more pronounced daily torpor in summer than winter related to nectar availability, and this involves a seasonal change in physiology. Even in tropical areas, vespertilionids express short bouts of torpor lasting ∼5 h in winter; summer data are not available. In the arid zone, molossids and vespertilionids use torpor throughout the year, including during desert heat waves. Given the same thermal conditions, torpor bouts in desert bats are longer in summer than in winter, probably to minimise water loss. Thus, torpor in ANZ bats is used by members of all or most families over the entire region, its regional and seasonal expression is often not pronounced or as expected, and it plays a key role in energy and water balance and other crucial biological functions that enhance long-term survival by individuals.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85899201","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. We document changes in the avifauna of Longueville, a residential suburb of Sydney, between 1971–73 and 1977–79 based on daily bird lists, and make comparisons with the present avifauna based on surveys in 2013–14. Of the 31 most common native terrestrial bird species, 17 were ‘decreasers’, present in 1971–73 but not recorded in 2013–14 (although 16 of them were recorded in a large bushland remnant 5 km away), and 14 were ‘increasers’, seven of which were absent or very rare in 1971–73. Eleven species decreased during the 1970s, and six species afterwards. Eight species increased during the 1970s and six species afterwards. The decreasers were predominantly small insectivores and nectarivores. The increasers were of three main types: medium to large carnivores, large frugivores or granivores, and medium-sized nectarivores. Two of the nectarivores, the noisy miner (Manorina melanocephala) and rainbow lorikeet (Trichoglossus haematodus), now dominate the urban bird community of Longueville and are by far the most numerous birds. The increase of both species dates from the late 1970s. The noisy miner is highly aggressive towards other birds and its dramatic increase (it was absent in 1971–73) appears to be the chief cause of the decline of small native birds in Longueville.
{"title":"Radical changes in the avifauna of a Sydney suburb, 1971–2014","authors":"Philip Smith, Judy Smith","doi":"10.1071/ZO20019","DOIUrl":"https://doi.org/10.1071/ZO20019","url":null,"abstract":"Abstract. We document changes in the avifauna of Longueville, a residential suburb of Sydney, between 1971–73 and 1977–79 based on daily bird lists, and make comparisons with the present avifauna based on surveys in 2013–14. Of the 31 most common native terrestrial bird species, 17 were ‘decreasers’, present in 1971–73 but not recorded in 2013–14 (although 16 of them were recorded in a large bushland remnant 5 km away), and 14 were ‘increasers’, seven of which were absent or very rare in 1971–73. Eleven species decreased during the 1970s, and six species afterwards. Eight species increased during the 1970s and six species afterwards. The decreasers were predominantly small insectivores and nectarivores. The increasers were of three main types: medium to large carnivores, large frugivores or granivores, and medium-sized nectarivores. Two of the nectarivores, the noisy miner (Manorina melanocephala) and rainbow lorikeet (Trichoglossus haematodus), now dominate the urban bird community of Longueville and are by far the most numerous birds. The increase of both species dates from the late 1970s. The noisy miner is highly aggressive towards other birds and its dramatic increase (it was absent in 1971–73) appears to be the chief cause of the decline of small native birds in Longueville.","PeriodicalId":55420,"journal":{"name":"Australian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76935998","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}
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