Access the full text.
Sign up today, get DeepDyve free for 14 days.
Loading next page...
/lp/wiley/observations-on-the-utilisation-of-a-restored-wildlife-corridor-by-OgY0AAvrcJ
- Publisher
- Wiley
- Copyright
- Copyright © 2023 Ecological Society of Australia and John Wiley & Sons Australia, Ltd
- ISSN
- 1442-7001
- eISSN
- 1442-8903
- DOI
- 10.1111/emr.12576
- Publisher site
- See Article on Publisher Site
Abstract
IntroductionColonisation by various life forms is a commonly used indicator of restoration success in north Queensland's Wet Tropics (e.g., Freeman et al., 2009; Tucker & Simmons, 2009). Vegetation, birds and ground mammals are typical targets, providing an indication of the trajectory of recovery when compared to a reference site. There are, however, few, if any, studies examining the colonisation of restored sites by rainforest microbats, including wildlife corridors established specifically to improve habitat connectivity.When compared to better known local wildlife, the scarcity of rainforest microbat studies is matched by their absence in restoration literature. As noted in Inkster‐Draper's (2017) PhD study, although microbats comprise over 20% of the Wet Tropics bioregion's mammal fauna, the group is omitted from the Wet Tropics vertebrate atlas (Williams, 2006). Review shows the range of peer‐reviewed studies of Wet Tropics microbats is limited to Crome and Richards (1988) and papers detailing diet and pollination in the common blossom bat (Pteropodidae—Syconycteris australis) (Law & Lean, 1999; Law, 2001). Moreover, northern Queensland's microbat fauna includes two threatened species, the Bare‐rump Sheathtail Bat (Saccolaimus saccolaimus nudicluniatus) (Vulnerable—Environment Protection and Biodiversity Conservation Act 1999; Endangered—Nature Conservation Act 1992) and the Diadem Leaf‐nosed Bat (Hipposideros diadema) (Near Threatened – Nature Conservation Act 1992).Local studies in restored rainforest have shown planting age, habitat structure and connectivity influence the rate and nature of colonisation by ground mammals and birds (Paetkau et al., 2009; Freeman et al., 2015). It is unknown if microbats respond in similar fashion, however, their wing morphology is a reliable predictor of habitat preference. Norberg and Rayner (1987) showed that Aspect Ratio (AR) (wing length relative to width) is a key determinant of microbat flight. Using fast flight, high AR‐winged bats are adapted to open area foraging. Conversely, low AR‐winged species typically forage in forested habitats, where slower flight and the ability to manoeuvre in dense vegetation are required; these species are aptly described as ‘clutter adapted’.In their logging area study, Crome and Richards (1988) found that microbats were strongly influenced by habitat structure and could be grouped based on wing morphology. Adams et al. (2009) also concluded that habitat structure was a significant factor in the distribution of microbats in a south‐east New South Wales study. In Brazil, Rocha et al. (2018) found specialist ‘clutter adapted’ frugivorous microbats in secondary forest (15‐30 years) and suggested that restored corridors would benefit microbat conservation. A similar suggestion was made by Law (2001) based on data relating to common blossom bats in the north Queensland uplands. Collectively, these studies suggest that habitat structure and connectivity are potential determinants of microbat presence.In north Queensland's Wet Tropics, historical fragmentation and contemporary climate change threaten species persistence (Laurance, 1994; Williams & de la Fuente, 2021). As an adaptive management response to these threats, beginning in the mid‐1990s, wildlife corridor restoration projects were initiated to restore habitat connectivity on the Atherton Tablelands (Tucker & Simmons, 2009). Donaghy's Corridor is a 1.2 km restored riparian corridor along Toohey Creek, which links the Lake Barrine National Park fragment (498 ha) to Gadgarra (Wooroonooran) National Park (80,000 ha); both sites are part of the Wet Tropics World Heritage Area (Figure 1). Planting was conducted over four years (1995–1998) using 16800 seedlings of 100 local species. Monitoring of vegetation and ground fauna was completed over a 3‐year period immediately after establishment, with results reported in Tucker and Simmons (2009) and Paetkau et al. (2009). Members of the Dugulbara Yidin‐ji, Traditional Owners of the land, were active participants in the planning, implementation and monitoring of the corridor project.1FIGUREAnabat survey locations.The primary aim of this study was to determine any evidence of corridor utilisation and/or colonisation by microbats. In addition to documenting microbat presence in a tropical restoration site, this study aimed to record microbats in directly adjacent pasture, and in reference forest at either end of the corridor, to detect any differences in species composition between the three sites.MethodologyOver a 12‐month period in 2021, Anabat Swift (Titley Scientific) detectors were deployed in each of the four yearly corridor plantings (four sites), in adjacent pasture >100 m from forest (two sites), and in reference forest at either end of the corridor (two sites) (see Figure 1). A single detector was placed in the eight sites for four nights in March, September and December for a total of 12 detector nights/site. Anabats were secured to trees at breast height in corridor and forest sites, and on star pickets at the same height in pasture sites. Standard omnidirectional microphones were used. Echolocation analysis was performed in Anabat Insight (Titley Scientific, Brisbane).Call sequence files were processed through a noise filter to remove files containing only non‐bat sounds. A Decision Tree analysis (GF unpubl data) was applied to all remaining files to group, and tentatively label, detected bat calls based on a combination of call metrics derived from zero‐crossing analysis, for example characteristic frequency (Fc), pulse duration (Dur), time between pulses (TBC), slope (S1 and Sc) and pulse curvature. Preliminary call identities applied by the Decision Tree were then confirmed or adjusted manually by comparing the call spectrograms and derived metrics with those of reference calls from northern Queensland (GF unpubl data), and/or with published call descriptions (e.g., Reinhold et al., 2001; Milne, 2002; Armstrong et al., 2021).A number of studies were used to determine species AR including Norberg and Rayner (1987), Fullard et al. (1991), Brigham et al. (1997) and Rhodes (2002). AR for the Northern Freetail Bat (Chaerephon jobensis) was sourced from McKenzie et al. (2002). Where AR was not available for a species, the AR of congeneric species was derived from sources cited.Counts of species activity (i.e., numbers of call passes (a call of at least 1 s, separated from a similar call by at least 1 s) per species) at each site were summarised. Unresolved calls (i.e., those that could not be reliably attributed to a single species) were excluded.This 12‐month study is confined to three sampling efforts at six locations across a single site, in a relatively unique physical setting. Sample size and lack of replication do not permit reliable statistical evaluation. In this paper, we seek only to determine if the plantings at Donaghy's Corridor have attracted microbats, presenting the summed results of species call passes to confirm presence and record any differences between sites.ResultsMore than >95% of calls were reliably attributed to 12 species from six families, including 11 distinct species and one of the Long‐eared Bats (Nyctophilus). Three long‐eared bat species potentially occur in the study area, including N. bifax, N. geoffroyi and N. gouldi. Nyctophilus bifax AR (Rhodes, 2002) is used here, given it is the Long‐eared Bat most likely to occur locally (Churchill, 2008).Species composition is broadly similar within the corridor (Table 1), although the 1997 planting had lower call activity. All the low AR ‘clutter‐adapted’ species were also recorded in reference forest. Considering the structure and floristics of the corridor plantings are similar throughout, the cause of reduced diversity in the 1997 planting area is unknown and limited sampling effort renders any assumptions unreliable.1TABLEMicrobat call passes in corridor, reference forest and pasture sites (cogeneric species bracketed where species AR unknown).SpeciesAR1995199619971998Forest ReferencePastureAustronomus australis7.90000016Chaerephon jobensis8.0000001Hipposideros diadema6.21141002110Miniopterus australis6.614434512612458Miniopterus orianae (M. schreibersii)6.60000843Myotis macropus (M. moluccarum)6.0377016310420Nyctophilus (bifax)5.1080441744Ozimops lumsdenae (Mormopterus beccarii)6.9000001Ozimops ridei (Mormopterus sp.)7.20610058Rhinolophus megaphyllus6.12041512590Saccolaimus.sacc nudicluniatus (S. flaviventris)8.201600088Vespadelus pumilus6.37545021072Abbreviation: AR, Aspect Ratio.Activity in the corridor was dominated by species of forest environments, for example Eastern Horse‐shoe Bat (Rhinolophus megaphyllus) and the Near Threatened Diadem Leaf‐nosed Bat. High numbers of Diadem Leaf‐nosed Bat calls in the 1995 planting may be due to the close proximity of a roosting tree or hunting perch, but this is unknown. Prey associated with the aquatic habitats of Toohey Creek have attracted Large‐footed Myotis (Myotis macropus).Species composition in pasture sites differed from corridor and reference sites, being dominated by higher AR species, for example, White‐striped Free‐tail Bat (Austronomus australis), the Northern Free‐tail and other Molossid Bats (e.g., Ozimops spp.). ‘Clutter‐adapted’ species were rarely recorded in pasture sites (Table 1).Fewer calls overall were recorded during the September sampling, however, calls recorded during December and March were similar.This study extends the range of the threatened Bare‐rump Sheathtail Bat previously unrecorded in the uplands of the Atherton Tablelands, and known locally from only three Wet Tropics lowland sites (Atlas of Living Australia: accessed 13/01/2023). The species is possibly known from other tropical upland sites, but there are no records within the peer‐reviewed literature, nor lodged with relevant databases, so this paper represents the first published record. However, few records probably reflect the paucity of local microbat surveys and the difficulty of detecting the species prior to recent developments in echolocation call identification (e.g., Armstrong et al., 2021). A spectrogram of this record is provided (Figure 2).2FIGURESpectogram: Saccolaimus saccolaimus nudicluniatus.DiscussionSeparation exists between two groups of microbats with different foraging strategies (Fenton, 1990). With the exception of the Little Bent‐winged Bat (Miniopterus australis), which was recorded in all sites, and the Large‐footed Myotis, which is a specialised over‐water forager, the absence or much reduced activity levels of low AR species from pasture sites reflects preferential use of restored vegetation as habitat for these ‘clutter‐adapted’ species. Conversely, higher AR microbats adapted for open‐area foraging were rarely detected in corridor vegetation or reference forest. Occasional calls of high AR species detected in those sites are likely attributable to individuals foraging above the forest canopy where faster direct flight is required.These results align with Crome and Richards (1988) whose data showed differences between bats in closed rainforest canopies and those foraging in logging gaps, similar to the studies of Adams et al. (2009). McGregor et al. (2017) recorded the forest‐dependent microbats Nyctophilus and Myotis preferentially using a purpose‐built faunal overpass between forested areas. In a study of Mexican Phyllostomidae by de la Peña‐Cuéllar et al. (2015), similar delineation existed between species of open areas and those within forested riparian corridors. However, the low AR bats recorded in this study are found along large sections of Australia's east coast and none are rainforest‐dependant (Churchill, 2008), also occurring in sclerophyll vegetation. Local avoidance of open areas by ‘clutter adapted’ species may reflect greater levels of habitat specialisation in the tropics.Tng et al. (unpbl data) found that forest structure in Donaghy's Corridor, when compared to adjacent reference forest, was similar in terms of height, stem size class distribution, stem basal area and numbers of individual stems. Such structural similarity to adjacent reference forest is likely to provide a range of foraging opportunities for ‘clutter‐adapted’ species and as plantings mature, an increasing supply of roost sites. Microbat composition in reference forest and restored habitat was quite similar, suggesting that, for microbats, a level of structural connectivity now exists (Keitt et al., 1997).In a parallel 12‐month study of bird colonisation, Tucker and Freeman (unpubl data) recorded 43 species in the corridor from a number of guilds, although 30 of 43 species incorporate invertebrates in their diet. Encompassing 14 species, the largest foraging guild recorded were arboreal insectivores, employing a variety of foraging strategies including highly manoeuvrable hawking and gleaning, for example Grey Fantail (Rhipidura albiscapa) and Yellow‐breasted Boatbill (Machaerirhynchus flaviventer). There are differences in rainforest birds and microbats foraging strategies but the presence of specialised arboreal insectivorous birds does demonstrate prey abundance; prey is likely a key contributor to the presence of low AR species within the corridor. Continuous prey availability supports the notion that previously separated microbat populations may now be continuous and therefore connectivity for this group may also be functional (Tischendorf & Fahrig, 2000).However, without pre‐planting data, it is impossible to know whether habitat connectivity was a factor affecting microbat distribution, and therefore if structural and functional connectivity has been re‐established.Despite this limitation and the small size of the study, the separation seen here between high AR pasture bats and low AR forest bats indicates movement and foraging behaviour of low AR species are closely tied to habitat. If inter‐fragment movement of low AR microbats is constrained in this poorly studied group, the local effects of fragmentation and climate change may be as detrimental to microbats as that postulated for other vertebrate groups.Further replicated studies are required across a range of tropical and sub‐tropical ecosystems where researchers, students and practitioners should explore relationships between landscape connectivity, forest structure and tropical microbat populations. Land managers should be encouraged to retain and restore riparian vegetation, especially where inter‐fragment connectivity exists or can be re‐established.Conflict of inTerest StatementThe authors submit that they have no conflict of interest in the work or its publication.AcknowledgementOpen access publishing facilitated by James Cook University, as part of the Wiley ‐ James Cook University agreement via the Council of Australian University Librarians.ReferencesAdams M., Law B. and French K. (2009) Vegetation structure influences the vertical stratification of open‐ and edge‐pace aerial‐foraging bats in harvested forests. Forest Ecology and Management 258, 2090–2100.Armstrong K., Broken‐Brow J., Hoye G., Ford G., Thomas M. and Corben C. (2021) Effective identification of sheath‐tailed bats of Australian forests and woodlands. Australian Journal of Zoology 68, 346–363. https://doi.org/10.1071/ZO20044.Brigham R., Francis R. and Hamdorf S. (1997) Microhabitat use by two species of Nyctophilus bats: a test of ecomorphology theory. Australian Journal of Zoology 45, 553–560.Churchill S. (2008) Australian Bats, 2nd edn. Reed New Holland, Sydney.Crome F. and Richards G. (1988) Bats and gaps: microchiropteran community structure in a Queensland rainforest. Ecology 69, 1960–1969.de la Peña‐Cuéllar E., Benítez‐Malvido J., Avila‐Cabadilla L., Martínez‐Ramos M. and Estrada A. (2015) Structure and diversity of phyllostomid bat assemblages on riparian corridors in a human‐dominated tropical landscape. Ecology and Evolution 5 (4), 903–913. https://doi.org/10.1002/ece3.1375.Fenton M. (1990) The foraging behaviour and ecology of animal‐eating bats. Canadian Journal of Zoology 68, 411–422. https://doi.org/10.1139/z90‐061.Freeman A., Catterall C. and Freebody K. (2015) Use of restored habitat by rainforest birds is limited by spatial context and species' functional traits but not by their predicted climate sensitivity. Biological Conservation 186, 107–114.Freeman A., Freeman A. B. and Burchill S. (2009) Bird use of revegetated sites along a creek connecting rainforest remnants. Emu 109, 331–338.Fullard J., Koehler C., Surlykke A. and McKenzie N. (1991) Echolocation ecology and flight morphology of insectivorous bats (Chiroptera) in South‐Western Australia. Australian Journal of Zoology 39, 427–438.Inkster‐Draper T. (2017) Biogeography of bats in the Australian Wet Tropics: current distribution and response to future climate change. PhD thesis, James Cook University.Keitt T., Urban D. and Milne B. (1997) Detecting critical scales in fragmented landscapes. conservation ecology. Online1(1): 4. Accessed October 28, 2002. http://www.consecol.org/vol1/iss1/art4/.Laurance W. (1994) Rainforest fragmentation and the structure of small mammal communities in tropical Queensland. Biological Conservation 69, 23–32.Law B. (2001) The diet of the common blossom bat (Syconycteris australis) in upland tropical rainforest and the importance of riparian areas. Wildlife Research 28, 619–626.Law B. and Lean M. (1999) Common blossom bats (Syconycteris australis) as pollinators in fragmented Australian tropical rainforest. Biological Conservation 91 (2–3), 201–212.McGregor M., Matthews K. and Jones D. (2017) Vegetated Fauna overpass disguises road presence and facilitates permeability for Forest microbats in Brisbane, Australia. Frontiers in Ecology and Evolution 5, 1–10. https://doi.org/10.3389/fevo.2017.00153.McKenzie N., Start A. and Bullen R. (2002) Foraging ecology and organisation of a desert bat fauna. Australian Journal of Zoology 50, 529–548.Milne D. (2002) Key to the bat calls of the top end of the Northern Territory. Technical Report No. 71, Parks and Wildlife Commission of the Northern Territory, Darwin.Norberg U. and Rayner J. (1987) Ecological morphology and flight in bats (Mammalia; Chiroptera): wing adaptations, flight performance, foraging strategy and echolocation. Philosophical Transactions of the Royal Society B 316, 335–427. https://doi.org/10.1098/rstb.1987.0030.Paetkau D., Vasquez E., Tucker N. and Moritz C. (2009) Monitoring movement into and through a newly planted rainforest corridor using genetic analysis of natal origin. Ecological Management and Restoration 10 (3), 210–216.Reinhold L., Law B., Ford G. and Pennay M. (2001) Key to the Bat Calls of South‐East Queensland and North‐East New South Wales. Department of Natural Resources and Mines, Brisbane.Rhodes M. (2002) Assessment of sources of variance and patterns of overlap in microchiropteran wing morphology in Southeast Queensland, Australia. Canadian Journal of Zoology 80, 450–460.Rocha R., Ovaskainen O., Lopez‐Baucells A. et al. (2018) Secondary forest regeneration benefits old‐growth specialist bats in a fragmented tropical landscape. Scientific Reports 8, 3819. https://doi.org/10.1038/s41598‐018‐2199.Tischendorf L. and Fahrig L. (2000) On the usage and measurement of landscape connectivity. Oikos 90, 7–19.Tucker N. and Simmons T. (2009) Restoring a rain forest habitat linkage in North Queensland: Donaghy's corridor. Ecological Management and Restoration 10, 98–112.Williams S. (2006) Vertebrates of the Wet Tropics rainforests of Australia: specia7890es distributions and biodiversity. Cooperative research centre for Tropical Rainforest ecology and management p. 282. Rainforest CRC, Cairns, Australia.Williams S. and de la Fuente A. (2021) Long‐term changes in populations of rainforest birds in the Australia Wet Tropics bioregion: a climate‐driven biodiversity emergency. PLoS One 16, e0254307. https://doi.org/10.1371/journal.pone
Journal
Ecological Management & Restoration – Wiley
Published: Jan 1, 2023
Keywords: connectivity; evaluation; faunal habitat; monitoring; rainforest; World Heritage Sites