Roost-Tier Preference in Roost-Trees: A Case Study in the Bats Pteropus giganteus

The Indian flying foxes Pteropus giganteus are habituated to spend the day hours roosting in suitable roost trees. They are seen hanging here and there in a roost tree. It is not known whether they have preferred roost sites rather hanging spots in the concerned roost tree. To testify the said hypothesis we selected two roost trees, Albizia lebbeck and Tamarindus indica locating at distant places (75 km apart) in the arid zone of West Bengal, India during the period of last ten years. It is revealed that P. giganteus preferred branches of the roost tree which are locating in the mid-tier of tree. But depending upon the situations the less preferred sites are not spared as these sites are used by the late comers. Statistical tests following application of one-way ANOVA justified significant effect of the roost branch on the abundance of bat population (P<0.05), abundance of bats in the roost branches is highly correlated in respect to the study years (r=0.96) is also justified from the study of normality distribution plot, and the results of GLMM strongly support the hypothesis irrespective of the variables, that is branches of the roost tree and the year of observations (P = 0.0).

Conventional wisdom on roosting behaviour of Australian flying foxes - a critical review, and evaluation using new data

1. Fruit bats (Family: Pteropodidae) are animals of great ecological and economic importance, yet their populations are threatened by ongoing habitat loss and human persecution. A lack of ecological knowledge for the vast majority of Pteropodid bat species presents additional challenges for their conservation and management. 2. In Australia, populations of flying-fox species (Genus: Pteropus) are declining and management approaches are highly contentious. Australian flying-fox roosts are exposed to management regimes involving habitat modification, either through human-wildlife conflict management policies, or vegetation restoration programs. Details on the fine-scale roosting ecology of flying-foxes are not sufficiently known to provide evidence-based guidance for these regimes and the impact on flying-foxes of these habitat modifications is poorly understood. 3. We seek to identify and test commonly held understandings about the roosting ecology of Australian flying-foxes to inform practical recommendations and guide and refine management practices at flying-fox roosts. 4. We identify 31 statements relevant to understanding of flying-fox roosting structure, and synthesise these in the context of existing literature. We then contribute contemporary data on the fine-scale roosting structure of flying-fox species in south-eastern Queensland and north-eastern New South Wales, presenting a 13-month dataset from 2,522 spatially referenced roost trees across eight sites. 5. We show evidence of sympatry and indirect competition between species, including spatial segregation of black and grey-headed flying-foxes within roosts and seasonal displacement of both species by little red flying-foxes. We demonstrate roost-specific annual trends in occupancy and abundance and provide updated demographic information including the spatial and temporal distributions of males and females within roosts. 6. Insights from our systematic and quantitative study will be important to guide evidence-based recommendations on restoration and management and will be crucial for the implementation of priority recovery actions for the preservation of these species into the future.

Conventional wisdom on roosting behaviour of Australian flying foxes -- a critical review, and evaluation using new data

1. Fruit bats (Family: Pteropodidae) are animals of great ecological and economic importance, yet their populations are threatened by ongoing habitat loss and human persecution. A lack of ecological knowledge for the vast majority of Pteropodid bat species presents additional challenges for their conservation and management. 2. In Australia, populations of flying-fox species (Genus: Pteropus) are declining and management approaches are highly contentious. Australian flying-fox roosts are exposed to management regimes involving habitat modification, either through human-wildlife conflict management policies, or vegetation restoration programs. Details on the fine-scale roosting ecology of flying-foxes are not sufficiently known to provide evidence-based guidance for these regimes and the impact on flying-foxes of these habitat modifications is poorly understood. 3. We seek to identify and test commonly held understandings about the roosting ecology of Australian flying-foxes to inform practical recommendations and guide and refine management practices at flying-fox roosts. 4. We identify 31 statements relevant to understanding of flying-fox roosting structure, and synthesise these in the context of existing literature. We then contribute contemporary data on the fine-scale roosting structure of flying-fox species in south-eastern Queensland and north-eastern New South Wales, presenting a 13-month dataset from 2,522 spatially referenced roost trees across eight sites. 5. We show evidence of sympatry and indirect competition between species, including spatial segregation of black and grey-headed flying-foxes within roosts and seasonal displacement of both species by little red flying-foxes. We demonstrate roost-specific annual trends in occupancy and abundance and provide updated demographic information including the spatial and temporal distributions of males and females within roosts. 6. Insights from our systematic and quantitative study will be important to guide evidence-based recommendations on restoration and management and will be crucial for the implementation of priority recovery actions for the preservation of these species into the future.

Status of an Anomalous Population of Northern Long-Eared Bats in Coastal North Carolina

Although previously well-documented in the mountains of the Blue Ridge Ecoregion of western North Carolina, the northern long-eared bat Myotis septentrionalis was only recently discovered in coastal North Carolina in 2007. After being listed as a federally threatened species in April 2015, a five-year effort of mist net surveys and tracking was initiated to better understand the species’ distribution and behavior in eastern North Carolina. Since 2015, 163 healthy northern long-eared bats have been captured, and the documented range of the species has expanded from 4 coastal counties to 19. Captures occurred in all months of the year and mostly occurred in or adjacent to wetland forests. Captures were limited to the Middle Atlantic Coastal Plain Ecoregion of the state, and the maximum distance from the Atlantic Ocean or associated sounds was &lt;87 km. Northern long-eared bats have not been documented in the Southeastern Plains or Piedmont Ecoregions of North Carolina. The lack of captures in the middle portion of the state suggests geographically disjunct populations of the species in North Carolina. During late fall–winter netting and tracking, northern long-eared bats were observed to be active throughout most of the winter and roosted in trees. Across three late fall–winter seasons from 2015–2018, 43 northern long-eared bats were tracked to 165 winter roost trees. Most (94.6%) winter roost trees occurred in wetland forest. Winter roost trees varied greatly in species, diameter-at-breast-height, status (dead or live), and type of roost (cavity, crack, crevice, or exfoliating bark). The species’ lack of long-term hibernation in coastal North Carolina documents a vastly different survival strategy as opposed to the well-documented hibernation strategy the species is known to use in the rest of its range. This portion of the state is nearly devoid of caves or mines suitable for hibernacula, but also experiences milder winters with low-level insect activity. During spring 2019, 21 reproductive females were captured in the northernmost portion of the coastal plain of North Carolina and tracked to 64 maternity roost trees. Pregnant females began to be captured on April 25, and juveniles began to be captured on June 16. This indicates that pups are likely born in late May in the northern portion of the coastal plain of North Carolina, but birth likely occurs earlier in the southern portion of the coastal plain of the state. Most (92.2%) maternity roost trees occurred in wetland forest. Maternity roost trees varied greatly in species, diameter-at-breast-height, status, and type of roost. Swab samples collected during late fall–winter from 198 bats from species susceptible to white-nose syndrome provided no evidence of Pseudogymnoascus destructans. Since northern long-eared bats in coastal North Carolina are active most of the winter and not dependent upon caves or mines for hibernation, they are likely not susceptible to white-nose syndrome. With the species in sharp decline elsewhere due to white-nose syndrome, this coastal North Carolina population and a recently discovered coastal South Carolina population may serve as a refugium for the species.

Wedgie Gold: Using metal detectors to recover PIT tags under areas used by wedge-tailed eagles and barn owls

A metal detector was used to recover passive integrated transponder (PIT) tags from below wedge-tailed eagle and barn owl nests and roost trees. The effectiveness of four different metal detectors to locate PIT tags and Australian Bird and Bat Banding Scheme (ABBBS) bands were compared. Twenty PIT tags from 14 golden bandicoots, five burrowing bettongs and one rufous hare-wallaby were recovered from wedge-tailed eagle sites. One unreadable PIT tag was recovered from a barn owl site. This technique has potential for use in determining the survivorship of translocated threatened species.

Roosting selection by red and blue Lory (Eos histrio Muller, 1776) in Karakelang Island North Sulawesi

The Red and blue lory is an endemic parrot species from Talaud Islands, North Sulawesi. The use of existing resources is suspected that occurs of selection including the roosting trees. The research aims to identifying the characteristics of Red and Blue Lory roost tree and determining variables in its selection. We measured 14 variables to identify the characteristics and selection of roost tree. Mann-Whitney test, T-test, Chi-sqare test and Binary Logistic Regression were employed to analyze data. We detected 11 roost trees in study field, there are Gehe (Pometia coriacea Radkl) nine individual, Binsar (Ficus variegata) and Lawean (Sterculia sp) one individual. The Chi-square test identified five variables which related to roost tree selection, i.e; branch-free bole length, canopy diameter, canopy density and the number of trees around the roost tree on diameter 20 - 40 cm and > 41 cm. The Logistic regression analysis detected three variables that gave the most influence on roost tree selection, but branch-free bole length gave the most influence on roost tree selection.

Observations on roost use by the yellow-bellied sheathtail-bat (Saccolaimus flaviventris) in northern New South Wales, Australia

Hollow-bearing trees are recognised as essential habitat features for insectivorous bats and provide sites for mating, the rearing of young, hibernation, protection from predators, and social interaction. The characteristics of hollow-bearing trees used as roosts by insectivorous bats in Australia are poorly known. To help fill this gap, this note presents data on tree roost characteristics for the yellow-bellied sheathtail-bat (Saccolaimus flaviventris) obtained from northern New South Wales, Australia. Of the 19 roost trees observed, most were live Eucalyptus albens trees with an incomplete crown with substantial numbers of dead limbs. Roosts selected were, on average, 9.3 m high with an entrance diameter of 12.7 cm in trees with a mean diameter at breast height of 49.5 cm. All entrance hollows were located at the end of a rotten spout formed when a branch had broken off the tree. These observations are some of the first to document the characteristics of roost trees for this species in New South Wales and this information can be used by land managers to identify and retain suitable roosting habitat for S. flaviventris in the landscape.

Identification of Sampiri Birds Colonies Roosting Tree Species in Karakelang Island Talaud Islands North Sulawesi

The aims of this study was to identify the species and describe the morpohology of roosting tree used by sampiri colonies. The research was conducted form February to May 2014. Direct observation and recording morphology characteristic of the roosting tree were used as methodology. Data were analyzed descriptively and qualitatively and then displayed in the form of images and tables. There were six sampiri colonies using different roost trees. The roost trees were gehe (Pometia corriacea Radkl), binsar (Ficus variegata Blume), lawean (Sterculia sp.), dominated by gehe.

Subtle use of a disturbance mosaic by the south-eastern long-eared bat (Nyctophilus corbeni): an extinction-prone, narrow-space bat

Context Studies of habitat suitability in disturbed landscapes based on species traits can improve predictions about how alternative management strategies are likely to affect threatened species. Aims We studied the south-eastern long-eared bat (Nyctophilus corbeni), which represents a group of bats prone to extinction due to attributes that adapt it to flight within cluttered forest vegetation, typically making them forest-dependent. To support decisions about management of the species in timber production forests, we investigated roost selection and characterised diet in a mosaic of disturbance histories in the Pilliga forests of north-western New South Wales. Methods We caught 54 N. corbeni, radio-tracked 39 individuals and located 41 unique maternity roost trees. Attributes of roost trees were compared with the local neighbourhood and the landscape mosaic of habitat types and logging treatments (recently logged, recently thinned and old regrowth). Preliminary observations were collected on foraging movements. Diet was characterised for maternity and non-maternity seasons using faecal DNA techniques. Key Results Small maternity colonies (<10 bats) were found in hollows and fissures often in exposed locations of trees with a small diameter (means range 23–39 cm) that were usually dead (82.5% of roosts). Buloke Allocasuarina luehmannii was most commonly used for roosting (49%), yet has been overlooked previously as a source of hollows for fauna. Landscape-scale habitat use was subtle: bats avoided roosting in commercially thinned stands and selected old regrowth. Logged and mechanically thinned stands were used in proportion to availability. Nyctophilus corbeni consumed a diverse range of prey in spring (November) and autumn (March), dominated by moths. Conclusions Areas of high stem density, especially those containing dead trees, provide key roosting habitat for N. corbeni and this is likely to be a significant factor explaining the species rarity. Implications Roosting ecology as well as foraging ecology contributes to a species’ sensitivity to disturbance consistent with trait-based predictions. Heterogeneity in the landscape should be maintained when the habitat of N. corbeni is manipulated (e.g. thinned) by retaining a diversity of stem densities, including dense patches (especially with dead A. luehmannii).