Roost Boxes Research Articles

Roost fidelity partially explains maternity roosting association patterns in Myotis lucifugus

Resources that draw individuals to a specific location may result in the formation of groups and development of individual social preferences. Simultaneously considering both ecological and social factors can therefore reveal underlying mechanisms of group formation and organization. Females of some temperate bat species roost in groups during the spring and summer months within which they give birth to and nurse their pups. Females switch roosts frequently, but the factors that influence roost switching remain poorly understood. To characterize the structure of a bat maternity group and gather evidence for the role of social preference in shaping this structure, we used roost co-occurrence data from little brown myotis, Myotis lucifugus , implanted with passive integrated transponder tags and roost boxes monitored with passive readers in Salmonier Nature Park, Newfoundland, Canada. By developing informed null models, we more directly investigate hypotheses that may explain why bats roost together. Although our results suggest that association patterns of maternity groups can largely be explained by similar interindividual patterns in bats' roosting frequencies within a given roost box (roost fidelity), other factors are likely to contribute to the observed structure. We thus provide support for the potential influence of roost and social preferences in shaping maternity group structure. • Female bats frequently switch roosts, changing who they roost with each day. • Some bats did not roost together at frequencies expected by chance. • Other bats occasionally roosted together more than expected by chance. • Social preferences may be important in influencing roosting decisions.

Simultaneous Monitoring of the Same Animals with PIT Tags and Sensor Nodes Causes No System Interference

Recent technological advances have multiplied the variety of biologgers used in wildlife research, particularly with small-bodied animals. Passive integrated transponders (PIT) have been used for decades to log visits of tagged animals at reader-equipped artificial feeders or roost boxes. More recently, novel miniaturized sensor nodes can collect data on social encounters among tagged individuals in any location. Combining these systems allows researchers to gather high-resolution tracking data on certain individuals from their long-term PIT-tagged animal populations. However, there can be a risk of interference among tracking systems. Here we tested whether placing an additional biologging sensor on top of a PIT tag might attenuate the magnetic field reaching the PIT tag and, in turn, hamper reading success of the radio-frequency identification (RFID) reader. We also evaluated data transmission by a digital sensor node in the presence of a magnetic field created by the RFID antenna. The combination of this RFID system and wireless biologging sensors works without error, suggesting that the simultaneous use of PIT tags and other digital biologgers, e.g., miniaturized GPS-loggers, should also work together properly when communication channels do not overlap. The combination of long-term monitoring with PIT tags and short-term tracking with biologging sensor nodes creates exciting new opportunities to gather rich social data when individuals are not present at RFID reader stations.

Do bats use guano and urine stains to find new roosts? Tests with three group-living bats.

Many animals use social cues to find refuges. Bats can find roosts using the echolocation and social calls of conspecifics, but they might also use scent cues, a possibility which is less studied. The entrances of bat roosts are often marked by guano and urine, providing possible scent cues. We conducted eight experiments to test whether bats use the scent of guano and urine to find potential roosts. In field experiments, we tested if Molossus molossus (velvety free-tailed bats) in Panama and Eptesicus fuscus (big brown bats) in Ohio would investigate artificial roost boxes that were scented with guano and urine more often than a paired unscented control. We did not detect any difference in flights near the scented versus unscented roosts, and we detected only one entrance into any artificial roost (scented). In six captive experiments, we tested for the attraction of Desmodus rotundus (common vampire bats) and Molossus molossus to areas scented with guano and urine, under several conditions. Results were mixed, but overall suggested that the scent of guano and urine does not act as a strong lure for the tested bat species. We suggest that further tests of olfaction-based roost choice in bats should manipulate existing scent cues on familiar roosts.

Use of Artificial Roost Boxes Installed as Alternative Habitat for Bats Evicted from Buildings

Some cavity-dwelling vertebrates have adopted buildings in response to the loss of natural cavities in human-disturbed landscapes. Unfortunately, public health concerns surrounding human–bat interactions often lead to the exclusion of bats from structures. Provisioning evicted bats with roost boxes is a common management strategy; however, factors influencing bats' use of roost boxes are poorly understood. Using data from roost boxes monitored by conservation groups in New Jersey, we tested the importance of exclusion history in predicting use of roost boxes by bats relative to roost-box characteristics and installation practices thought to be important. We found that boxes installed after a bat exclusion were most likely to be used by bats (effect size = 2.07 [CI: 0.76, 3.39]), particularly if installed on a building rather than a non-building (effect size = 4.17 (CI: 2.53, 6.88]). Our results support the use of roost boxes to ameliorate potential negative impacts to bats that have been excluded from structures and to reduce human–bat conflicts.

Helmeted Woodpeckers roost in decay-formed cavities in large living trees: A clue to an old-growth forest association

AbstractWoodpeckers (Picidae) are broadly associated with forests but vary in sensitivity to habitat alteration, with some species restricted to mature and old-growth forests, usually because of their foraging or nesting requirements. Roosting sites have rarely been considered a critical resource for woodpecker conservation because nearly all woodpecker species roost year-round in excavated cavities similar to their nest sites. A possible exception is the globally vulnerable Helmeted Woodpecker (Celeus galeatus) of the Atlantic Forest of South America. To determine whether roosting ecology may explain their association with mature forest, we radio-tracked 12 Helmeted Woodpeckers in old-growth and selectively logged forests in Argentina, monitored roost cavities, and provided 9 roost boxes. Unlike other woodpeckers, Helmeted Woodpeckers roosted year-round in decay-formed cavities (n = 21), with perching space above the entrance, in the living trunks of large trees. Adults usually roosted alone, but after nesting (in excavated cavities), each adult roosted with one juvenile in a shared, decay-formed cavity for up to 67 days, implying that cavities need enough space for 2 birds. We did not observe use of roost boxes. Helmeted Woodpeckers travelled up to 1,482 m between nests and roosts, reused roost cavities over multiple years (sometimes changing ownership), and interacted aggressively with other cavity-nesting birds at roost cavities, indicating that suitable cavities are a scarce resource. Because logging is likely to have a strong negative impact on the availability of this resource, we urge managers in the Atlantic Forest region to retain large living trees with decay-formed cavities and to allow more selectively logged areas to become old growth.

Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans.

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission.

Arrival ≠ Survival

AbstractSeed dispersal is commonly a limiting process in ecosystem recovery, and several recent studies have proposed novel methods for overcoming this important biological barrier, particularly in tropical pastures. Multiple experiments in various regions have shown that bird perches attract birds and increase seed dispersal but not seedling recruitment in degraded habitats. New bat‐focused restoration applications, such as roost boxes and fruit oils, have proven capable of attracting animals and augmenting seed dispersal, but these applications have yet to be vetted by seedling establishment data. Seeds and seedlings in pastures have low probability of survival, attributable to predation, dessication, rot, and competition with ruderal vegetation. As such, these novel applications are unlikely to have the desired effect of accelerating tropical forest succession. Given that seed dispersal is meaningless if arriving seeds cannot survive, and that seedling recruitment measurements are not prohibitively difficult to take, we suggest that studies of novel seed dispersal techniques should include a measure of seedling recruitment. Without this information, it cannot be assumed that such applications accelerate forest recovery.

Ecological Role of the Great TitParus majoras a Seed Disperser During Winter

To determine the annual and seasonal patterns in the transport of seeds by Great Tits Parus major, we investigated the species and number of seeds in the feces of Great Tits deposited in roost boxes during the winters of 1992–99. At least 63 morphological types of seeds were considered to have been transported after they were eaten by the tits and excreted into the feces. Forty-nine of the 63 seed types were excreted only in one of the seven winters. These results suggest that Great Tits transported seeds of various plant species sporadically.

Use of artificial tree hollows by Australian birds and bats

Artificial tree hollows (nest or roost boxes) may be of considerable importance to the conservation and management of Australian hollow-using birds and microbats. This is suggested by recognition that the rate of collapse of hollow-bearing trees may exceed replacement in some landscapes. We review the published literature to synthesise current information on the use of artificial hollows by Australian birds and bats, and to provide guidance to future research and management. The use of artificial hollows has been documented in some detail for 15 native bird and eight microbat species. A range of hollow designs has been employed but there is a limited understanding of favoured designs. General designs (e.g. front-entry plywood boxes) have been used extensively by some species and should continue to be used until more effective designs are identified. Species tend to use artificial hollows that have entrance sizes just sufficient for their body size, and this should guide hollow design. Competitive interactions with a range of non-target species (native and non-native) may have a pronounced influence on artificial hollow use and must be considered in any management program involving artificial hollows. We highlight some design elements that may reduce interference by non-target species. Temperature inside artificial hollows may have a particular influence on their use by bats due to the role of microclimate in bat thermoregulation. Trials are needed to investigate this factor and to inform general approaches to positioning of artificial hollows. Several distinct management uses exist for artificial hollows, including assisting threatened species recovery, e.g. Kangaroo Island glossy black-cockatoo (Calyptorhynchus lathami halmaturinus) and orange-bellied parrot (Neophema chrysogaster). Artificial hollows offer an interim solution to hollow shortage but their full potential will only be realised when preferences for different designs are better understood. This will require a commitment to monitoring and should be conducted in an adaptive management context. Increased knowledge of the use of artificial hollows by Australian birds and bats should be of global relevance to the management of hollow-using species because it provides an independent test of ideas and strengthens any generalisations.

T.12.5. Regulation of Autoimmune and Allergic Inflammation by Intracellular Delivery of Cell Permeable Foxp3 Protein

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission.

Assessment of Management Techniques to Reduce Woodpecker Damage to Homes

Abstract: Woodpecker damage to homes and buildings is a widespread and locally severe problem in vertebrate pest control. Woodpeckers may cause an average of $300 (United States currency) in damage to affected houses, resulting in millions of dollars of property damage annually in the United States. However, there is no known, practical, consistently effective technique to prevent woodpecker damage. We tested the effectiveness of 6 woodpecker control techniques available commercially, used anecdotally by homeowners, and recommended by wildlife specialists in different Cooperative Extension publications. These deterrents included Prowler Owls, Irri‐TapeTM, the Bird Pro Sound System, Scare‐Eyes (all manufactured by Bird‐X, Inc., Chicago, IL), suet feeders, and roost boxes. We conducted our study in late spring and autumn during August 2003 through December 2004 in the Town of Ithaca, Tompkins County, New York, USA. We evaluated 16 homes with active woodpecker damage, and visited each house about 3 times per week to determine a rate of new woodpecker holes per day. We then placed a deterrent at the house and monitored the rate of new holes per day. Although none of the deterrents that we tested was completely successful in keeping woodpeckers from creating new holes in house siding, homes where Irri‐Tape was installed exhibited the greatest reduction in woodpecker damage. Avoiding earth‐tone stain and paint colors may be the best long‐term solutions for preventing woodpecker damage in wooded areas. Homeowners should avoid using natural‐colored stains, as brightly painted houses (white, light blue, pastels) were less likely to attract woodpeckers.

Toxicity and tissue distribution of pentachlorophenol and permethrin in pipistrelle bats experimentally exposed to treated timber

The dependence of bats in Britain on houses as roosts may result in them being exposed to pesticides used in remedial timber treatments. Pentachlorophenol (PCP) and permethrin are used as a fungicide and an insecticide for timber treatment, respectively. The present study investigated toxicity and distribution in body tissues of these two pesticides in pipistrelle bats. Four groups of nine to ten bats were kept in separate outdoor flight enclosures and were provided with roost boxes treated with either PCP only, permethrin, PCP/permethrin mixture or solvent only (control). At the start of the experiment, mean (±SE) PCP and permethrin concentrations on the surface of wooden blocks that had been treated in the same way as roost boxes were 69·32±6·76 mg g −1 ( n = 6) and 3·3±1·6 mg g −1 ( n = 3), respectively. All bats exposed to PCP and PCP/permethrin treated boxes died within 24 and 120 h, respectively; nine out of the ten controls survived the 32 day experimental period ( P < 0·001; both groups compared with control). Bats exposed to permethrin treated boxes survived as well as controls. Mean (±SE) carcass PCP concentration (excluding deposits on fur) of bats exposed to PCP and PCP/permethrin treated boxes was 13·11±2·52 μg g −1 BW ( n = 20). PCP burdens on fur were positively correlated with total weight of PCP in the carcass ( P < 0·001). PCP was present in fat depots, liver, kidney and the remainder of the body which, despite containing low PCP concentrations, was the main PCP reservoir (66·4±5·0% of carcass PCP load; n = 20). Total PCP in the carcass was significantly correlated with lipid weight ( P < 0·005). Permethrin was not detectable in body washes and tissues of bats exposed to PCP/permethrin mixture or permethrin.

Uptake of gamma-HCH (Lindane) by pipistrelle bats and its effect on survival

Adult pipistrelle bats were caught at two roosts in Eastern England and kept in captivity on an ad lib diet of mealworms. In Experiment 1, two groups of eight bats were each kept in identical outdoor enclosures where the bats could fly freely and where they had a choice of five roost boxes, one of which was heated. One of these groups was exposed to gamma-HCH applied to planed pine blocks which had been immersed in a hexane solution of gamma-HCH. An initial concentration, estimated from surface wood scrapings, of 9·94 ± 1·15 mg m −2 was used for the first 44 days, while 866 ± 51 mg g −2 was used for a further 44 days. Blocks were placed in the roost boxes to simulate the type of exposure experienced by wild bats. Blocks dosed with solvent alone were given to the other group of bats (controls). Six of the eight bats in the group exposed to gamma-HCH died, while all bats in the control group survived (P < 0·007). In Experiment 2, three groups of five bats were kept in identical cages. Two groups were exposed to identical wood blocks dosed with gamma-HCH, which gave a concentration of 211 mg m −2 in surface scrapings taken 1–2 h after dosing, while the other group received a wood block treated with solvent alone (control). All bats in the groups exposed to gamma-HCH died within 17 days, while all bats in the control group survived (P < 0·001). Tissues of bats were analysed for gamma-HCH by gas chromatography. There was a critical concentration of 622±102 μg gamma-HCH g −1 extractable lipid at which bats died. The total weight of gamma-HCH in bat carcasses was directly related to the weight of extractable lipid. On average, bats died when the gamma-HCH concentration in the whole body reached 27·9 ± 4·8 μg g −1, but this value increased as body weight increased. This study confirmed the results of a previous study that gamma-HCH is toxic to bats in conditions simulating exposure in the wild.