Article

Photopollution impact on the nocturnal behaviour of the Sugar Glider (Petaurus breviceps)

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Abstract

Night light pollution is an important environmental problem impacting on many animals including a variety of insects, amphibians, reptiles, birds, and mammals. While some impacts of night light pollution are well-known such as misorientation of sea turtle hatchlings and deaths of migratory birds, other less obvious impacts on reproduction, communication, competition, and predation have recently been reported. As some natural areas in New Guinea and Australia face agricultural and industrial development, conflicts between wildlife and photopollution will add to existing problems of habitat fragmentation and degradation. I report on the photopollution impacts on the nocturnal behaviour of the sugar glider (Petaurus breviceps). Captive sugar gliders were monitored using a "super nightshot" camcorder for baseline nocturnal behaviour following a 12 hour daylight/12 hour dark regime. Treatment consisted of 12 hour daylight/12 hour simulated ambient low and high luminosity street light photopollution (average 7.0 and 12.0 lux). Over 575 sugar glider-hours were analyzed. The results show marked behavioural impacts under high luminosity treatment, including almost total cessation of high level activity. Although impacts were reduced under the low luminosity treatment, even 7.0 lux reduced foraging time. This is the first report of photopollution impacts on sugar glider foraging and activity levels. Further research, particularly with wild populations, is needed to elucidate the extent of photopollution impacts on sugar gliders and their endangered and vulnerable relatives.

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... Abiotic factors influence animal behaviour, and moon phase, for example, can influence biological processes such as the timing of breeding, foraging and navigation (Pyle et al. 1993;Lang et al. 2006;Grant et al. 2009). Higher nocturnal illumination is associated with increased antipredator vigilance behaviour in sugar gliders (Petaurus breviceps) and artificial street lighting has been associated with reduced activity and richness of insectivorous bats (Barber-Meyer 2007;Nersesian et al. 2012;Linley 2017). ...
... During periods of low illumination (half and new moon) CWR predator species showed increased activity whereas medium-sized herbivore species showed less variation in activity in response to nocturnal illumination and cloud cover. Nocturnal illumination can negatively affect the activity of some mammals (Barber-Meyer 2007;Linley 2017), with the general consensus suggesting that prey are typically less active during periods of high lunar illumination, but conjecture exists (Lockard and Owings 1974;Clarke 1983;Prugh and Golden 2014). ...
Article
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Moon phase and variation in ambient light conditions can influence predator and prey behaviour. Nocturnal predators locate prey visually, and prey may adjust their activity to minimise their predation risk. Understanding how native mammals in Australia respond to varying phases of the moon and cloud cover (light) enhances knowledge of factors affecting species’ survival and inference regarding ecological and population survey data. Over a two-year period within a fenced conservation reserve, in south-eastern Australia, with reintroduced native marsupial predator and prey species (eastern barred bandicoot, southern brown bandicoot, long-nosed potoroo, rufous bettong, Tasmanian pademelon, brush-tailed rock-wallaby, red-necked wallaby, eastern quoll, spotted-tailed quoll, and naturally occurring swamp wallaby, common brushtail possum, common ringtail possum), we conducted monthly spotlight surveys during different moon phases (full, half and new moon). We found an interaction between cloud cover and moon phase, and an interaction of the two depending on the mammal size and class. Increased activity of prey species corresponded with periods of increasing cloud cover. Predators and medium-sized herbivores were more active during times of low illumination. Our findings suggest that moon phase affects the nocturnal activity of mammal species and that, for prey species, there might be trade-offs between predation risk and foraging. Our findings have implications for: ecological survey design and interpretation of results for mammal populations across moon phases, understanding predator and prey behaviour and interactions in natural and modified (artificial lighting) ecosystems, and potential nocturnal niche partitioning of species.
... The encroachment of ungulates on to land used by humans often leads to conflicts (Putman and Moore 1998;Warren 2011;Mattila and Hadjigeorgiou 2015): as a consequence, habitats may be fenced off (Boone and Hobbs 2004;Harrington and Conover 2006) and the animals culled (Brown et al. 2000;Warren 2011). Yet another danger for terrestrial animals may be light pollution, which can interfere with their orientation abilities and thus with their movements (Longcore and Rich 2004;Beier 2006), while long-term exposure to artificial lighting can disrupt their biological rhythm (Yeates 1949;Lincoln and Guinness 1972;Barber-Meyer 2007); they may therefore tend to avoid strongly illuminated areas (Robert et al. 2015). ...
... Although the mechanism of avoiding artificial light has not been well documented, experimental modifications of the photoperiod have shown that artificial light can lead to hormonal changes in ungulates that alter their reproductive cycles as well as moult strategies for the maintenance of suitable body temperatures (Yeates 1949;Lincoln and Guinness 1972). The adverse effects of light pollution have also been demonstrated in other mammals: the extended photoperiod in urban areas lit up at night led to changes in their diurnal activity, thereby significantly affecting their time budget (Foster and Provencio 1999;Biebouw and Blumstein 2003;Barber-Meyer 2007) or causing them to avoid areas affected by artificial light (Robert et al. 2015). Our work has shown that light pollution could be used as an additional predictor of ungulate occurrence: there is therefore an urgent need for further studies of the influence of artificial light on the ecology of this group of animals. ...
Article
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... Both animals are nocturnal, and the studies were conducted under captive conditions. Under street lighting conditions, the foraging and activity of the glider were negatively impacted by reducing the time spent foraging, to the point under high street light illumination (12 lux) where almost all high level activity (foraging) was ceased (Barber-Meyer 2007). This was potentially due to artificial lighting aiding the Sugar Glider's predators (owls, kookaburras, goannas and cats) (Barber-Meyer 2007). ...
... Under street lighting conditions, the foraging and activity of the glider were negatively impacted by reducing the time spent foraging, to the point under high street light illumination (12 lux) where almost all high level activity (foraging) was ceased (Barber-Meyer 2007). This was potentially due to artificial lighting aiding the Sugar Glider's predators (owls, kookaburras, goannas and cats) (Barber-Meyer 2007). In contrast, wallabies tended to forage more and allocate less time to anti-predator vigilance under artificial light conditions (Biebouw & Blumstein 2003). ...
Article
Global population growth and associated urban development are having profound effects on biodiversity. Two major outcomes of expanding development that affect wildlife are light and noise pollution. In this paper, we review literature reporting the effects of light and noise on biodiversity, and assess implications for conservation planning in Australia. Our results clearly indicate that light and noise pollution have the potential to affect the physiology, behaviour and reproduction of a range of animal taxa. Types of effects include changes in foraging and reproductive behaviours, reduction in animal fitness, increased risk of predation and reduced reproductive success. These could have flow-on consequences at the population and ecosystem levels. We found a significant gap in knowledge of the impact of these pollutants on Australian fauna. To reduce the effect of light and noise pollution, there needs to be careful planning of urban areas in relation to protected areas, and for biodiversity more generally. Potential measures include strategically planning the types of development and associated human activities adjacent to protected areas, and the use of shields and barriers, such as covers for lights or the use of dense native vegetation screens, while still allowing movement of animals. Changes in government standards and regulations could also help to reduce the impacts of light and noise pollution.
... Garber 38 used the term "night light niche" to describe the extension of diurnal species activity near artificial lighting at night. More recent studies, using similar conditions of altered nighttime light levels, also demonstrated that nighttime light decreases overall activity and changes the duration of the active phase [40][41][42][43][44][45][46][47] . ...
Article
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Artificial nighttime lights have important behavioral and ecological effects on wildlife. Combining laboratory and field techniques, we identified behaviorally relevant levels of nighttime light and mapped the extent of these light levels across the city of Chicago. We began by applying a Gaussian finite mixture model to 998 sampled illumination levels around Chicago to identify clusters of light levels. A simplified sample of these levels was replicated in the laboratory to identify light levels at which C57BL/6J mice exhibited altered circadian activity patterns. We then used camera trap and high-altitude photographic data to compare our field and laboratory observations, finding activity pattern changes in the field consistent with laboratory observations. Using these results, we mapped areas across Chicago exposed to estimated illumination levels above the value associated with statistically significant behavioral changes. Based on this measure, we found that as much as 36% of the greenspace in the city is in areas illuminated at levels greater than or equal to those at which we observe behavioral differences in the field and in the laboratory. Our findings provide evidence that artificial lighting patterns may influence wildlife behavior at a broad scale throughout urban areas, and should be considered in urban habitat planning.
... Skogslevande arter såsom salamandrar som är nattaktiva och anpassat sig till månsken har visat sig påverkas negativt genom minskat eller fördröjt födointag när de exponerades för artificiellt ljus i skogen (Wise 2007). Andra studier har visat att två nattaktiva arter (assapan eller mindre nordamerikansk flygekorre Glaucomys volans och korthuvad flygpungekorre Petaurus breviceps) i skogsmiljöer som utsätts för artificiellt ljus dröjer med att vakna upp på natten och får minskad födosökningsaktivitet (DeCoursey 1986;Barber-Meyer 2007). Artificiellt ljus i skogsmiljöer kan även fördröja nytetablering av myrkolonier och myror har visat sig attraherade till det artificiella ljuset vilket kan leda till reducerad överlevnad på grund av ökad risk för predation (Moser et al. 2004). ...
Technical Report
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Lysdiod-belysning (Light Emitting Diode; LED) används i allt större omfattning utomhus på vägar och gator och utgör idag ofta enda valbara alternativet. Det finns många fördelar med att använda LED-belysning men det har alltmer börjat uppmärksammas att artificiellt ljus även har många ekologiska nackdelar eftersom det sker en påverkan på djur och natur. Biologiska effekter av artificiella ljuskällor är sedan tidigare väl studerat och det är därför exempelvis känt att det finns effekter på många olika typer av arter. Detta projekt har fokuserat på att sammanfatta vilka specifika ekologiska effekter som LED-belysningen kan orsaka samt hur dessa kan åtgärdas. Syftet med rapporten har varit att: kartlägga påverkan av LED-belysning på djur och natur, identifiera särskilt känsliga djur eller organismer men också att utreda under vilka förhållanden eller förutsättningar (områden, tid på dygnet/året) som en ekologisk påverkan kan förväntas ske, samt slutligen att ge konkreta rekommendationer för att minimera påverkan på djur och natur. Rekommendationerna är särskilt anpassade till att vara tillämpbara i de nordiska länderna. En systematisk litteratursökning genomfördes under 2017 för att hitta relevant litteratur om effekter av LED-belysning på djur och natur. Sökningen var en bra utgångspunkt men räckte inte för att identifiera alla typer av relevanta underlag som krävdes för att utföra projektet och därför har litteratursökningar utförts kontinuerligt under projektets gång, utifrån vilken typ av information som behövdes när kapitlen författades. I rapporten redovisas kunskap om LED som ljuskälla och dess egenskaper jämförs exempelvis med andra ljuskällor. Arbetet inkluderar att ljus uppfattas olika och påverkar olika beroende av art och har sammanställts uppdelat i olika djurgrupper för att få en översikt över hur djur påverkas av artificiellt ljus. Effekter av LED-belysning på arters fysiologi, beteende och ekologi har utgått från hittills utförda studier inom området och visar på varierande resultat beroende på vilka arter som studerats. Samtidigt saknas studier för väldigt många arter; ibland saknas kunskap om påverkan på hela grupper av djur såsom exempelvis större däggdjur, groddjur och många fågelarter. En viktig slutsats är att det inte går att utesluta att förekomsten av himlaglim kan ha ekologiska konsekvenser över stora geografiska områden. Prioriteringar för naturvårdande åtgärder har behandlats utifrån ett nationellt/nordiskt perspektiv men även ur perspektivet att det finns både områden och ljuskänsliga arter som behöver extra skydd från artificiellt ljus. I rapporten har även redovisats hur man kan göra anpassningar till olika miljöer och ekosystem, samt hur man skulle kunna arbeta med zoner och på landskapsnivå med dessa frågor i det vidare arbetet. För stadsmiljöer och urbana miljöer är det relevant att reducera himlaglim och att säkerställa att områden med skyddade arter inte blir belysta. Vattenära miljöer bör speciellt beaktas på grund av förekomsten av många skyddade och ljuskänsliga arter, exempelvis bör säkerställas att inte ljuskällorna sprider ljus i vattnet eller åstadkommer polarisering. Rekommendationerna för hur man ska minimera ekologisk påverkan är uppdelad i fem (redan etablerade) områden: förhindra och begränsa nya områden från att belysas, begränsa omfattningen av belysta områden, begränsa tiden med belysning, begränsa belysningsstyrkan/ljuskvantiteten samt anpassningar i ljusets våglängdsfördelning. Slutsatserna sammanfattar de rekommendationer som särskilt bör prioriteras förutsatt att man ämnar ha belysning utomhus. LED-belysning har många fördelar och erbjuder bra möjligheter att reducera ekologisk påverkan. Störst potential att reducera ekologisk påverkan både direkt och indirekt genom himlaglim och via påverkan av vitt ljus på seendet samt icke-visuellt ljus (främst blått ljus < 500 nm) är att reducera spilljus och ljusföroreningar från belysningen genom att begränsa ljusets rumsliga spridning från ljuskällor. Exempelvis rekommenderas att alla typer av uppljus bör elimineras utan undantag för att reducera mortaliteten av migrerande och skyddade arter. Bakljus, framljus och luminans bör genom god ljusdesign starkt begränsas i den fysiska miljön för att reducera ljusföroreningar i omgivningen. Begränsningar i ljusets spridning kommer att reducera risken att aktivera dagsljusseendet hos arter som har både fotopisk och skotopisk syn samtidigt som påverkan på nattaktiva arter kommer att reduceras eftersom arealen som är belyst kommer att minskas. För extra ljuskänsliga och skyddade arter som potentiellt kan vara påverkade negativt av himlaglim är det oklart ifall några av de föreslagna åtgärderna räcker. Därför är det rimligt att ansvaret för att säkerställa mörkerområden för dessa arters fortlevnad bör ligga hos de som förvaltar artskydd (till exempel kommuner och länsstyrelser som beslutar om och förvaltar naturreservat). Det är i beslutsprocessen och i förvaltningen som önskvärda begränsningar i ljusföroreningarna kan beskrivas och implementeras. För att stärka skyddet av arter som förflyttar sig bör rekommendationerna som tagits fram implementeras i någon form på en övergripande nationell nivå. Skyddade miljöer såsom Natura 2000-områden kan/bör använda sig av de i rapporten föreslagna striktare riktlinjerna (som tagits fram av IDA, International Dark Association) för att säkerställa en minimal ljuspåverkan på skyddade arter. Mängden blått ljus i utomhusbelysningen bör förmodligen reduceras eftersom det är väl känt att sådant ljus kan påverka många arters dygnsrytm. Det kommer inte inom en rimlig framtidshorisont gå att få fram tillräckligt med kunskap om de exakta nivåerna för exponering till blått ljus och dess konsekvenserna för alla olika typer av arter som kan påverkas och därför bör försiktighetsprincipen tillämpas. Alla kommersiellt tillgängliga ljuskällor på marknaden bör redovisa mängden förekommande blått ljus (speciellt avseende < 500 nm) för att underlätta val av produkter med låga mängder blått ljus. Nattsläckning och nattreduktion bör tillämpas så långt det är möjligt för att undvika ekologisk påverkan på största möjliga antalet arter och för att reducera attraktionen hos migrerande arter. En utmaning med att ta fram rekommendationerna avseende ekologisk påverkan av utomhusbelysning är att det finns brister i de vetenskapliga studier som utförts. Exempelvis redovisas inte tillräckligt mycket information för att upprepa experimenten och det kan saknas grundläggande information om ljuskällor eller experimentdesign som gör att resultaten inte är användbara. Ljusföroreningar bör beaktas i högre grad i arbetet med ljusplanering men även i arbetet med naturmiljöfrågor och på landskapsnivå för att säkerställa att inte skyddade arter påverkas. Planeringen av infrastruktur med tillhörande utomhusbelysning måste därför integreras i arbetet med övriga miljöfrågor i kommuner och på regional och nationell nivå.
... For example, onset of foraging time is delayed in lesser horseshoe bats (Rhinolophus hipposideros) when exposed to lighting and the lit areas of hedgerows were avoided (Stone et al., 2009). This pattern of delay is now seen in multiple taxa, from salamanders (Wise, 2007) to sugar gliders (Petaurus breviceps) (Barber-Meyer, 2007) to bats (Boldogh et al., 2007). ...
Chapter
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Since the invention of the electric light bulb in 1879, a significant portion of the planet has been transformed from experiencing a natural pattern of light and dark determined by the sun, moon, stars and occasional other transient lights to being subjected to intermittent and perpetual illumination from human civilisation that is unprecedented in the history of Earth. The pervasiveness of this phenomenon and its exponential growth has measurable and significant consequences for living organisms. The results of recent research have extended knowledge about the geographic scope and specific impacts of artificial night lighting on animal behaviour, physiological processes and ecological interactions across a range of taxa and its broader ecosystem effects.
... This has been shown experimentally with dim artificial lights installed in a forest environment (Wise 2007). In two different experiments, lighting delayed the emergence time of nocturnal mammals (DeCoursey 1986, Barber-Meyer 2007) and reduced foraging activity (Barber-Meyer 2007). For sugar gliders, a nocturnal forest mammal native to Australia, light equivalent to that produced by streetlights (7-12 lux) reduced the time individuals were active at night (Barber-Meyer 2007). ...
Technical Report
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Artificial night lighting represents a growing challenge for managers of parks and protected lands. The disruption of natural patterns of light and dark, which have been more or less reliable for millions of years, has a range of adverse consequences for wildlife across taxonomic groups and landscape types. This document reviews effects of artificial night lighting by habitat type and discusses the approaches available to land managers to mitigate and avoid certain adverse effects of artificial night lighting.
... Generally, trees with higher activity were located in dark areas (both urban and rural areas). These results are supported by an experiment by Barber-Meyer (2007), who found that captive sugar gliders decreased activity and foraging time under two artificial light treatments, designed to be similar to street lighting. Threlfall et al. (2013) suggested that large patches (>40 ha) of native vegetation are required to prevent such light pollution from having an impact on bats and other species. ...
Article
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Context Loss and degradation of habitat from urban development is a key threat to the squirrel glider (Petaurus norfolcensis), because its distribution coincides where most people live in Australia. Squirrel gliders are known to occur in or around urban fringes where native vegetation is retained; however, little is known about specific anthropogenic factors that may affect their persistence. Aims We investigated the relative influence of biophysical and urban factors on the use of large hollow-bearing Eucalyptus trees, which are a key resource for squirrel gliders. The study was located in a typical urban growth area located in southern New South Wales. Methods A stratified random sampling approach was used to survey squirrel gliders in urban and rural areas. Infrared, motion-sensor cameras were placed in 34 selected trees for 17 nights to record squirrel glider occupancy and activity. Data on urban (e.g. light and noise pollution levels, road and housing density) and biophysical (e.g. tree height, hollow-bearing tree density, vegetation cover) variables were recorded at each survey tree. Data were statistically analysed using general linear modelling approaches. Key results Squirrel gliders were detected more frequently in the rural matrix (23.4% of camera trap-nights) than in urban areas (9.5%). Model results showed that tree height, and the distance to neighbouring trees, had a significant influence on the occurrence and activity of squirrel gliders. Road density and light pollution were included in 'best' models to explain glider activity (a negative influence), and noise pollution negatively influenced glider occurrence. Although gliders used large trees in both urban and rural areas, activity generally decreased as levels of urbanisation increased. Conclusions and implications Access to and availability of key resources such as tall, hollow-bearing trees is critical for gliders to persist in urban environments. Squirrel gliders will tolerate human stressors such as roads, noise and light pollution to a certain extent, but impacts on population viability remain largely unknown. Novel solutions need to be developed to lessen the effects of anthropogenic factors (such as light and noise) on patches of native vegetation retained in urban areas for conservation purposes.
... The effects of ecological light pollution vary across taxa and environments (Longcore & Rich 2004;Rich & Longcore 2006). Effects can be negative, for example the disorientation of hatchling sea turtles near lights (Witherington 1992;Salmon 2003), reduction of mating activity in some frogs (Rand et al. 1997;Baker & Richardson 2006), light trapping and subsequent death of migratory birds and flying insects (Ali et al. 1986;Kolligs 2000;Longcore & Rich 2004), impairment of some species' ability to avoid predators (Svensson & Rydell 1998), changes to arthropod community composition (Davies et al. 2012), and reduced activity in nocturnal mammals (Barber-Meyer 2007;Rotics et al. 2011). Artificial lights can also have positive effects for individuals or species (although often to the detriment of other species), such as extending activity periods for diurnal animals (Perry & Fisher 2006;Perry et al. 2008;Rotics et al. 2011) and increasing foraging efficiency for insectivores due to the clumping of insects near lights (Bustard 1970;Frank 1988;Rydell 1992;Perry & Fisher 2006). ...
Article
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There is increasing concern about the ecological effects of light pollution, as artificial lighting spreads with urban expansion. While artificial lighting can negatively affect some species, others use it in novel ways. In tropical and subtropical regions, artificial lighting has created a novel niche: the ‘night light’ niche. Geckos living as human commensals (house geckos) are apparently well adapted to occupy this niche. In an urban area in north-eastern Australia, we found that the invasive Asian house gecko Hemidactylus frenatus (Gekkonidae) occupies a broader range of light environments in the field than does the native gecko Gehyra dubia (Gekkonidae). Experimental removal of the invasive species from a building indicated that it did not behaviourally influence the light environments chosen by the native species in the short term; they continued to use darker areas even after the invasive species was removed. In Y-maze experiments, neither species showed a significant preference for light or dark areas; however, preliminary data suggest the invasive species was more willing to explore the Y-maze than the native species. The willingness of H. frenatus to forage closer to lights, where insect abundance is typically higher, might account for its success as a global invader of human environments, even in areas where other gecko species are established.
... Both animals are nocturnal, and the studies were conducted under captive conditions. Under street lighting conditions , the foraging and activity of the glider were negatively impacted by reducing the time spent foraging, to the point under high street light illumination (12 lux) where almost all high level activity (foraging ) was ceased (Barber-Meyer 2007). This was potentially due to artificial lighting aiding the Sugar Glider's predators (owls, kookaburras, goannas and cats) (BarberMeyer 2007). ...
Article
Full-text available
Identifying the relationships between species traits and patch-scale vegetation characteristics in areas designated for urban development can improve our understanding of how animal communities may change with urbanization. We explored the implications of this premise to the urban planning process in a mixed-use landscape in Canberra (Australia), prior to its development into new suburbs. We used RLQ analysis to relate bird foraging, nesting and body size traits to patch-scale vegetation characteristics. Relationships between species traits and vegetation characteristics within the development zone suggest that species that forage and nest on the ground and in the understory strata, and smaller-bodied species will be most negatively affected by urbanization. Identifying the relationships between species traits and vegetation characteristics may be used by urban planners to (i) identify potentially critical habitat and species at risk from development, (ii) inform the choice of impact mitigation measures, and/or (iii) distinguish between high and low mitigation measures. Analyses conducted early in the planning process can then be used to allocate proposed land uses in an ecologically sensitive way, and to plan appropriate mitigation measures.
... Pocillopora damicornis) larvae;Moser et al. (2004) observed delays in the dawn mating flights in leafcutting ants (Atta texana);Riley et al. (2012) reported disruption to the diel migratory pattern of wild Atlantic salmon smolts leaving their natal stream; and delays in the onset of foraging have been reported in the redback salamander (Plethodon cinereus)(Wise, 2007), the sugar glider (Petaurus breviceps)(Barber-Meyer, 2007), and in lesser horseshoe bats (Rhinolophus hipposideros)(Stone et al., 2009). ...
Article
There has been a decline in the abundance of Atlantic salmon (Salmo salar) despite significant conservation measures designed to reduce fishing mortality. Populations at the southern edge of their historical distribution, where anthropogenic impacts on the freshwater environment may be greater, have suffered the largest decline. In this investigation, we compared the timing of Atlantic salmon fry dispersal from incubators in an aquarium under control and ecologically relevant broad spectrum street-lit conditions (median night light intensity = 12 lx). Fry dispersal occurred 2.8 days later (F = 82.9, df = 1,8, p < 0.001), and on average the fry were smaller at dispersal (0.017 g, se = 0.0012, p < 0.001, n = 730), in the incubators exposed to street lighting. Significant disruption to the diel pattern of fry dispersal was also observed. Dispersal under control conditions was significantly directed around a mean time of 4:17 h after dusk (p < 0.001, r = 0.76, n = 1990) with very few fry (<2%) dispersing during daylight hours. Under street lighting, the dispersal of fry was significantly delayed (mean time 6:38 h after dusk; p < 0.001, r = 0.39, n = 2413) with a significant proportion (32%) dispersing during daylight hours. Survival to dispersal in the controlled aquarium conditions was not lower under street-lit conditions (p = 0.21, n = 5000 eggs across 10 incubators). However, in the wild, the period between fry emergence and the establishment of feeding territories is considered to be of critical importance in the dynamics of salmonid populations and any disruption may reduce fitness.
Article
Interactions between humans and wildlife have increased dramatically over the past century as human populations increase and occupy areas formerly dominated by native animals. In Australia, increases in land clearing and farming close to riparian areas has brought humans into contact with the common wombat (Vombatus ursinus), a relatively large-bodied, semifossorial marsupial. The common wombat is regarded as a pest in some agricultural areas due to its habit of burrowing beneath buildings, destroying fences and destabilising stream banks. We examined the effectiveness of artificial lighting to deter wombats from using the subfloor cavity under an historic cottage at 'Bundanon' in southern New South Wales, Australia. The response of wombats to artificial light (10 weeks on followed by 10 weeks off) was assessed using heat- and motion-sensing cameras continuously over a period of 58 weeks. While the main focus was on light effects on wombats, the study also allowed us to record non-nuisance animals using the subfloor cavity. Of the total of 1086 animal detections over the 58-week period (2.67 detections day(-1)), 965 (89%) were of mammals, 106 birds and 15 reptiles. Wombats (622; 57%) and kangaroos (228; 22%) made up 79% of all detections. Nocturnal activity of wombats remained unchanged in response to lighting (on: 266; off: 268), but there were significantly more diurnal detections when the lights were on (58) than off (30). For kangaroos, there were more nocturnal detections when lights were off, but more diurnal detections when lights were on. More antechinus were detected at night (night: 107; day: 8), and with the lights off (99 cf. 8), and insectivorous birds were detected almost entirely during the day, mostly with the lights on (66 cf. 39). Our study showed that, overall, the lighting regime we used was ineffective at reducing wombat activity under the building.
Article
The main objective of this study was to determine the extent of influence that a large city's ecological conditions have on the singing behaviour of urbanised birds. The singing activity of selected bird species was examined using the "animal focus sampling" method. The observations were carried out from the beginning of March to the beginning of June 1995 in a 10 ha inner city park, the Westpark (WP) in Dortmund (NRW, Germany). An area of equal size in a forest south of Dortmund, the Niederhofer Wald (NW) was chosen as a control area. In the Westpark the Blue Tit, Great Tit and Chaffinch started to sing significantly earlier in the morning than in the control area. This difference could be due to the artificial lighting of the park at night as well as the noise of traffic. There was no difference in the three species' singing activities between the two areas, but there were differences in the temporal pattern of the Chaffinch's morning singing activity in comparison of the two areas. In the Niederhofer Wald the Chaffinch was almost equally active at all times whereas it showed a pattern similar to the Tit's "dawn chorus" in the Westpark. Food supply, distribution and predictability within the two areas are discussed as causes for this difference. However, the negative correlation between singing activity and the frequency of pedestrians crossing the birds' territories may also play a role. In the Westpark, a correlation between the Chaffinch's singing activity and the frequency of passing pedestrians was noted. The more people crossed the focus animal's territory, the less its singing activity and the more frequently "pinks" occurred. Thus, pedestrians do indeed disturb the Chaffinch which reacts with a change of singing behaviour.