Adamany, S. L., M. Salmon, et al. (1997).Behavior of sea turtles at an urban beach: III. Costs and benefits of nest caging as a management strategy. Florida Scientist 60(4): 239 - 253.
At a sea turtle nesting beach in Boca Raton, Florida, all nests are covered with a wire cage to protect the eggs from beach traffic and predators. The front panel of the cage (facing the ocean) is of larger mesh that allows hatchlings to escape. In this study we determined if cages impede hatchling migration. No effect was apparent at dark beach sites but at illuminated beach areas, hatchlings crawled toward lights behind the beach rather than toward the ocean, and were trapped within the cage. Trapped turtles eventually escaped, either later that evening (as lighting was reduced toward midnight) or at dawn (as natural levels of background illumination increased). However at night, enough lighting remained to attract turtles after they left the cage. At dawn, escaped hatchlings crawled to the sea but were probably vulnerable to visual predators. We conclude that at urban sites exposed to luminaires, cage use compromises hatchling survival. Thus at urban rookeries, caging is only effective if coupled with efforts to eliminate beach-front lighting.
Beier, P. 1995. Dispersal of juvenile cougars in fragmented habitat. Journal of Wildlife Management 59(2): 228 to 237.
There is little information on the spatiotemporal pattern of dispersal of juvenile cougars (Felis concolor) and no data on disperser use of habitat corridors. I investigated dispersal of radio-tagged juvenile cougars (8 M, 1 F) in a California landscape containing 3 corridors (1.5, 4.0, and 6.0 km long) and several habitat peninsulas created by urban growth. Dispersal was usually initiated by the mother abandoning the cub near an edge of her home range. The cub stayed within 300 m of that site for 13-19 days and then dispersed in the direction opposite that taken by the mother. Mean age at dispersal was 18 months (range 13-21 months). Each disperser traveled from its natal range to the farthest part of the urban-wildland edge. Dispersing males occupied a series of small ( lt 30% the area used by ad M in the same time span), temporary (10-298 days) home ranges, usually near the urban-wildland interface, and often with its longest border along that edge. Each of the 3 corridors was used by 1-3 dispersers, 5 of the 9 dispersers found and successfully used corridors, and 2 dispersers entered but failed to traverse corridors. Dispersing cougars will use corridors that are located along natural travel routes, have ample woody cover, include an under-pass integrated with roadside fencing at high-speed road crossings, lack artificial outdoor lighting, and have lt 1 dwelling unit/16 ha.
Bergen, F. and M. Abs (1997). Etho-ecological study of the singing activity of the blue tit (Parus caeruleus), great tit (Parus major) and chaffinch (Fringilla coelebs). Journal fuer Ornithologie 138(4): 451 to 467.
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.
Borg, V. (1996). Death of the night. Geographical Magazine. 68: 56.
Night light pollution is becoming an increasingly important environmental problem as well as an impediment to people enjoying the panorama offered by the stars. Certain animals, such as sea turtles in the Mediterranean and migratory birds that fly by night, are disturbed in their reproductive and migratory habits by the excess light being given off by lit towns and cities. The answer is to cap night lights to reduce the glare that is given off into the sky.
Buchanan, B. W. 1993. Effects of enhanced lighting on the behaviour of nocturnal frogs. Animal Behaviour 45(5): 893 to 899.
Biologists studying anuran amphibians usually assume that artificial, visible light does not affect the behaviour of nocturnal frogs. This assumption was tested in a laboratory experiment. The foraging behaviour of grey treefrogs, Hyla chrysoscelis, was compared under four lighting conditions: ambient light (equivalent to bright moonlight, 0.003 lx), red-filtered light (4.1 lx), low-intensity 'white' light (3.8 lx), and high-intensity 'white' light (12.0 lx). The treatments were chosen to correspond to standard methods of field observation of frog behaviour. The foraging behaviour of frogs in the four treatments was observed using infra-red light that was invisible to the frogs. The ability of the frogs to detect, and subsequently consume prey was significantly reduced under all of the enhanced light treatments relative to the ambient light treatment. Thus, the use of artificial light, within the visible spectrum of the frog's eyes, can influence the outcome of nocturnal behavioural observations. These results lead to the recommendation that anuran biologists use infra-red or light amplification devices when changes in frogs' visual capabilities may influence the conclusions drawn from a study.
Contor, C. R. and J. S. Griffith (1995). Nocturnal emergence of juvenile rainbow trout from winter concealment relative to light intensity. Hydrobiologia 299(3): 179-183.
This study examined the relationship between light intensity and the number of juvenile rainbow trout (Oncorhynchus mykiss) visible to a snorkeler during February in the Henrys Fork of the Snake River, Idaho, USA. Fish were concealed in the substratum during daylight. Emergence from concealment was observed from 30 to 80 min after real sunset time and began when stars were first visible (pyranometric irradiance, 4.5 times 10-3 W-2). Densities of visible fish were negatively correlated with light intensity (r-2 = 0.81, P lt 0.001). Later at night, densities decreased in the presence of moonlight and artificial light. Fish were observed to feed at night.
Derrickson, K. C. (1988). Variation in repertoire presentation in northern mockingbirds. Condor 90(3): 592 to 606.
Male Northern Mockingbirds (Mimus polyglottos) have exceptionally large vocal repertoires. The manner of presenting this extensive repertoire, as described using five measures, varied with reproductive stage, among situations, and among individuals. All three versatility measures peaked during courtship declined significantly during incubation, and then slowly increased during nestling and fledgling stages. A fourth measure, bout length, increased as the season progressed, being shortest during courtship and longest during the fledgling stage. A final measure, recurrence interval (number of intervening bouts between two bouts of a particular song type) was shorter during the nestling and fledging stages than during courtship. Recurrence interval was shortest during patrolling and countersinging with neighboring males. Over 25% of the song types occurred only once in the sampling of singing behavior of four males each over 2 years. Mockingbirds sang these rare song types most commonly during prefemale and courtship stages, thereby increasing the recurrence interval and versatility during these stages. The pattern just described resulted in the greatest number of song types being sung per unit of time during courtship and provide circumstantial support for the hypothesis that song functions intersexually in mockingbirds. The ability to alter the manner of presentation may provide mockingbirds with the flexibility to emphasize particular functions at certain times and other functions at other times. Males with the highest versatility measures and lowest bout length tended to be the first to acquire mates and begin to nest. However, the importance of versatility in attracting females remains speculative and requires further experimental testing because these results were from only four males. Songs sung at night were presented in a manner most similar to the period before a female arrived on a male's territory. Interestingly, under natural lighting conditions, only unmated males sang extensively at night.
Frank, K. D. (1988). Impact of outdoor lighting on moths: An assessment. Journal of the Lepidopterists' Society 42(2): 63-93.
Outdoor lighting has sharply increased over the last four decades. Lepidopterists have blamed it for causing declines in populations of moths. How outdoor lighting affects moths, however, has never been comprehensively assessed. The current study makes such an assessment on the basis of published literature. Outdoor lighting disturbs flight, navigation, vision, migration, dispersal, oviposition, mating, feeding and crypsis in some moths. In addition it may disturb cicadian rhythms and photoperiodism. It exposes moths to increased predation by birds, bats, spiders, and other predators. However, destruction of vast numbers of moths in light traps has not eradicated moth populations. Diverse species of moths have been found in illuminated urban environments, and extinctions due to electric lighting have not been documented. Outdoor lighting does not appear to affect flight or other activities of many moths, and counterbalancing ecological forces may reduce or negate those disturbances which do occur. Despite these observations outdoor lighting may influence some populations of moths. The result may be evolutionary modification of moth behavior, or disruption or elimination of moth populations. The impact of lighting may increase in the future as outdoor lighting expands into new areas and illuminates moth populations threatened by other disturbances. Reducing exposure to lighting may help protect moths in small, endangered habitats. Low-pressure sodium lamps are less likely than are other lamps to elicit flight-to-light behavior, and to shift circadian rhythms. They may be used to reduce adverse effects of lighting.
Frank, K. D. (1989). Impact of outdoor lighting on moths. Light Pollution, Radio Intereference, and Space Debris, Washington, DC, Astronomical Society of the Pacific.
Gorenzel, W. P. and T. P. Salmon (1995). Characteristics of American Crow urban roosts in California. Journal of Wildlife Management 59(4): 638 to 645.
American crows (Corvus brachyrhynchos) roost in urban areas across the United States creating problems resulting from fecal droppings, noise, and health hazards. With little information about roosts, managers have been unable to respond to questions from the public about roost problems or design control programs. We counted crows flying into Woodland, California, to roost, surveyed roosts for occupancy, and recorded features of 87 roost trees and 62 randomly selected nonroost trees from August 1992 through July 1994. Some crows roosted in town all year, with peak abundance from September through January. Roost trees had greater height, diameter at breast height (dbh), and crown diameter and volume than nonroost trees (P < 0.001 all cases). Most roost trees were located over an asphalt or concrete substrate (P < 0.001) in commercial areas of the city, rather than in residential areas (P < 0.001), and were subjected to greater disturbance from vehicles and people (P < 0.01). Ambient light levels and interior canopy temperatures during winter were greater at roost trees than nonroost trees (P < 0.001 both cases). There were seasonal changes in roost trees selected with an increased (P < 0.001) use of deciduous trees (elms (Ulmus spp.), mulberries (Morus spp.), oaks (Quercus spp.), and ashes (Fraxinus spp.)) in residential areas during summer months as opposed to the concentrated use of evergreen oaks, alders (Alnus spp.), and conifers (Pinus spp. and Sequoia spp.) in commercial areas during winter. We developed a logistic regression model with 4 variables that correctly classified status of 85% of roost or nonroost trees.
Klotz, J. H. and B. L. Reid 1993. Nocturnal orientation in the black carpenter ant Camponotus pennsylvanicus Degeer (Hymenoptera: Formicidae). Insectes Sociaux 40(1):95 to 106.
The black carpenter ant Camponotus pennsylvanicus (DeGeer), a predominantly nocturnal Formicine ant, responds to a hierarchy of visual and tactile cues when orienting along odor trails at night. Under illumination from moonlight or artificial light, workers rely upon these beacons to mediate phototactic orientation. In the absence of moonlight or artificial lights, ants were able to orient visually to terrestrial landmarks. In the absence of all landmarks, save for overhanging tree branches, ants could negotiate shortcuts or make directional changes in response to visual landmarks presented within the tree canopy on a moonless night. When experimental manipulations placed the ants in total darkness, they could no longer negotiate shortcuts and would resort to thigmotactic orientation along structural guidelines to reach a food source. The hierachical organization of these diverse cues in a foraging strategy is discussed, as well as their adaptive significance to C. pennsylvanicus.
Nein, R. A Robin uses artificial light for feeding at night. Beitraege zur Naturkunde der Wetterau 9(2): 213.
Peters, A. and K. J. F. Verhoeven 1994. Impact of artificial lighting on the seaward orientation of hatchling loggerhead turtles. Journal of Herpetology 28(1): 112 to 114.
Salmon, M., R. Reiners, et al. 1995. Behavior of loggerhead sea turtles on an urban beach. I. Correlates of nest placement. Journal of Herpetology 29(4): 560 to 567.
Loggerhead sea turtles nesting in Florida sometimes deposit their clutches on urban beaches. This study was undertaken at a city beach to determine correlations between physical variables and where nests were placed. Over a four year period, the distribution of nests on the beach was statistically identical. Nesting density variation at particular sites was unrelated to offshore depth profiles or to beach width, but was strongly correlated with the presence of tall objects (clusters of mature Australian pine trees and rows of multi-storied condominiums) located between the beach and the city. There are no reports that females nest preferentially in front of tall objects (dune or vegetation) at natural rookeries. The response may be unique to urban rookeries where the nesting habitat is exposed to artificial lighting. Tall buildings and trees shielded the beach from city light, with the magnitude of the effect (and the number of nests) positively related to object elevation. Planting vegetation and reestablishing dunes on urban beaches may be effective methods for attracting nesting turtles to these sites.
Salmon, M., M. G. Tolbert, et al. (1995). Behavior of loggerhead sea turtles on an urban beach. II. Hatchling orientation. Journal of Herpetology 29(4): 568 to 576.
At several locations on an urban nesting beach, loggerhead hatchlings emerging from their nests did not orient toward the sea. The cause was city lighting which disrupted normal seafinding behavior. Observations and experiments were conducted to determine why females nested where hatchlings were exposed to illumination, and how hatchlings responded to local conditions. In some cases, females nested late at night after lights were turned off, but hatchlings emerged earlier in the evening when lights were on. In other cases, the beach was shadowed by buildings directly behind the nest, but was exposed to lights from gaps between adjacent buildings. In laboratory tests, "urban silhouettes" (mimicking buildings with light gaps) failed to provide adequate cues for hatchling orientation whereas natural silhouettes (those without light gaps) did. Adding a low light barrier (simulating a dune or dense vegetation) in front of the gaps improved orientation accuracy. The data show that hatchling orientation is a sensitive assay of beach lighting conditions, and that light barriers can make urban beaches safer for emerging hatchlings. At urban beaches where it may be impossible to shield all luminaires, light barriers may be an effective method for protecting turtles.
Salmon, M. and B. E. Witherington (1995). Artificial lighting and seafinding by loggerhead hatchlings: Evidence for lunar modulation. Copeia 1995(4): 931 to 938.
Hatchling sea turtles generally emerge from nests at night and crawl immediately toward the ocean ("seafinding orientation"). On natural, dark beaches their orientation is usually appropriate, but where oceanfront buildings are present, hatchlings may crawl toward artificial lighting behind the beach. A systematic survey during the 1993 nesting season documented that, on Florida's beaches, such abnormal behavior ("disrupted orientation") occurred most often on dark nights around new moon and least often under full-moon illumination. Experiments on an urbanized Florida beach (Boca Raton, Palm Beach County) showed that background illumination from the moon, and not an attraction to the moon itself, restored normal seafinding orientation. Background illumination reduced, but did not eliminate, light intensity gradients imposed by artificial lighting. Thus, when seafinding was restored, hatchlings moved toward dimmer, not brighter, horizons. These results suggest that loggerhead hatchlings can locate the sea using mechanisms other than a positive phototaxis (the most widely held view). An alternative hypothesis, supported by these results, is that batchlings locate the ocean by crawling away from objects behind the beach (dune, vegetation, or buildings) using shape and/or elevation cues.
Simon, D. (1999). Vanishing Night Skies. Washington, DC, National Parks and Conservation Association.
Summers, C. G. (1997). Phototactic behavior of Bemisia argentifolii (Homoptera: Aleyrodidae) crawlers. Annals of the Entomological Society of America 90(3): 372-379.
First instars (crawlers) of Bemisia argentifolii Bellows and Perring were observed in the field and laboratory to move upward on plants, presumably in search of acceptable feeding sites. Laboratory experiments were conducted on a host plant and an artificial surface to determine if this movement was random, or a response to light (phototaxis) or gravity (geotaxis). Greenhouse-reared B. argentifolii crawlers were positively phototactic in experiments conducted on a host plant and on an artificial surface of black construction paper. Crawlers moved up or down the petiole of cheeseweed. Malva parviflora L., with equal facility, toward a light source placed either above or below the leaf blade. Response was always toward the light (positive phototaxis) and there was no response to gravity, either positive or negative. Crawlers placed on an artificial surface in a dark arena and presented with a point light source had a significant mean angular dispersion toward the light. Crawlers illuminated with uniform overhead lighting or kept in darkness moved about the arena at random. Crawlers maintained in darkness on cheeseweed and the artificial surface moved a significantly shorter distance from their origin than did those exposed to light. Such behavior suggests that some minimal light intensity may be necessary to stimulate crawler activity. The positive phototactic response may contribute to survival of B. argentifolii by enabling individuals eclosing from fall laid eggs, on leaves that become senescent during the winter, to find suitable leaves for development higher on the plant.
Telfer, T. C., J. L. Sincock, et al. (1987). Attraction of Hawaiian Seabirds To Lights Conservation Efforts and Effects of Moon Phase. Wildlife Society Bulletin 15(3): 406-413.
Tessmer, J. W., C. L. Meek, et al. 1995. Circadian patterns of oviposition by necrophilous flies (Diptera: Calliphoridae) in southern Louisiana. Southwestern Entomologist 20(4): 439 to 445.
Circadian ovipositional activities of calliphorid flies on poultry carcasses were assessed during two 24-h periods in mid-summer 1994 during full (July study) and new moon (August study) phases in urban habitats with artificial lighting and in rural habitats without artificial lighting. Immatures of Cochliomyia macellaria (F.) and Phaenicia sericata (Meigen) were the predominant species collected during each of the two 24-h field studies. Flies oviposited during the afternoon diurnal hours and during the morning diurnal period of the following day of the July and August studies. However, egg deposition did not occur on any poultry carcass between the nocturnal hours of 2100 and 0500-h CDST for either study period regardless of the presence or absence of artificial or natural (i.e., full moon) lighting.
Upgren, A. R. (1996). Night blindness: Light pollution is changing astronomy, the environment, and our experience of nature. The Amicus Journal Winter: 2225.
Wehr, T. A. (1997). Melatonin and seasonal rhythms. Journal of Biological Rhythms 12(6): 518 to 527.
The pineal hormone melatonin plays a ubiquitous role in biology as a chemical mediator of the effects of season on animal physiology and behavior. Seasonal changes in night length (scotoperiod) induce parallel changes in the duration of melatonin secretion (which occurs exclusively at night), so that it is longer in winter and shorter in summer. These changes in duration of nocturnal melatonin secretion, in turn, trigger seasonal changes in behavior. The retinohypothalamic-pineal (RHP) axis's responses to light are highly conserved in humans. Like other animals, humans secrete melatonin exclusively at night, and they interrupt its secretion when they are exposed to light during the nocturnal period of its secretion. In many individuals, the RHP axis also is capable of detecting changes in the length of the night and making proportional adjustments in the duration of nocturnal melatonin secretion, producing the type of melatonin message that animals use to trigger seasonal changes in their behavior. This has been shown both in naturalistic studies in which melatonin profiles were compared in summer and winter and in experimental studies in which melatonin profiles were compared after chronic exposure to long and short artificial "nights." Individuals who live in modern urban environments differ in the degree to which, or even whether, the intrinsic duration of melatonin secretion (the duration measured in constant dim light) responds to seasonal changes in the length of the solar night. Changes in the intrinsic duration of melatonin secretion that are induced by changes in the scotoperiod are highly correlated with changes in the intrinsic timing of the morning offset of secretion and are only weakly correlated with changes in the intrinsic timing of evening onset of secretion. This finding suggests that differences in the way in which individuals are exposed to, or process, morning light may explain differences in their responsiveness to changes in duration of natural and experimental scotoperiods. Although the human RHP axis clearly is capable of detecting changes in the length of the night and in producing the melatonin message that other animals use to trigger seasonal changes in their behavior, it is not yet known whether or how the human reproductive system or other systems respond to this message.
White, A. G. (1974). Excessive light as a form of urban-created pollution: a selected bibliography. Monticello, Ill., Council of Planning Librarians.
Hoving, E. J. and S. G. Sealy (1987). Species and age composition of a sample of birds killed in Fall 1979 at a Manitoba (Canada) TV tower. Prairie Naturalist 19(2): 129-134.
Examination was made of a sample of 220 birds of 21 species killed in collision with a TV tower near Ste. Agathe, Manitoba, in late August 1979. All of the individuals were passerines, except for one immature sora (Porzana carolina). One hundred and eighty-six individuals were aged. Sample sizes were small for all species except the Swainson's thrush (Catharus ustulatus) and red-eyed vireo (Vireo olivaceus): 76% of the Swainson's thrushes were immatures, 92% of the red-eyed vireos were adults. One adult Swainson's thrush had not begun its wing molt. The wing molt was still underway in one unaged Tennesses warblet (Vermivora peregrina) and one adult rose-breasted grosbeak (Pheucitus ludovicianus).
Ogden, L. J. E. (1996). Collision Course: The Hazards of Lighted Structures and Windows to Migrating Birds. Toronto, World Wildlife Fund Canada and Fatal Light Awareness Program.
Braden, C. (1998). Bright light thretens migratory flight. BBC Online. 1999.
Milius, S. (1999). Nocturnal spider favors artificial lights. Science News 155(26): 407.
Rydell, J. and H. J. Baagoe (1996). Street lamps increase bat predation on moths. Entomologisk Tidskrift 117(part 4): 129135.
Streets and roads lit by mercury vapour streetlamps provide important feeding habitats for several species of bats, because the lights attract insects, including moths, which thus become easily accessible to the predators. Some common Scandinavian bat species, mostly the northern bat (Eptesicus nilssonii), the particoloured bat (Vespertilio murinus) and the serotine (Eptesicus serotinus), occur at high densities near streetlights (usually 2-5 bats per km, occasionally up to 20 per km). Bats foraging around streetlights catch male moths in large numbers. The effect of the increased predation on the moth populations is unknown. Mercury vapour lights are currently replaced by environmentally more friendly orange sodium lights in many areas. Sodium lamps do not attract insects to the same extent. The replacement will therefore result in decreased food availability for bats that forage near lights (such as those mentioned above). Our threatened bat species seldom feed near streetlights, and will therefore not be affected directly by the replacement.
Upgren, A. R. (1996). Night blindness: Light pollution is changing astronomy, the environment, and our experience of nature. The Amicus Journal, Winter: 2225.
Verheijen, F. J. (1958). The mechanisms of the trapping effect of artificial light sources upon animals. Netherlands Journal of Zoology 13: 1 to 107.
Verheijen, F. J. (1985). Photopollution: Artificial light optic spatial control systems fail to cope with. Incidents, causations, remedies. Experimental Biology 1985:118.
Woodford, J. (1999). Bridge plan puts stars in bad light. Sydney Morning Herald. Sydney, Australia.
Svensson, A. M. and J. Rydell (1998). Mercury vapour lamps interfere with the bat defence of tympanate moths (Operophtera spp.; Geometridae). Animal Behaviour 55(1):223 to 226.
Bats often forage near streetlamps, where they catch moths in particular. At least two hypotheses may explain the apparent increase in the availability of moths to bats feeding around streetlamps: (1) the moths become concentrated near the light and therefore more profitable to exploit; and (2) the light interferes with the moths' evasive flight behaviour. We tested the second of these hypotheses by exposing flying male winter moths, Operophtera spp., to bursts of ultrasound (26 kHz, 110 dB sound pressure level) from an electronic source. The light from a 125 W mercury vapour lamp had a quantitative effect on the moths' evasive flight response at close range (within ca 4 m), inhibiting it totally in nearly half (43%, N = 125) of the cases. By contrast, moths flying in the surrounding woodland and without interference from the lamp always responded to the sound. Streetlamps of the mercury vapour type (white lamps) thus interfere with the defensive behaviour of moths and presumably increase their vulnerability to echolocating bats. This may have implications for the conservation of both moths and bats.
This bibliography was complied by The Urban Wildlands Group - www.urbanwildlands.org