Roosting Grey-headed Flying Foxes (Pteropus poliocephalus), Yarra Bend Park, Melbourne: photo by Ruizhen, 14 December 2012
When I went into my room, at mid-morning, Say ten o'clock . . . My room, a crash-box over that great stone rattle The Via de' Bardi. ... When I went into my room at mid-morning Why? . . . a bird_! A bird Flying round the room in insane circles. In insane circles! . . . A bat! A disgusting bat At mid-morning! . . . Out! Go out! Round and round and round With a twitchy, nervous, intolerable flight, And a neurasthenic lunge, And an impure frenzy; A bat, big as a swallow. Out, out of my room! The Venetian shutters I push wide To the free, calm upper air; Loop back the curtains. . . . Now out, out from my room! So to drive him out, flicking with my white handkerchief: Go! But he will not. Round and round and round In an impure haste, Fumbling, a beast in air, And stumbling, lunging and touching the walls, the bell-wires About my room! Always refusing to go out into the air Above that crash-gulf of the Via de' Bardi, Yet blind with frenzy, with cluttered fear. At last he swerved into the window bay, But blew back, as if an incoming wind blew him in again. A strong inrushing wind. And round and round and round! Blundering more insane, and leaping, in throbs, to clutch at a corner, At a wire, at a bell-rope: On and on, watched relentless by me, round and round in my room, Round and round and dithering with tiredness and haste and increasing delirium Flicker-splashing round my room. I would not let him rest; Not one instant cleave, cling like a blot with his breast to the wall In an obscure corner. Not an instant! I flicked him on, Trying to drive him through the window. Again he swerved into the window bay And I ran forward, to frighten him forth. But he rose, and from a terror worse than me he flew past me Back into my room, and round, round, round in my room Clutch, cleave, stagger, Dropping about the air Getting tired. Something seemed to blow him back from the window Every time he swerved at it; Back on a strange parabola, then round, round, dizzy in my room. He could not go out, I also realised. . . . It was the light of day which he could not enter. Any more than I could enter the white-hot door of a blast-furnace. He could not plunge into the daylight that streamed at the window. It was asking too much of his nature. Worse even than the hideous terror of me with my hand-kerchief Saying: Out, go out! . . . Was the horror of white daylight in the window! So I switched on the electric light, thinking: Now The outside will seem brown. . . . But no. The outside did not seem brown. And he did not mind the yellow electric light. Silent! He was having a silent rest. But never! Not in my room. Round and round and round Near the ceiling as if in a web, Staggering; Plunging, falling out of the web, Broken in heaviness, Lunging blindly, Heavier; And clutching, clutching for one second's pause, Always, as if for one drop of rest, One little drop. And I! Never, I say. . . . Go out! Flying slower, Seeming to stumble, to fall in air. Blind-weary. Yet never able to pass the whiteness of light into freedom . . . A bird would have dashed through, come what might. Fall, sink, lurch, and round and round Flicker, flicker-heavy; Even wings heavy: And cleave in a high corner for a second, like a clot, also a prayer. But no. Out, you beast. Till he fell in a corner, palpitating, spent. And there, a clot, he squatted and looked at me. With sticking-out, bead-berry eyes, black, And improper derisive ears, And shut wings, And brown, furry body. Brown, nut-brown, fine fur! But it might as well have been hair on a spider; thing With long, black-paper ears. So, a dilemma! He squatted there like something unclean. No, he must not squat, nor hang, obscene, in my room! Yet nothing on earth will give him courage to pass the sweet fire of day. What then? Hit him and kill him and throw him away? Nay, I didn't create him. Let the God that created him be responsible for his death . . . Only, in the bright day, I will not have this clot in my room. Let the God who is maker of bats watch with them in their unclean corners. . . . I admit a God in every crevice. But not bats in my room; Nor the God of bats, while the sun shines. So out, out you brute! . . . And he lunged, flight-heavy, away from me, sideways, a sghembo! And round and round and round my room, a clot with wings, Impure even in weariness. Wings dark skinny and flapping the air. Lost their flicker. Spent. He fell again with a little thud Near the curtain on the floor. And there lay. Ah death, death You are no solution! Bats must be bats. Only life has a way out. And the human soul is fated to wide-eyed responsibility In life. So I picked him up in a flannel jacket, Well covered, lest he should bite me. For I would have had to kill him if he'd bitten me, the impure one. . . . And he hardly stirred in my hand, muffled up. Hastily, I shook him out of the window. And away he went! Fear craven in his tail. Great haste, and straight, almost bird straight above the Via de' Bardi. Above that crash-gulf of exploding whips, Towards the Borgo San Jacopo. And now, at evening, as he flickers over the river Dipping with petty triumphant flight, and tittering over the sun's departure, I believe he chirps, pipistrello, seeing me here on this terrace writing: There he sits, the long loud one! But I am greater than he . . . I escaped him. . . . Florence
sghembo! (Italian): obliquely
pipistrello (Italian): bat
D. H. Lawrence (1885-1930): Man and Bat, from Birds, Beasts and Flowers: Poems (1923)
D. H. Lawrence (1885-1930): Man and Bat, from Birds, Beasts and Flowers: Poems (1923)
Grey-headed Flying Foxes (Pteropus poliocephalus), roosting at a daytime camp near Allora, Queensland: photo by Bruce Thomson, 23 September 2008
A small group of Black Flying Foxes (Pteropus alecto): photo by Justin A. Welbergen, 18 June 2003
Groups of Black Flying Foxes (Pteropus alecto) resting in a tree: photo by Justin A. Welbergen, 23 April 2003
Black Flying Fox (Pteropus alecto), seen on a walk around Florence Falls, Northern Territory, Australia: photo by Jon Clark (jonclark2000), 18 January 2013
Roosting Grey-headed Flying Foxes (Pteropus poliocephalus), New South Wales: photo by Justin A. Wellbergen, 13 August 2009
Baby bat burden back again. Grey headed Flying Fox (Pteropus poliocephalus), carrying pup, North Parramatta, Sydney. I appeal to all to recognise that dangerous climate change is already here. On 18 January 2013 Sydney experienced its highest temperature in recorded history -- 46'C (115'F). These bats (especially the babies) are at extreme risk of dying from heat stress at temperatures over 43'C. 500 bats (90% were pups) died on this day in one colony alone (Parramatta). These "babies" are getting so big it is hard for mum to stay aloft! Bat babies get it good (but not in this heat!) -- suckling mumma's milk while getting carried everywhere: photo by Peter (snowed under without any snow)(pppumpkine), 18 December 2012
Black Flying Fox (Pteropus alecto), Parramatta, Sydney. I appeal to all to recognise that dangerous climate change is already here. On 18 January 2013 Sydney experienced its highest temperature in recorded history -- 46'C (115'F). These bats (especially the babies) are at extreme risk of dying from heat stress at temperatures over 43'C. 500 bats (90% were pups) died on this day in one colony alone (Parramatta): photo by Peter (snowed under without any snow)(pppumpkine), 18 January 2013
Thirsty bat on a very hot day, Sydney. Grey headed Flying Fox (Pteropus poliocephalus), Parramatta. Get home quickly without spilling too much! This is the way that bats drink -- dunk their hairy chest in the river, fly back to their roost, enjoy a cool hairy drink by licking their fur. She really needed this drink after a 40'C day, and there was hotter weather to come: photo by Peter (snowed under without any snow)(pppumpkine), 8 January 2013
Ka-sploosh! Dunking the chest for a cool drink back at the branch. North Paramatta, Sydney: photo by Peter (snowed under without any snow)(pppumpkine), 8 January 2013
Adult male Grey-headed Flying Fox (Pteropus poliocephalus), suffering from heat stress, Emu Plains, New South Wales: photo by Justin A Welbergen, 18 January 2013
Cluster of juvenile Grey-headed Flying Foxes (Pteropus poliocephalus) dying of heat stress, Emu Plains, New South Wales: photo by Justin A. Welbergen, 18 January 2013
Flying foxes will commonly use wing-fanning to cool themselves. As temperatures rise further they will seek shade by coming down onto the trunk of the tree under the canopy. Thermal imaging has shown the trunk to be significantly cooler than the surrounding air. When these strategies are no longer adequate, panting and licking can be effective but the loss of body water is significant. At this stage they face death. There have been several mass deaths in the last decade where up to 8000 animals have died in one day.
Climate change and the impacts of extreme events on Australia's Wet Tropics Biodiversity: Dr Justin Welbergen, Centre for Tropical Biodiversity and Climate Change, School of Marine and Tropical Biology, James Cook University (2013)
The nursery. Grey-headed Flying Foxes (Pteropus poliocephalus), North Parramatta, Sydney: photo by: photo by Peter (snowed under without any snow)(pppumpkine), 18 January 2011
Over the past 100 years, the global average temperature has increased by approximately 0.74±0.18°C and is projected to continue to rise at a rapid rate. Changes in climate are significant for natural systems as they can affect population abundance, shifts in species range distributions and the number of species invasions and extinctions. Recently, extreme weather events have gained in importance relative to gradual climatic trends as mechanistic drivers of broad ecological responses to climatic change.
Temperature extremes that exceed physiological limits can cause widespread mortality, as evidenced by the 2003 heat wave in Europe that resulted in more than 15 000 human fatalities in France alone. However, very little is known about the kinds of effects that temperature extremes have on natural systems. This is a matter of increasing concern now that current climate models predict a dramatic increase in the frequency, intensity and duration of temperature extremes, through the combined effects of a shift towards warmer and more variable temperatures.
In this study, we examined the effects of temperature extremes on the behaviour and demography of Australian flying-foxes (Pteropus spp.). The grey-headed flying-fox (Pteropus poliocephalus) and the black flying-fox (Pteropus alecto) are among the largest species of fruit bats. Pteropus poliocephalus is endemic to coastal southeastern Australia and it extends into higher latitudes than any other pteropodid. In northern New South Wales and southern Queensland, P. poliocephalus shares colonies with P. alecto . The range of P. alecto extends from Papua New Guinea and Indonesia into the forested areas of northern NSW along the east coast of Australia. At night, both pteropodids forage for nectar, pollen and fruit, and during the day they roost in large aggregations (colonies/roosts/camps) that may contain thousands of individuals. They provide important ecosystem services, including pollination of wild and cultivated crops and seed dispersal. However, they are exposed to threatening anthropogenic factors, the most serious of which are ongoing loss of foraging and roosting habitat, direct killing of animals in orchards and harassment and destruction of roosts. The species are listed as Vulnerable on the NSW Threatened Species Conservation Act 1995 (P. alecto and P. poliocephalus), and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (P. poliocephalus). Because flying-foxes roost among the exposed branches of canopy trees, they are particularly sensitive to the effects of extreme temperatures, and therefore are convenient indicators for assessing the impact of temperature extremes on the natural environment.
On 12 January 2002, weather stations in coastal eastern Australia recorded maximum temperatures that were up to 16.5°C higher than the 30-year average mean daily maximum. This single extreme temperature event was associated with the death of thousands of flying-foxes, providing a unique opportunity to assess directly the effects of a temperature extreme on large terrestrial vertebrates.
Our main study site (Dallis Park) is occupied by a mixed-species colony and is located near the southern end of the zone of range overlap between P. poliocephalus and P. alecto. The colony has been the subject of an intensive ecological study since 2000. On 12 January 2002, we documented individual behaviour, thermoregulatory responses and changes in roosting patterns, commencing at 06.00 hours until approximately 15.00 hours. At approximately 11.30 hours, the behaviour of animals started to depart notably from normal. Observations were supplemented by time-coded photographics.
On January 13 and 14, we systematically searched the Dallis Park colony and adjacent areas for corpses, and classified a total of 1361 bodies by species (i.e. P. alecto versus P. poliocephalus)...
As the temperatures were rising in the Dallis Park colony on 12 January 2002, both P. alecto and P. poliocephalus showed the following sequence of behaviours: (i) wing-fanning (start: approx. 10.00 hours), (ii) shade-seeking (start: approx. 11.15 hours), (iii) panting (start: approx. 13.15 hours) and (iv) saliva-spreading (start: approx. 13.45 hours). Later, individuals began falling from the trees (start: approx. 13.53 hours). Fallen individuals became increasingly lethargic and died within 10–20 min.
The behavioural sequence displayed by both species closely resembled that reported elsewhere and seems adaptive for maintaining body temperature (Tb) against increasing ambient temperature (Ta). Wing-fanning facilitates thermoregulation by forced convection and shade-seeking lowers Tb by reducing direct radiation absorption from sunlight. When the Ta exceeds Tb, wing-fanning and shade-seeking are no longer adequate for heat dispersal, but panting and saliva-spreading can still reduce Tb by increasing evapotranspiration. The loss of body water will be significant, however, and animals should deploy this strategy only when Tb has risen close to lethal limits.
Animals started dying approximately 1 hour before the temperature at the nearest weather station reached an all time high of 42.9°C, which was 3.1 s.d. higher than the average monthly summer maximum (35.3°C), and a 13.8°C departure from normal. The same weather station recorded 40.2, 40.7, 40.9 and 41.2°C in summer 2002, 2001, 2004 and 1994, respectively, without any evidence of mortality.
The minimum number of bats that died in the colony on 12 January 2002 was 1453 (approx. 5–6% of the bats present). Mortality was significantly higher among P. alecto than P. poliocephalus (10–13% versus less than 1%...). This suggests that P. alecto has lower species-specific physiological limits for coping with high temperatures than P. poliocephalus.
from Climate change and the effects of temperature extremes on Australian flying-foxes: Justin A. Welbergen et al.: Proceedings of the Royal Society (Biological Sciences), vol. 75 no. 1633, 22 February 2008
Temperature extremes have caused the death of tens of thousands of Australian flying-foxes in the last decade alone causing some of the most dramatic mass die-offs ever to have been recorded in mammals. Such extremes selectively affect the effective breeding population and recruitment of the species, which further exacerbates their impact. Since temperature extremes are expected to increase in the future, mass die-offs will become more frequent and widespread, and will occur at lower latitudes than previously. This will undoubtedly increase the threat to the survival of the species in addition to the anthropogenic factors that have already been identified.
from The grey-headed flying-fox, Pteropus poliocephalus: Justin A. Welbergen, Behavioural Ecology Group, Department of Biology, School of Biological Sciences, University of Cambridge
Colony of Grey-headed Flying Foxes (Pteropus poliocephalus), roosting, North Parramatta, Sydney: photo by: photo by Peter (snowed under without any snow)(pppumpkine), 18 January 2011