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Crows Causing Fire

Hiroyoshi HIGUCHI
Laboratory of Biodiversity Science, School of Agriculture and Life Sciences,
The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japane-mail: higuchi@es.a.u-tokyo.ac.jp
Abstract
Crows carry candles from exterior holders at Fushimi-Inari shrine, Kyoto, Japan, and may becausing field fires. This behavior was studied through fieldwork that included making video
recordings. Jungle crows carried the candles to an area within a 50-100 m radius of the study site,which had a candle holder. After stealing the candle, the crows perched in a nearby tree gnawing on
the candle held in one or both feet. Then, the crows carried the candle into the forest and hid it indebris on the forest floor. No clear evidence could be obtained on how field fires were occurring, but
we can speculate about the possibility of the candle still being alight when hidden by crows and soigniting the material used to cover it.
Key words: candle, crows, field fire, food storing, Fushimiinari-Taisha shrine, Kyoto

1. Introduction
Conflicts between crows and humans are on the increase in urban areas like Tokyo. Problems include thecrows dispersing rubbish, attacking people (Higuchi &Morishita, 2000), placing stones on railway lines(Higuchi & Morishita, 1997) and stealing soap
(Higuchi et al., 2003). Here I report on another serious crow behavior: candle carrying and storage withsubsequent field fires.
At Fushimiinari-Taisha shrine in Kyoto, western
Honshu, Japan, it is known that crows have beenstealing candles. If these candles are still burning,
this activity could result in field fires in the surrounding area. The reason the crows carry thecandles, or exactly how the fires result, is unknown.
I studied this behavior through fieldwork that
included making video recordings. Here, I willreport the results, concentrating on four aspects:
1) which species is stealing the candles, the jungle
crows (Corvus macrorhynchos) or carrion crow, C.
corone, 2) how the crows respond to candles placed ina holder, 3) how the crows manage the candles after
carrying them, and 4) how the field fires occur.

2. Study Area and Methods
The shrine is located in the southeastern part of
Kyoto city. It has a total area of 87 ha, more than
80% of which is occupied by broad-leaved evergreen

forest and Cedar groves. There are nearly 10,000
candle holders placed outside along the shrine’s pathways. On a busy day, for example in mid-August orat the beginning or end of the year when holidays
bring many visitors, thousands of candles may beplaced in these holders.
I studied the crow behavior with regard to candles
in September and October of 2002. Two or threecandles were placed in a chosen holder, and a video
camera was set up nearby to record crow response tothe candle stimuli. The candles used were the oldstyle, with a thicker wick, which are sold at the shrine.
These are 190 mm in length, 25 mm wide at the top,and 15 mm wide at the base, with a 6 mm thick wick.
The wick is three times thicker than in modern candlesof the same size.
I walked around the grounds of the shrine area,observing the behavior of crows, particularly when
they were near candle holders or were carrying acandle. I spent a total of about 30 hours walking andobserving the crows.

3. Results
The video footage showed that crows visited thecandle site 12 times during the 5.5-hour period oftaping. All of these were jungle crows, as were 32
observed within the forest. Three or four crows may
have visited the holder at the same time, but only one
reached for the candle. In response to lit candles, the166

H. HIGUCHI

Fig. 1 A jungle crow eating the melting wax on the top of acandle at the holder. The crow showed no fear of
the flame.

crow ate the melting wax in three out of the twelve
visits (Fig. 1). In five visits, the crow ate there-hardened wax after it had melted from the candles
main body, and in the remaining four visits the crowbroke off the candle and carried it away.
At the holder, the crow used its wings for balanceand cut through the candle with its beak, severing thestring and enabling it to pull the candle away. Whenthe crow left with the candle, it was still alight (Fig. 2).
The crows showed no fear of the flame.
The crows carried the candles to an area within a
50-100 m radius of the candle site. After stealing thecandle, in three out of four cases, the crow wasobserved perching in a nearby tree gnawing on thecandle held in one or both feet. After this the crowcarried the candle into the forest and hid it in debris on
the forest floor, although the details of this process
could not be observed. In the remaining case thecrow carrying the candle was lost to observation
during flight.
At each of the two forested areas, which were300-350 m from each other and from the candle site, acrow was witnessed placing an extinguished candle
among leaves on the forest floor and then covering itwith more leaves.

4. Discussion
No clear evidence could be obtained on how field
fires were occurring, but from the videotapes andobservations we can speculate about the possibility of
the candle still being alight when hidden by crows andso igniting the material used to cover it. The type ofcandle used at the shrine has a thicker wick that lasts
longer than those of modern candles, thereby making
it susceptible to re-ignition. From April 1999 toDecember 2002, a total of seven field fires haveoccurred in the shrine area. They were suspected tohave been the work of crows (Hisami Iizuka, personalcommunication).
The candle carrying seems to be an aspect of foodstoring behavior that is well known in crows Corvidaeand tits Paridae (e.g., Vander Wall, 1990; Krebs, 1990;
Bugnyar & Kotrschal, 2002). Crows store acorns,walnuts, or man-made foods such as bread, meat, andfried eggs when they are abundant (Higuchi &Morishita, 1997; 2000; National Science Museum
Nature Education Garden, 2002). Soap storing is
also known in jungle crows (Higuchi et al., 2003).
Crows in Kyoto will carry and store candles when
they are plentiful.
The candles seem to be a favorite food among
crows in this area, as they visit the holders frequently.
The candles are made from solid fats, obtained fromparaffin and Rhus trees. Fats are also contained infoods such as meat and mayonnaise, which are preferred by crows in urban areas (Higuchi & Morishita,
2000; National Science Museum Nature Education
Garden, 2002). It is possible that crows eat candles
in pursuit of nutrients associated with fats.
Shrines have a long history, around 100-150 years,of placing candles outside (Hisami Iizuka, personalcommunication), so the crows’ behavior should also
have a long history. Crows are generalists, eatingwhatever is commonly available at a given time andplace. It can be shells and crabs on beaches in
Hokkaido, nuts from trees or fallen on the floor innorthern Honshu (Nihei & Higuchi, 2001), garbage inurban areas like Tokyo (Higuchi & Morishita, 2000)
or soap available outside houses and buildings incentral Honshu (Higuchi et al., 2003). So if we cansay that crows have local culture food habits, taking
the candles could be considered one such example.
In Kyoto, several other temples and shrines place
candles outside, and it is plausible that the crows
exhibit the same behavior here. However, fires do
not result at these sites because the candles are placedoutside only at certain times, for example at night
when crows are not active or because the candles used
are of the modern style which are extinguished moreeasily, for example when the crow flaps its wings. It
would be interesting to study the distribution of pastfire sites with unknown causes as, in the past, shrines
and temples used the old style candles and it ispossible that crows could have been the cause of thefires.

Aknowledgements
I thank Tamaki Taketoshi and Harumi Higuchi forcollecting information on the crows’ behavior, Hisami
Iizuka for permitting me to study at FushimiinariTaisha shrine and giving me information on field fires
possibly made by crows, and La Bariftxonoodiel forcomments on the draft.

Crows Causing Fire

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Fig. 2aFig. 2bFig. 2cFig. 2d

Fig. 2 Consecutive pictures in which a crow steals a lit candle from the outdoor holder. The pictures were developed
from videotape.

References
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(Received 3 October 2003, Accepted 2 December 2003)