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Self-anointing by wild hedgehogs, Erinaceus Europaeus, in New Zealand
Anita. Behav., 1976, 24, 68-71 SELF-ANOINTING
BY WILD
HEDGEHOGS,
IN NEW
ERINACEUS
EUROPAEUS,
ZEALAND
BY ROBERT BROCKIE
Zoology Department, Victoria University of Wellington Abstract. Of 929 wild hedgehogs examined, nineteen bore signs of recent self-anointing. The spittle deposited on the hedgehogs' backs usually gave off a sharp smell, clearly detectable some metres downwind. Nestling animals anointed themselves when removed from their nests, possibly as a means of advertising their whereabouts to their mothers. The habit was not detected among newly-independent young animals nor among sub-adults. Among adult hedgehogs, self-anointing was confined to the breeding season, and on five occasions was elicited in the presence of other hedgehogs of the opposite sex. In this context self-anointing may serve as a form of sexual signal. When brought into captivity the self-anointing reflex is triggered by novel objects or odours and, in this unnatural context, it is argued that the behaviour falls into the category of a displacement activity, being inappropriate to the situation and seemingly purposeless. The hedgehog's curious habit of plastering itself with its own saliva was first recorded by Heck (1912). Since then, Herter (1938, 1965a) and Burton (1969) have extended the range of observations and speculation about the possible purpose of the behaviour. Herter has described how hedgehogs Erinaceus europaeus, E.
stimulatory substances, including distilled water, was endless. Poduschka & Firbas (1969) discovered that the saliva so produced contained quantities of an exudate secreted by Jacobson's organ. The function of self-anointing has long been the subject of speculation. Herter (1965a) suggested that its purpose is to cover the natural smell of the hedgehog in order to make its discovery by enemies more difficult. Burton (1969) lists the following possible explanations: (1) It is a form of greeting. (2) It is a form of sexual behaviour. (3) It is a means of getting rid of ectoparasites. (4) It makes the hedgehog unpalatable to its enemies. (5) It keeps the spines supple. (6) Foreign substances on the spines make them poisonous. From his compendious range of observations, Burton goes on to point out that none of these explanations is satisfactory as, for example, self-anointing occurs even with solitary animals and so cannot be a form of greeting; it also occurs with nestlings so it cannot be a form of sexual activity; it occurs with clean and parasitized animals so it cart have little significance as a means for getting rid of parasites, etc. He then suggests that, like the frenzied reaction of many cats to the scent of catnip, self-anointing may be an incomplete relic of some once-useful activity, possibly a cooling mechanism inherited from the hedgehog's tropical ancestors.
roumanicus, Aetheehinus algirus, Paraechinus aethiopieus, Hemieehinus auritus, H. auritus persieus, and Atelerix pruneri, on coming into contact with certain objects, sniff them assiduously, lick them and, if the objects are small enough, take them into their mouths and chew them, this activity producing an abundance of foamy saliva. After a few minutes the hedgehog will turn its head backwards or to the side and, with the aid of its tongue, place the foam on its spines. This salivation appears to be released by a chemical stimulus because the objects eliciting the behaviour usually have a strong smell or taste, or both. Herter recorded animals responding to bookbinder's glue, cigarette ends, paper soaked in human sweat, hyacinth flowers, perfume, soap, decaying crabs, newsprint, toad's skin, and valerian. He continues 'Another hedgehog also produces this stimulus if it is a stranger and it will be treated in the same way as an inanimate object. In some eases the reaction was released by certain smells in the air, such as cigar smoke or varnish. Patently, autosalivation is released by strong chemical stimuli which are unfamiliar or unaccustomed . . . . ' Burton (I957, 1969) gathered much more information about self-anointing among British hedgehogs and concluded that the range of
Observations Most observations Oll self-anointing have been on animals brought into the house or laboratory, but these conditions isolate the animals from
68
BROCKIE: SELF-ANOINTING BY HEDGEHOGS
69
Table I. Observations on Self-Anointing Date
Specimen no.
Sex
Body wt.
Locality
Notes
11. 8.70
497
M
790
Karori, Wellington
20. 9.70 6.10.70 19.10.70 3.11.71
519 526 551 908
M M M M
960 780 630 610
Wadestown, Lower Hurt .... ....
8.12.71
948
M
710
22.12.71
971
M
700
Wadestown, Wellington Lower Hurt
2. 1.72
656
M
660
20. 1.72
619
M
800
14. 1.72
808
M
490
1.72 1.72 2.71 2.72 2.72 2.71
583 642 655 1066 931 1010
F F F F F F
830 810 400 960 930 670
5. 3.57
274
F
400
17. 3.71
689
F
660
Point Howard, Wellington Palmerston Nth.
22. 3.72
1106
M
470
Lower Hutt
30. 29. 8. 12. 19. 21.
,,
.... .... .... .... .... ....
One of six wild animals which came to the door to be fed nightly. Powerful-smelling saliva on back. Clear spittle on left flank. Clear spittle on back. Spittle on nape and shoulders. Trace of spittle on muddy back. 10 m upwind of adult female no. 907. Snorting and pushing adult female 947. Clear spittle on right shoulder. Nape and rump smeared with clay-discoloured spittle. Back smeared with saliva smelling powerfully and resembling the smell of horse urine. Adult female no. 809 crouched beside him and another male (No. 908) 20 m up-wind of this pair. Clear spittle on back and smelling powerfully. This animal had been recaptured twelve times over the previous year but showed no earlier traces of self-anointing. Clear spittle on back. This animal seen on seven previous occasions but showed no earlier traces of self-anointing. Spittle on back. Muddy spittle on left flank. Spittle on left flank. Black spittle on back. Back anointed with clear frothy saliva. Spittle on back interspersed with granular red brick-like substance. Right flank smothered with spittle. One month earlier her flanks matted with excrement. Back anointed with crumbly white substance and spittle. Spittle on back. 30 m down-wind of adult male 1105 and t0 m across-wind from adult female 1107.
The following observations were made on young hedgehogs: 3.12.70
No. 567
17. 2.72
No. 1000
19. 8.72
No. 1087
Female 220 g. Kelburn, Wellington, When a strange male was introduced to the hutch this animal attempted to suckle from him. After 3 min she frothed at the mouth and anointed her back and flanks. Male. 140 g. York Bay, Wellington. Estimated age 16 days. Self-anointed when taken outside and placed in sandpit used by cats. Male. 180 g. York Bay, Wellington. One month old. Repeatedly self-anointed in response to carpet sandals, and the leg of a chair.
any n at u ral intercourse with their fellows and, outside their n o r m a l surroundings, m a y distort or m a s k the n at u r al purposes o f the behaviour. I n an a t t e m p t to cast s o m e light on the n a tu r a l occurrence o f self-anointing a m o n g wild hedgehogs I have r e c o r d e d its frequency a m o n g a tagged p o p u l a t i o n o f 207 free-ranging animals captured o n t wo g o l f courses at Melling, a suburb o f L o w e r Hurt, N e w Zealand. O n e h u n d r e d a n d sixteen o f these animals were re-
c a p t u r e d at varying intervals over a 2-year p e r i o d while an additional 500 animals f r o m the greater Wellington area were e x a m i n e d f o r traces o f spittle or other signs o f self-anointing. These results are s u m m a r i z e d in Tab l e I. Th e m o s t i m p o r t a n t p o i n t to emerge f r o m these observations is that the saliva usually gave off a sharp, r a n k smell resembling horse or h e d g e h o g ' s urine. O n a mildly w i n d y night, I co u l d detect this o d o u r 5 to 10 m d o w n - w i n d .
ANIMAL
70
BEHAVIOUR,
Earlier writers do not appear to have remarked on this odour, which m a y hold the key to its explanation. Signs of self-anointing were seen only in those months when courting or copulating were also observed; that is, from late winter (August) until early autumn (March). During this period, 19 (2.5 per cent) of 755 hedgehogs examined, bore signs of self-anointing. This contrasts with the 174 animals examined between April and July, none of which had anointed themselves. Of the nineteen animals bearing spittle on their spines, five were found in the company of other hedgehogs of the opposite sex. On two occasions a second male was also present a short distance away. In social contexts one or other, or both the anointed animals, were, as far as could be determined, new to the area. Between 8 August and 14 January, all ten anointed animals were males. Eight of the nine anointed animals seen later in the season were females. One male animal (No. 908) was involved in two self-anointing incidents with other animals present or nearby. On the first occasion, he was found 10 m up-wind of an adult female and on the second occasion was seen 20 m up-wind of another courting couple, one of which was anointed with strong-smelling spittle. Records were kept of the time of night, the phases of the moon, the direction and strength of the wind, and the incidence of ectoparasites, but no connection between these variables and the occurrence of self-anointing was established. Discussion
The strong smell of saliva thrown up while selfanointing may help to explain the purpose of this behaviour. Lindemann (1951) and Brettung (1972) conducted laboratory and field tests which established the primacy of the hedgehog's sense of smell. F r o m their evidence it is reasonable to assume that these animals can detect the smell of their spittle over a much greater distance than can a human. Self-anointing can then be interpreted as a signalling device whose function is to advertise the animal's presence to other hedgehogs. Both nestling juveniles and sexually mature adults may wish to draw attention to themselves, but for different reasons. Suckling hedgehogs occasionally stray from the nest and, in these circumstances, set up a piercing, chirping or whistling sound to attract their mother's attention. Now, removing a youngster from its nest and placing it in strange
24,
1
surroundings often stimulates the animal to anoint itself. A young animal bearing spittle in this way would stand a better chance of being found by its mother. The habit appears to be lost after weaning, for no independent youngsters or sub-adults have been observed to anoint themselves. Among mature adults the habit emerges again, but in a different context. Adult hedgehogs have been seen anointing themselves only during the breeding season (see Table II) which suggests some connection between the two forms of behaviour, and other evidence for a connection can be found in the literature. Herter (1965b), describing the ritual pattern in the behaviour of courting hedgehogs, records that, after sniffing each other, then usually defecating and urinating, the male animal shoves and butts the female with his head then opens his mouth very widely, draws back his upper lips and stretches his tongue wetl out. The animals then begin to circle each other and this may lead to copulation. Herter does not mention self-anointing as being part of the courting Table II. The Monthly Incidence of Self-Anointing
Month
No. of occasions on which hedgehogs No. of No. of self- ~ of self- seen courthedgehogs anointed anointed ing or examined animals animals copulating
Jan.
202
5
2"5
10
Feb.
110
4
3"6
6
Mar.
96
3
3 "1
2
Apr.
69
0
0
0
May
48
0
0
0
June
39
0
0
0
July
18
0
0
0
Aug.
46
1
3'3
1
Sept.
47
1
2.1
2
Oct.
81
2
2'5
5
Nov.
89
1
1.1
7
Dec.
84
2
2"5
12
929
19
Totals
45
BROCKIE: SELF-ANOINTING BY HEDGEHOGS ritual but it may well be an extension of the gaping or 'flehmen' behaviour he describes. The parallel between the premating activities of the hedgehog and the pig, Sus scrofa, as described by Perry (1972) is so striking that it is appropriate to mention here. He reported that an odoriferous compound, 3-a-hydroxy-5-a-andros -16-ene, closely related to the androgen steroids, is present in the submaxillary glands of mature boars and is exhaled with their breath. This substance makes them acceptable to oestrous sows and retains its effectiveness when dissolved and presented to the sows in the form of an aerosol spray. Boars whose submaxillary glands had been extirpated were unacceptable to oestrous sows, who approached their prospective mates face to face, as though testing for the presence of the pheromone. The same face-to-face encounter and the male gaping appears to be a preliminary to copulation among hedgehogs, but self-anointing is an optional extra, presumably prompted as an excited response to the scent of a prospective mate, and may serve to make one partner acceptable to the other. When hedgehogs are brought indoors or are held in a laboratory, the novelty of the situation, or the strange new odours and objects encountered there, may be enough to stimulate the
71
self-anointing reflex. In these surroundings, the behaviour could perhaps be described as a displacement activity, being apparently inappropriate and purposeless. REFERENCES
Brettung, H. (1972). Die Bestimmung der Riechschwellen bei Igeln (Erinaceus europaeus L.). Z. Siiugetiermitt, 37, 5, 286-311. Burton, M. (1957). Hedgehog self-anointing. Proc. zool. Soc. Lond., 129, 452-453. Burton, M. (1969). The Hedgehog. London: Andre Duetsch. Heck, L. (1912). Die Siiugetiere. I. Brehms Tierleben. 4. Aufl. 10. Leipzig and Vienna. Herter, K. (1938). Die Biologie der Europaischen Igeln. Monograf der Wildsiiugetiere, 5, Leipzig. Herter, K. (1965a). Hedgehogs. London: Phoenix House. Herter, K. (1965b). Uber das Paarungsverhalten der Igel. Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin. (N.F.) 5, 2: 57-76.
Lindemann, W. (1951). Zur Psychologie des Igels. Z. Tierpsychol., 8, 224. Perry, G. C. (1972). P~oceedings of the 7th International
Congress on Animal Reproduction and Artificial Insemination. Munich.
Poduschka, W. & Firbas, W. (1969). Das Selbstbespeicheln des Igels Erinaceus europaeus roumanicus Linne 1758 steht in Bezichung zur Funktion des Jacobsonschen Organes. Z. Siiugetier., 33, 160172. (Received 22 November 1974; MS. number: 1387)
BY WILD
HEDGEHOGS,
IN NEW
ERINACEUS
EUROPAEUS,
ZEALAND
BY ROBERT BROCKIE
Zoology Department, Victoria University of Wellington Abstract. Of 929 wild hedgehogs examined, nineteen bore signs of recent self-anointing. The spittle deposited on the hedgehogs' backs usually gave off a sharp smell, clearly detectable some metres downwind. Nestling animals anointed themselves when removed from their nests, possibly as a means of advertising their whereabouts to their mothers. The habit was not detected among newly-independent young animals nor among sub-adults. Among adult hedgehogs, self-anointing was confined to the breeding season, and on five occasions was elicited in the presence of other hedgehogs of the opposite sex. In this context self-anointing may serve as a form of sexual signal. When brought into captivity the self-anointing reflex is triggered by novel objects or odours and, in this unnatural context, it is argued that the behaviour falls into the category of a displacement activity, being inappropriate to the situation and seemingly purposeless. The hedgehog's curious habit of plastering itself with its own saliva was first recorded by Heck (1912). Since then, Herter (1938, 1965a) and Burton (1969) have extended the range of observations and speculation about the possible purpose of the behaviour. Herter has described how hedgehogs Erinaceus europaeus, E.
stimulatory substances, including distilled water, was endless. Poduschka & Firbas (1969) discovered that the saliva so produced contained quantities of an exudate secreted by Jacobson's organ. The function of self-anointing has long been the subject of speculation. Herter (1965a) suggested that its purpose is to cover the natural smell of the hedgehog in order to make its discovery by enemies more difficult. Burton (1969) lists the following possible explanations: (1) It is a form of greeting. (2) It is a form of sexual behaviour. (3) It is a means of getting rid of ectoparasites. (4) It makes the hedgehog unpalatable to its enemies. (5) It keeps the spines supple. (6) Foreign substances on the spines make them poisonous. From his compendious range of observations, Burton goes on to point out that none of these explanations is satisfactory as, for example, self-anointing occurs even with solitary animals and so cannot be a form of greeting; it also occurs with nestlings so it cannot be a form of sexual activity; it occurs with clean and parasitized animals so it cart have little significance as a means for getting rid of parasites, etc. He then suggests that, like the frenzied reaction of many cats to the scent of catnip, self-anointing may be an incomplete relic of some once-useful activity, possibly a cooling mechanism inherited from the hedgehog's tropical ancestors.
roumanicus, Aetheehinus algirus, Paraechinus aethiopieus, Hemieehinus auritus, H. auritus persieus, and Atelerix pruneri, on coming into contact with certain objects, sniff them assiduously, lick them and, if the objects are small enough, take them into their mouths and chew them, this activity producing an abundance of foamy saliva. After a few minutes the hedgehog will turn its head backwards or to the side and, with the aid of its tongue, place the foam on its spines. This salivation appears to be released by a chemical stimulus because the objects eliciting the behaviour usually have a strong smell or taste, or both. Herter recorded animals responding to bookbinder's glue, cigarette ends, paper soaked in human sweat, hyacinth flowers, perfume, soap, decaying crabs, newsprint, toad's skin, and valerian. He continues 'Another hedgehog also produces this stimulus if it is a stranger and it will be treated in the same way as an inanimate object. In some eases the reaction was released by certain smells in the air, such as cigar smoke or varnish. Patently, autosalivation is released by strong chemical stimuli which are unfamiliar or unaccustomed . . . . ' Burton (I957, 1969) gathered much more information about self-anointing among British hedgehogs and concluded that the range of
Observations Most observations Oll self-anointing have been on animals brought into the house or laboratory, but these conditions isolate the animals from
68
BROCKIE: SELF-ANOINTING BY HEDGEHOGS
69
Table I. Observations on Self-Anointing Date
Specimen no.
Sex
Body wt.
Locality
Notes
11. 8.70
497
M
790
Karori, Wellington
20. 9.70 6.10.70 19.10.70 3.11.71
519 526 551 908
M M M M
960 780 630 610
Wadestown, Lower Hurt .... ....
8.12.71
948
M
710
22.12.71
971
M
700
Wadestown, Wellington Lower Hurt
2. 1.72
656
M
660
20. 1.72
619
M
800
14. 1.72
808
M
490
1.72 1.72 2.71 2.72 2.72 2.71
583 642 655 1066 931 1010
F F F F F F
830 810 400 960 930 670
5. 3.57
274
F
400
17. 3.71
689
F
660
Point Howard, Wellington Palmerston Nth.
22. 3.72
1106
M
470
Lower Hutt
30. 29. 8. 12. 19. 21.
,,
.... .... .... .... .... ....
One of six wild animals which came to the door to be fed nightly. Powerful-smelling saliva on back. Clear spittle on left flank. Clear spittle on back. Spittle on nape and shoulders. Trace of spittle on muddy back. 10 m upwind of adult female no. 907. Snorting and pushing adult female 947. Clear spittle on right shoulder. Nape and rump smeared with clay-discoloured spittle. Back smeared with saliva smelling powerfully and resembling the smell of horse urine. Adult female no. 809 crouched beside him and another male (No. 908) 20 m up-wind of this pair. Clear spittle on back and smelling powerfully. This animal had been recaptured twelve times over the previous year but showed no earlier traces of self-anointing. Clear spittle on back. This animal seen on seven previous occasions but showed no earlier traces of self-anointing. Spittle on back. Muddy spittle on left flank. Spittle on left flank. Black spittle on back. Back anointed with clear frothy saliva. Spittle on back interspersed with granular red brick-like substance. Right flank smothered with spittle. One month earlier her flanks matted with excrement. Back anointed with crumbly white substance and spittle. Spittle on back. 30 m down-wind of adult male 1105 and t0 m across-wind from adult female 1107.
The following observations were made on young hedgehogs: 3.12.70
No. 567
17. 2.72
No. 1000
19. 8.72
No. 1087
Female 220 g. Kelburn, Wellington, When a strange male was introduced to the hutch this animal attempted to suckle from him. After 3 min she frothed at the mouth and anointed her back and flanks. Male. 140 g. York Bay, Wellington. Estimated age 16 days. Self-anointed when taken outside and placed in sandpit used by cats. Male. 180 g. York Bay, Wellington. One month old. Repeatedly self-anointed in response to carpet sandals, and the leg of a chair.
any n at u ral intercourse with their fellows and, outside their n o r m a l surroundings, m a y distort or m a s k the n at u r al purposes o f the behaviour. I n an a t t e m p t to cast s o m e light on the n a tu r a l occurrence o f self-anointing a m o n g wild hedgehogs I have r e c o r d e d its frequency a m o n g a tagged p o p u l a t i o n o f 207 free-ranging animals captured o n t wo g o l f courses at Melling, a suburb o f L o w e r Hurt, N e w Zealand. O n e h u n d r e d a n d sixteen o f these animals were re-
c a p t u r e d at varying intervals over a 2-year p e r i o d while an additional 500 animals f r o m the greater Wellington area were e x a m i n e d f o r traces o f spittle or other signs o f self-anointing. These results are s u m m a r i z e d in Tab l e I. Th e m o s t i m p o r t a n t p o i n t to emerge f r o m these observations is that the saliva usually gave off a sharp, r a n k smell resembling horse or h e d g e h o g ' s urine. O n a mildly w i n d y night, I co u l d detect this o d o u r 5 to 10 m d o w n - w i n d .
ANIMAL
70
BEHAVIOUR,
Earlier writers do not appear to have remarked on this odour, which m a y hold the key to its explanation. Signs of self-anointing were seen only in those months when courting or copulating were also observed; that is, from late winter (August) until early autumn (March). During this period, 19 (2.5 per cent) of 755 hedgehogs examined, bore signs of self-anointing. This contrasts with the 174 animals examined between April and July, none of which had anointed themselves. Of the nineteen animals bearing spittle on their spines, five were found in the company of other hedgehogs of the opposite sex. On two occasions a second male was also present a short distance away. In social contexts one or other, or both the anointed animals, were, as far as could be determined, new to the area. Between 8 August and 14 January, all ten anointed animals were males. Eight of the nine anointed animals seen later in the season were females. One male animal (No. 908) was involved in two self-anointing incidents with other animals present or nearby. On the first occasion, he was found 10 m up-wind of an adult female and on the second occasion was seen 20 m up-wind of another courting couple, one of which was anointed with strong-smelling spittle. Records were kept of the time of night, the phases of the moon, the direction and strength of the wind, and the incidence of ectoparasites, but no connection between these variables and the occurrence of self-anointing was established. Discussion
The strong smell of saliva thrown up while selfanointing may help to explain the purpose of this behaviour. Lindemann (1951) and Brettung (1972) conducted laboratory and field tests which established the primacy of the hedgehog's sense of smell. F r o m their evidence it is reasonable to assume that these animals can detect the smell of their spittle over a much greater distance than can a human. Self-anointing can then be interpreted as a signalling device whose function is to advertise the animal's presence to other hedgehogs. Both nestling juveniles and sexually mature adults may wish to draw attention to themselves, but for different reasons. Suckling hedgehogs occasionally stray from the nest and, in these circumstances, set up a piercing, chirping or whistling sound to attract their mother's attention. Now, removing a youngster from its nest and placing it in strange
24,
1
surroundings often stimulates the animal to anoint itself. A young animal bearing spittle in this way would stand a better chance of being found by its mother. The habit appears to be lost after weaning, for no independent youngsters or sub-adults have been observed to anoint themselves. Among mature adults the habit emerges again, but in a different context. Adult hedgehogs have been seen anointing themselves only during the breeding season (see Table II) which suggests some connection between the two forms of behaviour, and other evidence for a connection can be found in the literature. Herter (1965b), describing the ritual pattern in the behaviour of courting hedgehogs, records that, after sniffing each other, then usually defecating and urinating, the male animal shoves and butts the female with his head then opens his mouth very widely, draws back his upper lips and stretches his tongue wetl out. The animals then begin to circle each other and this may lead to copulation. Herter does not mention self-anointing as being part of the courting Table II. The Monthly Incidence of Self-Anointing
Month
No. of occasions on which hedgehogs No. of No. of self- ~ of self- seen courthedgehogs anointed anointed ing or examined animals animals copulating
Jan.
202
5
2"5
10
Feb.
110
4
3"6
6
Mar.
96
3
3 "1
2
Apr.
69
0
0
0
May
48
0
0
0
June
39
0
0
0
July
18
0
0
0
Aug.
46
1
3'3
1
Sept.
47
1
2.1
2
Oct.
81
2
2'5
5
Nov.
89
1
1.1
7
Dec.
84
2
2"5
12
929
19
Totals
45
BROCKIE: SELF-ANOINTING BY HEDGEHOGS ritual but it may well be an extension of the gaping or 'flehmen' behaviour he describes. The parallel between the premating activities of the hedgehog and the pig, Sus scrofa, as described by Perry (1972) is so striking that it is appropriate to mention here. He reported that an odoriferous compound, 3-a-hydroxy-5-a-andros -16-ene, closely related to the androgen steroids, is present in the submaxillary glands of mature boars and is exhaled with their breath. This substance makes them acceptable to oestrous sows and retains its effectiveness when dissolved and presented to the sows in the form of an aerosol spray. Boars whose submaxillary glands had been extirpated were unacceptable to oestrous sows, who approached their prospective mates face to face, as though testing for the presence of the pheromone. The same face-to-face encounter and the male gaping appears to be a preliminary to copulation among hedgehogs, but self-anointing is an optional extra, presumably prompted as an excited response to the scent of a prospective mate, and may serve to make one partner acceptable to the other. When hedgehogs are brought indoors or are held in a laboratory, the novelty of the situation, or the strange new odours and objects encountered there, may be enough to stimulate the
71
self-anointing reflex. In these surroundings, the behaviour could perhaps be described as a displacement activity, being apparently inappropriate and purposeless. REFERENCES
Brettung, H. (1972). Die Bestimmung der Riechschwellen bei Igeln (Erinaceus europaeus L.). Z. Siiugetiermitt, 37, 5, 286-311. Burton, M. (1957). Hedgehog self-anointing. Proc. zool. Soc. Lond., 129, 452-453. Burton, M. (1969). The Hedgehog. London: Andre Duetsch. Heck, L. (1912). Die Siiugetiere. I. Brehms Tierleben. 4. Aufl. 10. Leipzig and Vienna. Herter, K. (1938). Die Biologie der Europaischen Igeln. Monograf der Wildsiiugetiere, 5, Leipzig. Herter, K. (1965a). Hedgehogs. London: Phoenix House. Herter, K. (1965b). Uber das Paarungsverhalten der Igel. Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin. (N.F.) 5, 2: 57-76.
Lindemann, W. (1951). Zur Psychologie des Igels. Z. Tierpsychol., 8, 224. Perry, G. C. (1972). P~oceedings of the 7th International
Congress on Animal Reproduction and Artificial Insemination. Munich.
Poduschka, W. & Firbas, W. (1969). Das Selbstbespeicheln des Igels Erinaceus europaeus roumanicus Linne 1758 steht in Bezichung zur Funktion des Jacobsonschen Organes. Z. Siiugetier., 33, 160172. (Received 22 November 1974; MS. number: 1387)