Journal of Threatened Taxa | www.threatenedtaxa.org | 26 September 2026 | 18(9): 29721–29728

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)

https://doi.org/10.11609/jott.9950.18.9.29721-29728

#9950 | Received 29 May 2025 | Final received 15 August 2026| Finally accepted 22 August 2026

First record of interspecific allopreening among Gyps vultures in the Aravalli Range, India

Hemsingh Gehlot ¹ , Anil Kumar Sharma ² & Narayan Lal Choudhary ³

¹ Wildlife Conservation Laboratory, Department of Zoology, Jai Narain Vyas University, Jodhpur, Rajasthan 342011, India.

² Department of Zoology, Dr. B.R. Ambedkar Govt. PG College, Nimbahera, Rajasthan 312601, India.

³ Department of Zoology, Government College Sirohi, Rajasthan 307001, India.

¹ gehloths@gmail.com, ² anilkumarsharma031995@gmail.com, ³ narayanlalchoudhary1995@gmail.com (corresponding author)

Editor: H. Byju, Coimbatore, Tamil Nadu, India. Date of publication: 26 September 2026 (online & print)

Citation: Gehlot, H., A.K. Sharma & N.L. Choudhary (2026). First record of interspecific allopreening among Gyps vultures in the Aravalli Range, India. Journal of Threatened Taxa 18(9): 29721–29728. https://doi.org/10.11609/jott.9950.18.9.29721-29728

Copyright: © Gehlot et al. 2026. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

Funding: None.

Competing interests: The authors declare no competing interests.

Author details: Dr. Hemsingh Gehlot is the director of Wildlife Reserach and Conservation Awarness Centre (WRCAC) and an Assistant Professor in Department of Zoology at Jai Narain Vyas University, Jodhpur, Rajasthan. He has been teaching UG and PG students form the last 15 years and has been activiely engaged in reserach on wild faunna in the Thar Desert since 2003. Dr. Anil Kumar Sharma is an Assistant Professor in Department of Zoology at Dr. Bhimrao Ambedkar Govt. PG College, Nimbahera, Rajasthan, India. His main research work focuses on avian diversity and its conservation. Dr. Narayan Lal Choudhary is a guest faculty (Vidhya Sambal Yojana) in Department of Zoology, Government College Sirohi. Rajasthan. His main reserach work focuses on eco-biology and conservation of birds and mammals including the vultures.

Author contribution: NLC—observation and data collection, manuscript editing. HG and AKS—manuscript writting and proof reading.

Acknowledgements: We are thankful to Dr. Satish Kumar Sharma (Retired Forest Officer) and prof. Anil Kumar Tripathi, MLV College Bhilwara for their valuable suggestions on the preparation of manuscript this interesting behaviour of vultures.

Abstract: We report an observation of interspecific allopreening behaviour among the Indian Vulture Gyps indicus, Himalayan Griffon Gyps himalayensis, and Eurasian Griffon Gyps fulvus in the village of Kailashpuri in the Udaipur District of Rajasthan. A total of 623 seconds of interspecific allopreening behaviour was recorded. In the first instance, a G. indicus preened the neck of a G. himalayensis for 296 seconds; in another instance, a G. fulvus preened the neck of a G. indicus for 162 seconds; and further, a G. fulvus preened the neck and shoulder of a G. himalayensis for 165 seconds. All three species also engaged in self-preening activity during the observation period; G. indicus spent the maximum time (376 seconds), followed by G. fulvus (300 seconds), and G. himalayensis spent the minimum time in self-preening (257 seconds). This is the first documented record of interspecific allopreening behaviour among these vulture species in India. This observation contributes to interspecific interactions that are important for understanding the complex social structures between G. indicus and G. himalayensis and G. fulvus in their natural habitat. Interspecific allopreening is a complex ecological behaviour that contributes to individual health by managing parasites and fostering social tolerance, thereby reducing competition and aggression within the community. Although the functional significance of the behaviour could not be determined from this single observation, interspecific allopreening may have hygienic and social functions similar to those across species boundaries in wild birds.

Keywords: Aggression, Behaviour, Competition, Gyps fulvus, Gyps himalayensis, Gyps indicus, Interaction, Natural habitat, self-preening, social structure.

INTRODUCTION

Preening and scratching are collectively known as grooming behaviours (Carter & Leffer 2015). Grooming and preening behaviours have been recorded in several social animals, including birds and mammals (Baker & Aureli 2000; Lewis et al. 2007; Gill 2012; Carter & Leffer 2015). Among birds, allopreening is defined as the act of one individual preening the neck, shoulders, and feathers of another individual of the same species, in which one individual preens the feathers of another individual, potentially providing hygienic benefits through the removal of ectoparasites and debris, as well as social benefits (Cullen 1963; Brooke 1985; Villa et al. 2016). Additionally, it helps maintain pair bonds between mating partners, mitigates aggression between conspecifics, and facilitates cooperation during parental care (Radford & Du Plessis 2006; Lewis et al. 2007; Takahashi et al. 2017; Gillies et al. 2021). Intraspecific allopreening behaviour has been observed in several animal species, including numerous birds under natural conditions (Barbour & DeGange 1982; Radford & Du Plessis 2006; Choudhary & Chishty 2020, 2021), while interspecific allopreening (allopreening between two different species) is rarely observed in animals, including birds (Mo 2016; Cortes 2017; Zhou & Zhang 2022). These studies document interspecific allopreening behaviour in non-captive environments such as that of the Black Vulture Coragyps atratus and Crested Caracara Caracara plancus (Ng & Jasperson 1984; Palmeira 2008; Souto et al. 2009; Sanabria 2015), Razorbill Alca torda and Common Murres Uria aalge (Walsh et al. 2001), Royal Spoonbill Platalea regia and Australian White Ibis Threskiornis molucca (Mo 2016), Mitred Psittacara mitratus and Monk Parakeet Myiopsitta monachus (Cortes 2017), and Spot-necked Babbler Stachyris strialata and Nonggang Babbler Stachyris nonggangensis (Zhou & Zhang 2022).

Prevailing hypotheses regarding the function of allopreening behaviour emphasise its role in parasite removal (Freeland 1976) and its significance in facilitating intra-social interactions (Call et al. 2002; Radford & Du Plessis 2006). According to Souto et al. (2009), the interspecific allopreening observed between Black Vulture and Crested Caracara likely reflects a multifaceted social and ecological interaction. The increased vigilance afforded by mixed-species flocks, the complementary vocal abilities of caracaras that compensate for vultures’ morphological limitations, and the opportunistic benefits caracaras gain in locating food all contribute to reinforcing their association.

The underlying mechanism of interspecific allopreening in these species is probably distinct, as they actively pursue preening from other species by engaging in chasing, followed by displays inviting allopreening (Selander & La Rue Jr 1961). In this study, we observed the first interspecific allopreening behaviour among three species of vultures in non-captive environments: Indian Vulture Gyps indicus, Himalayan Griffon Gyps himalayensis, and Eurasian Griffon Gyps fulvus.

Study area

Kailashpuri Village is located at 24.45° N, 73.43° E in the southern Aravalli ranges in Udaipur District of Rajasthan. The site supports several resident and migratory vulture species and serves as an important roosting area. The rock cliff area of the study site is a permanent nesting colony for vultures (Image 3). There are approximately 10 G. indicus nests and two Egyptian Vulture Neophron percnopterus nests in this region. The vulture nesting colony was approximately 350 m wide. The average elevation of G. indicus nests ranged 670–680 m. A cow shelter located near the vulture study site occasionally provides a potential food resource in the form of livestock carcasses. Additionally, the presence of two large water bodies, Indra Sarovar Talab and Bagela Lake, fulfils the demand for water throughout the year. The presence of green patches, rocky cliffs, agricultural landscapes, and these water bodies supports a variety of birds and mammals. Tropical dry deciduous forest occurs in the study area with dominant plant species such as Palash Butea monosperma, Euphorbia spp., Peepal Ficus religiosa, Neem Azadirachta indica, Gonda Cordia dichotoma, Jamun Syzygium cumini, Desi Babool Vachellia nilotica, Banyan Ficus benghalensis, Mahua Madhuca indica, Emli Tamarindus indica, and Danda-thor Euphorbia caducifolious. Apart from this, mammalian species including Leopard Panthera pardus, Jungle Cat Felis chaus, Indian Jackal Canis aureus, Striped Hyena Hyaena hyaena, Hanuman Langur Semnopithecus entellus, and Rhesus Macaque Macaca mulatta occur.

MATERIAL AND METHODS

Study site selection was based on earlier experience and secondary data gathered from the Forest Department of Rajasthan regarding the presence of vultures in the region. Vultures were observed using Nikon 8 × 42 binoculars. Photographs and video clips of vulture behaviour were recorded using a long-distance zoom camera (Nikon P1000 with 125x zoom). Observations were conducted on a single day (28 January 2025) at 0800–1200 h and 1600–1800 h, and a total of six hours of observation were conducted. Behavioural observations were conducted using the focal sampling method, with particular attention to individuals involved in interspecific allopreening. Interspecific allopreening was defined as the directed manipulation of the feathers of one individual by another individual belonging to a different species. Vulture species were identified using a field manual and identification guide, as prescribed by Ali & Ripley (1987), Kazmierczak (2006), Grimmett et al. (2011), and Vyas (2013).

RESULTS

During the six-hour observation period on a single day, intraspecific and interspecific allopreening behaviour was recorded. G. indicus is a resident breeding species of the Aravalli ranges, whereas G. himalayensis and G. fulvus are winter migrants in this region. During the field survey on 28 January 2025, we found 21 vultures in the village of Kailashpuri. Of these, 12 individuals were G. indicus, five were G. himalayensis, and the remaining four were G. fulvus. The recorded interspecific allopreening behaviour was exhibited by one individual of each of the three species in the study. They were sitting very close to each other and displaying self-preening and interspecific allopreening behaviour. Multiple episodes of self-preening and interspecific allopreening were noted between three vulture species during a six-hour observation period (Tables 1 & 2).

During the six-hour observation period, interspecific allopreening was recorded for a total of 623 s. G. indicus preened the neck of G. himalayensis for 296 s, G. fulvus preened the neck of G. indicus for 162 s, and G. fulvus preened the neck and shoulder of G. himalayensis for 165 s (Table 1; Image 1).

In addition to self-preening and interspecific allopreening behaviour, the three vulture species, namely Indian, Himalayan and Eurasian Griffon, showed various behavioural activities. These activities encompassed walking, resting, wing and neck stretching, flying, soaring, and interspecific territorial fights (Table 2; Images 2 & 6). Tables 1 & 2 provide a comprehensive account of these behavioural episodes, illustrating the complexity and diversity of vulture activity patterns. A review of the literature revealed no previous record of interspecific allopreening behaviour by G. indicus, G. himalayensis, and G. fulvus in this region. To the best of our knowledge, this represents the first documented observation of interspecific allopreening among three vulture species in the Aravalli region of Rajasthan, India, as we found no previously published record.

DISCUSSION

Allopreening is associated with a “preening invitation” or “head-down” display (David & Jasperson 1984). Interspecific allopreening behaviour is more complex when it occurs between different animal species and is rarely observed in wild or non-captive environments. Interspecific allopreening has been documented in Black Vultures and Crested Caracaras (David & Jasperson 1984). Black Vultures showed allopreening behaviour, in which one vulture nibbled the feathers of the lower neck of the other individual, and the latter that individual responded by nibbling the neck feathers of the first (Haverschmidt 1977). Intraspecific allopreening has also been reported for vultures in wild environments (Haverschmidt 1977), similar to the “head-down” display described by Selander & La Rue (1961). During this one-day observation, it was observed that G. indicus preened the neck of the G. himalayensis, whereas G. fulvus preened the shoulder of the G. himalayensis, and G. fulvus preened the neck of the G. indicus. Vultures may spend considerable time sunbathing or wing-spreading in extended postures, as a thermoregulatory behaviour (Manigandan et al. 2021). Self-preening is an important component of plumage maintenance and may contribute to the removal of ectoparasites, debris, and other materials from their feathers. Thermoregulatory or sunbathing time varies according to the climatic conditions or seasons in a particular area. For instance, G. indicus spends more time on thermoregulation during the winter months than during the summer months (Chishty & Choudhary 2020). In this manner, intra- and interspecific allopreening behaviour is a complex social interaction that goes beyond mere grooming and may contribute to social tolerance and maintenance of affiliative interactions among individuals. Through allopreening, individuals not only enhance hygiene by removing ectoparasites and debris but also strengthen social bonds that are essential for group stability. This observation was based on a single day of field observation and therefore does not allow inference about the frequency, seasonality, or generality of interspecific allopreening among these species. Repeated observations across seasons and sites would be necessary to determine whether the behaviour represents a regular component of interspecific social interactions or an occasional association.

Table 1. Duration of interspecific allopreening behaviour among three species of vulture: Indian Vulture (IV), Eurasian Griffon (EG), and Himalayan Griffon (HG), during six hours.

Study hours (in h)	Time duration (in h)	Species interaction	Direction/ interaction	Time duration of interspecific allopreening (in s)
0800–0900	0811–0820	EG-HG	EG→HG	40
0901–1000	0900–0910	IV-HG	IV→HG	38
	0921–0930	IV-HG	IV→HG	42
	0931–0940	IV-HG	IV→HG	10
	0941–0950	IV-HG	IV→HG	27
		EG-HG	EG→HG	44
1000–1100	1000–1010	EG-HG	EG→HG	40
	1031–1040	IV-HG	IV→HG	40
	1041–1050	IV-HG	IV→HG	68
		EG-IV	EG→IV	58
	1051–1100	EG-IV	EG→IV	40
1100–1200	1100–1110	EG-HG	EG→HG	25
	1111–1120	IV-HG	IV→HG	40
	1121–1130	EG-HG	EG→HG	16
	1131–1140	IV-HG	IV→HG	31
	1141–1150	EG-IV	EG→IV	29
	1151–1200	EG-IV	EG→IV	35
1600–1700	1600–1700	Interspecific allopreening behaviour was not performed during this duration.
1700–1800	1700-1800	Interspecific allopreening behaviour was not performed during this duration.
Total observation time	06 h	Three types of interspecific interaction were observed: EG-HG; IV-HG; EG-IV.	Direction of interspecific allopreening: EG→HG; IV→HG; EG→IV.	Total time duration of interspecific allopreening: 623 s (EG→HG =165 s; IV→HG = 296 s; EG→IV = 162 s).

Table 2. Ethogram of three species of vultures: IV—Indian Vulture | EG—Eurasian Griffon | HG—Himalayan Griffon during the observation period. Activity: +—activity was performed | -—activity was not performed.

Time duration (in h)	Behaviour	Species of vulture			Time spent in Interspecific allopreening behaviour in a particular hours.
		IV	EG	HG
0800–0900	Self-preening	+ (153 s)	+ (79 s)	+ (105 s)	EG preens neck of HG (40 s)
	Body movement	+	+	+
0900–1000	Self-preening	+ (60 s)	+ (104 s)	+ (46 s)	IV preens neck and body of HG (117 s); EG preens neck of HG (44 s)
	Thermoregulation	-	+	+
1000–1100	Self-preening	+ (97 s)	+ (43 s)	+ (38 s)	IV preens neck of HG (108 s); EG preens neck of IV (98 s); EG preens neck of HG (40 s)
	Walking on rock	-	+	+
1100–1200	Self-preening	+ (49 s)	+ (36 s)	+ (49 s)	IV preens neck of HG (71 s); EG preens neck of IV (64 s); EG preens neck of HG (41 s)
	Wing stretching and thermoregulation	+	-	+
	Walking on rock	-	+	-
1600–1700	Self-preening		+ (38 s)	+ (19 s)
	Resting	+	+	+
	Wing stretching and thermoregulation	+	+	+
	Flying / soaring	+	-	+
1700–1800	Self-preening	+ (17 s)	-	-	-
	Walking on rock	+	-	-
	Flying / soaring	-	+	+
	Resting	+	+	+

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