Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 June 2020 | 12(9): 16013–16020
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.4539.12.9.16013-16020
#4539 | Received 31 August 2018 | Final
received 06 May 2020 | Finally accepted 27 May 2020
Observations on breeding
behaviour of a pair of endangered Egyptian Vultures Neophron
percnopterus (Linnaeus, 1758) over three
breeding seasons in the plains of Punjab, India
Charn Kumar 1, Amritpal Singh Kaleka 2 &
Sandeep Kaur Thind 3
1 Department of Biology, A.S.
College, Khanna, Ludhiana District, Punjab 141402, India.
2,3 Department of Zoology and
Environmental Sciences, Punjabi University, Patiala, Punjab 147002, India.
1 charnkumar@yahoo.com, 2 apskaleka@gmail.com, 3 sandee.thind@gmail.com (corresponding author)
Editor:
Chris Bowden, Royal Society for the
Protection of Birds, Sandy, UK. Date of publication: 26 June 2020 (online &
print)
Citation: Kumar, C., A.S. Kaleka
& S.K. Thind (2020).
Observations on breeding
behaviour of a pair of endangered Egyptian Vultures Neophron
percnopterus (Linnaeus, 1758) over three
breeding seasons in the plains of Punjab, India. Journal
of Threatened Taxa 12(9): 16013–16020. https://doi.org/10.11609/jott.4539.12.9.16013-16020
Copyright:
© Kumar et al. 2020.
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: Charn Kumar is currently affiliated with A.S.
College, Khanna as an Associate Professor of Zoology and interested in breeding
behavior of common resident birds dwelling in agricultural landscape of
Punjab. Amritpal Singh Kaleka is serving as
Assistant Professor in the Department of Zoology & Environmental Sciences,
Punjabi University. His research fields include insect taxonomy and avian
biology. He successfully completed research projects from CSIR, DST, UGC and
currently a research project under AICOPTAX scheme of MoEFCC
is in progress. Sandeep Kaur Thind is a PhD
scholar affiliated with Department of Zoology and Environmental Sciences,
Punjabi University, and is engaged in faunistic surveys and avian breeding
behavior.
Author contribution: Study
design and field work: Sandeep Kaur Thind and Amritpal Singh Kaleka;
video-reviews, analysis and article drafting: Charn
Kumar.
Acknowledgements: The authors are grateful
to the head, Department of Physics for giving permission to install the CCTV
camera in the space observatory of the department to record various stages of
brooding. The authors also thank Mr.
Ravinder Singh, incharge, Space Observatory, Punjabi
University, Patiala for extending logistic support during the tenure of this
study.
Abstract: The present study has been
conducted to document information on breeding behaviour
of Egyptian Vultures Neophrons percnopterus from Punjab. This study is based on 688 hours of video
records documenting breeding behaviour of a pair of
endangered Egyptian Vultures Neophrons percnopterus occupying the same nesting site over three
consecutive breeding seasons from 2015 to 2017. The site is located in the
hollow of a ventilation window of the Space Observatory in Punjabi University,
Patiala, Punjab. During the third breeding period (February to August 2017),
the nest activity has been extensively video-recorded in egg laying and incubation
period, and chick rearing period using a Dome CCTV Camera. Both parents
participated in nest building, and of the total recorded incubation time of
339.39h over 23 days the nest was attended for 199.35 and 139.46h by the female
and male respectively, and unattended for 0.58h. The incubation period was 42
to 43 days, and the egg laying/hatching intervals between eggs/chicks was five
days. A total of six young ones hatched and fledged from three broods of two
eggs each. All chicks survived to fledging and no mortality or siblicide of younger chick occurred due to
aggression/starvation by elder chick. The high fledging success rate indicates
a healthy habitat and food source in the nesting area.
Keywords: Ecological role, feeding,
habitat, incubation, nest, scavengers.
INTRODUCTION
Punjab is
primarily an agrarian state, with 84 percent of its area under agriculture and
6.5 percent under forest (Singh et al. 2014).
Since independence many local environments have been impacted by
deforestation, industrialization, increased transportation networks, modern
agricultural practices, urbanization, and other anthropogenic factors. As a result, Punjab has lost much of its
forest and dominant wildlife. Vultures
are important to human beings and the environment because they feed upon the
carcasses of dead animals and act as scavengers. On the basis of road transect surveys
conducted from 1991 to 2003 in and around 18 national parks and wildlife
sanctuaries spread across the northern, western, and eastern parts of India,
Cuthbert et al. (2006) recorded an 80% decline in the population of Egyptian Vulture
(EV) Neophrons percnopterus,
due to poisoning by the veterinary drug diclofenac and other factors. The rapid decline in populations in India
(Cuthbert et al. 2006), combined with severe long-term declines in Europe,
western Africa and the rest of its African range, has led this species to be
classified as Endangered in the IUCN Red List of Threatened Species since 2007
(BirdLife International 2017).
As per Grimmett & Inskipp (2010),
there are seven species of vultures in Punjab and the EV is an not-common
resident. Nevertheless, Punjab is not an
exception to the global population decline of vultures, and Kler
& Kumar (2014) while monitoring 18 animal flaying/disposal sites located in
nine districts of Punjab under an All India Network Project on Agricultural
Ornithology, reported occurrence of only EV from only two sites located in
districts of Ropar and Kapurthala.
Presently, this species is sighted at only a few animal carcass dumping
sites located nearer to Shivalik foothills in Punjab
and there exists no study documenting the breeding aspects of any vulture
species from the agricultural plains of Punjab.
Vultures provide a variety of economic, ecological, and cultural
services (Ogada et al. 2012), and studies on habitat
requirements of endangered species are crucial for conservation purposes (Manly
et al. 1993; Noss et al. 1997).
The present study
documents aspects of the breeding biology of EV that include breeding time,
nesting site, clutch size, incubation, nestling period, feeding and nestling
growth pattern, reproductive success, and parental care.
Background
Perusal of
available sources reveals that barring a few studies documenting EV sightings
at animal carcass disposal sites, by Malhi & Kaur
(1999), Kler (2004), and Kler
& Kumar (2014), no attempt has been made to study the breeding biology,
habitat ecology, distribution, and impact of human disturbances of vultures
living in the plains of Punjab. Naoroji (2006) gave definitive account of status,
distribution, feeding, and breeding aspects of EV from the Indian
subcontinent. Although the EV was well
known to ornithologists of the 19th and 20th centuries,
detailed accounts of nesting are few (Ramirez et al. 2016). Cuthbert et al. (2006) and Galligan et al.
(2014) documented population declines of EV from India. Other studies exploring aspects like
distribution, dispersal, effect of human activities, and conservation of EV
from different regions include: Donázar &
Ceballos (1989), Liberatori & Penteriani
(2001), Margalida & Boudet
(2003), Sara & Vittorio (2003), Carrete et al.
(2007), Zuberogoitia et al. (2008), Hernández & Margalida (2009), Elorriaga et
al. (2009), Angelov et al. (2013), Zuberogoitia et al. (2014), and Tauler-Ametller
et al. (2017).
Study Area
The study area is
located within a radius of 3km from the Space Observatory located at
geographical coordinates 30.3590N & 76.4450E in
Punjabi University, Patiala (Punjab).
The university campus of over 323 acres is situated in the outskirts of
Patiala City, surrounded by adjoining semi-urban and cropland areas. This territory is characterized by the
presence of urban patches, open croplands, an old drain ‘Badi Nadi’, small forest patches,
slaughter houses and rubbish dumps/animal carcass disposal sites. The climate is typical of the Punjab plains
in being hot in summer and cool in winter.
Habitat components around the nesting site provide a mixture of feeding
sites, natural vegetation, agricultural lands, and human settlements suitable
for EV breeding.
MATERIALS AND METHODS
During the course of weekly field surveys (2015–2017) undertaken to
document the avifauna dwelling in the agricultural plains of district Patiala,
a pair of EV was first sighted at a rubbish dump/animal carcass dumping site
located at 30.3610N & 76.4410E near the village Saifdipur at the time of pre-laying period in February
2015. Municipal waste and animal
carcasses are dumped at this site.
Following the direction of flight over the fields and examining likely
sites, a nesting site was located about 1km away from rubbish dump/animal carcass dumping sites
in the Space Observatory of Punjabi University.
Repeated site visits were undertaken from 2015 to 2017, and video data
was recorded in 2017. During the first
and second breeding periods (February–August, 2015 & 2016) observations on
incubation, feeding, breeding success, and activities of chicks were made from
a secure distance using Olympus 10x50 DPS binoculars, and also via direct nest
visits. During the third breeding period
(February–August 2017) the nest was monitored during egg laying, incubation,
and chick rearing period using a Dome CCTV camera with inbuilt-SD Card (32GB)
recording. The camera (9.3 x 7 x 9.3 cm)
was mounted in the window corner opposite to the nest, and data were extracted
every third/fourth day by replacing the SD card without disturbing incubating
birds or chicks. The nest was built on
the ventilation window platform of the observatory store, allowing observation
to be performed discretely from inside the store through a partly-opened
frosted glass window. A 3.5m long wooden
ladder was placed against the wall in the store to reach the window. The incubating parent did not directly notice
the presence of the observer except for observer’s hand extending in the window
corner to remove the camera. The parent
never left the nest during the first week, and at times tried to attack the
observer’s hand. Before the start of
incubation, the nest site was inspected twice a day to document egg
laying. Still photography was done using
a Sony A-57 DSLR camera fitted with Tamron 18-200mm telephoto lens. Nest activities were also monitored from a
secure distance using binoculars. Location
measurements were obtained using a Bosch GLM 40 laser distance meter. Video records spanned 23 days and 688 hours,
supplemented by photographs and direct observations.
OBSERVATIONS AND RESULTS
Nest Site and Nest Construction
During January and February (the
pre-laying period), both members of the pair were first sighted visiting the
nest site (Space observatory and nearby academic block) in the early morning
and evening hours, carrying nest material to the cuboid hollow (1.9m x 0.66m x
0.5m) of the ventilation window of the space observatory (Image 1), 25.9m above
ground level. The aspect of the hollow
was towards the south. The addition of
nest material continued during the incubation period. The nest material haphazardly placed over the
entire platform (1.9m X 0.66m) included branched/unbranched dried twigs, dried
bark and leaves of Eucalyptus, pieces of cardboard packing boxes, towel
and soiled cloth pieces, thick strips of sawdust board, polythene sheet pieces,
empty poly milk pouches, coconut coir, wool, cotton pulled from disposed
beddings, jute rug pieces, dried human faeces, pieces of writing paper,
sanitary napkins, animal fur, pieces of polypropylene cement bags, pieces of
sink hose, rotten pumpkin, and other debris.
At the time of laying the first egg (03 March 2017), these contents of
the nest were seen scattered all over the nest platform, however, after laying
of the second egg (08 March 2017), contents including cotton, woolen fragments and jute rug pieces were arranged to form
a scrape (inner width 10” & outer width 14”) around the eggs (Image
2). Most of this nest material was from
waste items, and about four days before the hatching of first chick (10 April
2017) both the parents piled dry twigs along the open side of the platform, as
if to form a barricade to prevent chicks from falling. During the chick rearing period, remains of
food items including the bones of pigeons, rats, snakes and dogs, and bird
feathers appeared in the nest. During
the subsequent 42 days of incubation till hatching of the second egg (19 April
2017), the incubating parents maintained the scrape edges by repeatedly
arranging the lining material (cotton, soiled cloth pieces, jute rug pieces,
sanitary napkins) using their hooked beaks.
Egg Laying and Incubation
The interval between the laying of the first (03 March 2017) and second
eggs (08 March 2017) was five days. Eggs
are oval, non-glossy, dull-white, partly smeared, and streaked with
reddish-brown. Egg shell was 0.66mm in
thickness and rough with small protrusions.
The extent of reddish-brown streaking was variable between eggs. During the three consecutive successful
breeding seasons (2015, 2016, 2017), the clutch size was two eggs/per
year. No change in egg coloration
happened during the course of incubation.
The breeding adults were sexed on basis of difference in face colour
(Newton & Olsen 1990; Clark & Schmitt 1998), presence or absence of
black smudge below eyes (Levy 1990) and the size and appearance of brood
patches. In consonance with these, the
female had a yellow face colour and no black smudge below the eyes, whereas the
male had an orange-yellow face colour and a black smudge below the eyes. A yellow coloured, well-marked, larger brood
patch was visible since the first week of incubation in the female. In case of the male a small sized brood patch
was seen during the sixth week of incubation.
Coupled with these characters, the presence of a dark patch on forehead
of male proved as a distinct marker in all the video records.
Both the parents incubated the eggs (Images 3 & 4). Partial incubation was observed during the
egg laying period and hatching period.
Wang & Beissinger (2011) also observed
such incubation. In partial incubation,
the adult/s attended the nest but were observed sitting on the egg less
regularly in a non-rhythmic manner as compared to the intensity of incubation
after completion of the clutch. A review
of 131 video clips spanning 64.99 hours of observation time (OT) spread over
five days and four nights of hatching period (Table 1) revealed that the nest
platform remained unoccupied by the parents only for two short diurnal absences
of 0.07% (0.05 hour) OT and the parent/s were in the nest for 99.93% (64.94
hours) OT. During their stay in the
nest, the parents were engaged in partial incubation of the egg for 53.96%
(35.07 hours) OT, male incubating for 15.94% (10.36 hours) OT and female
incubating 38.02% (24.71 hours) OT. They
alternatively changed the incubation shifts 20 times, and male and female stayed
two nights each in the nest. While
sitting on the eggs in partial incubation, the incubating parent adopted a
posture different than that in the full incubation by keeping the neck raised
above the edge of the nest scrape.
The parents, however, were observed investing much time in full
incubation after completion of clutch till the hatching of elder chick. A review of 688 video clips spanning 339.39
hours OT referable to 23 days and 17 nights of full incubation (Table 2)
revealed that the nest platform remained unattended by the parents only for 16
short diurnal absences of 0.17% (0.58 hour) OT and the parents stayed in the
nest for 99.83% (338.81 hours) OT, male incubating for 40.90% (138.81 hours) OT
and female incubating 58.52% (198.61 hours) OT.
There occurred 32 incubation shift changes during 339.39 hours full
incubation OT.
During full
incubation period, the eggs were kept below the body one behind the other and
the incubating parent used to maintain a firm body contact with the eggs by
exerting a grip over the nest rim with its hooked beak. In avian incubation, egg turning behavior plays an important role in ensuring proper
embryonic development (Taylor et al. (2018).
Both the incubating parents regularly turned the eggs using beak or feet
for a total of 983 times, male and female 416 and 567 times, respectively.
The incubating
male was very sensitive to disturbances near the nest and produced hoarse
warning hisses to the Black Kites flying near the nest. During the course of incubation, both the
parents maintained sanitation of the nest scrape and never defecated inside or
over the rim of the nest scrape. An
incubating parent left the nest scrape and moved away to other side of the nest
platform to defecate. While sitting on
the eggs, they also maintained the scrape rim by resetting the nest
material. The male and female parent
contributed 181 and 177 nest resetting attempts, respectively. The floor material of the nest scrape below
the eggs was made soft and fluffy from time to time by the incubating parent
using its curved beak. The male and
female made 278 and 693 nest softening actions, respectively.
Hatching, Feeding and Fledging of nestlings
During the 2017
breeding season, an incubation period of 42 days and asynchronous hatching period
of five days were recorded as the two eggs laid on 03 March and 08 March 2017
hatched on 14 and 19 April respectively.
After hatching of the elder chick, both the egg and chick were incubated
by the parents till hatching of the younger chick. Newly hatched chicks had naked faces, open
eyes and bodies with fluffy, creamish down (Image
5). Both the parents brought food (dead
pigeons, rats, snakes, human faeces, etc.) for the nestlings at regular
intervals, and food was also kept in reserve scattered on the nest
platform. Parents held food items in
their claws and broke small pieces provided to the chicks. The body plumage markedly changed after four
weeks with emergence and growth of new feathers (Image 6–9). During third week after hatching, the nestlings
left the nest crater and were confined to one corner of the nest platform till
completion of fifth week, and then they started moving around the window
platform. During this phase the parents
were seen sitting on the observatory dome nearer to the nest window. The fledglings were observed out of nest
platform exploring adjacent windows 94 days after hatching, and on the dome of
the space observatory 98 days after hatching.
They left the nesting site 112 days (16 weeks) after hatching. At the time of fledging they had a darker
body, grayish face and short feathers on neck and
crown.
DISCUSSION
Food availability
is an important determinant of nest site quality and productivity of breeding
pairs (Newton 1979; Levy & Segev 1996; Liberatori & Penteriani
2001). As opportunistic scavengers (Ali
& Ripley 1983; Naoroji 2006), vultures feed on
the remains of small animals, debris or rubbish dump, insects in dung, human
and ungulate faeces, and vegetable matter (Prakash & Nanjappa
1988; Naoroji 2006; Angelov
et al. 2013; Jha 2015). Active nesting
sites are present near rubbish dumps (Liberatori
& Penteriani 2001). During the present study, the vicinity of the
observed nesting site contained urban patches, open croplands, an old drain,
rubbish dumps, patches of trees and slaughter houses. Adults were often seen feeding at
rubbish/carcass dumps, which served as a source of consistently available food
for their young, and also primary sources of nest material.
It has been
reported that an EV clutch generally contains two eggs (Brown & Amadon 1968; Cramp & Simmons 1980; Naoroji
2006), of which one usually hatches (Naoroji 2006),
although Angelov et al. (2013) reported an EV clutch
of four eggs from Masirah Island. In the present study the clutch size was two
eggs per year, and all eggs (n=6) hatched and nestlings fledged successfully
over three consecutive years (2015–2017).
According to Mendelssohn & Leshem (1983),
hatching interval in EV varies from three to eight days, and when the age
difference between siblings is large the younger chick generally dies due to
competition with the elder chick. In the
present study the hatching interval was five days, nestlings faced no shortage
of food supply by the parents and sibling aggression was not observed (Morandini & Ferrer 2015). Margalida et al.
(2004) have reported siblicide of the younger chick
due to sibling aggression during feeding bouts in the Bearded Vulture Gypaetus barbatus. In the 2017 breeding season the EV nestlings
fledged 94–98 days after hatching, whereas fledging periods of 70 days (Donazar & Ceballos 1989), 75–80 days (Naoroji 2006), and 70–90 days (Bilgecan
2012) have been reported. The complete
breeding season stretched from February to July in the years 2015, 2016, and
2017. As per Dharmakumarsinhji
(1955) the breeding season of EV extends from end February/March to June,
mainly February to May and some birds may initiate as early as December.
EV shows
recognizable philopatry and long-term nest occupancy year after year (Newton
1979; Donázar et al. 1996; Sara & Vittorio 2003; Carrete et al. 2007).
Ramirez et al. (2016) reported long-term occupancy (1900-–2015) of an EV
nest and suggested that some high-quality breeding sites provide important
resources for long term nest occupancy.
The authors have monitored this nesting site since 2015, but it may have
been under long-term occupancy prior to this study. In view of sharp decline in EV populations
throughout Punjab, the present observations on breeding biology have important
implications for future management and conservation initiatives for breeding
sites at the regional level.
Table 1. Time budget of partial incubation in Egyptian
Vulture during hatching period (14–19 April 2017) On basis of video records:
total observation time (OT) of 64.99 hours.
Incubating parent |
Total stay in nest |
Stay with partial incubation |
Stay without partial incubation |
Nest unattended |
Male |
49.94% OT (32.45 hours) |
15.94% OT (10.36 hours) |
34% OT (22.09 hours) |
0.07% OT (0.05 hours) |
Female |
49.99 % OT (32.49 hours) |
38.02% OT (24.71 hours) |
11.97% OT (7.78 hours) |
|
Total |
99.93% OT (64.94 hours) |
53.96% OT (35.07 hours) |
45.97% OT (29.87 hours) |
Table 2. Time budget of full incubation in Egyptian
Vulture (09 March–10 April 2017). On basis of video records: total observation
time (OT) of 339.39 hours.
Incubating parent |
Total stay in nest |
Stay with full incubation |
Stay without incubation |
Nest unattended |
Male |
41.09% OT (139.46 hours) |
40.90% OT (138.81 hours) |
0.19% OT (0.65 hours) |
0.17% OT (0.58 hours) |
Female |
58.74 % OT (199.35 hours) |
58.52% OT (198.61 hours) |
0.22% OT (0.74 hours) |
|
Total |
99.83% OT (338.81 hours) |
99.42% OT (337.42 hours) |
0.41% OT (1.39 hours) |
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