Barve e t al.: Nesting biology of Indian birds 1
When and how to study the nesting biology of Indian birds:
Research needs, ethical considerations, and best practices
Sahas Barve, T. R. Shankar Raman, Aparajita Datta & Girish Jathar
Barve, S., Raman, T. R. S, Datta, A., & Jathar, G., 2020. When and how to study the nesting biology of Indian birds: Research needs, ethical considerations,
and best practices. Indian BIRDS 16 (1): 1–9.
Sahas Barve, Smithsonian National Museum of Natural History, 10th Street and Constitution Avenue NW, Washington, D.C. 20560.
E-mail: email@example.com. [Corresponding author.]
T. R. Shankar Raman, Nature Conservation Foundation, 1311, ‘Amritha’, 12th A Main, Vijayanagar 1st Stage, Mysore 570017, Karnataka, India.
Aparajita Datta, Nature Conservation Foundation, 1311, ‘Amritha’, 12th A Main, Vijayanagar 1st Stage, Mysore 570017, Karnataka, India.
Girish Jathar, Bombay Natural History Society, Hornbill House, Dr Salim Ali Chowk, Shaheed Bhagat Singh Road, Mumbai 400001, Maharashtra, India.
Manuscript received on 03 February 2020.
The nesting biology of a bird species is likely the most important component of its life history and it is affected by several ecological and environmental
factors. Various components of avian nesting biology have proved to be important traits for testing fundamental ecological and evolutionary hypotheses,
and for monitoring the efﬁcacy of biological conservation programs. Despite its signiﬁcance, the nesting biology of most Indian bird species is still poorly
understood. The past few years have, however, seen a signiﬁcant increase in the number of submissions to Indian BIRDS, of observational studies of
avian nesting biology, which promises an exciting new wave of ornithological natural history research in India. Although there is great need for such
research, there are several biological, legal, and ethical aspects to consider before studying bird nests through direct observation or by using new
technological and digital monitoring techniques. Here, we outline the merit and need for studying the nesting biology of birds in India, but also suggest
best practices, speciﬁc to the Indian context, which will help to ensure that the research is done legally, ethically, and in a way that can provide important
new information to advance Indian ornithology without compromising the welfare of birds.
For a wide array of bird species, ornithologists and birdwatchers
have studied and documented many aspects related to nesting
biology such as: pair formation, courtship, copulation, nest
availability, nest site selection, nest building, nest maintenance,
clutch size, incubation period, hatching success, ﬂedgling survival
and growth; parental care and parent – offspring behaviour;
moult, nest re-use, and population dynamics (Birkhead et. al.
2014). Nesting biology is a highly signiﬁcant aspect of a bird’s
life-history and is directly related to ecological aspects such as
habitat selection and survival, as well as evolutionary aspects
such as reproductive success and sexual selection. The nests that
birds make are extremely varied, from swiftlets nesting in caves,
grebes and jacanas nesting on open waterbodies or marshes,
babblers nesting in tall grass, mound-nesting megapodes, primary
or secondary cavity- or hole-nesting birds such as woodpeckers,
kingﬁshers, owls, bee-eaters, and hornbills, ground nesters like
lapwings and larks, birds that breed on cliffs, in houses, and on
rooftops, to brood-parasites like many cuckoos that do not build
nests but lay their eggs in other birds’ nests (Lovette & Fitzpatrick
The nesting season is a particularly vulnerable time for birds
as their eggs and young are nearly defenceless against predators,
although parent birds may go to substantial lengths to protect
nests and young through defensive, or evasive, behaviours and
by careful selection of nest sites in secure or hidden locations.
It is also an energetically demanding and sensitive period as
adults provision the nestlings, revisit the same location multiple
times, and spend considerable time incubating eggs, and feeding
young. During this crucial nesting period, when birdwatchers and
researchers observe birds to study and document their nesting
ecology or behaviour, it is possible that the presence of human
observers and their methods of observation may affect birds in
different ways. Scientiﬁc and ethical concerns have been raised
that human observer-related disturbances may compromise the
accuracy of research ﬁndings or the welfare of the birds concerned
(Götmark 1992; Farnsworth & Rosovsky 1993; Crozier & Schulte-
Hostedde 2015). In the case of nesting birds, ﬁeld research or
disturbances due to human observers, such as ecotourists and
birdwatchers, may lead to changes in nesting habitat, nest site
availability and safety, increase exposure and stress, compromise
the survival of chicks and adults, cause nest desertion, or modify
predator behaviour and predation rates, all of which may affect
nesting birds in ways that are negative, neutral, or even positive
(Götmark 1992; Müllner et al. 2004; Weidinger 2008; Ibáñez-
Álamo et al. 2012). The unscrupulous or insensitive behaviour
of human observers, such as disturbing nest sites and nesting
birds for the purpose of bird photography, which is unethical and
detrimental to birds, has been criticized and conservationists have
called for the adoption of better guidelines (Dattatri & Sreenivasan
2016; Podduwage 2016). The excessive use of call playback to
attract birds has also been a matter of concern as there could be
possible effects on bird breeding, stress, and survival, especially
in the breeding season (Sen 2009; Kannan & Santharam 2015).
Organisations concerned with birdwatching and bird conservation
have provided guidelines for birdwatchers, including a code of
behaviour (ABA 2012; RSPB 2019), and measures to minimise
disturbance during nest observations (BTO 2019). Birdwatchers
who are aware and sensitive to these concerns are more likely
to change their behaviour to beneﬁt birds (Weston et al. 2015).
2Indian BIRDS vol. 16 No. 1 (PuBl . 13 July 2020)
Within India, professional ornithologists and birdwatchers
continue to carry out ﬁeld research and natural history
observations on the nesting habits of many bird species to build
our knowledge of nesting birds. There has been an increase in
the number of natural history and anecdotal notes on nesting
biology submitted to Indian BIRDS journal in the last few years
(over 30 manuscripts since September 2015). The need for
scientiﬁc and natural history journals to consider ethical aspects
related to the research or observations they publish has been
widely highlighted (Marsh & Eros 1999; Kannan & Santharam
2015; Costello et al. 2016). Most journals that publish research
on animals now require that authors adhere to international
standards and best practices, with due attention to ethical
considerations in their work before it can be considered for
publication (e.g., Animal Behaviour 2020). In India, as an
increasing number of amateur birdwatchers, citizen scientists,
students, and scientists carry out studies on bird nests, it is
important to bring into consideration, from the planning stage
through observation and publication, aspects such as: ethics,
appropriateness and repeatability of the research methods,
permits and training, and the trade-off between new information
generated versus potential negative impacts on nesting birds. In
this paper, we brieﬂy outline the need for nesting biology studies,
discuss how studies at bird nests may affect birds negatively or
positively, and provide some guidelines and resources that may
help researchers make decisions about when and how to study
the nesting ecology of Indian birds.
Nesting biology studies
Some basic aspects of nesting biology have been described for
a majority of the Indian bird species (Ali & Ripley 1983), but
there is much to learn, particularly in relation to variation within
and across species, and across different habitats and regions.
Many aspects of bird reproductive ecology are similar across
closely-related species (phylogenetically conserved) and have
been described in the ornithological literature. For example, all
woodpecker species around the world excavate cavity nests
and all lapwings nest on the ground (del Hoyo et al. 1992), so
observations that merely provide additional site or photographic
records or descriptions of such woodpecker or lapwing nests
may not add signiﬁcantly to existing knowledge. On the other
hand, studies that yield information on what kinds of trees a
woodpecker species uses to nest in, say, urban parks versus
forests, or on lapwings nesting on rooftops of buildings, may add
interesting new knowledge and improve our understanding of
how species adapt to different habitats.
In contrast to phylogenetically conserved traits, other
aspects such as clutch size and incubation period may be highly
variable across closely related species (Barve & Mason 2015).
Moreover, while there are some well-known macroecological
patterns in avian reproductive biology (such as the increase in
clutch size with latitude, across bird species; Jetz et al. 2008),
there are other aspects such as, variation in relation to elevation
(Boyce et al. 2015), which are less well documented. Additional
documentation and studies on these aspects will help build
our corpus of knowledge on Indian birds and improve our
understanding of the ecological correlates of breeding patterns.
Aspects of the reproductive biology of individual birds (e.g.,
nest placement, clutch size, and reproductive success) may be
inﬂuenced by a variety of proximate mechanisms such as, social
system (Barve et al. 2019), population density (Dhondt et al.
1992), food availability (Aranzamendi et al. 2019), predator
density (Fontaine & Martin 2006), body condition (Crossin et
al. 2017), habitat alteration, such as due to logging (Srinivasan
et al. 2015), environmental ﬂuctuations (Pinaud & Weimerskirch
2002), and environmental pollution (Marzluff 2001). Research
on the breeding biology of birds has provided empirical evidence
for many ecological and evolutionary theories and may also
illuminate how bird life history attributes relate to their vulnerability
to extinction and their conservation needs (Birkhead et al. 2014;
Xiao et al. 2017). Nest monitoring studies have been instrumental
in revealing important insights in natural selection (Grant &
Grant 2019), intra- and inter-speciﬁc ecological interactions
(Samplonius & Both 2019), population ecology (Clutton-Brock
& Sheldon 2010), social behaviour (Koenig et al. 2016), and
conservation actions (Rane & Datta 2015). However, despite its
signiﬁcance for ecology, evolutionary biology, and conservation
science, the nesting ecology of many birds, especially tropical
forest species, is poorly known (Xiao et al. 2017). For Indian
birds, gaps in knowledge vary from no information on the nesting
ecology of some species (e.g., Marsh Babbler Pellorneum
palustre, Black-headed Shrike-Babbler Pteruthius ruﬁventer, and
Ward’s Trogon Harpactes wardi), to a dearth of information on
the spatial and temporal variation in nest placement, clutch size,
phenology, provisioning of nest inmates, and ﬂedging success
for many widespread species (Padmanabhan & Yom-Tov 2000).
Lastly, the effects of environmental and ecological factors such
as habitat degradation, predator density, or nest site availability,
on the reproductive ecology of most species remain virtually
Effects of nest studies on birds: need for care, caution,
and ethical guidelines
While there are signiﬁcant opportunities to study the nesting
biology of birds, there are also concerns on how observations
may impinge on the birds themselves. It is therefore important
that concerns for the welfare of birds, and the best practices that
address these concerns, are kept in the forefront as one embarks
on bird nesting studies. In an early review, Götmark (1992)
highlighted a number of potential effects of observer-related
disturbance on birds including increased exposure to predation
and extreme temperatures, effects on nest-site selection and
breeding density, and altered behaviour of parents and young.
Götmark (1992) particularly highlighted negative effects on
nesting birds due to increase in nest predation. This prompted
many observers and researchers to take care to minimise
disturbance and harm to nesting birds by using appropriate ﬁeld
methods and less intrusive methods. Since Götmark’s 1992
paper, there have been numerous studies on the nesting ecology
of birds, including many that speciﬁcally compared the nesting
success of birds under close, or regular, observation with that
of nests that were not similarly observed. However, a recent
review of this literature, analysing data from 18 experimental
studies involving 25 bird species from six avian orders, came to a
contrasting conclusion (Ibáñez-Álamo et al. 2012). Ibáñez-Álamo
et al. (2012) found that researcher activities did not generally
affect the incidence of nest predation and, surprisingly, nest
survival of passerines increased weakly with researcher activities.
They also found signiﬁcant positive effects of researcher activity on
nest survival for species breeding on coastal areas and for species
nesting on the ground. While their patterns were inconsistent
among avian orders and are based on a limited set of species,
they highlight that careful observation (carried out using proper
protocols) has the potential to increase our knowledge of nesting
ecology without harming the birds being observed.
New technology is also increasingly being deployed to
study birds at nests through photography or videography
(Franzreb & Hanula 1995; Boom & Fuller 2003; Margalida
et al. 2006; Robinson et al. 2015), such as by using remote
cameras mounted near nests, specially designed video cameras,
unmanned aerial vehicles (drones), and remote-operated
vehicles (rovers). It is known that disruptive and intrusive nest
photography or videography by unscrupulous observers can
harm birds and should be strictly avoided (Podduwage 2016;
Dattatri & Sreenivasan 2016). However, cameras, drones, and
rovers deployed with proper care, to minimise disturbance to
birds, can be valuable assets in bird research (e.g., Palkar 2016;
Mori et al. 2017). The use of such technology in bird studies is
relatively new to India. Species such as the White-bellied Sea-
eagle Haliaeetus leucogaster (Bhau Katdare, verbally, dated 15
December 2013), Brown Fish Owl Ketupa zeylonensis (Vyas
et al. 2013), White-rumped Vulture Gyps benghalensis, Indian
Vulture G. indicus (Prakash et al. 2012; Pande et al. 2015), Indian
Pitta Pitta brachyura (Solanki et al. 2018), Indian Grey Hornbill
Ocyceros birostris (Gadikar 2017; Kasambe 2020), and Malabar
Pied Hornbill Anthracoceros coronatus (Mandar Sawant, verbally,
dated 15 December 2013) are some notable examples. So far,
closed-circuit television (CCTV) cameras, web cameras with
television or computer monitors, digital single-lens reﬂex (DSLR)
cameras, and infra-red cameras with motion sensors have been
used in these studies.
The breeding biology of White-bellied Sea-eagles was studied
using CCTV units in 2000 (Bhau Katdare, verbally, dated 15
December 2013). Since then, CCTV technology has also been
used to study Oriental Dwarf Kingﬁsher Ceyx erithaca nests
(Palkar et al. 2009). Vyas et al. (2013) used infra-red video
camera traps to reveal the nesting behaviour of the nocturnal
Brown Fish Owl. Similar studies have been done for the Indian
Grey Hornbill (Gadikar 2017, Kasambe 2020) and the Indian
Pitta (Solanki et al. 2018).
There is little information, or experimental studies, on how
cameras affect nesting birds, particularly for tropical and forest
bird species. For a small set of temperate bird species in
North America, Richardson et al. (2009) reviewed studies and
concluded that on average, the use of camera equipment may
reduce nest predation rates, but the differences they observed
varied according to region, study duration, and vegetation type,
and were not always signiﬁcant. They cautioned that researchers
using camera surveillance to monitor nests must be aware that
the equipment may affect rates of predation and possibly bias
data collected on predator identity. Similarly, Ibáñez-Álamo et al.
(2012) suggested that nest predators may be more sensitive
to the human observer-related disturbance, implying the need
for caution in interpreting studies of predation at nests as well
as the need for research on effects of observer-disturbance
on nest predators. Recent research on the use of drones and
rovers to study nesting birds such as gulls, ducks, waders, and
penguins has highlighted that such technology can potentially
be deployed in ways that cause less disturbance to nesting birds
than direct observations that involve handling birds or imply
greater proximity of human observers to nests (Sardà-Palomera
et al. 2012; Le Maho et al. 2014; Vas et al. 2015). As research
on this aspect is still nascent and the effects of the use of such
technology on a majority of bird species, particularly forest birds,
remains unknown, it is better to take a precautionary approach
and maintain high standards of care, ethics, and sensitivity while
deploying these methods to study nesting birds.
Questions to ask before one begins a nesting study
Given the above context and the need for studies of nesting
biology as well as the need for care in how such studies are
conducted, we would like to suggest a set of questions that one
could answer prior to launching such studies. These questions
are not meant to be comprehensive, nor do they address all
possible issues that may arise in the context of studies of any
particular species. The researchers or observers should ideally
adopt a practice of critical and continuous self-questioning and
sensitivity to understand and address the various issues related
to their study species. The questions we provide here are more
in the nature of broad guidelines for observers to help identify
relevant information and adopt best practices in preparation for
studying birds at their nests.
1. Have I made a comprehensive review of the
available literature on the species to assess what
additional contributions my research will add to
Although limited in comparison to the information available for
European or North American birds, there is much information that
can be found on many Indian bird species. An essential starting
point in any research is a survey of the available literature on the
species or question. Ali & Ripley (1983) is, to this day, the most
comprehensive resource on Indian ornithology and may be a ‘go-
to’ resource for most species. This publication comprehensively
collates data from various important sources such as Hume
(1873, 1874, 1875), and Baker (1895, 1896), and the series on
nidiﬁcation of Indian birds by Lamba (e.g., Lamba 1963). Most
academic papers published on Indian birds, over the last thirty
years, are also available in online repositories and can be searched
using appropriate keywords on academic literature search
engines like Google Scholar (http://scholar.google.com), or
the Searchable Ornithological Research Archive, SORA (https://
sora.unm.edu/). A comprehensive bibliography of scientiﬁc
literature on Indian avifauna can also be found at http://www.
southasiaornith.in/ (Pittie 2019). Less than 10% of Indian bird
species are endemic to the country (Jathar & Rahmani 2007);
species more widely distributed may have been studied in other
range countries. Therefore, it is also important to refer to more
global databases such as the Handbook to the Birds of the World
Series (del Hoyo et al. 1992), Ebird.org (Sullivan et al. 2014),
AviBase (Lepage et al. 2014), the IUCN Red List (IUCN 2017),
and other sources for information, including regions outside
India where the species may have been already studied. Gaps
in knowledge about a species, and the justiﬁcation for its study,
should be decided only after completing a thorough literature
review. A good literature review on the species of interest may
highlight that your observations are signiﬁcant as they represent
a breeding record for the species in a new region, habitat, or
elevation. It may reveal an unknown nest placement type, or nest
Barve e t al.: Nesting biology of Indian birds 3
type for the species, or highlight behavioural differences such as
the presence of non-parent “helpers” at the nest. In many cases,
literature reviews reveal that some observations are not novel.
Undertaking such studies may not be worthwhile, particularly
if they are associated with some level of disturbance to birds.
Focussing your observations on the novelty of your ﬁnding may
also streamline your research methods and the effort involved in
However, the novelty of an observation or the validity of
a particular academic question may not be the only criterion
to decide on whether a nest observation study should be
undertaken. Long-term nest monitoring is increasingly critical
for biodiversity conservation, and to identify trends, changes,
and threats that may be affecting the breeding of a species. For
example, long-term studies are being carried out on ﬁve hornbill
species in Arunachal Pradesh, India, since 1997, led by one of us
(AD). While these species had already been studied in Thailand,
and at least one species in southern India earlier (Kannan &
James 1997; Poonswad et al. 2005), nothing was known of their
breeding biology from north-eastern India. Studies involving nest
observations were carried out to document hornbill breeding
biology in Arunachal Pradesh (Datta 2001; Datta & Rawat 2004).
One could argue that the incremental knowledge, or the small
differences one sees between sites or regions, does not warrant
more studies, but there is a need for, and value in, studies of the
same species in different sites or across its range as they may
reveal interesting differences that yield new ecological insights.
They also provide a more comprehensive knowledge of the
biology of a species across its range: for instance, we know from
these studies that the breeding season of hornbills is different
across these three regions, possibly due to differences in climate
and phenology (fruit availability). Additionally, long-term studies
are important for conservation: determining changing threats to
species status in speciﬁc areas, and trends in breeding activity or
timing in relation to ecological variables such as food availability
and climate. For example, the peak ripe fruit availability in north-
eastern India occurs in the middle of the breeding season, while
in Thailand it peaks after chicks ﬂedge. Two sites in Thailand have
had arguably the longest-running hornbill projects in Asia, studying
the breeding of several sympatric hornbill species (Poonswad et
al. 2005). These long-term studies in Thailand and India have
yielded insights into the interspeciﬁc competition for nest sites
between hornbill species, nest turnover and re-use/longevity
of nest trees, variation in timing of breeding, nesting success,
and duration. Long-term monitoring has shown the shortage of
nest sites and resulted in repair of limiting nest cavities along
with nest box provisioning (Poonswad et al. 2005; Datta et al.
unpubl. data). Pioneering efforts in Thailand on hornbill research
and conservation with the help of communities outside Protected
Areas have now been replicated in India in the Western Ghats
(Bachan et al. 2011), north-east India (Datta et al. 2012; Rane &
Datta 2015), Malaysia (Yeap 2019), and the Philippines (Alabado
et al. 2009).
Another example of research involving hornbills is the study
of Indian Grey Hornbills by an amateur ornithologist in Indore
city for 12 years. It has revealing unusual breeding sites (Gadikar
2017), and changes in their breeding pattern and timing thanks
to the long-term observations of nests (A. Gadikar, unpubl. data).
For the last two to three years, it has been noted that the Indian
Grey Hornbill is initiating nesting 15 days earlier than in the past
(A. Gadikar, unpubl. data). In north-eastern India, the median
nest entry date of Great and Wreathed Hornbills was 29 days
earlier than what was recorded in the previous 16 years (A. Datta,
unpubl. data). A third example is of a study of nesting colonies
of the Finn’s Weaver (Ploceus megarhynchus), over a period
of 21 years, which helped in monitoring the population decline
at a landscape level, as well suggesting a revision of the IUCN
status of the species from Vulnerable to Critically Endangered or
Endangered (Bhargava 2017).
2. What do I want to study and how generalizable are
my results given my sample size (number of nests
Given the vulnerability of nesting individuals, studying nesting
biology requires understanding the trade-offs between any new
information a study may generate and the disturbance it may
cause for the birds in question. For example, when nothing is
known about the reproductive ecology of a species, careful
and continuous observation and monitoring of a single nest
may provide valuable new information. However, for species
whose basic biology is well known, information on an additional
one, or a few nests, may not be of sufﬁcient scientiﬁc rigour to
add new or useful knowledge, while carrying the risk of such
a study being intrusive and potentially deleterious for the birds.
Similarly, if the motive is to study the effect of an ecological
mechanism, a robust sample size is required to reach ecological
conclusions with adequate statistical support and signiﬁcance.
Take for instance a familiar species, the Baya Weaver Ploceus
philippinus, for which basic aspects of nesting and breeding
have been described by multiple earlier observers (Ali 1931;
Ambedkar 1964; Crook 1964; Davis 1971). Nevertheless,
many ecological and behavioural aspects of their breeding—for
instance, the inﬂuence of nest height, location, or orientation of
nest-openings on reproductive success—remained unknown or
inconclusive. To answer such questions, Quader (2003, 2006)
studied a sample of 1,445 nests of the Baya Weaver using both
observations and experimental manipulations (sample size of
nests for speciﬁc comparisons and hypotheses testing ranged
from 9 to 864 nests). Such careful studies with adequate sample
size, appropriate methods, and experimental manipulations may
be necessary to answer behavioural-ecological and evolutionary
questions, but on occasion even these may be insufﬁcient, as
Quader (2006) observed:
“...Behavioural ecologists and evolutionary biologists
are often hesitant to carry out extreme manipulations.
Nevertheless, such manipulations may be necessary to
reveal certain natural and sexual selection pressures that
would otherwise be hidden from scrutiny. If manipulating
nest traits is impossible, large sample sizes and careful
analyses will often be required (but might still not be
sufﬁcient) to detect selection on nest attributes.”
Having clear objectives when studying breeding birds is
critical to ensure that the nesting individuals are not disturbed
unnecessarily. Hence, observers should avoid ‘ﬁshing expeditions’
where data is collected ﬁrst, and then the study is designed
around it to be described in a manuscript form. To make your
research comparable to others, and reliable enough to add new
knowledge to the literature on the species, it is important to have
clear a priori objectives, assess what sample sizes you plan to
4Indian BIRDS vol. 16 No. 1 (PuBl . 13 July 2020)
get or are feasible, and use appropriate methods of observation,
analysis, and inference.
In certain cases, nest monitoring is done for species
conservation, to ensure nesting individuals are not hunted or
that their nest sites are not disturbed, to ensure nesting success.
It is especially important in such scenarios that researchers or
ﬁeld staff are trained to cause minimal disturbance during their
3. Am I using the right research methods and those
that are least intrusive for the purpose?
It is important to choose a research methodology that is (1)
repeatable, (2) reliable and appropriate for the question or
objective of the study, (3) provides the most information while
minimizing the impact on the nesting birds, and (4) ensures the
welfare and safety of birds and researchers. An exhaustive review
of the best methods to study birds, particularly at their nests,
is beyond the scope of this manuscript. Besides textbooks and
handbooks on bird biology (e.g., Lovette & Fitzpatrick 2016), a
number of handbooks of techniques and research methods are
available, which can be consulted as starting points (Ralph et al.
1993; Sutherland et al. 2004; Ferguson-Lees et al. 2011).
Several ‘public’ protocols have been published to involve
citizen scientists in amassing information on the nesting ecology
of common birds across huge spatial scales, such as over the
whole of North America (Neighborhood NestWatch: https://
Online certiﬁcation programs have also been established
to provide guidelines for nest monitoring (The Cornell Lab
of Ornithology’s NestWatch, https://nestwatch.org/). Such
programs strongly discourage unethical practices such as clearing
of vegetation around the nest, repeated visits to the nest, and
playing bird song near the nest as such methods alter the natural
behaviour of birds and thus render the research unreliable and
not comparable to other studies.
4. What is the legal status of the bird species, and do I
have the required permits and experience to carry out
Another basic question to ask is whether there are speciﬁc permits
and expertise (or training) that you require before you embark
on a study of nesting birds. Within India, if your observations
are being carried out in any wildlife reserve (Wildlife Sanctuary,
National Park, Tiger Reserve, or Community or Conservation
Reserves), according to the Wild Life (Protection) Act, 1972, you
will need to apply for and secure relevant entry and research
permits from the Chief Wildlife Warden of the State where the
reserve is located. If the study site is located in a Reserved Forest
or Protected Forest, permits from the respective wing of the
Forest Department will need to be obtained. Note that it is not
just permits from government authorities that may be required.
If your work is on private or community land, you will need to
inform and secure permits from the corresponding owners or
community institutions (such as Village Council or Panchayat)
before working in the area.
The legal status and conservation status of the study species
also matters. This includes the international status under the
IUCN Red List of Threatened Species (www.iucnredlist.org), and
the Convention on International Trade in Endangered Species of
Wild Fauna and Flora (henceforth, CITES; www.cites.org), and
the national status under the Wild Life (Protection) Act, 1972.
Birdwatchers and researchers should adopt procedures of due
care when studying species that are Critically Endangered,
Endangered, Vulnerable, or Near Threatened (Rahmani 2012).
CITES regulates trade in live birds and specimens (including parts
of a bird such as feathers, eggs, or bones) with prohibitions or
strict regulations for species listed in Appendices I to III.
Under India’s Wild Life (Protection) Act, 1972, endangered
species are listed in Schedule I, while other protected species
or taxonomic groups are listed in Schedules II to IV (WLPA
1972). Under this Act, the capture or handling of birds, even
for the purpose of research, is categorised under ‘hunting’,
which is generally prohibited under Section 9. However, under
Section 12, birds can be ‘hunted’ (meaning captured/collected)
under a special permit from the Chief Wildlife Warden for the
purposes of education, research, or collection of specimens for
recognised zoos and museums. Permission shall be granted
to foreigners or non-resident Indians or institutions owned
by foreigners or non-resident Indians only if the project has
been sanctioned, and permission issued by the Government
of India, Ministry of Environment, Forests and Climate Change
(henceforth, MoEFCC), Ministry of External Affairs, Ministry of
Home, and by the National Biodiversity Authority, as referred
to in Section 3 of the Biological Diversity Act, 2002. In case
of research that involves the capture, and handling of, or the
collection of biological samples from any species listed in
Schedule I, the award of approval would lie with the Director
(Wildlife Preservation), Government of India (Additional
Director General (Wildlife) and Director, Wildlife & Preservation,
MoEFCC). In all cases, the proposal should be submitted to the
Chief Wildlife Warden, and a copy to the Additional Director
General (Wildlife), MoEFCC, Government of India. For studies
requiring the capture and handling of bird species in Tiger
Reserves, a no-objection letter is also required from the National
Tiger Conservation Authority.
In the speciﬁc case of observations of birds at nests, another
legal aspect applies. In India’s Wildlife (Protection) Act, 1972, the
deﬁnition of ‘hunting’ under Section 2(16-c) of the Act states
that ‘hunting’ includes “injuring or destroying or taking any part
of the body of any such animal, or in the case of wild birds
or reptiles, damaging the eggs of such birds or reptiles, or
disturbing the eggs or nests of such birds or reptiles” (emphasis
ours). Damaging or disturbing the eggs or nests of birds can thus
be construed as ‘hunting’ under the Act and therefore liable for
prosecution. Because of these legal provisions, it is very important
that nest observers and researchers obtain required legal permits
and exert due care in how they conduct their work.
Besides the required legal permits, observers may need to gain
necessary training and experience in nest and bird observations
and research techniques. This is particularly important for studies
that involve (a) the capture and handling of birds by mist-netting
and ringing, morphometric measurements, radio-telemetry, and
geo-locator tagging studies, (b) experimental protocols and
manipulation such as collection of blood or regurgitates, plumage
alteration, nest modiﬁcation, and egg or nestling experiments.
Many institutions train birdwatchers and ornithologists in best
practices and standard research methodologies (e.g., observation
of animals, taking blood samples, mist-netting, bird ringing) and
observers who plan to use these methods should seek out
appropriate training and develop their credentials and expertise.
Barve e t al.: Nesting biology of Indian birds 5
The Bombay Natural History Society undertakes bird ringing and
trapping courses (www.bnhsenvis.nic.in) under the Green Skill
Development Programme of MoEFCC, Govt. of India. In most
cases, besides hands-on training and practice, researchers may
have to pass a test following the training and may be provided
certiﬁcates upon its successful completion. When writing reports
or manuscripts based on observations and studies, it is important
to indicate, in appropriate places, the following details: legal
permits obtained, community consent, and training experience
or expertise in capture and handling or experimental protocols
used in the study.
5. Does my work conform to international standards
and guidelines for the ethical conduct of research?
An additional, and overarching, aspect that is very important
in bird nesting biology research, is ethics. Even if an observer
has chosen appropriate objectives and observation methods,
secured relevant legal permits, and acquired any relevant training
or experience, there may be ethical considerations that apply.
For instance, an observer may choose to carry out experimental
manipulation of nests or use call-playback experiments to study
aspects of breeding behaviour. The repeated manipulation of
nests, or call-playbacks within the territories of nesting birds may,
however, negatively affect birds if they become stressed, or are
forced to expend extra energy, or take time away from other
activities to respond to playback (Harris & Haskell 2013; Kannan
& Santharam 2015). Ethical considerations may then dictate
restrictions on the use of such methods or identify limited use
such as a single manipulation or playback experiment per pair per
breeding season (Sen 2009; Sibley 2011).
Most bird research, and long-term studies around the
world follow international standards and methods as well as
institutionally-approved ethical guidelines for research. Although
such guidelines may be available, studies that involve potential
harm or disturbance to birds would generally require to be
considered on a case-by-case basis by relevant Institutional
Review Boards or Research Ethics Committees. Institutions
such as the Nature Conservation Foundation (henceforth, NCF),
Ashoka Trust for Research in Ecology and the Environment, Indian
Institute of Science Education and Research, National Centre for
Biological Science, Bombay Natural History Society (henceforth,
BNHS), and others have ethics committees that screen research
proposals before the work is carried out. In BNHS, the Research
Subcommittee reviews all prerequisites for projects that
involve conservation breeding, bird handling, and bird ringing,
including aspects such as permissions, necessary compliance,
and training of people involved. The institutions also sensitise
and train researchers in broad aspects of research ethics, and
in the speciﬁc application of ethical considerations to research
that may involve animal or human subjects, experiments, or
manipulations. Institutional ethics guidelines are based on the
synthesis of a large and growing body of global research on the
effect of scientiﬁc research on animals, researchers, and human
subjects who may be involved in the work. The NCF research
ethics guidelines, for instance, take a 4Rs approach to ethical
research (NCF Research Ethics Committee 2015), stating that:
Researchers in NCF will carry out their research on animals,
plants, and habitats, with care, compassion, and concern,
by adopting methods and approaches that will, to the extent
• Replace animal subjects by other alternatives when
available and appropriate (e.g., including choice of non-
invasive sample collection, modelling studies, etc.).
• Reduce the number of animals, specimens, or research
samples (e.g., using improved techniques, existing
specimens or data, and optimising experimental/study
• Reﬁne methods to minimise harm and suffering, and
advance animal welfare (e.g., by modifying capture and
handling techniques, methods to minimise disturbance).
• Refuse to carry out research that violates fundamental ethical
considerations (e.g., inhumane and unethical treatment of
animals, use of force on local communities).
Above all else, if adhered to closely, ethical research practices
ensure that both researchers and research subjects remain
unharmed and endure the least amount of stress during the
research period. Thus, it is important for researchers at an institution
that neither have such committees nor requires compliance with
institutional ethics guidelines, or amateur ornithologists who are
not associated with research institutions, to take the time to read
up on research ethics and guidelines (such as those listed in
Table 1) and apply them to their work. This will help ascertain, and
ensure, that as far as possible their observations do not unwittingly
disturb or harm their research subjects.
When observers report their research or submit manuscripts
for publication, their manuscript should detail, in the Methods
section, how ethical issues were considered and how the
adopted methods were modiﬁed or reﬁned to address them.
Authors should include a statement about what ethical guidelines
were followed, citing relevant publications or documents such as
general institutional guidelines or speciﬁc internationally accepted
protocols or guidelines for the kind of work undertaken. While
some researchers insert a line in the Acknowledgements section
of their paper, that the work was carried out with ethics approval,
some journals carry a separate section, ‘Ethics statement’, after
Acknowledgements, for authors to provide such a statement, or
information on ethical aspects.
Indian ornithology and bird conservation face the dual challenges
of widespread habitat loss and associated population declines of
many Indian bird species along with a lack of understanding of
even the basic biology and life history of many of these species.
Data on the breeding biology of bird species are fundamental not
only for academic research in behavioural ecology or evolutionary
biology, but also to understand the impacts on birds of
environmental changes from the local scale (e.g., pollution, habitat
alteration) to regional (e.g., habitat fragmentation), and global
scales (e.g., climate change). There is a need for studying the
breeding and nesting biology of birds for a better understanding
of their ecology, behaviour, and conservation needs. There
is also, simultaneously, a need to carry out observations in
a manner that is sensitive to the welfare of the birds because
breeding birds are often vulnerable to disturbances associated
with human observers. This dual need is the inspiration behind
Observers must ensure that they are well informed and aware
of any potential detrimental aspects of making observations on
birds, particularly at their nests, and implement measures to
6Indian BIRDS vol. 16 No. 1 (PuBl . 13 July 2020)
avoid, or minimise, disturbance for scientiﬁc, legal, and ethical
reasons. Additionally, observers must balance the potential gains
in new knowledge against possible harm to birds, with adequate
preparation, choice of proper research methods, and justiﬁcation,
before embarking on such studies. We have outlined points to
consider before studying the nesting biology of birds that will
ensure their well-being, and likely increase the scope, reliability,
and utility of the study. We fully understand that researchers will
have to weigh trade-offs over the ﬁve questions outlined in this
manuscript, when designing their own study. Such trade-offs
and considerations are common in virtually all research, so it is
important to be aware of them and to give them due attention
during your research, from planning to execution to publication.
We hope this article serves as a springboard for further discussion
and the evolution of best practice protocols and guidelines for
the study of Indian birds. We also hope that it enables further
research and observations on birds that builds our knowledge of
Indian birds in a manner that places the welfare of the birds at
We thank the editors of Indian BIRDS for inviting us to write this manuscript. We
thank Ragupathy Kannan and Divya Mudappa for useful discussions. TRSR thanks
the Science and Engineering Research Board, India, for supporting (SERB grant
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Barve e t al.: Nesting biology of Indian birds 9
With the compliments of
G.B.K. CHARITABLE TRUST
Unit No. T-6C, Phoenix House, S. B. Marg, Lower Parel,
Mumbai 400013, India.