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J. Bio. & Env. Sci.
2015
32 | Shah et al.
RESEARCH PAPER OPEN ACCESS
Breeding biology of barn swallow
(Hirundo rustica)
at Tehsil
Balakot, Pakistan
Noman Shah
1
, Shabir Ahmed
1
, Sajid Mahmood
1
, Muhammad Awais
2*
, Shaukat Ali
1
,
Imad-Ul-Din Zangi
2
1
Department of Zoology, Hazara University, Mansehra, KP, Pakistan
2
Department of Wildlife Management, PMAS-Arid Agriculture University, Rawalpindi, Pakistan
Article published on December 12, 2015
Key words: Balakot, Clutch size, Fledglings, Hatchlings, Mansehra.
Abstract
This study was conducted at Tehsil Balakot in District Mansehra, during the breeding season February to June
2014. Details about nests and eggs characteristics are provided. All nests were attached to vertical walls and roofs
of buildings and situated at mean height 2.8±0.43 m above ground with nest diameter 14.78±3.13cm, nest
depth3.97±0.90 cm, nest cup diameter10.91±2.46 cm and nest cup depth3.27±0.80 cm. Nests attached to
cemented walls were (46.3%), plastic surfaces (20.4%), wooden materials (16.7%), soil walls (11.1%) and to
mirrors (5.6%). The average clutch size was 3.7 ranged 2 - 5. Mean egg length was 18.50±1.6 mm, breadth
13.6±1.2 mm, egg volume 1.80±0.5 cm
3
,egg shape index 1.36±0.03 andegg weight was recorded 1.81±0.1 g. Egg
and nest success was 76%and 85%.Hatchling and fledgling produced per nest was 2.84 and 2.44. Main causes for
reproductive failures were unhatched and broken eggs, predation and observer’s disruption.
*
Corresponding Author: Muhammad Awais awais.zoology.hu@gmail.com
Journal of Biodiversity and Environmental Sciences (JBES)
ISSN: 2220-6663 (Print) 2222-3045 (Online)
Vol. 7, No. 6, p. 32-40, 2015
http://www.innspub.net
J. Bio. & Env. Sci.
2015
33 | Shah et al.
Introduction
Family Hirundinidae includes 84 species of
Passerines widely distributed in Tropical and
Temperate regions, and among Hirundinidae Barn
Swallow (Hirundo rustica)is the most widespread
species of swallows in the world (Turner and Rose,
1989; Turner, 2004).But local declines in populations
of the many areas have been reported (Tucker and
Heath, 1994; Robinson et al. 2003).Still very little is
known about the population trends and breeding
biology of Barn Swallows in Pakistan.Although in
Pakistan, Barn Swallow is a well-known summer
breeding bird in the western hill tracts and in
northern mountainous areas (Roberts, 1992). It is a
small bird with steel-blue colored upper parts, white
under parts and a rufous-chestnut forehead, chin and
throat(Higgins et al. 2006). A well-defined blue
breast-band and long outer tail feathers help
distinguish the species. Sexes are similar but females
lack the length in tail streamers (tail feathers are
forked in both sexes) and the white markings on outer
tail feathers are also shorter (Higgins et al.
2006).These birds are highly aerial and exclusively
insectivores (Turner, 2004). The Barn Swallow is a
common bird known from Andamans, Myanmar,
Malay Peninsula and Indonesia (Ali and Ripley,1987;
Turner, 2004).
Available information on the reproductive traits of
hirundines that breed in the tropics shows significant
deviation from the typical traits of tropical birds
(Hails, 1984; Ali and Ripley, 1987; Turner 2004).
Many of them have large clutch size and longer
developmental periods compared to that of temperate
birds (Ali and Ripley, 1987; Turner, 2004). Many
investigations have been carried out to know the
breeding aspects of Barn Swallows during past two
decadesincluding (Robert, 1992;Moller, 1994;Jaunet
al. 1998;Dolenec,2002;Sakraouiet al. 2005;Pawel
andPiotr, 2008;Balakrishnan, 2010; Patrick and
John, 2010;Dolenec, 2013) but no scientific work is
done in Pakistan so far,so it is a first kind ofpublished
paper related to Breeding Biology of Barn Swallow in
Pakistan. The aim of this paper is to present;(1)
Breeding timing and nest characteristics including
nest height, architecture, attachments and
dimensions.(2) Clutch size and egg characteristics
includingegg dimensions (length, breadth,
volume/size and egg shape index). (3) Breeding
success and failures of Barn Swallows.
Timing of egg laying, hatchlings and fledglings,
hatchling and fledgling weight and body
measurements are some of the aspects which still
need to be investigated in the study area.
Material and methods
Study area
This study was conducted at Tehsil Balakot 34°33′N
and 73°21′E in Mansehra District thatis famous
tourist destination of the region and the gateway to
Kaghan Valley. It is located at about thirty-eight
kilometers east of Mansehra city. Tehsil Balakot is
bordered in west with the Tehsil Mansehra of the
District Mansehra while in east it is bordered with the
Muzafarabad District of Azad Jammu and Kashmir,
in north it is bordered with the Kohistan District and
in south it is bordered with the Abbottabad District.
Tehsil Balakot is the largest Tehsil of District
Mansehra. It has humid subtropical climate with hot
summers and cool winters. Rainfall is much higher
than in most other parts of Pakistan. Average rain fall
hold by Tehsil Balakot is 1744 mm per year.
Sampling
The duration of the study spanned 5 months,
February to June 2014.Nests search begun in the
early February. All the nests were found during that
time. In this way 54 nests of Barn Swallow were found
and later 45 nests become active.All the nests were
inspected directly to see the anterior of nest and for
that purpose 10 feet long ladder was used.
Photographs were taken by Traveller XS-4000 digital
camera with 4X optical zoom and 5.0-20.0 mm
lenses. Statistical analyses were performed by using
One Way ANOVA and all the mean values are given
with Standard Deviation (Mean±SD).
J. Bio. & Env. Sci.
2015
34 | Shah et al.
Nest height from ground and nest dimensions (depth
and diameter) were measured by common measuring
tape. Egg weight was taken on common weighing bar.
Egg length and breadth was measured by Vernier
Calliper with Least Count 0.1 mm. Egg volume was
calculated from the length and breadth using the
formula (Hoyt, 1979).
V=0.51 x L x B
2
/ 1000.
Where V is volume in cm
3
, L is length and B is
breadth in mm. An egg shape index (ESI) was
calculated by dividing L/B.
Murray (2000) was followed to calculate egg and nest
success as measures of reproductive success. Egg
success is “the proportion of eggs that produces
young” and nest success is “the proportion of clutches
that produces young”. Thus, number of young that
leaves the nests divided by total number of eggs gave
egg success while number of clutches that produces
young was divided by total number of clutches to
obtain nest success.
Results
Breeding timing and nest attachments
Total of 54 Barn Swallow nests were found during the
breeding period of February to June 2014. Of these 54
nests, later 45 nests found to be active.First clutch
was found in the mid-March and none of the clutch
was found after the late May.Barn Swallow usually
made nests on artificial structures. In the study area
all the nests were found on artificial structures,
among 54 nests, most of nests were attached to
cemented walls n=25 (46.3%),plastic surfaces n=11
(20.4%), wooden materials n=9 (16.7%), soil
wallsn=6 (11.1%) and mirror n=3 (5.6%) see (Table 1).
Table 1. Number and Percentage of Barn Swallows nests attached to different surfaces.
Materials
n
%
Nest attached to woods
9
16.7
Nest attached to plastic contents
11
20.4
Nest attached to cemented walls
25
46.3
Nest attached to mirrors
3
5.6
Nest attached to soil walls
6
11.1
Total
54
100
n= number of nests, %= percentage of nests.
Nest architecture and nest dimensions
The nest of Barn Swallow is usually cup shaped and is
made with mud pellets as major structural
constituent. The mud pellets used to build the nest
consist of sand and smaller amounts of silt and clay.
The nest chamber is lined sparingly with grasses, hair,
and feathers.The mean nest height of nest from the
ground was measured to be 2.8±0.43 m (Range=2.5-
2.9 m), mean diameter of the nest was 14.7±3.13 cm
(Range=14.8-15.3 cm) and mean nest depth was
3.9±0.90 cm (Range=3.7-4.3 cm). While mean nest
cup diameter was measured 10.91±2.46 m
(Range=10.5-11.4 m) and nest cup depth was
measured to be 3.3±0.80 (Range=3.2-3.6 cm)given in
(Table 2).
Table 2. Dimensions of Barn Swallow nests.
Nest Dimensions
Values
Range
R
Nest cup dimensions
Values
Range
R
Height (m)
2.8±0.43
2.5-2.9
-
-
-
Diameter (cm)
14.7±3.13
14.8-15.3
Diameter (cm)
10.9±2.46
10.5-11.4
Depth (cm)
3.9±0.90
3.7-4.3
Depth (cm)
3.3±0.80
3.2-3.6
J. Bio. & Env. Sci.
2015
35 | Shah et al.
Clutch size and egg traits
Clutch size refers to number of eggs laid in a nest.
Clutch size of Barn swallow was 3.7 with eggranges
from 2-5 and most of clutches contained 4 eggs. The
eggs were cream to pinkish white color, with spots
that can be brown, lavender or gray (Fig.1). Total of
167 eggs were recorded from 45 active nests, clutches
with 2 eggs were found to be 6 (7.19%), clutches with
3 eggs were found to be 11 (19.76%), clutches with 4
eggs were found to be 18 (43.1%) and clutches with 5
eggs were found to be 10 (29.9%) given in (Table 3).
Table 3. Clutch size range, total number of clutches and eggs of Barn Swallow.
S. No
Clutch Size Range
(R)
Clutches
(N)
Eggs
(n)
Percentage
%
1
2
6
12
7.19
2
3
11
33
19.76
3
4
18
72
43.1
4
5
10
50
29.9
Total
2-5
45
167
100
Mean egg length of Barn Swallow egg was measured
18.50±1.6 mm (Range=16.0–21.0 mm), mean egg
breadth13.6±1.2 mm (Range=12.0–16.0 mm), mean
egg volume1.80±0.5 cm
3
(Range= 1.18–2.74 cm
3
),
mean egg shape index 1.36±0.0 (Range=1.31–1.38)
and mean egg weight was recorded to be 1.81±0.1 g
(Range=1.6–2.0 g) given in (Table 4).
Table 4. Egg traits of Barn Swallow.
Egg traits
Mean±SD
R
N
Egg width (mm)
13.63±1.2
12.0–16.0
167
Egg length (mm)
18.5±1.6
16.0–21.0
167
Egg volume(cm
3
)
1.80±0.5
1.18 –2.74
167
Egg shape Index
1.36±0.03
1.31–1.38
167
Egg weight (g)
1.81±0.1
1.6–2.0
167
SD= Standard Deviation, R= Range, N= No of eggs.
Statistical analysis between the egg dimensions of the
barn Swallow shows that egg length and width has no
significant difference (P> 0.05), similarly egg weight
and egg shape index also has no significant difference
(P> 0.05) whileegg shape index and volume has
significant difference (P< 0.05).
Breeding success
Egg success and nest success
Total of 167 eggs were recorded from the 45 clutches.
Of these 167 eggs 128 chicks hatched from eggs, so
egg success was 76.0 % (128/167). Of these 128
newborns from 45 nests, only 110 produce successful
fledglings so nest success was 85.0 % (110/128).
Number of hatchling produced per nest was 2.84
(128/45) and number of fledglings produced per nest
was 2.44 (110/45) given in (Table 5).
Table 5. Reproductive achievements of Barn Swallow.
List
Reproductive Achievement
No. of nests
54
No. of active nests
45
Total no. of eggs
167
No. of hatchlings
128
No. of fledglings
110
Clutch size
3.71
Egg success
76.6
Nest success
85.9
Fledglings/nest
2.44
J. Bio. & Env. Sci.
2015
36 | Shah et al.
Breeding failures
Egg failures
Of 167eggs found in 45 clutches only 128 eggs
hatched. Eggs remained unsuccessful were 39 due to
these reasons; eggs remained unhatched were n=25
(15 %), eggs destroyed by House sparrow n=5 (3.0 %),
eggs destroyed accidently during inspection n=3 (1.8
%), broken eggs found in the nestsn=6 (3.6 %). A total
egg failure in the study area was 23.4% (Table 6).
Table 6. Causes of Barn Swallow eggs and hatchlings failures.
Causes of Failures
Egg Failures
n
Percentage
%
Hatchling Failures
N
Percentage
%
Unhatched eggs
25
15.0
-
-
Predated by House Sparrow
5
3.0
7
5.5
Eggs destroyed during inspection
3
1.8
-
-
Broken eggs found from nests
6
3.6
-
-
Bad location of nests
-
-
3
2.3
Mortality (Unknown causes)
-
-
8
6.3
Total Failures
39
23.4%
18
14.1%
Hatchling failures
Of 128 nestlings only 110 will become able to fledge
and18 failed to produce fledglings due to these
reasons: Chicks found dead due to predation of House
sparrow was n=7(5.5 %), chicks fallen from
nestn=3(2.3%)and chicks found dead due to unknown
causesn=8(6.3 %). Total hatchlings failure in the
study area 14.1%(Table 6).
Discussion
Hirundines display substantial geographical
differences in the timing of breeding.Swallow
breeding time is March to June in Baghdad (Al-
Raway and George, 1966).In North Africa and South
Spain, Swallow startslaying in march reported by
Turner (1994). Nesting is limited to wet season in
tropics and subtropics when insects are in plenty and
some time it occurs during rainy season (Turner,
2004). Majority of birds breed during March-July in
India reported by Ali and Ripley(1987). In study area
breeding of Barn Swallow is restricted to rainy season
(Feb to June) and is contrasted with breeding season
(March to May) records of Ali and Ripley (1987) in
Southern India. In Algeria, breeding season was
between April and May reported by Sakraouiet al.
(2005) and is similar to our study area. Similarly, Feb
to April records of Balakrishnan (2010) in Western
Ghats, India. In Srilanka few nests were also recorded
(November to December) and indicated breeding
season starts from December to June (Ali and Ripley,
1987). Substantial regional variation in time of
breeding is seen by different authors so additional
studies are required to know factors like plenty of
insects, rainfall, temperature etc.
All most all species of Swallows are known to use
artificial structures for roosting and nesting (Hails,
1984; Ali and Ripley, 1987;Oatley, 2002; Jackson
andSpottiswoode, 2004; Turner, 2004).In the
Western Palearctic barn Swallow prefer buildings for
their nests where livestock is kept (Moller, 1983;
Cramp, 1988; Turner, 1994). Barn Swallow places the
nest close to ceiling, beams, and walls at a specific
height reported by Pikula andBeklova(1987). All nests
of Barn Swallow in this study were attached to
artificial structures like walls, roofs, wooden materials
and mirrors etc. Swallows nested in different man-
made structures in Algeria including factories,
garages and balconies in buildings (Sakraouiet
al.2005).Barn Swallows attach their nests to diversity
of structures including walls or rock-face, under road
culverts or in tunnels and most commonly under
eaves or against ceiling beams and rafters in houses
reported by Ali and Ripley (1987).
J. Bio. & Env. Sci.
2015
37 | Shah et al.
Barn Swallow built its nest at a specific height in
study area, height of nest from ground was measured
to be 2.8 m (Range=2.7-2.9) and contrasted to
present study, Moller (1985) found nest height 2.0-
5.0 m, similarly Mcginn and Clark (1978) found the
majority of nests at 3.0–4.5 m above the ground
which is slightly greater in value while nests were
situated at a height of 1.5–4.5 m above ground
reported by Roberts(1992) and nest dimensions were
also greater as contrasted to present investigation
found by other authors.Nests were found at height of
2.5 m in North West Croatia (Dolonec, 2002) which is
slightly less in value recorded by us.Barn Swallow
built their nest at height of 3.9 m in Algeria recorded
by Sakraouiet al.(2005) which is more recorded by us
in study area.
Fig. 1. Different clutches of Barn Swallow; (a) clutch with 2 eggs (b) clutch with 3 eggs (c) clutch size with 4 eggs
(d) clutch size with 5 eggs.
Clutch size of Hirundines in the temperate habitats is
3-6 eggs and sometimes up to 8 eggs (Turner, 2004),
though the usual clutch size in the tropics is 2-5 eggs
(Ali and Ripley, 1987; Turner and Rose, 1989; Turner,
2004).Clutch size recorded by Dolonec (2002) was
4.56 eggs which was greater than recorded by us.
Average clutch size of Barn Swallow in the study is
3.71 with egg range 2-5 reported similar to swallow
breeding in mainland India (Hirundo rustica: 4-6
eggs, H. smithii: 3-5 eggs, H. flavicola: 3-4 eggs, H.
daurica: 3-5 eggs, H. striolata: 3-5 eggs; (Ali and
Ripley,1987). The mean clutch size of Barn Swallows
is significantly smaller to the conspecific House
Swallow Hirundo tahiticain Malaysia (mean=2.98,
range=2-5 eggs(Hails, 1984). The median clutch size
(3.5 eggs) reported for the passerines in India
aresimilar to Barn Swallow (Ali and Ripley, 1987;
Pramod and Yom-Tov, 2000).In most of hirundines
seasonal failure of clutch size is reported (Hails,
1984;Sakraouiet al. 2005; Turner, 2004), however
this could be attributed to the late breeding of young
inexperienced birds which normally lay lesser
clutches (Turner, 2004). Although, such seasonal
declines were not identified in nesting of Barn
Swallows. The results of egg dimensions including
length recorded 18.5 mm and breadth 13.6 mm of this
study agree with those of many others, Horaket al.
(1995) have shown that egg length is more variable
than breadth, Cramp et al. (1988) gives an egg length
of 19.7 mm and egg breadth 13.6 mm and Verheyen
J. Bio. & Env. Sci.
2015
38 | Shah et al.
(1967) reported egg length and breadth of 20.2 and
13.7 mm.Egg length and breadth was more recorded
byDolonec (2002)and Sakraouiet al.(2005) was also
greater in size than recorded by us.In birds, clutch
size and egg size vary with laying date (Hails,1984)
female age (Desrochers andMagrath, 1993) year
(Perrins, 1969), laying order (Murphy, 1994) food
availability (Boekelheide andAinley, 1989) female
condition (Horaketal. 1995), heritage (Noordwikjet
al. 1980) and other factors.
High hatching (90% or more) and fledgling success
(38-80%) rates are commonly reported for most
species of hirundines (Turner, 2004). The overall
nesting success of Barn Swallow 85 % in study area
calculated based on the Murray (2000) method was
slightly higher to other hirundines. Sakraouiet
al.(2005) in Annaba breeding success 70.6% which is
less than recorded by us. Predation at the nests was
reported minimal in majority of the hirundines
species studied (Earle, 1989; Jackson
andSpottiswoode, 2004; Turner, 2004). As compared
to other studies in present investigation predation
reported was minimal;3.3% of eggs and 5.5% of
hatchlings were predated by House Crow. Other
potential predators reported by other authors in
range of species were snakes (Indian Rat Snake Ptyas
mucosa), owls (unidentified species) and several
species of bats (Indian False Vampire Bat
Megadermalyra) and lizards (Gekko gecko or
Gekkostentor) for H. tahitica(Hails, 1984). Further
concentrated studies using advanced methods (Video
Surveillance Monitoring) are required to identify the
nest predators of H. rustica.
Acknowledgements
The authors shouldshow gratitude to all the people of
the Department of Zoology, Hazara University,
Department of Wildlife Management, PMAS-
UAARand others who helped us with our field work
during the study period. Corresponding author
Muhammad Awais also would like to thank Editor in
Chief for his valued comments and for improving the
manuscript.
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