ArticlePDF Available

Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus): effects of temperature, rainfall, and humidity

Authors:

Abstract and Figures

Abstract: This study was conducted on the campus of the regional department of the forestry service, encompassing 2.25 ha in Antalya city center. The area has gardens and is surrounded by trees, providing nesting and feeding opportunities for many songbird species. The study aimed to determine clutch and egg size variation, breeding success, and productivity of the House Sparrow (Passer domesticus), in terms of clutch size and breeding attempts, and to evaluate variation in temperature, rainfall, and humidity in terms of breeding attempts and years, and their possible effects on given parameters of the species. In total, 2016 eggs were laid in 393 clutches and clutch size varied from 1 to 11 eggs; the clutches most commonly contained 4-6 egg in the 3 consecutive years. Mean egg length, width, weight, volume, and sphericity index were 21.16 ± 0.03 mm, 14.99 ± 0.01 mm, 2.02 ± 0.01 g, 2.38 ± 0.01 cm3, and 71.01 ± 0.09, respectively. Breeding attempts were affected by temperature (r = 0.97 P < 0.0001) and rainfall (r = −0.84 P < 0.001). Egg length was affected by rainfall (r = 0.60 P < 0.041), humidity (r = 0.59 P < 0.044), and temperature (r = −0.81 P < 0.002), and egg volume was affected by temperature (r = −0.68 P < 0.015). This study shows that the House Sparrow population in the study area exhibited important variation in clutch and egg size, which was affected by changes in temperature, rainfall, and humidity.
Content may be subject to copyright.
255
Research Article
Turk J Zool
34 (2010) 255-266
© TÜBİTAK
doi:10.3906/zoo-0811-22
Clutch and egg size variation, and productivity of the House
Sparrow (Passer domesticus): eects of temperature, rainfall,
and humidity
Aziz ASLAN1,*, Mustafa YAVUZ2
1Akdeniz University, Faculty of Education, Department of Primary Education, 07058 Antalya - TURKEY
2Akdeniz University, Faculty of Arts and Sciences, Department of Biology, 07058 Antalya - TURKEY
Received: 28.11.2008
Abstract: is study was conducted on the campus of the regional department of the forestry service, encompassing
2.25 ha in Antalya city center. e area has gardens and is surrounded by trees, providing nesting and feeding
opportunities for many songbird species. e study aimed to determine clutch and egg size variation, breeding success,
and productivity of the House Sparrow (Passer domesticus), in terms of clutch size and breeding attempts, and to evaluate
variation in temperature, rainfall, and humidity in terms of breeding attempts and years, and their possible eects on given
parameters of the species. In total, 2016 eggs were laid in 393 clutches and clutch size varied from 1 to 11 eggs; the clutches
most commonly contained 4-6 egg in the 3 consecutive years. Mean egg length, width, weight, volume, and sphericity
index were 21.16 ± 0.03 mm, 14.99 ± 0.01 mm, 2.02 ± 0.01 g, 2.38 ± 0.01 cm3, and 71.01 ± 0.09, respectively. Breeding
attempts were aected by temperature (r = 0.97 P < 0.0001) and rainfall (r = −0.84 P < 0.001). Egg length was aected by
rainfall (r = 0.60 P < 0.041), humidity (r = 0.59 P < 0.044), and temperature (r = −0.81 P < 0.002), and egg volume was
aected by temperature (r = −0.68 P < 0.015). is study shows that the House Sparrow population in the study area
exhibited important variation in clutch and egg size, which was aected by changes in temperature, rainfall, and humidity.
Key words: House Sparrow, Passer domesticus, breeding success, clutch size
Ev Serçesi (Passer domesticus)’nin yumurta küme büyüklüğü, yumurta boyutları ve
verimliliği: sıcaklık, yağış ve nemin etkisi
Özet: Çalışma, Antalya’nın şehir merkezinde 2.25 hektarlık araziye sahip olan Orman Bölge Müdürlüğünün bahçesinde
yürütülmüştür. Çalışma alanında bulunan ve ağaçlarla çevrili olan küçük bahçeler, birçok ötücü kuş türüne yuvalanma
ve beslenme olanağı sağlar. Çalışmanın amacı, Ev Serçesi (Passer domesticus)’nin yumurta küme büyüklüğü ve yumurta
boyutlarındaki farklılıkları, üreme başarısını ve verimliliğini, yumurta küme büyüklüğü ve kuluçka dönemlerine bağlı
olarak tespit edilmesi ve ayrıca kuluçka dönemleri ve yıllar baz alınarak sıcaklık, yağış ve nem oranlarındaki değişimlerin
ve bu değişimlerin ilgili parametrelere olası etkilerinin değerlendirilmesidir. Üç yıllık çalışma sonucunda, Ev Serçesinin
393 kuluçkaya 2016 yumurta bıraktığı, yumurta küme büyüklüğünün 1-11 adet yumurta arasında değiştiği ve yaygın
olarak 4-6 yumurtalı kümelerin yapıldığı tespit edilmiştir. Yumurtaların ortalama boy, en, ağırlık, hacim ve küresel indeksi
sırasıyla 21,16 ± 0,03 mm, 14,99 ± 0,01 mm, 2,02 ± 0,01 g, 2.38 ± 0.01 cm3ve 71,01 ± 0,09 olarak hesaplanmıştır. Kuluçka
* E-mail: aaslan@akdeniz.edu.tr
Introduction
Egg size varies greatly among avian populations,
but little within individuals (Christians, 2002). Egg
size varies with laying order, date of laying, and clutch
size (Slagsvold et al., 1984; Järvinen, 1991), and
genetic, ontogenetic, and environmental factors (Potti,
1993). Variation in the size and quality of eggs can
have important long-term consequences for the
survival of offspring (Williams, 1994). Hatchability of
eggs may also be affected by their size (Pinowska et
al., 2002), especially under severe weather conditions
(Järvinen and Väisänen, 1983; Nilsson and Svensson,
1993). For example, larger eggs tend to have higher
hatching success rates (Perrins, 1996), and lead to
larger hatchlings, faster nestling growth (Hipfner and
Gaston, 1999; Pinowska et al., 2004), and more male
offspring (Mead et al., 1987). Experimental studies
have shown that, even though egg size co-varies with
parental quality and age, egg size alone can have
important effects on the quality of nestlings (Bolton,
1991; Smith and Bruun, 1998; Strysky et al., 1999).
Ecological factors, such as food availability,
predator pressure, and weather, are well known to
influence the life history and reproductive success of
a species (Lack, 1968). In the last decade much effort
was expended to investigate the effects of climatic
factors on reproduction, survival, and population
dynamics (Yom-Tov, 2001; Lindström and Kokko,
2002; Laaksonen et al., 2006). Many researchers have
analyzed the effect of ambient temperature on egg size
and reproductive performance in birds (Järvinen and
Ylimaunu, 1986; Järvinen, 1994; Perrins, 1996;
Stevenson and Bryant, 2000; Barkowska et al., 2003;
Saino et al., 2004). The relationship between rainfall
and reproductive performance is thought to be due to
the positive effect of rainfall on food availability for
adults and/or chicks (Boag and Grant, 1984; Zann et
al., 1996). Recently, several studies that tested the
effects of rainfall-related factors on bird breeding
performance were based on testing specific
hypotheses rather than on looking for correlations
(Morrison and Bolger, 2002; Coe and Rotenberry,
2003; Bolger et al., 2005). For example, rainfall could
act as a proximate factor triggering the beginning of
specific physiological processes, such as sex hormone
production or gonad growth (Leitner et al., 2003; Hau
et al., 2004; Fulgione et al., 2005). In comparison to
temperature and rainfall, the influences of humidity
on clutch size, egg size, and other breeding parameters
are less known.
The aims of the present study were to determine
(1) the variation in clutch and egg size, breeding
success, and productivity, (2) the correlations between
egg dimensions, breeding attempts, and clutch size, as
well as between breeding attempts and productivity,
(3) the variation in temperature, rainfall, and
humidity between years and breeding seasons, and (4)
the effects of climatic factors on clutch size, egg size,
breeding success, and productivity of the House
Sparrow for 3 consecutive years.
Materials and methods
This study was conducted from 2001 to 2003 on
the campus of the regional department of the forestry
service covering an area of 2.25 ha located in the city
center (36°5300′′N, 30°4200′′E) of Antalya, Turkey
(Figure 1). Sixty-two 14 × 20 × 22-cm wooden nest-
boxes with 1.5-cm thick walls and a 3.5-cm entrance
hole were placed in trees and monitored for 3
breeding seasons. In order to determine the number
of breeding attempts by individual sparrows, 24 adult
females were tagged with a unique combination of 2-
or 3-colored plastic spiral rings in 2003. Nineteen of
the tagged females (79.1%) used the nest-boxes and
the number of breeding attempts did not differ
between tagged and non-tagged females during the 3
years (Aslan et al., 2005). The nest-boxes were
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
256
dönemlerinin sıcaklık (r = 0,97 P < 0,0001) ve yağış (r = −0,84 P < 0,001); yumurta boyunun yağış (r = 0,60 P < 0,041),
nem (r = 0,59 P < 0,044) ve sıcaklık (r = −0,81 P < 0,002); ve yumurta hacminin sıcaklık (r = −0,68 P < 0,015)
değişimlerinden etkilendiği belirlenmiştir. Bu çalışma ile incelenen Ev Serçesi populasyonunun yumurta küme
büyüklüğünün ve yumurta boyutlarının önemli farklılıklar gösterdiği ve bu parametrelerin sıcaklık, yağış ve nemdeki
değişimlerden etkilendiği ortaya konulmuştur.
Anahtar sözcükler: Ev Serçesi, Passer domesticus, üreme başarısı, yumurta küme büyüklüğü
checked twice daily (0800-1000 and 1600-1800) to
determine clutch initiation date, the number of
breeding attempts, egg size (length, width, weight,
volume, and sphericity index), clutch size (number of
eggs in the clutch), and breeding parameters
(unhatched and hatched eggs, dead nestlings, and
fledglings). The exact dates of the onset and
termination of breeding seasons were previously
evaluated in Aslan et al. (2005) and, therefore, the
timing of breeding is not discussed in this report.
Eggs were measured only in completed clutches
and were weighed to the nearest 0.5 g in a plastic bag
with a 5-g Pesola spring scale (accuracy ±0.01 g) in a
plastic tube that kept out wind. Length and width of
each egg were recorded with digital calipers to the
nearest 0.05 mm. We calculated egg volume using
Hoyts (1979) equation (V = 0.5 × L × B2), where V is
egg volume (cm3), L is egg length, and B is egg width
(both in mm). The sphericity index was calculated as
100 × B/L (Winkel, 1970). Mean egg size was
calculated by clutch size and by successive breeding
attempts. Values of breeding parameters by breeding
attempt and clutch size allowed us to estimate
breeding success and productivity (Appendix).
Breeding success was estimated for each clutch size
and breeding attempt was estimated with 2 different
methods. With the first method, breeding success was
defined as the number of all successful clutches with
at least 1 fledgling per specific clutch size (BS1 = 100 ×
FL/CS, where FL is the total number of fledglings in
each clutch size and CS is the total number of eggs per
clutch with at least 1 fledgling). With the second
method, breeding success was defined as the number
of clutches with at least 1 fledgling (BS2 = 100 × FL/H,
where H is the total number of eggs hatched with at
least 1 fledgling (Bairlein, 1996; Kiziroğlu, 2008,
2009)). Productivity was calculated for BS1 as 100 ×
H/Htotal and for BS2as 100 × FL/FLtotal for each clutch
A. ASLAN, M. YAVUZ
257
Arboretum
Antalya
TURKEY
0 200 m
N
2.25 ha
Building Green Area Nest
Figure 1. Geographic location of the study area.
size and breeding attempt. Values of climatic factors
(temperature, precipitation, and humidity) were
obtained from the Antalya Meteorological Station,
which is about 5 km from study area, and are
presented in Table 1.
Statistical analysis
Data were analyzed using SPSS v.11.0 for
Windows. Variation in climatic factors between
breeding seasons (from the beginning of April to the
end of July) was determined with ANOVA. Variations
in egg dimensions and breeding parameters for each
clutch size and breeding attempts were determined
using ANOVA, and differences and similarities
between egg dimensions and breeding parameters for
each clutch size and breeding attempts were compared
using Duncans multiple comparison analysis. Groups
represented by the same letter are significantly similar
and the others are significantly different. Those
represented by more than 1 letter are similar to groups
represented by the same letter. Furthermore, breeding
success was compared between clutch sizes and
breeding attempts using ANOVA. Correlations
between egg parameters and climatic factors were
determined with Pearson’s correlation test.
Significance was set at P < 0.05 for all statistical tests.
For each test, degrees of freedom (df) and significance
levels are reported. All results are presented as mean
± standard error (SE).
Results
Clutch and egg size
Clutch size varied from 1 to 11 eggs; however, only
2-8 eggs per clutch were found in all years. One-egg
clutches (n = 3 eggs) were abandoned by females and
none of them hatched; therefore, these clutches were
included in the statistical analyses to determine
differences between breeding parameters, but were
excluded from calculations on breeding success and
productivity due to hatching failure. Clutches of 9-11
eggs (n = 60 eggs) were laid by more than 1 female
and were added to the statistical analysis because of
hatching. In total, 153 (38.9%), 121 (30.8%), 91
(23.2%), and 28 (7.1%) clutches were laid in the 1st,
2nd, 3rd, and 4th attempts, respectively (Figure 2).
Most clutches contained 4-6 eggs and the most
common was 5 eggs. Three-year mean clutch size was
5.17 ± 0.07 eggs and differences in mean clutch size
between each breeding attempt were statistically
significant (F3-389 = 20.082, P < 0.0001). Mean clutch
size and numbers decreased from the first 2 to the last
2 attempts (Figure 3).
In all, 1941 (75 eggs could not be measured) eggs
from 378 clutches were measured, and egg length,
width, weight, volume, and sphericity index were
determined as 21.16 ± 0.03 mm, 14.99 ± 0.01 mm,
2.02 ± 0.01 g, 2.38 ± 0.01 cm3, and 71.01 ± 0.09,
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
258
Table 1. Mean monthly temperature, rainfall, and humidity in the study area.
Months
Climatic factors Year
JFMAMJ JASOND
2001 11.4 11.5 15.9 16.8 21.7 25.6 28.5 28.7 25.6 21.0 14.2 11.1
Temperature (°C) 2002 9.1 12.5 14.3 15.9 21.0 26.6 29.3 28.7 24.3 20.6 15.6 10.0
2003 12.7 8.9 11.7 15.8 23.1 26.5 29.7 29.6 24.5 20.8 15.5 11.5
2001 217.7 96.2 9.5 97.3 62.0 - 0.4 - 2.0 16.3 907.2 483.2
Rain (mm) 2002 52.0 22.3 48.8 118.0 9.9 0.1 20.4 1.3 5.5 40.8 68.1 584.4
2003 368.0 122.7 398.8 128.5 84.1 10.5 - - 8.0 21.6 53.8 577.6
2001 67.5 59.8 66.6 67.8 61.0 63.4 69.1 68.6 67.7 55.5 67.9 71.6
Humidity (%) 2002 56.0 63.2 71.3 78.8 73.5 62.7 63.8 63.1 69.9 58.2 65.1 64.3
2003 73.1 51.5 60.3 66.5 57.7 57.3 50.2 54.3 58.1 62.7 61.4 64.9
respectively. The size of eggs differed between
breeding attempts (Table 2); egg length, width,
weight, and volume values for the first 2 attempts
were higher and clearly decreased in the last 2
attempts; in contrast, sphericity index values
increased from the first to last breeding attempt.
Egg dimensions also differed between clutch sizes
(Table 3). Clutch size (r = −0.30, P < 0.0001), and
egg length (r = −0.20, P < 0.0001), width (r = −0.12,
P < 0.0001), weight (r = −0.08, P < 0.0001), and
volume (r = −0.20, P < 0.0001) were negatively
correlated with breeding attempt, while the
sphericity index was positively correlated with
breeding attempt (r = 0.12, P < 0.0001). Moreover,
egg length (r = 0.07, P < 0.003), width (r = 0.09, P
< 0.0001), and volume (r = 0.10, P < 0.0001) were
positively correlated with clutch size.
Differences in temperature and rainfall between
years were not statistically significant (P > 0.05),
whereas differences in humidity were significant (F3-
12 = 4.517, P < 0.024). Differences in temperature and
rainfall between breeding attempts were statistically
significant (temperature: F3-12 = 159.121, P < 0.0001;
rainfall: F3-12 = 14.338, P < 0.0001), while no differences
in humidity were observed (P > 0.05). The number of
breeding attempts was positively correlated with
temperature (r = 0.97, P < 0.0001), but negatively
correlated with rainfall (r = −0.84, P < 0.001). Egg
length was positively correlated with rainfall (r = 0.60,
P < 0.041) and humidity (r = 0.59, P<0.044), while it
was negatively correlated with temperature (r = −0.81,
P < 0.002). Furthermore, there was a negative
correlation (r = −0.68, P < 0.015) between temperature
and egg volume.
A. ASLAN, M. YAVUZ
259
60
50
40
30
20
10
0
1st
2nd
3rd
4th
Number of cluthes
1 2 3 4 5 6 7 8 9 10 11
Clutch Size
Figure 2. Frequency distribution of clutch size based on breeding
attempts.
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
Mean clutch size
1 2 3 4
Breeding attempts
cc
b
a
Figure 3. Mean clutch size of breeding attempts (letters denoting
differences are given below the error bars).
Table 2. Differences and similarities in egg size between breeding attempts.
Breeding Attempts
Egg sizes ANOVA
1st 2nd 3rd 4th
Length 21.33 ± 0.04 c 21.24 ± 0.04 c 20.85 ± 0.06 b 20.48 ± 0.11 a F3-1937: 30.58, P < 0.0001
Width 15.00 ± 0.02 c 15.08 ± 0.02 c 14.87 ± 0.03 b 14.73 ± 0.05 a F3-1937: 20.15, P < 0.0001
Weight 2.03 ± 0.01 bc 2.04 ± 0.01 c 1.99 ± 0.02 b 1.92 ± 0.03 a F3-1937: 8.04, P < 0.0001
Volume 2.41 ± 0.01 c 2.42 ± 0.01 c 2.31 ± 0.01 b 2.23 ± 0.02 a F3-1937: 37.79, P < 0.0001
Sph. Index 70.48 ± 0.13 a 71.15 ± 0.17 ab 71.53 ± 0.21 bc 72.11 ± 0.45 c F3-1937: 9.37, P < 0.0001
n 788 634 423 96
n: Total number of eggs measured.
Breeding success and productivity
When data for the 3-year period were pooled, the
mean number of unhatched, hatched, dead nestlings,
and fledglings per clutch was 2.28 ± 0.09, 2.85 ± 0.09,
1.05 ± 0.06, and 1.80 ± 0.07, respectively, and differed
between clutch sizes (Table 4). Analysis showed that
5-egg clutches and the first breeding attempt were the
most productive.
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
260
Table 3. Egg size according to clutch size.
Clutch size n Length (mm) Width (mm) Weight (g) Sphericity index Volume (cm3)
1 3 20.74 ± 0.27 ab 14.87 ± 0.10 ab 2.09 ± 0.08 b 71.72 ± 0.81 ab 2.30 ± 0.05 a
2 14 20.65 ± 0.30 ab 14.82 ± 0.18 a 2.02 ± 0.05 b 71.95 ± 1.38 ab 2.27 ± 0.06 a
3 63 20.98 ± 0.16 ab 14.86 ± 0.09 ab 1.98 ± 0.05 b 71.01 ± 0.55 ab 2.33 ± 0.04 ab
4 324 20.85 ± 0.07 ab 14.90 ± 0.03 ab 2.00 ± 0.01 b 71.67 ± 0.23 ab 2.32 ± 0.01 ab
5 625 21.29 ± 0.05 bc 14.99 ± 0.02 ab 2.01 ± 0.01 b 70.58 ± 0.16 ab 2.39 ± 0.01 ab
6 588 21.22 ± 0.04 abc 15.03 ± 0.02 ab 2.06 ± 0.01 b 70.97 ± 0.16 ab 2.40 ± 0.01 ab
7 224 21.11 ± 0.07 abc 14.97 ± 0.04 ab 2.01 ± 0.02 b 71.11 ± 0.30 ab 2.37 ± 0.01 ab
8 40 21.24 ± 0.18 bc 15.20 ± 0.08 bc 1.95 ± 0.02 b 71.73 ± 0.49 ab 2.46 ± 0.04 bc
9 18 21.30 ± 0.17 bc 14.78 ± 0.12 a 1.98 ± 0.02 b 69.51 ± 0.96 a 2.33 ± 0.03 ab
10 20 20.52 ± 0.24 a 14.92 ± 0.09 ab 1.59 ± 0.08 a 72.97 ± 1.19 b 2.28 ± 0.02 a
11 22 21.77 ± 0.19 c 15.36 ± 0.07 c 2.32 ± 0.07 c 70.63 ± 0.44 ab 2.57 ± 0.04 c
Total 1941 21.16 ± 0.03 14.99 ± 0.01 2.02 ± 0.01 71.01 ± 0.09 2.38 ± 0.01
ANOVA F10-1930=27.38, F10-1930=3.83, F10-1930=10.74, F10-1930=2.52, F10-1930=6.41,
P < 0.0001 P < 0.0001 P < 0.0001 P < 0.005 P < 0.0001
n: Total number of eggs measured for each clutch size.
Table 4. Breeding parameters according to clutch size.
Clutch size n Unhatched eggs Hatched eggs Dead nestlings Fledglings
1 3 1.00 ± 0.00 a 0.00 a 0.00 a 0.00 a
2 7 1.43 ± 0.20 ab 0.57 ± 0.20 ab 0.00 ± 0.00 a 0.57 ± 0.20 ab
3 21 1.45 ± 0.26 ab 1.55 ± 0.26 abc 0.41 ± 0.17 ab 1.14 ± 0.22 ab
4 86 1.66 ± 0.15 ab 2.34 ± 0.15 abcd 0.86 ± 0.12 abc 1.48 ± 0.13 abc
5 130 2.24 ± 0.14 ab 2.76 ± 0.14 bcde 0.95 ± 0.11 abc 1.81 ± 0.12 abc
6 103 2.67 ± 0.19 ab 3.33 ± 0.19 cdef 1.30 ± 0.14 abc 2.03 ± 0.16 abc
7 32 2.72 ± 0.35 ab 4.28 ± 0.35 def 1.69 ± 0.24 abc 2.59 ± 0.27 bc
8 5 3.00 ± 0.00 ab 5.00 ± 0.00 ef 2.60 ± 0.51 c 2.40 ± 0.51 bc
9 2 3.50 ± 0.50 b 5.50 ± 0.50 f 2.00 ± 1.00 bc 3.50 ± 0.50 c
10 2 8.00 ± 2.00 c 2.00 ± 2.00 abcd 0.50 ± 0.50 ab 1.50 ± 1.50 abc
11 2 8.50 ± 2.50 c 2.50 ± 2.50 bcd 0.00 ± 0.00 a 2.50 ± 2.50 bc
Total 393 2.28 ± 0.09 2.85 ± 0.09 1.05 ± 0.06 1.80 ± 0.07
ANOVA F10-382 = 8.96, F10-382 = 8.20, F10-382 = 4.08, F10-382 = 3.72,
P < 0.0001 P < 0.0001 P < 0.0001 P < 0.0001
n: Total number of each clutch size.
There were no significant differences between the
breeding success of clutch sizes and breeding
attempts, according to ANOVA (BS1: F7-378 = 1.99, P >
0.436 and BS2: F7-306 = 1.42, P > 0.198) (Figure 4A-D).
In contrast, BS2(Figure 4 B) for clutch size, and BS1
and BS2for breeding attempts differed according to
Duncans test (Figure 4C-D). In addition, clutch size
correlated with BS1 (r = −0.17, P < 0.005) and BS2(r =
A. ASLAN, M. YAVUZ
261
70
60
50
40
30
20
60
55
50
45
40
80
75
70
65
60
55
110
100
90
80
70
60
50
40
30
123 4
01 2 34
567 118910
Clutch Size
Bs1 (%)Bs2 (%)
Bs2 (%)
Bs1 (%)
123 4 56 7 118910
Clutch Size
Number of breeding attempts
01234
Number of breeding attempts
A
B
CD
34.2
20.1
6.4
Figure 4. Breeding success and productivity according to clutch size (A and B) and breeding attempts (C and D) (productivity of each
clutch size and breeding attempt as a percentage, and letters denoting differences in breeding success are given above and
below the error bars).
−0.18, P < 0.003), but no relationships were observed
between breeding success and breeding attempts.
Productivity of breeding attempts clearly decreased
from the 1st to 4th attempts (r = −0.988, P < 0.0001 for
BS1and r = −0.981, P < 0.0001 for BS2).
Discussion
In the House Sparrow, clutch size usually ranges
from 2 to 7 eggs (Haartmann, 1969; Balat, 1974). In
Iraq and Israel, clutch size varies from 2 to 7 and from
3 to 7 eggs, and the modal clutch size and most
successful clutch size is 5 and 6 eggs per clutch,
respectively (Al-Dabbagh and Jiad, 1988; Singer and
Yom-Tov, 1988). In contrast, Seel (1968) reported that
clutches of 4 eggs are the most common and the most
successful in England. According to Erdoğan and
Kiziroğlu (1995), and Sıkı (1992), clutch size in
Turkey ranges from 3-6 and 3-7 eggs, respectively, and
the most common and most successful clutch size was
5 eggs per clutch. In the present study, clutch size
ranged from 1 to 11 eggs and clutches of 4-6 eggs were
common. The most common and most successful
clutch size was 5 eggs. These results support Murphy’s
claim (1978) that females lay fewer eggs than their
maximum reproductive capacity allows. Jones and
Ward (1976) also suggested that females inherit the
ability to vary clutch size within a certain range and
that the upper limit of clutch size is firmly fixed.
Nonetheless, as reported by Charnov and Krebs
(1974), there might be a trade-off between a females
longevity and her level of reproduction in a particular
time. Seasonal variation in clutch size has been
reported by Seel (1968) and Murphy (1978), as clutch
size is variable between breeding attempts. The
differences in seasonal clutch size observed in the
present study seem to support this variation. We
observed that mean clutch size was the highest in the
first 2 breeding attempts, and decreased slightly with
the 3rd and 4th breeding attempts. Lack (1966)
reported that seasonal changes in clutch size can be
adaptive; larger clutches should be laid when
conditions for raising young are most suitable. Our
results support this hypothesis, as the first 2 clutches,
which were larger, occurred when conditions in the
study area were suitable. A decrease in food supplies
and variation in climatic conditions result in a
decrease in breeding performance (Lack, 1968). The
seasonal variation in food supplies during the
breeding period in the study area is also thought to be
the reason for clutch and egg size differences between
breeding attempts.
For several bird species temperature close to the
upper critical level could have a negative effect on egg
size (Lorenz and Almquist, 1936; Kendeigh, 1941;
Mueller, 1961; Clark and Amin, 1965). In the present
study, 1st and 2nd breeding attempts with larger
corresponding clutches were recorded in April and
May, whereas the 3rd and 4th breeding attempts with
smaller clutches were recorded in June and July (Aslan
et al., 2005). Mean temperature during these months
ranged from 16.2 °C in May to 29.2 °C July (Table 1).
This suggests that the more suitable temperatures
ranged from 16 to 22°C, and that higher temperatures
had negative effects on both clutch size and egg size.
Productivity of the studied population also declined
as temperature increased. It was observed that an
increase in temperature resulted in an increase in the
number of breeding attempts; however, temperature
had a negative effect on clutch size and, consequently,
clutch size and egg size decreased from the first to last
2 breeding attempts. In contrast, rainfall had a positive
effect on the number of breeding attempts. In
addition, egg length was positively affected, not only
by rainfall, but also by an increase in humidity.
Rainfall rates, as opposed to humidity, during the
breeding period were significantly different and
clearly decreased from April to August.
It was reported that the production of eggs by
passerines is energetically expensive (Ricklefs, 1974;
Murphy, 1978; Pinowska, 1979; Järvinen and
Väisanen, 1984), but others reported that it is not
(Krementz and Ankney, 1986; Ward, 1996). There was
a positive correlation between clutch size and egg size
in the present study, suggesting that larger clutches
contain larger eggs, which must require much more
energy and should be expensive for the females.
Lack’s hypothesis (1954, 1966) implies that the
modal clutch size is more productive than other clutch
sizes, whereas Klomp (1970), and Jones and Ward
(1976) argued that birds are capable of laying clutches
that vary in size and a modal clutch size can be smaller
than the most productive one. The negative
correlation between clutch size and breeding success
observed in the present study supports Lack’s
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
262
hypothesis (1954, 1966) that larger clutch sizes are not
necessarily associated with improved breeding success
and that modal clutch size is more important for
breeding success. Clutch size, the number of
unhatched eggs, hatched eggs, dead nestlings, and
fledglings are the most important patterns for
determining breeding success and productivity in
birds (Deckert, 1969; Kiziroğlu, 1981).In the present
study, means of breeding parameters based on clutch
size were significantly different, whereas no
differences were observed between breeding successes
using ANOVA. Nonetheless, Duncan’s test results did
show significant differences between BS2. Despite
differences in breeding patterns, the effect of climatic
conditions, decreases in food supplies, and reduced
breeding desire of females during the breeding period,
no differences were observed between the breeding
successes of breeding attempts by ANOVA, but
according to Duncan’s test results, the differences were
significant. Clutches of 4-6 eggs were the most
productive and productivity of the breeding attempts
decreased from the first to the last breeding attempt
during the breeding season. These results show that
the House Sparrow had consistent breeding success
and productivity during the breeding season in the
study area.
In conclusion, the results obtained in the present
study and our previous work (Aslan et al., 2005) show
that nesting House Sparrows have a flexible response
to changes in environmental conditions. Overall,
temperature and rainfall had a greater effect on clutch
size, egg size, and reproductive performance than did
humidity. It is thought that data from this study and
our previous study could provide a basis for
monitoring future changes and to test specific
hypotheses concerning the breeding ecology of the
House Sparrow in the study area.
Acknowledgements
This study was supported by the Scientific
Research Projects Unit of Akdeniz University. We
thank D. Summers-Smith and J. Pinowski for their
valuable comments on the draft manuscript. We also
wish to thank the numerous students that helped
collect data during the study.
A. ASLAN, M. YAVUZ
263
Al-Dabbagh, K.Y. and Jiad, J.H. 1988. The breeding biology of the
House Sparrow in central Iraq. Intern. Stud. Sparrows 15: 22-43.
Aslan, A., Yavuz M. and Erdoğan, A. 2005. A comparative study of
the breeding ecology of the House Sparrow (Passer domesticus
L.): timing of breeding and breeding success. Isr. J. Zool. 51:
361-380.
Bairlein, F. 1996. Ökologie der Vögel. Fischer, Stuttgart
Balat, F. 1974. Gelegegrosse und Brutverlust des Haussperlings, Passer
domesticus L. İn Mittelmahren. Zool. Listy. 23: 229-240.
Barkowska, M., Pinowski, J. and Pinowska, B. 2003. The effect of
trends in ambient temperature on egg volume in the tree
sparrow Passer montanus. Acta Ornithol. 38: 5-13.
Boag, P.T. and Grant, P.R. 1984. Darwin’s finches (Geospiza) on Isla
Daphne Major, Galapagos: breeding and feeding ecology in a
climatically variable environment. Ecol. Monogr. 54: 463-489.
Bolger, D.T., Patten, M.A. and Bostock, D.C. 2005. Avian reproductive
failure in response to an extreme climatic event. Oecologia 142:
398-406.
Bolton, M. 1991. Determinants of chick survival in the lesser black-
backed gull: relative contributions of egg size and parental
quality. J. Anim. Ecol. 60: 949-960.
Charnov, E.L. and Krebs, J.R. 1974. On clutch size and fitness. Ibis
116: 217-219.
Christians, J.K. 2002. Avian egg size: variation within species and
inflexibility within individuals. Biol. Rev. 77: 1-26.
Clark, C.E. and Amin, M. 1965. The adaptability of chickens to
various temperatures. Poultry Sci. 44: 1003-1009.
Coe, S.J. and Rotenberry, J.T. 2003. Water availability affects clutch
size in a desert sparrow. Ecology 84: 3240-3249.
Deckert, G. 1969. Zur Ethologie und Okologie des Haussperlings.
Beitr. Vogelk. 15:1-84.
Erdoğan, A. and Kiziroğlu, İ. 1995. Brutbiologische Untersuchungen
am Feld-Passer montanus und P. domesticus in Beytepe/Ankara.
Orn. Verh. 25: 211-218.
References
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
264
Fulgione, D., Rippa, D., Caliendo, M.F. and Milone, M. 2005. Seasonal
Breeding In The Italian Sparrow: Plasma Androgen Levels And
Spermatogenesis. Isr. J. Zool. 51: 229-240.
Haartmann, L.V. 1969. The Nesting Habits of Finnish Birds I.
Passeriformes. Commentationes Biologicae Societal
Scientiarum Fennica 32: 1-187.
Hau, M., Wikelski, M., Gwinner, H. and Gwinner, E. 2004. Timing of
reproduction in a Darwins finch: temporal opportunism under
spatial constraints. Oikos 106: 489-500.
Hipfner, J.M. and Gaston, A.J. 1999. The relationship between egg size
and post-hatching development in the thick-billed murre.
Ecology 80: 1289-1297.
Hoyt, D.F. 1979. Practical methods for estimating volume and fresh
weight of bird eggs. Auk 96: 73-77.
Järvinen, A. and Väisänen, R.A. 1983. Egg size and related
reproductive traits in a southern passerine Ficedula hypoleuca
breeding in an extreme northern environment. Ornis Scand. 14:
253-262.
Järvinen, A. and Väisänen, R.A. 1984. Reproduction of Pied
Flycatchers (Ficedula hypoleuca) in good and bad breeding
seasons in a northern marginal area. Auk 101: 439-450.
Järvinen, A. 1991. Proximate factors affecting egg mass in subarctic
hole-nesting passerines. Ornis Fenn. 68: 99-104.
Järvinen, A. 1994. Global warming and egg size of birds. Ecography
17: 108-110.
Järvinen, A. and Yliamunu, Y. 1986. Intraclutch egg-size variation in
birds: physiological responses of individuals to fluctuations of
environmental conditions. Auk 103: 235-237.
Jones, D.J. and Ward, P. 1976. The level of reserve protein as the
proximate factor controlling the timing of breeding and clutch
size in the Red-billed Quelea quelea. Ibis 118: 547-573.
Kendeigh, S.C. 1941. Length of day and energy requirements for
gonad development and egg laying. Ecology 22: 237-248.
Kiziroğlu, İ. 1981. Ankara Beynam Ormanı’ndaki baştankara, Parus
L., cinsi (Aves) türlerinin biyoloji, ekoloji ve davranışları ile ilgili
araştırmalar. TÜBİTAK, TBAG-371, 216 pp.
Kiziroğlu, İ. 2008. Türkiye Kuşları Kırmnızı Listesi. Red Data Book
of the Turkish Birds. Ankamat Mar., Ankara, 168 pp.
Kiziroğlu, İ. 2009. Kürkiye Kuşları Cep Kitabı. The Pocketbook of the
Turkish birds. (in press).
Klomp, H. 1970. The determination of clutch size in birds. Ardea 58:
1-24.
Krementz, D.G. and Ankney, C.D. 1986. Bioenergetics of egg
production by female the House Sparrows. Auk 103: 299-305.
Laaksonen, T., Ahola, M., Eeva, T., Väisänen, R.A. and Lehikoinen,
E. 2006. Climate change, migratory connectivity and changes
in laying date and clutch size of the pied flycatcher. Oikos 114:
277-290.
Lack, D. 1954. The natural regulation of animal numbers. Oxford:
Clarendon Press.
Lack, D. 1966. Population studies of birds. Oxford: Clarendon Press.
Lack, D. 1968. Ecological adaptations for breeding in birds. Chapman
and Hall, London.
Leitner, S., Van’t Hof, T.J. and Gahr, M. 2003. Flexible reproduction in
wild canariesis independent of photoperiod. Gen. Compar.
Endocrinol. 130: 102-108.
Lindström, J. and Kokko, H. 2002. Cohort effects and population
dynamics. Ecol. Lett. 5: 338-344.
Lorenz, F.W. and Almquist, H.J. 1936. Seasonal variations in egg
quality. Poultry Sci. 15: 14-18.
Mead, P.S., Morton, M.L. and Fish, B.E. 1987. Sexual dimorphism in
egg size and implications regarding facultative manipulation of
sex in Mountain White-Crowned Sparrows. Condor, 89/4: 798-
803.
Morrison, S.A. and Bolger, D.T. 2002. Variation in a sparrow’s
reproductive success with rainfall: food and predator-mediated
processes. Oecologia 133: 315-324.
Mueller, W.J. 1961. The effect of constant and fluctuating
environmental temperatures on the biological performance of
laying pullets. Poultry Sci. 40: 1562-1571.
Murphy, E.C. 1978. Seasonal variation in reproductive output of the
House Sparrow: The determination of clutch size. Ecology 59:
1189-1199.
Nilsson, J.A. and Svensson, E. 1993. Causes and consequences of egg
mass variation between and within blue tit clutches. J. Zool.
Lond. 230: 469-481.
Perrins, C.M. 1996. Eggs, egg formation and the timing of breeding.
Ibis 138 (supplement): 2-15.
Pinowska, B. 1979. The effect of energy and building resources of
females on the production of the House Sparrow (Passer
domesticus L.) populations. Ekol. Pol. 27: 363-396.
Pinowska, B., Barkowska, M., Pinowski, J., Bartha, A., Hahm, K.H.
and Lebedeva, N. 2002. Influence of temperature on Tree
Sparrow Passer montanus egg mass according to laying
sequence. Intern. Stud. Sparrows 29: 33-47
Pinowska, B., Barkowska, M., Pinowski, J., Bartha, A., Hahm, K.H.
and Lebedeva, N. 2004. The effect of egg size on growth and
survival of the Tree Sparrow Passer montanus nestlings. Acta
Ornithol. 39: 121-135.
Potti, J. 1993. Environmental, ontogenetic and genetic variation in egg
size of Pied Flycatchers. Can. J. Zool. 71: 1534-1542.
Ricklefs, R.E. 1974. Energetics of reproduction in birds. In: Paynter
RA Avian Energetics. Nuttall Ornithological Club, Cambridge,
Massachusetts, pp 152-292.
Saino, N., Romano, M., Ambrosini, R., Ferrari, R.P. and Moller, A.P.
2004. Timing of reproduction and egg quality covary with
temperature in the insectivorous Barn Swallow, Hirundo rustica.
Functional Ecology 18: 50-57.
A. ASLAN, M. YAVUZ
265
Seel, D.C. 1968. Clutch size, incubation and hatching success in the
House Sparrow and tree sparrow Passer spp. at Oxford. Ibis 110:
270-282.
Sıkı, M. 1992. Ev Serçesi (Passer domesticus)’nin üreme biyolojisi
üzerine araştırmalar. Doğa – Tr. J. of Zoology 16: 243-247.
Singer, R. and Yom-Tov, Y. 1988. The breeding biology of the House
Sparrow Passer domesticus in Israel. Ornis Scand. 19: 139-144.
Slagsvold, T., Sandvik, J., Rofstad, G., Lorentsen, Ö. and Husby, M.
1984. On the adaptive value of intraclutch egg size variation in
birds. Auk 101: 685-697.
Smith, H.G. and Bruun, M. 1998. The effect of egg size and habitat
on starling nestling growth and survival. Oecologia 115: 59-63.
Stevenson, I.R. and Bryant, D.M. 2000. Climate change and
constraints on breeding. Nature 406: 366-367.
Strysky, J.D., Eckerle, K.P. and Thompson, C.F. 1999. Fitness-related
consequences of egg mass in nestling house wrens. Proc. R. Soc.
B 266: 1253-1258.
Ward, S. 1996. Energy expenditure of female Barn Swallows Hirundo
rustica during egg formation. Physiol. Zool. 69: 930-951.
Williams, T.D. 1994. Intraspecific variation in egg size and egg
composition in birds: effect of offspring fitness. Biol. Rev. 68:
35-39.
Winkel, W. 1970. Hinweise zur Art und Altersbestimmung von
nestlingen, Höhlenbrüten der Vogelarten anhand ihrer
körperentwicklung. Vogelwelt 91: 52-59.
Yom-Tov, Y. 2001. Global warming and body mass decline in Israeli
passerine birds. Proc. R. Soc. Lond. B 268: 947-952.
Zann, R.A., Morton, S.R., Jones, K.R. and Burley, N.T. 1996. The
timing of breeding by zebra finches in relation to rainfall in
central Australia. Emu 95: 208-222.
Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus):
eects of temperature, rainfall, and humidity
266
Appendix. Breeding parameter values according to breeding attempt, clutch size, and year.
Breeding Clutch n *n Unhatched Hatched Dead Fledglings
attempts size eggs eggs nestlings
I2122---
3515 7 8 1 7
42392 37 5525 30
5 57 285 140 145 56 89
6 48 288 142 146 49 97
71391 28 6324 39
8 2 16 6 10 5 5
919 4 5 1 4
10 1 10 6 4 1 3
11 2 22 17 5 - 5
Total 153 830 389 441 162 279
II 2 1 2 1 1 - 1
339 6 3 2 1
42288 43 4517 28
5 35 175 65 110 31 79
6 41 246 99 147 64 83
7 16 112 45 67 27 40
818 3 5 4 1
919 3 6 3 3
10 1 10 10 - - -
Total 121 659 275 384 148 236
III 1 2 2 2 - - -
248 6 2 - 2
3 7 21 14 7 1 6
4 29 116 47 69 22 47
5 30 150 70 80 28 52
61484 34 5021 29
7 3 21 14 7 3 4
8 2 16 6 10 4 6
Total 91 418 193 225 79 146
IV 1 1 1 1 - - -
212 1 1 - 1
3 6 18 5 13 2 11
41248 18 30 9 21
5 8 40 12 28 13 15
Total 28 109 37 72 24 48
Total 1 3 3 3 - - -
2 7 14 10 4 - 4
32163 29 34 9 25
4 86 344 145 199 73 126
5 130 650 290 360 125 235
6 103 618 275 343 134 209
7 32 224 87 137 54 83
8 5 40 15 25 13 12
9 2 18 7 11 4 7
10 2 20 16 4 1 3
11 2 22 17 5 - 5
Total 393 2016 894 1122 413 709
n: Total number of each clutch size; *n: total number of eggs for each clutch size.
... In the semi-arid region such as our study area, precipitation is strongly seasonal and often concentrated in one portion of the year. Thus, rainfall deficiency certainly has a negative effect on ground vegetation and associated insects (Wolda 1978) that female martin rely on to produce clutches (Aslan and Yavuz 2010). Furthermore, by testing some metabolic mechanisms in passerines, it was shown that the beginning of some specific physiological processes could be triggered by rainfall (Leitner et al. 2003;Hau et al. 2004;Fulgione et al. 2005). ...
... We observed that mean clutch size was higher in humid areas and decreased slightly when local weather conditions became more arid. This finding is in concordance with clutch size patterns for many bird species when number of eggs per nest was negatively affected by critical level of temperature and positively correlated with rainfall rates (Aslan and Yavuz 2010). As well as direct effects of temperature increase, clutch size can also be affected indirectly by other constraints of aridity. ...
Article
The Mediterranean climate of North Africa encompasses an interesting variety of sub-climates, from humid and sub-humid to semi-arid and arid. Such variability may provide vital insights into mechanisms that drive species distribution and offered us an ideal opportunity to test phenotypic variations along gradients. We aim in this study to investigate the breeding behaviour of house martin Delichon urbica (Linnaeus, 1758) populations along regional climatic gradients in north-eastern Algeria. During two consecutive breeding seasons (2016–2017), nine field sites (328 active nests) belonging to three different sub-climates: humid, sub-humid, and semi-arid were surveyed regularly from March to August. We used generalized linear models to test the relevance of local climate and several ecological variables on laying reproductive output. Laying dates were positively correlated with climate condition (GOF = 0.42), the semi-arid climate creating appropriate conditions for advancing the laying process, whereas sub-humid and humid climate delayed it. Clutch-size and number of chicks hatched per nest were affected by local climate conditions; they were greater in humid areas than in sub-humid and semi-arid ones. The other non-climatic variables as brood order, laying date, distance to fields, and distance to water were not significant. The spatial analysis around nest sites of house martins also showed that dense vegetation cover and reduced urbanization levels may be potential predictors of breeding behaviour. Nest sites located in humid areas with dense vegetation cover, and low urbanization levels that characterize the surrounding landscape provide high-breeding success rate to this species if compared to sub-humid and semi-arid areas. These findings can be a useful indicator of environmental change in a country that is already experiencing severe drought stresses, uncontrolled urbanization, and high deforestation rates.
... The increased egg weight observed from birds fed increasing levels of GH could be due to advancement in age. Older birds tend to lay larger eggs compared to younger ones (Aslan and Yavuz, 2010). . ...
Article
Full-text available
A total of 180, eight weeks old pullet weighing 600± 2.3g were used to investigate the inclusion rate and physiological effects of groundnut hull (GH) replacing wheat offal (WO) on performance, haematological indices and egg parameters over a seventeen-week experimental trials. The pullets were divided into five (5) treatment groups of 0, 25, 50, 75 and 100% GH replacing WO in a complete randomized design experimental layout. The result showed significant (p<0.05) increase in feed intake (FI) (82.55 to 94.83) and weight gain (WG) (737.3 to 907.00) with increase in GH replace WO up to 50%. White blood cell (WBC) MCV and MCH were significantly (p<0.05) higher with increase in GH than the control (100% WO). There was no significant (p>0.05) effect in egg parameters except for Albumin height and yolk colour which significantly (p<0.05) increased with increase in GH replacing WO. It was concluded that GH in pullet diets could be tolerated up to 100% replacement of WO. However, 50% replacement inclusion of GH produced optimal utilization and physiological wellbeing of pullets
... Past studies have use different proximate measures for egg size such as egg length, fresh egg mass and egg volume (Aslan & Yavuz, 2010;Krist, 2011). Egg volume was used as a measure of egg size in this study. ...
Article
Full-text available
Brood-parasitic cuckoos lay their eggs in the nests of other birds and thereafter abandon their young to the care of the host. Thus, all maternal investment is restricted to investment in the egg. Optimal investment at this stage is likely to have a large impact on maternal reproductive success. Many bird species optimize the size of their eggs to suit both the prevailing environmental conditions and the number of individuals that will provide care to the chicks. However, relatively few cues are available to avian brood parasites to facilitate optimal investment in their eggs. Moreover, optimization of egg size to suit environmental conditions or the social structure of the host group may be constrained by stronger selection for egg mimicry, which reduces the likelihood of detection and rejection of foreign eggs by the host. We aimed to test how the conflicting selection pressures of (1) selection for large eggs in harsh environmental conditions versus (2) rejection of large eggs by hosts interact to influence the size and shape of Horsfield's bronze-cuckoo, Chalcites basalis, eggs. Using a sliding window approach to investigate periods of climate sensitivity, we show that climatic variables did not predict egg size. Nor did cuckoos modify their egg size or shape in relation to the group size of the host (superb fairy-wren, Malurus cyaneus). Conversely, host defences did appear to have influenced cuckoo egg morphology: eggs that were relatively short and round had a higher probability of being abandoned by the host than eggs that were long and narrow. This suggests that host defences are the overriding selection pressure on cuckoo egg morphology, and, unlike their hosts, cuckoos do not adapt their eggs to the prevailing climate or host group size.
... In comparison to temperature and rainfall, the influence of humidity on clutch size, egg size and other breeding parameters were less known. Aslan and Yavuz (2010) observed that egg length was positively affected, not only by rainfall but also by an increase in humidity in House Sparrow. The water and air temperature was found to go more or less hand in hand presumably due to standing water and relatively small size of the water body in the present study. ...
... During the incubation of the birds in artificial nest boxes, we weighed parent birds with an electronic balance. The length of the tarsus was measured with vernier calipers (Sanz and Tinbergen 1999;Aslan and Yavuz 2010;Hwang 2014). ...
Article
Full-text available
This study was conducted to investigate the influence of atmospheric factors on the body and egg of great tits (Parus major), which were bred in artificial nest boxes from March to July of 2012 and 2013. The mean temperature and relative humidity were significantly higher in the spring season of 2012 than in 2013. Body masses of incubating parent birds differed between both years. Eggs which were laid in 2012 were larger and heavier than those of 2013. Hue and saturation values for background and spot colors were significantly different between 2012 and 2013. In 2012, there were warmer and wetter atmospheric conditions, which may influence vegetation and food availability for the birds. The large, heavy, and less vividly-colored eggs were laid in 2012 by parents with good body condition. Results showed that spring atmospheric factors influenced both body and egg of great tits. Further studies on the relationships between atmosphere, vegetation, and food availability of the birds are needed.
Article
Epigenetic modifications such as DNA methylation are important mechanisms for mediating developmental plasticity, where ontogenetic processes and their phenotypic outcomes are shaped by early environments. In particular, changes in DNA methylation of genes within the hypothalamic-pituitary-adrenal (HPA) axis can impact offspring growth and development. This relationship has been well documented in mammals but is less understood in other taxa. Here, we use target-enriched enzymatic methyl sequencing (TEEM-seq) to assess how DNA methylation in a suite of 25 genes changes over development, how these modifications relate to the early environment, and how they predict differential growth trajectories in the house sparrow (Passer domesticus). We found that DNA methylation changes dynamically over the postnatal developmental period: genes with initially low DNA methylation tended to decline in methylation over development, whereas genes with initially high DNA methylation tended to increase in methylation. However, sex-specific differentially methylated regions (DMRs) were maintained across the developmental period. We also found significant differences in post-hatching DNA methylation in relation to hatch date, with higher levels of DNA methylation in nestlings hatched earlier in the season. Although these differences were largely absent by the end of development, a number of DMRs in HPA-related genes (CRH, MC2R, NR3C1, NR3C2, POMC)-and to a lesser degree HPG-related genes (GNRHR2)-predicted nestling growth trajectories over development. These findings provide insight into the mechanisms by which the early environment shapes DNA methylation in the HPA axis, and how these changes subsequently influence growth and potentially mediate developmental plasticity.
Article
Full-text available
The present study deals with general trends in clutch-size of local birds and examined some of the hypotheses regarding the adaptive significance of the timing of breeding and variations in the clutch size, that have been put forth as possible explanations with in seasonal variation of average clutch-size of the birds. In the present work, recorded clutch size of 15 bird species belong to 10 families of 5 different orders most of them were passerines. Studies on clutch size helped to study life history traits of various birds, particularly Brahminy Myna Sturnus pagodarum and Indian Shikra Accipiter badius. Whereas clutch sizes of other birds provided an approximate measure about birth rate of that species. Clutch of each bird was observed approximately constant for that species. Further, this available information might be beneficial in future for detail study of that particular bird species from the local area. This study was carried out from Materials and methods: The study was carried out on local residential birds, for the study and record of clutch size field visit were carried out during breeding season, nest were located by observing behaviour of birds carrying nesting material and searching behaviour. During breeding season birds shows courtship, mating, nest building or renovation and incubation helping to locate the nest. The observations made regularly with binoculars or by naked eyes in some cases. The chief object of the present study was to obtain the information about general trends in clutch-size of
Article
This study was conducted to investigate the relationship between atmospheric conditions and breeding ecology of Paras sp. tits in artificial nest boxes at a deciduous forest between March 2009 and July 2010. In order to collect data regarding tit breeding, temperature and relative humidity, researchers installed a total of 45 artificial nest boxes equipped with Hobo® Pro V2 monitors. Artificial nest boxes had one of three different entrance diameters of 30, 35 and 40 mm. The mean temperature and relative humidity in 2010 were lower than in 2009. Marsh and great tits both had differences in incubation and nestling care periods based on temperature and relative humidity during the breeding season. In addition, increases in the body weight and tarsus length of juvenile tits were slower in 2010 than in 2009. To understand whether the breeding ecology of tits is affected by atmospheric conditions, further long-term ecological research is needed.
Article
Full-text available
To determine the daily and total energy expenditures of breeding female House Sparrows (Passer domesticus), we collected 276 females near London, Ontario between April 1981 and May 1983. Protein and fat content of developing follicles, eggs, and oviducts were determined and converted into their energy equivalents. Eight days were required to develop and lay a modal clutch of 4 eggs. Fat energy requirements were not estimable accurately because total body fat did not decline linearly over the egg production period; therefore, energy requirements were estimated as a range. Based on a 4-egg clutch, the maximum daily costs of reproduction, 16.5-17.6 kJ/day, equalled 44-47% of a female's standard metabolic rate. We estimate that daily costs very less than 10% for other clutch sizes (3 or 5). The total energy demand of reproduction was 66-71 kJ. Protein requirements comprised 59-63% of the total costs and were apportioned among oviduct (5-6%), yolk protein (17-19%), and albumen (36-39%). Fat requirements accounted for the remaining 37-41% of total costs. Based on our estimates of energy needed for reproduction, and on other evidence, we suspect that egg production by House Sparrows is not constrained by energy acquisition.
Article
Full-text available
The earlier theory suggest that the percent deviation of the last egg from the clutch mean (D) is imporatnt and identifies two strategies: brood-reduction strategy or brood-survival strategy. We examinated the validity of using the relative size of the final egg as a measure of intraclutch egg-size variation. We present an alternative hypothesis to account for patterns in D: Cold weather causes decreases in female weight. decreases in female weight necessarily decrease egg size (volume). No further strategic explanations are necessary.
Article
Full-text available
The effect of ambient temperature before and during laying on egg volume in birds has been studied by many authors. The objective of this paper is to show that trends in daily temperatures changes can also influence egg volume. The study was carried out near Warsaw, Poland in 1994 and 1995. We ascertained the laying sequence, size and volume of 1070 eggs in 211 clutches of the Tree Sparrow. The effect of the trend in temperature on the mean egg volume in a clutch explained 0.4% of its variation (0.03% to 4.2%, depending on the brood-period), and the effect of actual temperature explained 0.9% (0.5% to 1.6% depending on the brood-period). The joint effect of temperature and its trend explained 3.1% (1.7% to 8.9% depending on the brood-period) of variation in the mean egg volume in a clutch. The authors discuss possible mechanisms of the effect of temperature and temperature trend on egg volume.
Article
We studied relationships between female size, date of egg laying, clutch size, egg size, and breeding success in Pied Flycatchers (Ficedula hypoleuca) in a marginal area in northwestern Finnish Lapland (69°N). Average June temperatures in 1975-1981 were used to classify years into "good" (warm) and "bad" (cold) breeding seasons. In general, early and warm springs were followed by "good" breeding seasons: females were heavier, laying was earlier, clutches were larger and contained larger eggs, and hatching and fledging success were better than in late and cold springs. Mainly due to low nesting success in "bad" breeding seasons, the local population could not maintain itself; immigration from the south was needed. We suggest that spring weather may provide information concerning the character of the coming breeding season, which may help birds to maximize their lifetime production of young.
Article
House sparrow in Izmir incubates 2-3 times during the breeding period, incubation lasting for 9-12 days with a 53% success. -from English summary