Seasonality Affects the Surface Dwelling Fauna in Desert Ecosystem
Nuzhat Sial*, Muhammad Shafiq Chaudhry and Qazi Adnan Ahmad*
Department of Life Sciences, Islamia University of Bahawalpur, Bahawalpur, Pakistan.
Abstract:- A field survey aimed at determining the effect of seasonality on the abundance, frequency and
patterns of distribution of surface dwelling fauna was conducted in Cholistan desert, with the help of pit fall method
from January 2002 to December 2004. Insects were found with maximum abundance (68%), followed by 18%
arachnids, 5% scincidae, 4% lizards, 3% Squamata and 2% Mammalia. Maximum number of animals was captured
during the months of August, September and October of all the study years. It is concluded that the Cholistan desert
sustains a high faunal range and a wide range of habitat selection mainly depending upon their feeding habits and
seasonal activity. Family Scincidae (Skinks/sandfish), squamata (Lizards, snakes), lacerate (Geckos, monitors,
chameleons).
Key words: Surface dwelling fauna, Cholistan desert, biodiversity.
INTRODUCTION
The arid habitats of Cholistan desert cover an
area of about 2.6 million hectares, constituting the
southern part of Bahawalpur Division. It is located
between latitudes 27o 42` and 29o North and
longitudes 60o 57` East. The length of the desert is
about 480 km and breadth is from 32 to 192 km
(Akbar et al., 1996). Based on the heterogeneity of
its topography, parent material, soil and vegetation,
this desert has been divided into two geomorphic
regions. The northern region or Lesser Cholistan
borders by canal irrigated areas and covers about
7770 km² area and the southern region or Greater
Cholistan is comprised of 18130 km². The lesser
Cholistan consists of many saline alluvial flats
(locally called ‘dahars’) alternating with low sandy
ridges (Akbar et al., 1996; Akbar and Arshad,
2000).
The climate is tropical and continental
characterized by low and sporadic rainfall (176 –
250 mm per annum) high temperatures, low relative
humidity, high rate of evaporation and strong
summer winds (Akram et al., 1986). There is
considerable difference between day and night
temperatures. The day temperature may exceeds
50°C while the night temperatures may fall as low
as 10°C. The rainfall in the area is irregular,
unpredictable and scanty generally ranging between
100 to 250 mm per annum, occurring during
monsoon (July to September) (Akbar et al., 1996).
_____________________
*
Corresponding authors:
nuzhatiub@yahoo.com,qadnanahmad@gmail.com
.
However, the cumulative meteorological data for
the three study period is presented in Figure 1,
depicting that maximum average temperature was
during June (38.80°C) and maximum average
rainfall was during July (48.9 mm), while the
highest relative humidity was recorded during
January (67.7%). The drought is a recurring
phenomenon and mostly strikes back after every
three to four years. Whenever, there is long drought
spell, it significantly affects the ecology of the area
both directly (i.e., less production of green biomass
and habitat degradation for wildlife) and indirectly
(i.e., enhanced use of already limited natural
resources by human-beings and livestock).
The climate has multitude influences on the
various components of ecosystem including
distribution and activities of the organisms (Pearson
and Dawson, 2003). Other physical variables such
as soils formation and development, temperature,
availability of surface and sub-surface water
virtually influence the surface dwelling fauna
according to the habitat and species (Bachelet et al.,
2001). Climate also helps in interconnecting the
ecosystems by changing the rates of material
transport between them such as migratory animals,
vegetation and microbes (Vörösmarty et al., 2000).
These broad scale parameter not only effect the
present fauna and flora but also shape up the future
climatic patterns as well (Peters et al., 2008; IPCC,
2007)
Most of the herpetological studies carried out
in Pakistan are restricted to Sindh and Balochistan
Provinces (Murray, 1884, 1886; Boulenger, 1890;
Smith, 1935; Minton, 1966; Mertens, 1969),
Cholistan desert by Sial and Arshad (2003) and
N. SIAL et al
2
from Chagai desert by Baig et al. (2006).
Considering the pivotal and crucially important
position of faunal diversity in Cholistan desert the
present study was conducted to document seasonal
diversity of surface dwelling fauna of the area and
to study their biological aspects.
MATERIALS AND METHODS
The specimens were collected during January
2003 to December 2004. The area around the Field
Station of Cholistan Institute of Desert Studies
(CIDS), Islamia University, Bahawalpur comprised
desert part of the Baghdad-ul-Jadeed Campus that
represents the mini picture of Cholistan desert.
Three study sites were selected on the basis of
topography, vegetation composition and habitat
variations. Site I was located on the northern side of
Cholistan Institute of Desert Studies (CIDS) Field
Station with dense vegetation cover mainly of
grasses and shrubs. This site consists of small dunes
and hammocks with interdunal flat sandy areas. Site
II was located on the east of CIDS Field Station and
comprised of undulant topography with somewhat
plain sandy areas. The vegetation cover was
moderate and having large shrubs with little grass
component. Site III was located on the southern side
of the CIDS Field Station and comprised of small
dunes of 2-3 meters high. Due to ethnic
interventions, the vegetation cover was very low as
the area is near to the hostels.
Pit-fall technique was used for trapping the
surface dwelling fauna (Lövei and Sunderland,
1996). Ten pit-fall traps were fabricated randomly at
each study site and inspected after every three days
for the collection of a wide range of specimens. The
specimens collected were fixed in 10% formalin and
date of collection, locality and habitat were
recorded. The specimens were sent to Pakistan
Museum of Natural History for their identification.
The data collected was tabulated on the basis of the
diversity of animals among different months of the
year and according to the seasonality.
RESULTS AND DISCUSSION
Abundance and percent relative abundance
surface dwelling fauna in Cholistan desert from
2002 and 2004 are presented in Table I. Maximum
abundance and relative abundance of fauna was
found during April to August while minimum
during January to March and then October to
December. Among the most abundant organisms the
percent relative abundance of spiders and lizards
was high during April whereas snakes and scorpions
during May and June. Beetles were found almost all
the year round but mostly during August and
September.
Total of 3127 specimens were captured, out
of which 47.29% were insects followed by the
35.32% Arachnids 2.99% scincidae, 7.52% lacertae,
2.89% squamata and 3.19% mammals, respectively.
Arachnids (scorpion, spiders), Mammalia (Mouse,
rats), Reptilia (Order; squamata: lizards, snakes),
Lacertilia (Lizards, Geckos, Monitor, Chameleon),
Arthropoda (Beetles, centipeds etc), Amphibian
(Toads, frogs).
The diversity of surface dwelling fauna was
not only variable among different months of the
year but also differs among different years of the
study. During study year 2002 the maximum
diversity (22.27%) among the captured organisms
was recorded during May, whereas during the years
2002 and 2004 it was 20.95% during September and
23.13% during April. Minimum diversity was found
during the months of February and March. During
December and in the rest of the months diversity
among the organisms remained almost same with
little fluctuations.
This study reveals that beetles were the most
abundant fauna of all the other kinds trapped during
the whole study period. We recorded 1275 beetles
out of 3127 which makes 40.77% of the total
organisms captured. The high number of beetles
trapped in our study may be due to high species
diversity and favorable conditions due to minimum
anthropogenic and livestock disturbances. Another
plausible explanation may be the seasonal
fluctuations and availability of surface food which
may support the breeding behavior of this species as
there were enough rains during the first two study
years and more number were trapped during the
same years as compared to the last year of study
when there were less rains.
Scorpions gained the second place with
26.62% of the total organisms sampled during the
AFFECT OF SEASONALITY ON DESERT FAUNA
whole study period. Survival of desert animals
depends on their ability to avoid extremely high
temperatures. Soil temperatures beneath the desert
floor are lower than those at the surface and provide
relief from heat for desert fauna. Three basic faunal
groups are common in deserts: small mammals,
reptiles and arthropods. Individuals in these three
groups frequently survive by burrowing during hot
times of the day and being active during cooler
periods (Wallwork, 1982). Desert tortoises, lizards,
rodents, foxes, and termites, bees and wasps all use
this method.
On the other hand spiders were found to be
more common on the grasses litter/trash, dense
vegetation. Vegetation type and cover plays an
important role in the distribution, food chain,
behavior and ecological niche of the land dwelling
animals. Sandfish can be survived on bare sand
dunes to enter inner side of the sand to save
themselves from enemies but also to escape from
the high temperature of the summer. In contrast
beetles were more abundant during September to
December due to suitable temperature and moisture
availability. Moreover, it can be pointed out that
68% out of the total surface dwelling animals
trapped were insects (Fig.1). The harsh temperature
conditions usually limit the survival of insects but
within certain limits as temperature rises,
metabolism
rises,
leading
to
accelerated
development, increased reproductive activity and
ultimately, increased population growth. The
absence of amphibians is due to non-availability of
water. The reptiles (Skinks/Sandfish, snakes and
lizards) forms 25.41% of the total organisms
sampled. The anthropogenic activity in this area has
removed most of the snake population from the
area.
The ratio of sampled organisms remained
relatively high during 2002 and 2003 to that of
2004. This may be attributed to the climatic
conditions where there were enough rains during the
first two years and very less during the last year of
study (Fig. 2). Under the desert conditions
availability of moisture plays pivotal role in
controlling the surface productivity and food
availability.
It can be concluded that various seasonal
factors in the desert effect the faunal reproduction,
3
their existence etc. However further work is needed
to investigate the faunal tolerance or existence in
drought conditions under field conditions.
REFERENCES
AKRAM, M., WALLYAT, A.K. AND BASHIR, A.S., 1986.
Desertification processes in Cholistan Desert, PCRWR,
Pakistan.
AKBAR, G. AND ARSHAD, M., 2000. Developing sustainable
sterategies for Cholistan desert: opportunities and
perspectives. Sci. Vis., 5: 77-85.
AKBARR, G., KHAN, T.N. AND ARSHAD. M., 1996.
Cholistan desert, Pakistan. Rangeland., 18: 124-128.
BACHELET, D., NEILSON, R.P., LENIHAN, J.M. AND
DRAPEK, R.J., 2001. Climate change effects on
vegetation distribution and carbon budget in the United
States. Ecosystems, 4: 164–85.
BAIG. K.J., AWAN, M.R. AND ASHRIF, N., 2006. Ecological
studies and zoogeographic affinities of the amphibians
and reptiles found in Chagai Desert, Balochistan.
Pakistan. Pakistan J. Zool., 38: 145 – 151.
BOULENGER, G.A., 1890. The Fauna of British India
including Ceylon and Burma. In: Reptilia and
Batrachia. London, pp. 541.
BURY, B.R., 1982. Structure and composition of Mogave
Desert reptile communities determine with the removal
method. In: Herpetological communities (ed. N.J.
Scott). Wildl. Res. Rep., 13:135-142.
GEE, J.M. AND WARWICK, R.M., 1994. Metazoan
community structure in relation to the fractal
dimensions of marine macroalgae. Mar. Ecol. Prog.
Ser., 103: 141-150
GREENSLADE, P.J.M., 1964. Pitfall trapping as a method for
studying populations of Carabidae. J. Anim. Ecol., 33:
301–310
HALSALL, N.B. AND WRATTEN. S.D., 1988. The efficiency
of pitfall trapping for polyphagous predatory Carabidae.
Eco. Ent., 13: 293–299
HICKS, G.F.R., 1980. Structure of phytal harpacticoid copepod
assemblages and the influence of habitat complexity
and turbidity. J. exp. mar. Biol. Eco., l44: 157-192
HICKS, G.F.R., 1985. Meiofauna associated with rocky shore
algae. In: The ecology of rocky coasts (eds. P.G. Moore
and R. Seed). Hodder and Stoughton, London, pp. 3656.
IPCC (Intergovernmental Panel on Climate Change), 2007. The
physical science basis. Summary for policymakers.
Contribution of Working Group I to the fourth
assessment report of the Intergovernmental Panel on
Climate Change. IPCC. Geneva, Switzerland.
JARVIS, S.C. AND SEED. R., 1996. The meiofauna of
Ascophyllum nodosum (L.) Le Jolis: characterisation
of the assemblages associated with two common
3
4
N. SIAL et al
epiphytes, J. exp. mar. Biol. Ecol., 199: 249-267.
LŐVEI, G.L. AND SUNDERLAND. K.D., 1996. Ecology and
behaviour of ground beetles (Coleoptera: Carabidae).
Annu. Rev. Ent., 41: 231–256
MERTENS, R., 1969. Die Amphibian and Reptilians West
Pakistan. Stutt. Beit. Nat., 197: 1-96.
MINTON, S.A., 1966. A contribution to the herpetology of
west Pakistan. Bull. Am. Mue. nat. His., 134: 31-184.
MURRAY, J.A., 1884. The vertebrates of Sind. Richardson &
Co., London, pp. 415.
MURRAY, J.A., 1886. The reptiles of Sind. Richardson & Co.,
London, pp. 92.
PEARSON, R.G. AND DAWSON, T.P., 2003. Predicting the
impacts of climatechange on the distribution of species:
are bioclimate envelope models useful? Glob. Ecol.
Biogeogr., 12: 361–671.
PETERS, D.P.C., GROFFMAN, P.M. AND NADELHOFFER,
K.J., 2008. Living in an increasingly connected world: a
framework for continentalscale environmental science.
Front. Ecol. Environ., 6: 229–237.
POLLARD, E., 1968. Hedges, IV. A comparison between the
Carabidae of a hedge and field site and those of a
woodland glade. J. appl. Ecol., 5: 649–657
SIAL, N. AND ARSHAD, M., 2003. Biodiversity in the surface
dwelling fauna from Cholistan desert. Pakistan J. boil.
Sci., 6(13): 1195 – 1198.
SMITH, M.A., 1935. The fauna of British India including
Ceylon and Burma.Reptilia and Amphibia. 11th edn.,
Ralph Curtis Book, New York, USA.
WALLWORK, J.A., 1982. Desert soil fauna.
Praeger
Publishers, New York, USA.
VŐRŐSMARTY, C.J., GREEN, P., SALISBURY, J. AND
LAMMERS, R.B., 2000. Global water resources:
vulnerability from climate change and population
growth. Science, 289: 284–88.
AFFECT OF SEASONALITY ON DESERT FAUNA
60.0
80.0
Temp
Rain fall
Humidity
50.0
70.0
60.0
40.0
50.0
30.0
40.0
30.0
20.0
Relative humidity %
Rainfall mm & Temp. o C
5
20.0
10.0
10.0
0.0
0.0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Months
Fig. 1. Cumulative meteorological data of the study years from 2002 to 2004. Processed from the raw data
provided by Council of Research in water Resources, Regional Office, Bahawalpur
25.00
2002
Number captured
Number of the organisms
captured
20.00
2003
2004
15.00
10.00
5.00
Winter
Spring
Summer
Monsoon
Nov
Oct
Sep
Aug
July
June
May
April
March
Feb
Jan
Dec
0.00
Autumn
Fig. 2. Seasonal faunal diversity during the year 2002 to 2004.
5
N. SIAL et al
6
Table I.-
Abundance and percent relative abundance (in parenthesis) of surface dwelling fauna of Cholistan desert (2002-2004)
Months
Spiders
Lizards
Insects
Mouse
Toad/frogs
2002
2003
2004
2002
2003
2004
2002
2003
2004
2002
2003
2004
2002
2003
2004
January
-
-
-
-
-
-
-
1(7.14)
1(8.33)
-
6(14.29)
3(20.0)
-
2(40)
-
February
-
-
-
-
2(5.13)
2(1.61)
-
-
-
1(2.27)
1(2.38)
3(20.0)
-
-
-
March
-
-
-
-
-
11(8.87)
-
-
2(16.67)
-
2(4.76)
3(20.0)
-
-
-
April
59(43.07)
16(41.02)
17(39.53)
25(43.10)
4(10.26)
35(28.23)
4(21.05)
-
7(58.33)
1(2.27)
1(2.38)
2(13.37)
4(25)
1(20)
-
May
32(23.36)
7(17.95)
9(20.93)
7(12.07)
3(7.69)
35(28.23)
3(15.79)
3(21.43)
-
3(6.82)
2(4.76)
2(13.37)
3(18.75)
1(20)
-
June
17(12.41)
10(25.64)
11(25.58)
10(17.24)
7(17.95)
25(20.16)
2(10.53)
4(28.57)
2(16.67)
7(15.91)
5(11.90)
1(6.67)
4(25)
-
2(66.67)
July
6(4.38)
2(5.13)
-
7(12.07)
4(10.26)
5(4.03)
5(26.32)
1(7.14)
-
7(15.91)
4(9.52)
-
1(6.25)
-
1(33.33)
August
14(10.22)
2(5.13)
-
2(3.45)
3(7.69)
4(3.23)
1(5.26)
3(21.43)
-
3(6.82)
6(14.20)
1(6.67)
1(6.25)
-
-
September
5(3.65)
2(5.13)
-
2(3.45)
7(17.95)
5(4.03)
1(5.26)
2(14.29)
1(2.27)
9(21.43)
-
-
1(20)
-
October
2(1.45)
-
-
2(3.45)
3(7.69)
-
2(10.53)
-
-
3(6.82)
5(11.90)
-
2(12.5)
-
-
November
1(0.73)
-
3(6.98)
2(3.45)
1(2.56)
1(0.81)
-
-
-
13(29.55)
-
-
1(6.25)
-
-
December
1(0.73)
-
3(6.98)
1(1.72)
5(12.82)
1(0.81)
1(5.26)
-
-
5(11.36)
1(2.38)
-
-
-
-
42
15
16
5
3
Total
137
39
43
58
39
124
19
12
12
44
Table- I: continued
Months
Snakes
Scorpions
Skink
Beetles
Centipedes
2002
2003
2004
2002
2003
2004
2002
2003
2004
2002
2003
2004
2002
2003
2004
January
-
2(6.06)
-
-
1(0.22)
1(0.88)
-
4(11.43)
-
-
18(3.04)
17 (16.50)
-
3(5.66)
-
February
-
1(3.03)
-
-
3(0.65)
-
-
1(2.86)
-
-
13(2.20)
2(1.94)
-
10(18.86)
-
March
-
4(12.12)
5(27.78)
-
1(0.22)
3(2.65)
-
1(2.86)
2(10.53)
-
32(5.40)
22 (21.35)
-
1(1.89)
1(25)
April
6(17.14)
4(12.12)
2(11.11)
16(6.13)
19(4.15)
27(23.89)
10(31.25)
3(8.57)
4(21.05)
22(3.79)
44(7.43)
11(10.68)
5(15.63)
7(13.21)
-
May
12(34.29)
1(3.03)
2(11.11)
36(13.79)
34(7.42)
20(17.70)
5(15.62)
9(25.71)
4(21.05)
51(8.79)
23(3.89)
14 (13.59)
-
3(5.66)
-
June
2(5.71)
4(12.12)
1(5.56)
72(27.59)
148(32.31)
11(9.73)
2(6.25)
4(11.43)
-
12(2.07)
19(3.21)
-
1(3.13)
6(11.32)
-
July
3(8.57)
2(6.06)
1(5.56)
43(16.48)
82(17.90)
13(11.50)
6(18.75)
-
2(10.53)
21(3.62)
60(10.14)
-
2(6.25)
18(33.96)
-
-
4(12.12)
3(16.67)
20(7.66)
64(13.97)
14(12.39)
4(12.50)
4(11.43)
-
81(13.97)
108(18.24)
21 (20.39)
3(9.38)
1(1.89)
-
September
2(5.71)
7(21.21)
1(5.56)
34(13.03)
85(18.56)
15(13.27)
-
5(14.29)
4(21.05)
163(28.10)
154(26.01)
1 1(10.68)
10(31.25)
4(7.55)
-
October
4(11.43)
1(3.03)
-
27(10.34)
13(2.84)
-
2(6.25)
3(8.57)
-
71(12.24)
83(14.02)
-
3(9.38)
-
-
November
3(8.57)
-
2(11.11)
13(4.98)
8(1.75)
6(5.31)
2(6.25)
-
1(5.26)
79(13.62)
13(2.20)
2(1.94)
4(12.50)
-
2(50.0)
December
Total
3(8.57)
3(9.09)
1(5.56)
-
-
3(2.65)
1(3.12)
1(2.86)
2(10.53)
80(13.79)
25(4.22)
3(2.91)
4(12.50)
-
1(25.0)
35
33(
18
26
458
113
32
35
19
580
592
103
32
53
4
August