Avian species distribution along elevation at Doon Valley (foot hills of western Himalayas), Uttarakhand, and its association with vegetation structure

Published Date
Journal of Asia-Pacific Biodiversity
30 June 2015, Vol.8(2):158–167, doi:10.1016/j.japb.2015.04.002
Open Access, Creative Commons license, Funding information
Original article

• Author 

• Kamal Joshi ^a,,
• Dinesh Bhatt ^b

• aGraphic Era Hill University, Department of Environmental Science, Dehradun, Uttarakhand, India
• bGurukula Kangri University, Department of Zoology and Environmental Science, Haridwar, Uttarakhand, India

Received 19 March 2015. Revised 16 April 2015. Accepted 27 April 2015. Available online 5 May 2015. 

Abstract

We assessed a diverse avian population during February 2013 to February 2014 at Doon Valley forest. During the study period we recorded a total of 218 species (18,982 individuals) belonging to 50 families using line transect along with the fixed radius point count method in the study area. Avian species diversity, richness, and abundance showed a hump-shaped distribution pattern in the study range (325–2300 m above sea level). The association of vegetation structure with avian community illustrates the significantly positive correlation with shrub diversity and density/ha along the elevation. The presence of new records (habitat area extension), endangered species, and two near-threatened species concerns the conservation of birds and forest habitat in this area.

Keywords

avian diversity

conservation

Doon Valley

shrub density

vegetation structure

---

Introduction

Biodiversity is not evenly distributed across the Earth. It may be influenced by geography (Karr 1976). In recent decades, the relationship between species community and elevation at global level has been an important theme in ecology. Many studies (Cody, 1974, Able and Noor, 1976 and Rahbek, 2005) have been conducted on avian species distribution patterns at regional level in temperate regions and in tropical/subtropical regions (Terborgh, 1977, Brown and Gibson, 1983and Wu and Yang, 2010). Generally, the available knowledge about the avian species distribution pattern along an elevation is not clear approximately 49% of studies show peaked at mid elevation or humped shape patterns, 20% decrease and 24% high richness at low elevation respectively (Rahbek, 1995 and Rahbek, 2005). In general, forest provides a wide range of variation in bird habitat (Fuller 1995) and the important factors of this variation include vegetation structure (Cueto and de Casenave, 1999 and Holmes and Sherry, 2001). The Indian Himalayan range is well recognized for its biological diversity and ecological value (Bhattacharya and Sathyakumar 2007). Only a few studies (Acharya et al., 2011 and Bhatt and Joshi, 2011) have been conducted on avian species distribution and variation factors in the Himalayan region. By contrast in temperate regions, many studies have reported that productivity, forest structure, and vegetation cover influence the species distribution (McCoy, 1990, Rahbek, 1995 and Waterhouse et al., 2002). The Dehradun district is situated in the foothills of the western Himalayas. Knowledge of the avifauna of Doon Valley is based on only checklists (Osmaston, 1935, Mohan, 1992, Mohan, 1997 and Singh, 2000), and the available information about avian species distribution along elevations is insufficient. An attempt was made to understand the avian species distribution pattern and variation factors (especially vegetation structure) along the elevation at the forest habitat (local level) of Doon Valley.

Material and methods

Study area

The present study was carried out at Doon Valley (29°55′ N to 30°30′ N, 77°35′ E to 78°24′ E) from 300 m to 2300 m above sea level elevation ranges in the Dehradun district of Uttarakhand, India (Figure 1). The elevation range was divided into three major elevation zones as follows: low zones (30°02′ N, 78°15′ E–30°20′ N, 78°08′ E) from 300 m to 900 m above sea level, covering the Mohakampur, Laxman Siddh, Clementown, and Wild Life Institutes, dominated by the Sal (Shorea robusta), Terminalia bellerica, Cedrela toona, Shisam (Dalbergia sissoo), and Butea monoserma tree species; mid elevation zones (30°20′ N, 78°08′ E–30°25′ N, 78°04′ E) extending from 900 m to 1500 m above sea level and covering the Rajpur, Ladpur, Shikhar Falls, and Maldevta Forest areas, occupied by mixed vegetation, i.e., Dhola, Amla, Hared, Ghentela, Moist Sal (Shorea robusta), Shisam (Dalbergia sissoo) tree species, etc.; and high elevation zones (30°25′ N, 78°04′ E–30°27′ N, 78°06′ E) extending from 1500 m to 2300 m above sea level, namely the Lakhwar, Mussoorie, Lal Tibba, and Dhanaulty areas, which are dominated by Burans (Rhododendron arboretum), Banj (Quercus incana), Quercus dilatata, and Deodar (Cedrus deodara)trees.

Figure 1. Different study sites in Doon Valley of the Dehradun district (Uttarakhand).

The temperature varies from 10°C in winter (December–February) to 38°C in the summer months (April–July). The rainfall pattern in the study area is monsoon dependent. Dehradun receives the maximum rainfall between July and September (Pandey et al 1994).

Bird survey

The bird survey was conducted from February 2012 to February 2014 along the full elevation (300–2300m) range of Doon Valley. This range was divided into seven different elevation zones. Fixed-width line transect along with the fixed radius point count method (Bibby et al 2000) were used to quantify the diversity and abundance of avian species in each elevation zone of forest habitat. A total of 210 transects (7 elevation zones × 5 transects in each elevation zone × 12 months) were studied in 1 year and the same transects were revisited the following year. Transects varied in length from 700 m to 1000m, depending on vegetation and accessibility. The survey was carried out between 06.00–11.00 hours and 16.30–19.30 hours in the summer months (April–September) and between 07.00–11.30 hours and 15.00–16.00 hours in winter (October–March). Surveying was avoided during foggy weather and rainy days. Field guidebooks (Grimmett et al., 2011 and Kazmierczak and Perlo, 2012) were used for bird species identification in all the elevation zones, and birds were observed for approximately 5 minutes at each point for bird count. No specimens were collected, however, most species were photographed for reference.

Vegetation sampling

The trees and shrubs were sampled in each studied elevation zone of Doon Valley forest area. The vegetation samples were collected along transects used for the avian survey. We placed 10 quadrats (10 m × 10 m) to estimate the tree inventory, and 5 m × 5 m quadrats were placed into the 10 m × 10-m tree quadrats to estimate the shrub density. Thus, in each elevation zone of bird survey transect we recorded the richness and density of the trees and shrubs.

Data analysis

The Shannon–Weaver formula [H′ = – ∑p_i (ln p_i)] was used to estimate the avian diversity and vegetation structure in the different elevation zones of Doon Valley (Shannon and Weaver 1949). The avian species richness, and tree and shrub richness were calculated using Margalef’s formula [SR = (S – 1) / Log N] (Margalef 1951). The nonparametric estimators of Chao I, Chao II, and Jackknife were selected to explore the abundance and distribution of estimate species using Estimate S (ver. 7.5) software (Colwell 2005). Analysis of variance (1-way ANOVA) was applied to compare the avian species distribution among the elevation zones. Jaccard’s similarity index (cluster analysis) with a single linkage dendogram was applied to identify the similarity between avifauna and different elevation zones. We used correlation tests to explore the relationship between avian species and vegetation structure.

Results

Two hundred and eighteen species belonging to 50 families (Appendix 1) were reported during the bird survey at Doon Valley forest of Dehradun district (western Himalaya). Out of 50 families, Turdinae (n = 18) was dominant, followed by Picidae (n = 13) and Sylviinae (n = 12). Out of 218 species, 156 (71.55%) were reported as residential bird species, 14 (6.54%) were summer visitors from different states of India, 27 (12.16%) were winter visitors, and 21 (9.64%) bird species were altitudinal migratory. Among the residential species, one globally endangered and two near-threatened species namely Egyptian Vulture (Neophron percnopterus), Alexandrine Parakeet (Psittacula eupatria Linnaeus, 1766), and River Lapwing (Vanellus duvaucelii Lesson, 1826; International Union for Conservation of Nature 2013), were reported in the Doon Valley forest area. In addition, two Schedule I (highly protected, according to Indian Wildlife Protection Act 2001) species, Eurasian Golden Oriole (Oriolus oriolus Linnaeus, 1758) and Indian Peafowl (Pavo cristatus Linnaeus, 1758) were also recorded. Also, three species new to the region, namely White-rumped Munia (Lounchura striata Linnaeus, 1766), White-rumped Shama (Copsychus malabaricus Scopli, 1786), and Red-whiskered Bulbul (Pycnonotus jocosus Linnaeus, 1758), were reported at the study sites.

Species richness pattern

The present study results show that the avian species richness increased up to the mid-elevation zone (approximately 1300 m) of the study area. Above this elevation, species richness simultaneously declined. By contrast, the residential avian abundance was higher in terms of diversity and richness at the mid-elevation zone. Nonparametric estimators (Chao I, Chao II, and Jackknife) also support the species richness values (Figure 2). The numbers of species estimated at all the elevation zones were very close to the actual number of species observed (Table 1). Analysis of variance (1-way ANOVA) revealed that the avian community was more diverse and significantly higher (df = 6, F = 3.53, p = 0.01) at mid elevation compared with other elevation zones. Among the residential birds, eight species were shared in all the elevations. However, five species namely Spotted Dove, Jungle Crow, Great Tit, Himalayan Bulbul, and Oriental White-eye were found to be significantly abundant in the mid-elevation range. The remaining three species (Red-vented Bulbul, Blue Whistling Thrush, House Crow) were found to be significantly more common in the mid-elevation zone of the study area (Table 2). Thus, maximum avian abundance at the mid-elevation zone (approximately 1358 m) of the study area indicates a hump-shaped pattern of the species distribution along the elevation at local level. A comparison of avian species among the elevation ranges showed sequential similarity between elevation and avian community. Hierarchical cluster analysis indicates that five clusters were formed at a 0.85 similarity level. Maximum avian species were similar at low to mid elevation, followed by the mid- to high-elevation zone (Figure 3); this may be influenced by the vegetation structure in the study area.

Figure 2. Estimated avian species abundance (observed) with nonparametric values (Chao I, Chao II and Jackknife).

Table 1. Avian species observed in different elevation zones in the forest of Doon Valley.

Elevation category (m)	325	630	870	1100	1358	1800	2300
Coordinate
Elevation range (m above sea level)	250–450	530–730	770–970	1000–1200	1200–1400	1500–2100	2180–2420
Longitude	78°15′ E	78°05′ E	78°08′ E	78°05′ E	78°04′ E	77°52′ E	78°06′ E
Latitude	30°02′ N	30°19′ N	30°20′ N	30°24′ N	30°25′ N	30°42′ N	30°27′ N
Average temperature during survey (°C), range	18–35	17–35	19–36	18–34	15–27	14–22	15–21
Vegetation zone	Moist Siwalik Sal forest	Moist Siwalik Sal forest	Moist Siwalik Sal forest	Dry Siwalik Sal forest	Mixed deciduous forest	Ban Oak forest	Moist Deodar forest
Observation
Avian species observed	39	40	42	46	51	40	37
Number of individual	294	265	227	204	683	189	279
Chao I	37	41	40	45	50	38	38
Chao II	38	39	42	47	53	41	40
Jackknife	40	42	43	48	52	40	39
Avian diversity	3.25	3.46	3.63	3.65	3.68	3.18	3.28
Avian richness	10.11	11.75	12.41	12.44	12.56	5.39	5.90
Number of points studied	23	23	23	23	23	23	23
Covered study area (ha)	150	150	150	150	150	150	150
Human disturbance	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

Table 2. Mean abundance and 95% confidence interval of nine bird species in the different elevation zones.

	Elevation (m)	325			630			870			1100			1358			1800			2300
Common name	Scientific name	Mean	SD	95% CI	Mean	SD	95% CI	Mean	SD	95% CI	Mean	SD	95% CI	Mean	SD	95% CI	Mean	SD	95% CI	Mean	SD	95% CI
Spotted Dove	Streptopelia chinensis(Scopoli, 1786)	9.29	1.39	1.02	1.43	1.50	1.11	6.00	1.41	1.05	11.14	2.23	1.65	18.57	6.32	4.68	1.43	1.05	0.78	1.14	0.64	0.47
House Crow	Corvus splendens(Vieillot, 1817)	18.00	3.74	2.77	3.00	1.31	0.97	3.86	1.25	0.92	5.86	1.46	1.08	4.57	1.59	1.18	1.00	1.05	0.78	0.57	0.49	0.37
Jungle Crow	Corvus macrorhynchos(Wagler, 1827)	36.57	3.33	2.47	15.29	4.46	3.31	9.43	2.72	2.01	8.86	1.73	1.28	51.14	9.88	7.32	1.71	0.70	0.52	1.57	1.29	0.96
Great Tit	Parus major(Linnaeus, 1758)	33.86	2.03	1.50	12.57	2.61	1.93	24.71	4.63	3.43	18.43	3.80	2.81	19.29	5.80	4.30	0.86	0.83	0.62	1.71	0.45	0.33
Himalayan Bulbul	Pycnonotus leucogenys(Gray, 1835)	107.71	4.20	3.11	18.57	4.84	3.58	59.14	10.23	7.58	45.71	8.78	6.50	124.29	27.17	20.13	4.29	1.03	0.76	5.57	0.90	0.67
Red-vented Bulbul	Pycnonotus cafer(Linnaeus, 1766)	78.57	4.53	3.36	23.71	3.15	2.33	51.71	10.57	7.83	31.71	15.43	11.43	91.57	8.78	6.50	2.00	1.07	0.79	3.43	0.90	0.67
Blue Whistling-Thrush	Myiophonus caeruleus(Scopoli, 1786)	15.86	2.90	2.15	0.71	0.88	0.65	4.57	1.68	1.24	9.57	2.97	2.20	7.86	2.29	1.70	1.71	0.88	0.65	2.71	1.28	0.95
Oriental White-eye	Zosterops palpebrosus(Temminck, 1824)	17.43	2.06	1.53	10.29	1.28	0.95	17.00	4.31	3.19	6.57	1.29	0.96	19.43	5.29	3.92	1.86	0.83	0.62	1.71	0.45	0.33

CI = Confidence interval; SD = standard deviation.

Figure 3. Dendogram showing avian species similarity at different elevation zones.

Species–vegetation relationships

To explore the species–vegetation relationship, correlation tests were performed between avian species and vegetation structure. The pool abundance of avian species in each elevation zone was found to have a positive relationship with the vegetation structure. However, comparing the data set for all avian species and vegetation structure results illustrated that avian diversity was significantly positively correlated with shrub diversity (r = 0.82) and density/ha (r = 0.92). Similarly, avian richness was significantly positively correlated with shrub density/ha (r = 0.93) followed by shrub diversity (r = 0.77). However, avian diversity/richness shows a weak positive relationship with tree diversity and density/ha (Figure 4).

Figure 4. A, Relationship between avian diversity/richness and plant density/diversity: A, shrubs; B, trees.

Discussion

The findings of the present study illustrate the diverse population of avian species in the study area. However, the presence of a globally endangered vulture species and area extension of three species in the study sites shows that Doon Valley provides a suitable habitat to encourage avian species and populations. In our study, avifauna diversity indices increase at 325–1358 m above sea level and decrease at 1358–2300 m above sea level, thus avian distribution shows a bulge in the mid-elevation zone of the study area. On the avian distribution pattern along elevations, approximately 49% of studies have shown the highest species richness at mid elevation or a humped-shape pattern along the elevation gradient (Rahbek, 1995 and Rahbek, 2005). The species distribution results in the present study also support studies that have been conducted in temperate regions, such as the Madagascan rain forest (Colwell and Lees 2000), Bolivian Andes forest (Kessler et al 2001), and Columbian Andes forest (Kattan and Franco 2004), and in subtropical and tropical regions—the Taiwan mountain island forest (Shiu and Lee 2003), western Himalaya Nainital district, (Joshi and Bhatt, 2009, Joshi and Bhatt, 2013 and Bhatt and Joshi, 2011), and eastern Himalayan Sikkam at Teesta Valley (Acharya et al 2011). The high abundance of five species (commonly shared in all elevations) at mid elevation indicates that the mid-elevation range of the study area has rich food availability and provides good shelter and nesting sites. This may be due solely to the rich vegetation structure. However, environmental factors including sampling, area effects, temperature, human disturbance, and their combined effect also influence the species distribution along the elevation (McCain 2009). In the present study, the positive relationship between vegetation and avian species illustrated that the vegetation structure in terms of shrubs (diversity and density) and trees (diversity and density) plays a significant role to distribute the species along the elevation at local level. However, broad-leafed tree forest supports a wide range of avifauna at lower density (Batten 1976). Avian species assemblage shows a weak positive relationship with tree diversity and density/ha in the present study. Wilson et al (2006) reported that avian species assemblages are strongly dependent on forest structure but are not affected by tree species composition. The positive relationship between the avian community and vegetation (shrubs and trees) supports the nesting sites, shelter, and rich food availability to the avian species. A previous study (Joshi and Bhatt 2013) at different forests in the Nainital district also reported that mixed vegetation cover influences the avian species due to the presence of insects as food. Our study results support the previous study (Terborgh 1977) that habitat complexity increases the availability of insects, which increases the abundance of the bird population. Wiens and Rotenberry (1981) suggested that vegetation is an important habitat component for bird species, which provides variety of food, foraging opportunities, shelter or nesting substrate, and other conditions suitable for successful reproduction.

The presence of White-rumped Munia in the mid-elevation zone forest of the study area indicates that the species has extended its distribution range in Doon Valley. However, White-rumped Munia is known from the southern part of India to the northeast region (Grimmett et al., 2011 and Kazmierczak and Perlo, 2012). Earlier studies indicate the presence of White-rumped Munia in the Kumaun hills (Walton, 1900, Grimmett et al., 2011 and Kazmierczak and Perlo, 2012), however, there is no earlier record of sightings of the White-rumped Munia (Lounchura striata Linnaeus, 1766) in Doon Valley. Similarly, Red-whiskered Bulbul and White-rumped Shama were not reported in earlier records in Dehradun (Grimmett et al 2011). The three new records contribute additional information on the presence of avian species in Doon Valley. The present study recommends that the White-rumped Munia species is generally distributed in the western Himalaya region and that it is also a residential bird of Uttarakhand Himalaya. The presence of an endangered species (Egyptian Vulture) along with two Schedule I species (Eurasian Golden Oriole and Indian Peafowl), two threatened species (Alexandrine Parakeet and River Lapwing), and three new reports of the presence of White-rumped Munia, White-rumped Shama, and Red-whiskered Bulbul in the study area suggest the need for conservation efforts of avifauna and forest habitat in this area.

Acknowledgments

We are very grateful to the Uttarakhand State Biotech Department (USBD) (10/GEHU/NBRI/R&D Project-1/2011), Dehradun, Government of Uttarakhand for their financial support to carry out this work.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S2287884X15000254