Role of Ficus spp. in the avifauna conservation of Jahangirnagar University campus

A study was conducted on Ficus species to evaluate its role in avifauna conservat ion Jahangirnagar University campus from December 2012 to September 2013. Ficus benghalensis and Ficus rumphii were found to provide food and shelter to the bird community of Jahangirnagar University throughout the year becaus e of their asynchronous fruiting. A total of twenty four Ficus trees were selected for the study. Number of fruit providing trees varied in different months (x = 11.6, range = 4-22, sd ± 6.29). Twenty seven spec ies of birds were recorded from Ficus spp. throughout the year. Dependency of bird specie s on Ficus varied in different months (x = 18.1, sd ± 2.42, range = 16-22). Common Myna was found to visit Ficus tree more frequently while Oriental White Eye was l e s frequent. The height of the studied Ficus benghalensis ranged from 17 – 45 feet with the mean x = 26.67 ± 7.51 while Ficus rumphii ranged from 30-48 feet with the mean x = 39.33 ± 9.0.


INTRODUCTION
Ficus generally known as fig tree is one of the significant keystone species plays an important role in avifauna conservation (Shanahan et al., 2001;Snow, 1981).Ficus help in avifauna conservation for its aseasonal fruiting capacity.The diversity of frugivores is correlated with the abundance and diversity of fig species (Kissling et al., 2007).Frugivores, especially birds get support from fig species throughout the year.In Bangladesh 47 Ficus species have been recorded (Ahmed et al., 2009) and found as asynchronous fruiting tree providing food to the frugivore birds and other wild animals.Due to the year round fruiting capability of Ficus, frugivores depend on them in many ways.The university campus is the suitable habitat of 180 species of birds including 33 species of waders (Mohsanin & Khan, 2009).Several studies on ecology and behaviour of different bird species in Jahangirnagar university campus were conducted (Begum, 2000(Begum, , 2001(Begum, , 2002(Begum, , 2003;;Joarder, 1997;Akhtar et al., 2007Akhtar et al., , 2009)).Only a preliminary survey was conducted on Ficus species in Jahangirnagar university campus (Azmiri, 2011) but there is no information available on the dependency of avifauna on Ficus.Hence, the study was conducted to determine the dependency of avifauna on Ficus spp. in Jahangirnagar University (JU) campus.Jahangirnagar University Campus is situated at 32 km north of Dhaka city (90 0 47 .50 ´ N to 90 0 48 .10 ´ N and 23 0 4 ´ E to 23 0 4 .15 ´ E).Total area of this campus is 280 ha.The ground of the campus is slightly undulating and the soil is deep brown to yellowish red due to high iron content.It is a part of the Bhawal and Madhupur Tract.There are three main seasons: summer (March to May), monsoon (June to October) and winter (November to February).Average annual rainfall is about 2400 mm and mean relative humidity is 78.44%.The Campus has diverse ecological habitats and vegetation types including wetlands (24 ha), woodland, bushes and grasslands.Diverse habitat types of this campus provide feeding and breeding ground for many resident and migratory birds (Joarder, 1997;Begum, 2000;Akhtar et al., 2009).

MATERIALS AND METHODS
The study was conducted between December 2012 and September 2013.Twenty four fig trees were selected for the study.A total of 120 days in ten months were spent to determine the dependency of avifauna on Ficus.Binocular, Camera, GPS, measuring tape, field guide, pen & pencil and data sheet were used for data collection.All the selected fig trees were recorded with GPS coordinates and numbered with tag mark.Following parameters were considered for phenological study of Ficus (Feeroz et al., 2011).
Girth: It is a measurement of the distance around the trunk of a tree at the breast height.Tree height: From tree base to the tip of the highest branch of a tree.Bole height: From tree base to the first live branch on the main stem of a tree.Tree covered area: It is the area covered by a tree.Crown volume: Total measurement of crown.
Systematic observation on birds visiting fig trees were quantified using scan sampling (Akhtar et al., 2013;Hasan, 2003).The bird species were identified using Grimmett et al. (1999) and the number of individuals of each species visited Ficus tree was followed carefully.

RESUTLS AND DISCUSSION
Ficus abundance: Two species of Ficus viz.Ficus benghalensis and Ficus rumphii were recorded at Jahangirnagar University.Twenty one F. benghalensis and three F. rumphii were recorded and regularly followed for the study.Density of fig tree in Jahangirnagar University was 0.08 / ha.They are found scattered all over the campus.
Ficus benghalensis and Fiucus rumphii both are deciduous.Leafless condition of the trees was found from December to early march except January.Leafless condition of the trees was also found in May and September.Most of the new leaves bearing trees are found during March and April.Mature leaves dominate fig trees throughout the year (Fig. 1).

Fig. 1. Number of different types of leaf bearing trees in different months
Mature leaves, new leaves and leafless trees were found in December, February and March.Most of the trees were in new leaves in early April.From late April to September mature leaves were found available in the fig trees.Percentage of different types of leaf bearing trees per month were recorded (Fig. 2).
Fruits were available throughout the year with the highest productivity in summer.During Rainy season (June to September) fig production was relatively low.Most of the young fruit bearing trees were found in April, mature fruits in May and the ripe fruits in March (Fig. 3).

Bird dependancy:
Birds are largely dependent on fig tree.A total of 27 species of birds in 15 families (Table 1) those used Ficus in various purposes were recorded during the study period.Among the bird families 4 species of Sturnidae, 1 species each of Pycnonotidae, Zosteropidae, Passeridae, Muscicapidae, Halcyonidae, Alcedinidae, Phalacrocoracidae and Strigidae, 2 species of Sylviidae, Columbidae, Cuculidae, Megalaimidae and Picidae each and 5 species o Corvidae family were recorded.Birds of the Family Pycnonotidae were mostly visited Ficus while the birds of the Family Zosteropidae and Strigidae were less frequent (Fig. 4).
Different kinds of bird species visited Ficus for different purposes.Among the species Common Myna was found more frequently than the other species for food and resting purposes.Number of bird species visited Ficus per month were recorded (Fig. 5).
Birds were depended on fig tree for their food and resting especially when the trees bore fruits.Common Kingfisher and White Throated Kingfisher were found on fig tree for resting purposes which were located beside the lakes.Number of fruit bearing trees, seasonal variations and weather played an important role on bird species diversity such as Little cormorant was found only in winter season.Some species were very common throughout the year.Asian Koel and Coppersmith Barbet were very common in fruit bearing trees.It was found that fruits were available throughout the year and birds were highly dependent on fig trees for their food and resting purposes.From this study it is evident that fig trees revealed as keystone species provide a great support to the bird communities regardless of species.Birds are dependent on fig trees for their food especially when the trees bear fruits.From Chi-square test it has been found that fruits are growing successively in the campus (χ 2 = 25.06).Density of birds both frugivores and insectivores were high in fruit bearing trees because of huge amount of fruit and insect production at that time.From the statistical analysis it is seen that the number of birds was significantly correlated with the number of fruit bearing trees (r = 0.71).All the three types of fruits (Young, Mature and Ripe) were found from winter to summer season (December to June).The number of fruit bearing tree was less during the rainy season.Number of bird species and their density varied in different months.Out of twenty seven, twenty four species of birds were recorded in April when the fruiting condition of the fig trees was very good.

Fig. 2 .
Fig. 2. Percentage of different types of leaf bearing trees per month