Most interactions were of Crimson-backed Sunbird (Leptocoma minima) on cashew flowers (Anacardium occidentale).
CEROS

Effects of land-use intensification on nectar resources, bird assemblages and bird-flower interaction networks in the Western Ghats, India

Project Timeline: January-April 2024

People: Nandita Madhu, Vishal Sadekar, Rohit Naniwadekar

Collaborators: Rajah Jayapal

Funding: Wildlife Institute of India, Godrej Consumer Products Limited and Rohini Nilekani Philanthropies

What We Do?

Determining factors that maintain key plant-animal interactions such as nectar-feeding is becoming increasingly important in the face of land-use change such as agricultural expansion. In a cashew agriculture-forest matrix of the northern Western Ghats, our study aimed to assess floral resource availability, diversity of nectar-feeding birds and network-level properties of bird-flower communities across a gradient of land-use intensification. Our results suggest that plantations that retain native trees (agroforests) can partially offset the alterations caused in floral resource availability and nectar-feeding bird communities by cashew cultivation. 

Why This Matters?

In the face of global change processes such as land-use change by agriculture, it is imperative to go beyond species occurrences and explore the mechanisms or factors that potentially maintain their presence in modified systems. Resource availability and interactions are some accessible metrics to examine to assess the suitability of these systems for biodiversity. In the northern Western Ghats of Dodamarg, Maharashtra, agriculture is the major cause of land-use change, with cashew monocultures expanding at unprecedented rates. There are less intensive cashew agroforests also present in the landscape, that are much fewer in number and on the verge of being wiped out. Our findings highlight that agroforests can partially mitigate the loss in floral abundance and diversity, thus also potentially aiding the conservation of nectar-feeding bird communities.

Key Findings 

  • Floral abundance declined most sharply in cashew monocultures, followed by cashew agroforests. 

  • Abundance and diversity of nectar-feeding birds were the highest in cashew agroforests.

  • Forests had the highest floral diversity and bird-flower interactions. 

  • Agroforest and monoculture plant-nectarivore communities showed higher values of connectance, specialisation, and modularity than those of forest. 

Trees like Palash (Butea monosperma), when planted along plantation edges, can attract a large number of avian pollinators.

Publications

  1. Madhu, N., Sadekar, V., Jayapal, R., & Naniwadekar, R. (2025). Effects of land-use intensification on nectar resources, bird assemblages and bird-flower interaction networks in the Western Ghats, India. bioRxiv. https://doi.org/10.1101/2025.10.01.679556