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Research Interests: Behavioural ecology, landscape ecology, community ecology
Urbanization poses a major threat to biodiversity worldwide. We focused on birds as a well-studied taxon of interest, in order to review literature on traits that influence responses to urbanization. We review 226 papers that were published between 1979 and 2020, and aggregate information on five major groups of traits that have been widely studied: ecological traits, life history, physiology, behavior and genetic traits. Some robust findings on trait changes in individual species as well as bird communities emerge. A lack of specific food and shelter resources has led to the urban bird community being dominated by generalist species, while specialist species show decline. Urbanized birds differ in the behavioral traits, showing an increase in song frequency and amplitude, and bolder behavior, as compared to rural populations of the same species. Differential food resources and predatory pressure results in changes in life history traits, including prolonged breeding duration, and increases in clutch and brood size to compensate for lower survival. Other species-specific changes include changes in hormonal state, body state, and genetic differences from rural populations. We identify gaps in research, with a paucity of studies in tropical cities and a need for greater examination of traits that influence persistence and success in native vs. introduced populations.
Swaroop Patankar; Ravi Jambhekar; Kulbhushansingh Suryawanshi; Harini Nagendra. Which Traits Influence Bird Survival in the City? A review. Land 2021, 10, 92 .
AMA StyleSwaroop Patankar, Ravi Jambhekar, Kulbhushansingh Suryawanshi, Harini Nagendra. Which Traits Influence Bird Survival in the City? A review. Land. 2021; 10 (2):92.
Chicago/Turabian StyleSwaroop Patankar; Ravi Jambhekar; Kulbhushansingh Suryawanshi; Harini Nagendra. 2021. "Which Traits Influence Bird Survival in the City? A review." Land 10, no. 2: 92.
The Environment Impact Assessment (EIA) is a regulatory framework adopted since 1994 in India to evaluate the impact and mitigation measures of projects, however, even after 25 years of adoption, EIAs continue to be of inferior quality with respect to biodiversity documentation and assessment of impacts and their mitigation measures. This questions the credibility of the exercise, as deficient EIAs are habitually used as a basis for project clearances in ecologically sensitive and irreplaceable regions. The authors reiterate this point by analysing impact assessment documents for three projects: the doubling of the National Highway-4A, doubling of the railway-line from Castlerock to Kulem, and laying of a 400-kV transmission line through the Bhagwan Mahavir Wildlife Sanctuary and National Park in the state of Goa. Two of these projects were recently granted ‘Wildlife Clearance’ during a virtual meeting of the Standing Committee of the National Board of Wildlife (NBWL) without a thorough assessment of the project impacts. Assessment reports for the road and railway expansion were found to be deficient on multiple fronts regarding biodiversity assessment and projected impacts, whereas no impact assessment report was available in the public domain for the 400-kV transmission line project. This paper highlights the biodiversity significance of this protected area complex in the Western Ghats, and highlights the lacunae in biodiversity documentation and inadequacy of mitigation measures in assessment documents for all three diversion projects. The EIA process needs to improve substantially if India is to protect its natural resources and adhere to environmental protection policies and regulations nationally and globally.
Girish Punjabi; Anisha Jayadevan; Abhishek Jamalabad; Nandini Velho; Madhura Niphadkar-Bandekar; Pronoy Baidya; Ravi Jambhekar; Parag Rangnekar; Omkar Dharwadkar; Rhea Lopez; Marishia Rodrigues; Farai Divan Patel; H.S. Sathya Chandra Sagar; Sayan Banerjee; Manish Chandi; Nandini Mehrotra; Shashank Srinivasan; Sneha Shahi; Vidyadhar Atkore; Nirmal Kulkarni; Gowri Mallapur; Hanuman Gawas; Atul Borker; Rahul Prabhukhanolkar; Harshada S. Gauns; Dheeraj Halali; Vighnesh D. Shinde; Katrina Fernandez; Esme Purdie; Manoj R. Borkar. On the inadequacy of environment impact assessments for projects in Bhagwan Mahavir Wildlife Sanctuary and National Park of Goa, India: a peer review. Journal of Threatened Taxa 2020, 12, 1 .
AMA StyleGirish Punjabi, Anisha Jayadevan, Abhishek Jamalabad, Nandini Velho, Madhura Niphadkar-Bandekar, Pronoy Baidya, Ravi Jambhekar, Parag Rangnekar, Omkar Dharwadkar, Rhea Lopez, Marishia Rodrigues, Farai Divan Patel, H.S. Sathya Chandra Sagar, Sayan Banerjee, Manish Chandi, Nandini Mehrotra, Shashank Srinivasan, Sneha Shahi, Vidyadhar Atkore, Nirmal Kulkarni, Gowri Mallapur, Hanuman Gawas, Atul Borker, Rahul Prabhukhanolkar, Harshada S. Gauns, Dheeraj Halali, Vighnesh D. Shinde, Katrina Fernandez, Esme Purdie, Manoj R. Borkar. On the inadequacy of environment impact assessments for projects in Bhagwan Mahavir Wildlife Sanctuary and National Park of Goa, India: a peer review. Journal of Threatened Taxa. 2020; 12 (18):1.
Chicago/Turabian StyleGirish Punjabi; Anisha Jayadevan; Abhishek Jamalabad; Nandini Velho; Madhura Niphadkar-Bandekar; Pronoy Baidya; Ravi Jambhekar; Parag Rangnekar; Omkar Dharwadkar; Rhea Lopez; Marishia Rodrigues; Farai Divan Patel; H.S. Sathya Chandra Sagar; Sayan Banerjee; Manish Chandi; Nandini Mehrotra; Shashank Srinivasan; Sneha Shahi; Vidyadhar Atkore; Nirmal Kulkarni; Gowri Mallapur; Hanuman Gawas; Atul Borker; Rahul Prabhukhanolkar; Harshada S. Gauns; Dheeraj Halali; Vighnesh D. Shinde; Katrina Fernandez; Esme Purdie; Manoj R. Borkar. 2020. "On the inadequacy of environment impact assessments for projects in Bhagwan Mahavir Wildlife Sanctuary and National Park of Goa, India: a peer review." Journal of Threatened Taxa 12, no. 18: 1.
A key problem faced by foragers is how to forage when resources are distributed heterogeneously in space. This heterogeneity and associated trade‐offs may change with spatial scale. Furthermore, foragers may also have to optimize acquiring multiple resources. Such complexity of decision‐making while foraging is poorly understood. We studied the butterfly Ypthima huebneri to examine how foraging decisions of adults are influenced by spatial scale and multiple resources. We predicted that, at a small‐spatial scale, the time spent foraging in a patch should be proportional to resources in the patch, but at large‐spatial scales, due to limitations arising from large travel costs, this relationship should turn negative. We also predicted that both adult and larval resources should jointly affect foraging butterflies. To test these predictions, we laid eleven plots and sub‐divided them into patches. We mapped nectar and larval resources and measured butterfly behavior in these patches and plots. We found that adult foraging behavior showed contrasting relationships with adult resource density at small versus large‐spatial scales. At the smaller‐spatial scale, butterflies spent more time feeding in resource‐rich patches, whereas at the large‐scale, butterflies spent more time feeding in resource‐poor plots. Furthermore, both adult and larval resources appeared to affect foraging decisions, suggesting that individuals may optimize search costs for different resources. Overall, our findings suggest that the variation in foraging behavior seen in foragers might result from animals responding to complex ecological conditions, such as resource heterogeneity at multiple spatial scales and the challenges of tracking multiple resources.
Ravi Jambhekar; Kavita Isvaran. Foraging in nature: Contrasting responses to resource heterogeneity at small‐ and large‐spatial scales. Biotropica 2020, 53, 276 -285.
AMA StyleRavi Jambhekar, Kavita Isvaran. Foraging in nature: Contrasting responses to resource heterogeneity at small‐ and large‐spatial scales. Biotropica. 2020; 53 (1):276-285.
Chicago/Turabian StyleRavi Jambhekar; Kavita Isvaran. 2020. "Foraging in nature: Contrasting responses to resource heterogeneity at small‐ and large‐spatial scales." Biotropica 53, no. 1: 276-285.
. Invasive species are thought to influence native biodiversity through a wide range of direct and indirect effects. We examined the influence of an invasive plant, Lantana camara, on butterfly assemblages in a tropical forest in India. Lantana camara typically dominates the understorey in invaded areas and might therefore reduce the availability of resources and microhabitats essential for butterflies. We hypothesized that butterflies would show reduced use of lantana-dominated habitat when compared with native vegetation. We evaluated such reduced habitat use by testing for (1) reduced levels of behaviours other than feeding and (2) fewer butterfly species and individuals in lantana-dominated habitat patches. To test these expectations, three plots of 30 × 30 meters each were laid in lantana-dominated and native-vegetation patches. In total, three plots in native-vegetation and three in lantana-dominated habitat were marked. Butterfly behaviour was measured through focal-animal follows, and abundance and species numbers were investigated using point sampling inside these plots. We found that butterflies showed substantial behavioural differences between lantana-dominated and native-vegetation plots, indicating a possiblity that the invaded patches were relatively less suitable for several butterfly activities. Furthermore, fewer butterfly species and individuals were seen in lantana-dominated compared with native-vegetation habitat, indicating that lantana invasion results in reduced suitability of a habitat. Whether local behavioural effects of invasive plants, such as reduced habitat use, can lead ultimately to reduced population sizes and local extinctions will need to be examined.
Ravi M. Jambhekar; Kavita Isvaran. Impact of the Invasive Weed Lantana camara (Verbenaceae) on Butterfly Behaviour and Habitat Use in a Tropical Forest in India. The Journal of the Lepidopterists' Society 2016, 70, 302 -310.
AMA StyleRavi M. Jambhekar, Kavita Isvaran. Impact of the Invasive Weed Lantana camara (Verbenaceae) on Butterfly Behaviour and Habitat Use in a Tropical Forest in India. The Journal of the Lepidopterists' Society. 2016; 70 (4):302-310.
Chicago/Turabian StyleRavi M. Jambhekar; Kavita Isvaran. 2016. "Impact of the Invasive Weed Lantana camara (Verbenaceae) on Butterfly Behaviour and Habitat Use in a Tropical Forest in India." The Journal of the Lepidopterists' Society 70, no. 4: 302-310.