Assessing the impact of habitat fragmentation on the genetic diversity and foraging behavior of urban-dwelling insectivorous bats (Chiroptera) using acoustic monitoring and population genomics

Project Abstract

Habitat fragmentation is a pervasive urban ecosystem process that can alter the genetic structure and foraging dynamics of insectivorous bats, with cascading effects on ecosystem services such as pest control. This study investigates how urban landscape fragmentation shapes genetic diversity, gene flow, and foraging behavior in insectivorous bats (Chiroptera) by integrating acoustic monitoring, population genomics, and landscape genetics across a gradient of urbanization. We sampled bat populations from multiple roosts distributed along a fragmented urban-rural transect in order to quantify how patch size, edge effects, connectivity, and matrix hostility influence demographic parameters and spatial genetic structure. Acoustic monitoring provided high-resolution data on activity patterns, species richness, and foraging guilds across different habitat configurations, enabling fine-scale inference of foraging responses to habitat edges, noise pollution, light pollution, and prey availability. Genomic data were generated using reduced-representation sequencing to identify single nucleotide polymorphisms (SNPs) and assess genetic diversity (heterozygosity, allelic richness), population structure, and contemporary gene flow among habitat patches. Integrating these data within a landscape genetics framework, we tested hypotheses linking fragmentation metrics (patch size, isolation, connectivity corridors) to changes in genetic diversity and dispersal distances, while simultaneously examining correlations with behavioral metrics such as foraging height, prey encounter rate, and temporal activity windows derived from acoustic signatures. We employed generalized linear mixed models and spatially explicit simulations to disentangle the relative contributions of habitat structure, urban stressors (light and noise), and prey community composition to observed patterns. Our anticipated findings include reduced genetic diversity and increased population differentiation in highly fragmented urban patches, coupled with altered foraging strategies such as increased edge foraging, shifts to more conservative activity periods, and reliance on mosaicked green spaces as ecological corridors. The study also aims to identify critical landscape features that facilitate gene flow and sustain functional connectivity, including hedgerows, riparian corridors, and continuous green roofs, and to evaluate the buffering capacity of urban green networks against genetic erosion. Results will enhance understanding of how anthropogenic habitat modification impinges on the ecological resilience of aerial insectivores and their ecosystem services. Implications for urban planning include evidence-based recommendations for maintaining connectivity through multi-tiered green infrastructure, minimizing lighting and noise pollution in key foraging corridors, and prioritizing corridor width and quality to preserve genetic diversity. Policy-relevant outputs will include a framework for evaluating urban habitat networks in bat conservation, with transferable methods for other nocturnal vertebrates. Overall, the study advances integrative methodological approaches that bridge population genomics, bioacoustics, and landscape ecology to illuminate the mechanisms by which urban fragmentation shapes the evolutionary and behavioral trajectories of urban-dwelling insectivorous bats.

Project Overview

What This Project Is About

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A straightforward look at how habitat fragmentation in cities affects bats that eat insects. The project studies how breaking up green spaces changes where bats roam, how many different genetic groups exist, and how their hunting behavior adapts to smaller, patchier habitats. It uses simple, non-technical methods to connect the dots between landscape changes and bat life.

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The Problem It Addresses

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Urban development often divides habitats, which can reduce genetic diversity and alter how animals find food. For bats, fragmentation may limit movement, isolate populations, and change foraging patterns. Understanding these effects helps us protect biodiversity and improve urban planning for wildlife.

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Objectives of the Project

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1. Describe how urban habitat changes relate to bat movement and foraging.
2. Assess genetic diversity within and between bat groups across fragmented areas.
3. Identify changes in hunting strategies in smaller or isolated patches.
4. Provide practical recommendations for urban wildlife-friendly design.

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What You Will Do Step by Step

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1. Review basic concepts about bats, urban habitats, and genetics in simple terms.
2. Collect acoustic recordings to detect bat presence and foraging calls in different patches.
3. Collect non-invasive genetic samples (e.g., from guano) to compare diversity.
4. Analyze sounds to infer where and how bats hunt.
5. Analyze genetic data to measure diversity and relatedness.
6. Compare results across sites with varying levels of fragmentation.
7. Interpret findings in plain language and relate them to urban design.

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Expected Outcome

Clear understanding of how city fragmentation affects bat genetics and foraging, with simple recommendations for preserving diverse bat communities in urban areas.