Developing bio-acoustic monitoring: can current challenges be overcome?

Background
Measuring and monitoring faunal biodiversity across large scales is a challenge, especially for the smaller sized taxa such as invertebrates, and those active below-ground. A growing trend in ecology is to use the sounds of an area to non-invasively monitor species: providing information regarding spatial and temporal distribution of biodiversity, abundance, and the richness and composition of the community. Metrics (e.g. acoustic complexity) can quantify the sounds present and link these to diversity of the ecosystem. This technique is becoming standard in aquatic and above-ground temperate systems focussed on fish, bats, birds and anurans, but is yet to be explored fully below-ground and for invertebrates.
Working along disturbance gradients (principally grazing pressure) and across savanna habitats, this project seeks to advance the field of bio-acoustics by determining the potential of this sampling approach for quantifying invertebrate diversity both above and below-ground.

Novelty and Timeliness
Whilst a few sensors have been used to explore biotic signals in soil, none offer a reliable, cost-effective solution; a road-block in the current utility of acoustics for ground monitoring. This project will develop soil sensors and use AI-driven data processing offering the potential to develop a novel and widely applicable technology to aid conservation and biodiversity understanding.

Objectives
1. Explore the potential of above and below-ground terrestrial bioacoustics sampling and biodiversity quantification.
2. Determine if acoustic diversity indices can reflect true diversity by comparing biodiversity data from acoustic recording units, with that from field sampling and eDNA.
3. Determine to what extent differences in savanna habitats can be detected with bioacoustics biodiversity measures.
Based in the savanna landscapes surrounding Mount Kenya, the PhD student will work closely with the project CASE partner, Natural State (www.naturalstate.org), to refine the research questions and develop the field sampling design. Natural State will provide in-country support.

A growing trend in ecology and conservation is the use of sounds or vibrations to monitor biodiversity. This promising non-invasive monitoring method has a wide range of benefits; it can provide data regarding animal abundance, diversity, and spatial distribution of communities. Whilst ecoacoustics is now commonly used to assess aquatic and above-ground terrestrial taxa (e.g., fish, bats, birds, and anurans), few studies have applied the technique to below-ground systems or invertebrates. Typically, below-ground invertebrate sampling is conducted using traditional fieldwork techniques. Whilst proven to be successful, these methods are often time consuming, expensive, and cause disturbance to soils. This project aims to develop ecoacoustic monitoring to quantify above- and below-ground invertebrates. More specifically our objectives are: (1) explore the potential of above- and below-ground terrestrial ecoacoustic monitoring using a cost-effective sensor; (2) determine if ecoacoustic indices can reflect true abundance and diversity by comparing ecoacoustic data to traditional field sampling; and (3) determine the potential of using ecoacoustics to map invertebrate abundance and diversity in savanna habitats. We will collaborate with the project CASE partner, Natural State in Mount Kenya to conduct our fieldwork in savanna habitats. This will allow us to work along disturbance gradients (e.g., grazing pressure), assess the relationship between carbon storage and invertebrate biodiversity, and explore the impact of savanna habitat restoration on invertebrates. This research aims to support conservation efforts of invertebrates, and quantify the potential effects of disturbance, carbon storage and savanna restoration projects on these functionally important taxa.