Time series methods for cyclical ecological data

Biodiversity monitoring has entered an era of `big data', exemplified by a near-continuous collection of sounds, images, chemical, and other signals from organisms in diverse ecosystems. Such data streams have the potential to help identify new threats, assess the effectiveness of conservation interventions, as well as generate new ecological insights. However, appropriate analytical methods are often still missing, particularly with respect to characterizing cyclical temporal patterns. Here, we present a framework for characterizing and analyzing ecological responses that represent nonstationary, complex temporal patterns and demonstrate the value of using Fourier transforms to decorrelate continuous data points. In our example, we use a framework based on three approaches (spectral analysis, magnitude squared coherence, and principal component analysis) to characterize differences in tropical forest soundscapes within and across sites and seasons in Gabon. By reconstructing the underl..., We used acoustic data collected from eight sites in the Ogooué-Ivindo province of Gabon to demonstrate how time-series approaches can be leveraged to compare cyclical trends within and between groups of sites. All soundscape sampling occurred in closed, Gabonese rainforest with minimal habitat disturbance for at least twenty years. First, we sampled the soundscape in the rainy season at four sites within Ivindo National Park, between February 19th and March 2nd 2021 (referred to as the Ivindo sites). Second, we sampled the soundscape in the dry season at four sites near Massaha between July 17th and July 23rd 2021 (hereafter referred to as the Massaha sites, about 15km from the Ivindo sites). At the time of sampling, the Massaha sites were located within a logging concession but no logging activity had commenced and there was an ongoing petition for the area to be re-designated as a community conservation area. Additionally, we used one site from the Lope National Park.
At each site, we..., , # Time series methods for cyclical ecological data

[https://doi.org/10.5061/dryad.xpnvx0kn6](https://doi.org/10.5061/dryad.xpnvx0kn6)

Example dataset used for demonstrating the methods in \"Times Series Methods for the Analysis of Soundscapes and Other Cyclical Ecological Data\" Methods in Ecology and Evolution. This data represents soundscape data for eight tropical forest sites in Gabon collected between February and July 2021. See methods for more information. The soundscape is characterized using the soundscape index Power Minus Noise (PMN) for 256 frequency bins between 0-11 kHz for each minute of the day. PMN is a proxy for acoustic activity and provides a relatively simple index to demonstrate our methodological approach.

## Description of the data and file structure

Column names:

* Site: Site code (factor; 8 levels)
* DatetimeFinal: Date time information (datatime object)
* TotPMN: Values for characterizing the soundscape, Power minus noise (numeric)
* Season: Seasona...