Uncertainties in Species Occurrence Data: How to deal with False Positives and False Negatives

Post provided by Gurutzeta Guillera-Arroita

Species Surveys: New Opportunities and Ongoing Data Challenges

Technologies, such as drones, open new opportunities for wildlife monitoring ©J. Lahoz-Monfort, UMelb.

Technologies, such as drones, open new opportunities for wildlife monitoring ©J. Lahoz-Monfort, UMelb.

Monitoring is a fundamental step in the management of any species. The collection and careful analysis of species data allows us to make informed decisions about management priorities and to critically evaluate our actions. There are many aspects of a natural system that we can measure and, when it comes to monitoring the status of species, occurrence is a commonly used metric.

Ecologists have a long history of collecting species occurrence data from systematic surveys and our ability to gather species data is only going to grow! This is partly enabled by the fact that citizen science programs are starting to gain a prominent role in wildlife monitoring. There’s a growing recognition that well-managed citizen science surveys can produce useful data, while scaling up monitoring effort thanks to the increased human-power from large numbers of committed volunteers. Continue reading

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Refined DNA Tool Tracks Native and Invasive Fish

Below is a press release about the Methods paper ‘Long-range PCR allows sequencing of mitochondrial genomes from environmental DNA‘ taken from the Cornell University.

©Nick Hobgood

Rather than conduct an aquatic roll call with nets to know which fish reside in a particular body of water, scientists can now use DNA fragments suspended in water to catalog invasive or native species.

The research from Cornell University, the University of Notre Dame and Hawaii Pacific University was published July 14 in Methods in Ecology and Evolution.

“We’ve sharpened the environmental DNA (eDNA) tool, so that if a river or a lake has threatened, endangered or invasive species, we can ascertain genetic detail of the species there,” said senior author David Lodge, the Francis J. DiSalvo Director of the Atkinson Center for a Sustainable Future at Cornell, and professor of ecology and evolutionary biology. “Using eDNA, scientists can better design management options for eradicating invasive species, or saving and restoring endangered species.” Continue reading

Issue 7.11

Issue 7.11 is now online!

The November issue of Methods is now online!

This month’s issue contains four Applications articles and two Open Access articles, all of which are freely available.

– moveHMM: This R package allows ecologists to process GPS tracking data into series of step lengths and turning angles, and to fit a hidden Markov model to these data, allowing, in particular, for the incorporation of environmental covariates.

– BORIS: An open-source and multiplatform standalone program that allows a user-specific coding environment to be set for a computer-based review of previously recorded videos or live observations. Being open to user-specific settings, the program allows a project-based ethogram to be defined that can then be shared with collaborators, or can be imported or modified.

– inbreedR: An R package that provides functions to measure variance in inbreeding – through the strength of correlation in heterozygosity across marker loci – based on microsatellite and SNP markers with associated P-values and confidence intervals. Within the framework of Heterozygosity–fitness correlation theory, inbreedR also estimates the impact of inbreeding on marker heterozygosity and fitness.

– Terrestrial Precipitation Analysis: This package is comprised of the Precipitation Trends (P-Trend), Precipitation Attributes (P-Att) and Precipitation Manipulation (P-Man) tools. Combined, these web tools allow researchers to easily calculate fundamental precipitation statistics for past, present and projected future precipitation regimes for any terrestrial location in the world.

Continue reading

Issue 7.1

Issue 7.1 is now online!

The January issue of Methods is now online!

As always, the first issue of the year is our sample issue. You can access all of the articles online free of charge. No subscription or membership is required!

We have two Open Access articles and two Applications papers in our January issue.

Recognizing False Positives: Environmental DNA (eDNA) is increasingly used for surveillance and detection of species of interest in aquatic and soil samples. A significant risk associated with eDNA methods is potential false-positive results due to laboratory contamination. To minimize and quantify this risk, Chris Wilson et al. designed and validated a set of synthetic oligonucleotides for use as species-specific positive PCR controls for several high-profile aquatic invasive species.

BiMat: An open-source MATLAB package for the study of the structure of bipartite ecological networks. BiMat enables both multiscale analysis of the structure of a bipartite ecological network – spanning global (i.e. entire network) to local (i.e. module-level) scales – and meta-analyses of many bipartite networks simultaneously. The authors have chosen to make this Applications article Open Access.

Gemma Murray et al. provide this month’s second Open Access article. In ‘The effect of genetic structure on molecular dating and tests for temporal signal‘ the authors use simulated data to investigate the performance of several tests of temporal signal, including some recently suggested modifications. The article shows that all of the standard tests of temporal signal are seriously misleading for data where temporal and genetic structures are confounded (i.e. where closely related sequences are more likely to have been sampled at similar times). This is not an artifact of genetic structure or tree shape per se, and can arise even when sequences have measurably evolved during the sampling period.

Our January issue also features articles on Monitoring, Population Ecology, Genetics, Evolution, Community Ecology, Diversity and more. Continue reading