EDP Foz Tua: Bat Habitats - Ecological & Compensatory Measures Monitoring Programs [2011-2017]

Description

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 1,505 records.

1 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

osta H, Nuno S, Mesquita S, Mascarenhas M, Marques A T, Coelho H, Braz L, Gonçalves R, Ferraz C, Batista S, Ribeiro S B, Lemos J, Santos P, Sousa D, Paula J, Oliveira J, Caetano M, Silva R, Monteiro B, Pereira P, Silva M, Ferreira C, Pereira F, Neves T, Magalhães J, Romão F, Augusto M, Carmo M, Santos J, Queirós L, Moreira M, Santos J, Múrias T (2018): EDP Foz Tua: Bat Habitats - Ecologial & Compensatory Measures Monitoring Programs [2011-2017]. v1. EDP - Energias de Portugal. Dataset/Samplingevent.

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is EDP - Energias de Portugal. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 5b345642-64b5-4115-86b7-ba64d8e2c15b.  EDP - Energias de Portugal publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF Portugal.

Keywords

occurrence; Bats; observation; hibernation; reproduction; refuges; roosts

Contacts

Geographic Coverage

The data were collected within a 5-km radius buffer around the lower valley of River Tua (Northeast Portugal), up to 45 km from the mouth, in the municipalities of Alijó, Carrazeda de Ansiães, Vila Flor, Mirandela and Murça.

Taxonomic Coverage

The taxonomic coverage of this dataset spans 1 phylum, 1 class, 1 order, 4 families, 10 genus and 15 species positively identified. Additionally, a set of 9 potential species may be present in the 23 “species complexes” identified.

Temporal Coverage

Project Data

The dataset contains records of bats (Chiroptera) collected in suitable foraging habitats along the lower valley of River Tua. Data were collected in the scope of the Ecological Monitoring Program (PME) and Program of Mitigation/Compensation Measures (PMC), promoted by EDP – Energias de Portugal, S.A. Data were collected between August 2011 and October 2017, during field visits to 57 sampling points, stratified by habitat, within a 5-km radius buffer around the lower valley of River Tua. The occurrence of the target taxa was documented through 8269 observation events. In total, 16 taxa were identified, 15 to the species rank and 5 to the genus rank. The 23 “species complexes” identified could potentially add 9 more species to the list. The most common species (>1000 records) were Pipistrellus pygameus (1288 records), P. kuhlii (1272), P. pipistrelus (1247) and Tadarida teniotis (1223). The “species complex” Pipistrellus pygmaeus/Miniopterus schreibersii, with 616 records was also relevant. A substantial number of records (643) could not be identified beyond the Order.

The personnel involved in the project:

Sampling Methods

Sampling was designed to cover all suitable foraging habitats for bats in the study area. A stratified sampling procedure was used, with the number of samples allocated to each habitat in proportion to the area occupied and/or its significance for bats. A total of 57 sampling points was set in natural woodlands (10), forest plantations (mostly Eucalyptus and Pinus), (9) river margins (10), shrublands (9), orchards/olive orchards (6), vineyards (6) and dryland crops (7). Each point was visited 2-4 times per year in 2011-2014, and monthly (March - October) from 2014 to 2017. Acoustic sampling was made within ± 3 hours of sunset, beginning 30 minutes after it. Each point was sampled for 10 consecutive minutes. The detection of the specimens in flight was made with a bat detector (Pettersson Elektronik, D240X model), with a frequency range of 10-120 kHz. The detector was connected to an automatic digital recorder (model Sony ICD-PX312) which saved the recordings in a “Wave” format, at a frequency of 44 kHz and at an expanded mode of 10x, making them audible to the human ears while, at the same time, preserving the original acoustic characteristics. From 2011 to 2013 the analyses of bat sound records used the manual/traditional methodology based on the the software “Batsound Pro – Sound Analysis”, from Pettersson Elektronik. This software generates graphics (oscillograms, sonograms and power spectrums) that allow the identification of the detected species by comparing them with those available in reference bat sound libraries. The acoustic variables usually employed to manually identify the sounds are (1) the structure of the pulse, (2) the frequency of maximum energy (kHz), (3) the range of frequencies (kHz), (4) the pulse duration (ms), (5) the interval between pulses (ms), and (6) the pulse repetition rate (Hz). From 2014 onwards, a more automated and expeditious method based in a model developed by Silva et al. (2013) was employed for species identification. A semi-automatic program provided 19 diagnostic parameters of the pulses (16 spectral and 3 temporal parameters). Subsequently, a probabilistic model (Artificial Neural Networks, ANN) was run to compare these parameters with those of a reference database of more than 16000 individual pulses from 1400 individuals of 9 genera recorded in Continental Portugal. The ANN attributed the pulses to a species or group of species (phonic group or “species complex”), with an associated probability of certainty. The results of the classification model showed an average sensitivity of 95% and an average error of 4%. Only the classifications with a probability greater than 70% were considered correct. When the above threshold was not reached by the model, the records were analyzed by the manual/traditional method described above. The exact identification of the bat species by sound analysis is not always possible, due to problems in detectability and/or identifiability. In the context of this work, whenever it was not possible to perform the identification until the species, the binomials, multinomials or genera to which the identification was possible were considered to be present. Thus, the presence of all species constituting these phonic groups (or “species complexes”) was considered possible.

Method step description:

1. To be completed

Bibliographic Citations

1. Silva, B, Jacinto, G, Infante, P, Barreiro, S & Alves, P (2013) In Maia, M, Campos, P & Duarte Silva, P (eds.): Identificação automatizada de morcegos através de modelos estatísticos. In Estatística : novos desenvolvimentos e inspirações. Edições SPE, Lisboa. pp.257-270

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