Osteometric data of Avian Fauna of Armenia: A baseline for zoologists and archaeozoologists

Modern bird skeletons stored in the faunal collections of the Institute of Zoology of the Scientific Center of Zoology and Hydroecology NAS Armenia constitute a source material for this dataset. The osteological material in the scientific collections has been accumulated in the course of faunal studies in Armenia over the span of 60 years. The osteometric dataset sheds light on the country's species diversity and includes cranial and postcranial measurements (carpometacarpus, humerus, tibia, femur, tarsometatarsus, radius and ulna) of 141 bird skeletons which belong to 81 bird species, 34 families and 17 orders. Bird skeletons have been collected by means of specimen collection from the wild for scientific study prior to 1990s when the practice was common and recovered opportunistically after 1990s from birds found dead through natural causes and incidents. Recent bird skeletons (bones) serve as a unique comparative resource for zoological research and for identifying bird bones recovered from archaeological and natural deposits.


Value of the Data
• Osteometric data of birds facilitate comparative studies of avian bones measurements recovered from archaeological sites and natural deposits, allowing the observation of intraspecific variability and skeletal changes through time.• Faunal collections serve as tangible, first-hand, documented evidence that can be used to study past bird distribution, migration routes.• Archaeozoologists, ornithologists, anatomists, morphologists, paleontologists or researchers working in related disciplines will benefit from this dataset.

Data Description
The data article provides a description of the dataset of the linked repository which contains osteometric measurement data of modern bird skeletons deposited in the scientific collections of the Laboratory of Vertebrate Zoology the Institute of Zoology at the Scientific Center of Zoology and Hydroecology of NAS Armenia.The center's avian skeleton collection includes 165 specimens and is the largest avian osteology collection in Armenia.The information outlined in the database is not part of any published research article and is made available as a standalone data repository for scientists dealing with morphometric comparative studies of birds.
The linked Mendeley Data repository dataset contains an Excel file named 'bird osteometrics' with cranial and postcranial measurement data of modern bird specimens sampled over a period of 61 years (between 1961 and 2022).The featured measurement data is from 141 studied bird individuals which belong to 81 species, 34 families and 17 orders collected from 141 sampling points across all provinces of Armenia.Of these 141 individuals, 16 are female and 125 are male individuals.Table 1 provides an overview of the content of the linked dataset.
Standard measurements (cranial and postcranial) were taken following the data collection procedure described by A. von den Driesch 1976 [3] .Because for most individuals the cranium and some of the postcranial skeletal elements were not available, Table 2 provides the exact set of measurements (abbreviations and definitions) used in the dataset as described by A. von den Driesch 1976 [3] .Table 3 outlines the taxonomic list of birds for which the osteometric measurements is provided, number of individuals measured and geographic names of sampling locations.Because no geo-positioning technology was available in the early stages of material collection, names of the nearest settlements are used to describe the location of the sampling point.
The taxonomy and nomenclature used in Table 3 follow the Bird Life International Illustrated Checklist of the Birds of the World [ 5 , 6 ] and is based on the taxonomy published in the Handbook of the Birds of the World (HBW) [1] .
Also included in the linked dataset are four image files in .Tiff format named 'Map1.tiff','Map2.tiff','Map3.tiff'and 'Map4.tiff'showing sampling locations at which the bird specimens have been obtained.When several specimens of the same species are available, the find location of one specimen, chosen arbitrarily, has been located on the map.The original images have a resolution of 300 dpi, with a width of 1500 pixels and a height of 1412 pixels.'Map1.tiff'shows sampling locations for birds in the order Anseriformes, Galliformes, Phoenicopteriformes, Podicipediformes, Columbiformes, Apodiformes and Gruiformes .'Map2.tiff' shows sampling locations for birds in the order Charadriiformes, Ciconiiformes and Pelecaniformes .'Map3.tiff' shows sampling locations for birds in the order Strigiformes, Accipitriformes, Bucerotiformes, Coraciiformes and Falconiformes .'Map4.tiff' shows sampling locations for birds in the order Passeriformes which is the largest on the list.Bird species shown on the map are numbered and color-coded according to their families and are presented on four separate maps in order to accommodate all data.
Geography of sampled skeleton material included in this manuscript covers all of Armenia with 141 sampling sites.Fig 1 shows one of the four maps -Map1.tiffwith such sampling locations.Sampling sites are not geo-referenced because no geotracking devices were available in the early stages of material sampling and only locations are provided.

Material
The measurement material used in the article includes cranial measurements of 83 skulls (cranium, mandible) and postcranial measurements of 141 skeletal parts (carpometacarpus, humerus, tibia, femur, tarsometatarsus, radius and ulna) from 81 bird species which belong to 34 families and 17 orders.The bird skeletons stored in the scientific collection funds of the Scientific Center for Zoology and Hydroecology NAS Armenia have been collected over the span of 60 years and stored with the aim to create a comparative skeletal collection fund and data for archaeological and zoological research.
Our choice of measurements of the sampled skeletal material relied on the preservation quality and state of the bones.Fractured and fragmented bones were excluded from the measurements.Despite no restrictions are set with regards to which skeletal parts should be measured [ 3 , 4 ], we used same measurements from each skeleton to achieve maximum comparability of the osteometric results.
Prior to 1990s avian skeletons were obtained by means of specimen collection from the wild for scientific study which was a common practice in the country.Starting from early 1990s the practice of amassing specimen collection for science has been restricted for ethical concerns and the present-day bird skeletons were collected opportunistically, involving the salvage of birds found dead through natural causes, confiscated from illegal hunting with the help of Environmental Inspectorate or collected from wildlife rescue centers.

Location
Geographic area of sampling points of avian skeleton material collected over the period of 60 years cover all 11 administrative provinces of Armenia, including present-day protected areas (e.g.Lake Sevan National Park, Lake Arpi National Park).When a bird carcass has been found the original location where the distressed bird has been collected was used.

Preparing bird specimens
The bird specimens obtained in the course of scientific field expeditions (until 1990) and those collected after that date (using opportunistic methods) have been meticulously treated in the laboratory using both mechanical and chemical preparation methods.Despite the methods of specimen collection have changed over time, the specimen preparation protocols remained the same.First of all, after careful examination and proper data recording the study specimens have been skinned (feathers and skin separated from the carcass) using a scalpel, whereby the tissues and the internal organs (muscles, brain, etc.) have been removed.This was followed by the removal of the excess tissues, ligaments and other pieces of meat and subsequently the cleaning of the skeletal material by simmering it in a pot of warm water to help tissue separation.Final degreasing was done using the 3 % hydrogen peroxide solution (H2O2).Subsequently the study skeletons have been washed and dried.Each skeletal material and skull has then been numbered, labelled and catalogued to maximize the scientific value of our osteometric studies.Sexing was done both visually (in case of sexually dichromatic species) and through examination of gonads [8] .

Bone measurements
Measurements of skeletal material were taken based on the references [ 2 , 3 , 7 ], using a vernier caliper with precision to 0.5 mm.Only absolute measurement data are provided.At least three bones were measured for each individual.

Limitations
Our limitations in producing the current dataset referred to preservation quality and state of the bones.To this end, fractured and fragmented bones were excluded from the measurements and same measurements from each skeleton were used to ensure maximum comparability of the osteometric results.

Table Subject
collected from scientific faunal collections stored at the Zoological Museum of the Institute of Zoology, within the Scientific Center of Zoology & Hydroecology Armenian NAS.It was stored in poor conditions for a lengthy time period but it was possible to recover.Each skeleton bone was labelled, measured with an accuracy of 0.5 mm using a Vernier caliper, and described to the extent possible (sex, location and time the specimens were collected).
Direct URL to data: https://data.mendeley.com/datasets/8wfkb2mmns/1This dataset is curated by the Laboratory of Vertebrate Zoology of the Institute of Zoology, Scientific Center of Zoology & Hydroecology Armenian NAS

Table 2
Measurements used in the linked Mendeley dataset.

Table 3
Bird skeleton list for which osteometric measurements are provided.