Seasonal elevational dynamics of Central Himalayan mammals and birds: occurrences, richness metrics, abundance centres, boundary shifts, traits, and phylogeny

Published Jun 19, 2025 on Dryad. https://doi.org/10.5061/dryad.dfn2z35dh

Data files

Jun 19, 2025 version files 6.90 MB

data.zip

6.89 MB
README.md

9.05 KB

Abstract

This data package quantifies seasonal shifts in species diversity, traits, and elevational distributions of mammals and birds in the Gyirong Valley, Central Himalayas. Field surveys were carried out in two distinct climatic periods—the warm season (May to September) and the cold season (October to April)—along twelve contiguous 300 m elevational bands spanning ~1 400–4 000 m a.s.l.

For each band and season the package provides:

Species occurrences for every elevational band and sample plot.
Observed, interpolated, and Chao‑estimated species richness for mammals and birds.
Abundance centres (mid‑points of abundance distributions) for 14 focal genera and all constituent species.
Seasonal upper and lower elevational limits and the corresponding boundary‑shift values.
Species‑level trait data (body mass, tiet, forest dependency, habitat or breeding elevation, etc.).
Time‑calibrated phylogenies of the surveyed mammal and bird assemblages.

All tabular datasets are supplied as .csv files with explicit variable definitions; phylogenetic trees are provided in .nex format.

Important note: Analytical context, methods, and interpretation are detailed in the associated Ecography article, “Seasonal variation in community structure and elevational distributions of mammals and birds in the Central Himalayas.” Users are strongly encouraged to consult the paper when re‑using these data.

Released under open‑data best practices, the files support comparative macro‑ecological, biogeographic, and conservation research on montane biodiversity and its response to seasonal and climatic change.

Dataset DOI: 10.5061/dryad.dfn2z35dh

Description of the data and file structure

These data arise from a multi‑year field campaign designed to quantify how Himalayan mammal and bird communities shift with season and elevation. Between 2018 and 2022 we surveyed the Gyirong Valley (Central Himalayas, 1 800–4 000 m a.s.l.) in two climatic periods—warm (May–Sep) and cold (Oct–Apr)—across twelve contiguous 300 m elevational bands. Terrestrial mammals were sampled with four replicated snap‑trap sessions (5 sites × 30 traps × 6 days per band) and a network of camera traps (5 units per band, 60‑day windows matched to the snap‑trap months). Birds were censused along three 2.5 km line transects per band, repeated eight times (four warm‑, four cold‑season visits). The resulting tables report species occurrences, observed/interpolated/Chao‑estimated richness, abundance‑centre coordinates for 14 focal genera, seasonal boundary shifts, species traits, and matching phylogenies. These datasets underpin the analyses in the accompanying Ecography article on seasonal community dynamics along Himalayan mountain gradients.

Files and variables

File: data.zip

1 abundance centres of 14 genera and their species

It contains 14 Excel files, each named after a bird genus, corresponding to 14 different bird genera.

Recorded elevation: Recorded elevation (m) of species field observations
Abundance: Number of individuals recorded
Season: Season of field survey
Species: Scientific name
Abundance centres of species: The abundance centre of each species was calculated by weighting the elevation of its occurrences according to the recorded number of individuals
Abundance centres of genus: The abundance centre of each genus was calculated by weighting the elevations of all species occurrences within the genus based on their respective abundances

2 observed, interpolated, and estimated species richness in each elevational band

It contains two Excel files, corresponding to information on birds and mammals, respectively.

Season: Season of field survey
Elevation (m): Range of the elevation band (m)
Observed richness: Observed richness refers to the actual number of different species recorded in a elevational band
Chao2 statistic: The Chao2 statistic is a non-parametric estimator of species richness; the Chao2 statistic is expressed in the format of "estimate ± SD"
Survey effort (%): (Observed richness/Chao2 statistic)*100; Used to assess the intensity of field sampling
Interpolated richness: The interpolation method assumes that species exist at an elevation if they are recorded at both lower and higher elevations

3 species occurrences

The folder "species occurrences in each elevational band" contains two folders, corresponding to information on birds and mammals, respectively. The files "dry-bird/mammal" and "wet-bird/mamaml" represent presence–absence matrices of bird/mammal species recorded at different elevation bands during the dry and wet seasons, respectively. In the occurrence presence-absence matrix, each row represents an elevational band, and each column represents a species.
The folder "species occurrences in each sampling plot" contains data on the seasonal occurrences (abundance data) of 25 mammal species and 75 bird species across different transects and plots. Using birds as an example, the first column "transect" refers to the 36 specific transect lines surveyed. Rows numbered 1–36 represent data from the warm season, while 37–72 correspond to the cold season. For mammals, rows 1–60 represent the warm season, and 61–120 correspond to the cold season. The first row, labeled “s1, s2, s3, s4......”, represents repeated survey occasions.
The files "Standardized_siteCovs_mammal" and "Standardized_siteCovs_bird" contain Standardized environmental variables associated with each sampling plot for mammals and birds, respectively.

transect or site: The transect or plot ID corresponding to the entries in "species occurrences in each sampling plot"
ele: Elevation of the sampling plot
ele2: Square of the elevation of the sampling plot
ndvi: Normalized Difference Vegetation Index
sea: Season of the survey; w indicates the warm season, and c indicates the cold season
length: Length of bird transects

4 species traits, elevational boundary shifts, and phylogenetic information for 25 mammal and 75 bird species

The folder "species traits, elevational boundary shifts, and phylogenetic information for 25 mammal and 75 bird species" contains data for 25 mammal species (in the "mammal" subfolder) and 75 bird species (in the "bird" subfolder), including species traits, elevational boundary shifts, and phylogenetic information.
The Excel files “75birds” and “25mammals” contain species traits related to the elevational distribution ranges of each species.

Common: English name of the species
Species: Scientific name of the species
lower boundary warm: Lower elevational limit (m) of the species during the warm season
lower boundary cold: Lower elevational limit (m) of the species during the cold season
upper boundary warm: Upper elevational limit (m) of the species during the warm season
upper boundary cold: Upper elevational limit (m) of the species during the cold season
range size warm: Elevational range size (m) of the species during the warm season (upper minus lower limit)
range size cold: Elevational range size (m) of the species during the cold season (upper minus lower limit)
abundance center warm: Elevation (m) of the species' abundance center during the warm season
abundance center cold: Elevation (m) of the species' abundance center during the cold season
breeding elevation: Breeding elevation of birds; L, M, and H refer to low, mid, and high elevations, respectively.
habitat elevation: Habitat elevation of mammals during the warm season; L, M, and H refer to low, mid, and high elevations, respectively
flocking status: Indicates whether a bird species exhibits mixed-species flocking behavior; "flock" denotes presence of this behavior, while "non" denotes that the species does not exhibit this behavior
forest dependency: Indicates whether a species is dependent on forest habitats; "forest" denotes forest dependency, while "non" denotes lack of such dependency
hibernation: Indicates whether a mammal species exhibits hibernation; "hiber" denotes presence of this behavior, while "non-hiber" indicates absence
diet: Diet indicates the feeding behavior of the species. For mammals, “her” refers to herbivores, “car” to carnivores, and “omn” to omnivores that consume both plant and animal matter. For birds, “omnivore” refers to species that feed on both plant and animal matter; “plantSeed” denotes those that primarily consume plant materials such as leaves, buds, or seeds; “insectivore” describes species that specialize in feeding on insects and other small invertebrates; and “fruiNect” refers to those that mainly feed on fruits and nectar.

The Excel files "the significance of lower elevational range boundary shifts" and "the significance of upper elevational range boundary shifts" contain information on changes in the lower and upper elevational range boundaries, respectively, for 25 mammal and 75 bird species, along with their corresponding species traits. The trait abbreviations are consistent with those used previously.

mass(g): Body mass (g)
upper(m): Change in the upper elevational boundary (cold season minus warm season), measured in meters (m)
lower(m): Change in the lower elevational boundary (cold season minus warm season), measured in meters (m)
sig: Significance of the elevational range boundary shift (p < 0.05); 1 indicates significant, 0 indicates not significant.

The phylogenetic information file is in .nex format. We downloaded 5,000 phylogenetic trees from vertlife.org, based on the "mammal birth-death node-dated completed tree" (Upham et al., 2019) for mammals and the "Hackett All Species" tree (Jetz et al., 2012) for birds. Maximum Clade Credibility trees for both groups were computed using the R package phangorn (Schliep, 2011).