Patch size and vegetation structure drive changes to mixed-species flock diversity and composition across a gradient of fragment sizes in the Western Andes of Colombia
Description
This data set represents a series of 502 mixed-species bird flock compositions, and derived taxonomic, functional, and phylogenetic diversity indices, that were gathered along a gradient of forest fragment sizes (range = 10-173 ha) in the Colombian Western Andes. We sampled mixed-species flocks using transect surveys along 14 transects in 8 fragments and a continuous forest reference site in the same landscape and at the same elevation (~1900-2200 m.a.s.l.). We also used buffer analysis to quantify the proportion of forest cover and forest edge within 1 km of each transect, and calculated local vegetation density and complexity, as well as distance from edge, for each 100-meter transect segment (n = 70 segments). Flock composition data observed on a transect were used to calculate overall species richness and flock size as well as two indices of functional and phylogenetic diversity; we calculated the stadardized effect size (SES) of each measure to account for the correlation between these measures and species richness. We also provide the raw counts of each species for each flock composition. These data were used for the analyses in Jones and Robinson (2020).
Notes
Variable Descriptions
Flock_ID: A unique identifier for each flock composition.
Julian_Date: The Julian (numeric) date on which the flock was observed.
Season: Indicates whether the flock was observed during the boreal summer sampling period (0; June-August 2018) or the boreal winter sampling period (1; January-March 2019).
Site_Segment: Indicates the name of the transect on which the flock was observed followed by the 100-meter transect segment (1-5 for each transect). Where no value is given the flock was observed off of the transect but within 100 meters of the transect; these compositions were not used for analyses. Site characteristics and coordinates for each transect are described in Table 1, Jones and Robinson (2020).
Transect: The name of the transect that the mixed-species flock was observed on or near.
Site: Corresponds to the forest fragment number that the flock was observed in. In some cases, fragments had multiple transects present in them. Site numbers are ordered by increasing area; site 9 corresponds to a continuous forest reference site (RNC Cerro El Ingles). Site characteristics are listed in Table 1, Jones and Robinson (2020).
Minute and Minute_2: Numeric minute and minute squared of the day at which the flock was first detected. Zero corresponds to midnight.
Chlorospingus: This variable indicates whether Chlorospingus canigularis, a nuclear species in this Andean flocking system, was present in the flock composition.
Species: The total species richness of species observed in the flock during the survey.
Size: The total number of individuals of all bird species observed in the flock during the survey.
Furnariid_Sp: The total observed species richness of ovenbirds (Furnariidae) in the flock during the survey.
Tyrannid_Sp: The total observed species richness of tyrant flycatchers (Tyrannidae) in the flock during the survey.
Migrant_Sp: The total observed species richness of boreal migrant species observed in the flock during the survey.
Thraupid_Sp: The total observed species richness of tanager (Thraupidae) species observed in the flock during the survey.
SESFRic: The standardized effect size of the functional richness index of functional diversity present in the flock.
SESFDis: The standardized effect size of the functional dispersion index of functional diversity present in the flock.
SESPD: The standardized effect size of the PD measure of phylogenetic diversity present in the flock.
SESMPD: The standardized effect size of the mean pairwise distance measure of phylogenetic diversity present in the flock.
Dist_Edge: The straight-line distance in meters from the midpoint of the transect segment in which the flock was obsserved to the nearest fragment edge.
1km_forest: The percentage of forest land use in a 1 km buffer centered along the entire length of the transect. This variable was calculated at the transect (and not transect segment) level.
1km_edge: The edge density, calculated as the distance of forest edge in meters divided by the total area in hectares, for a 1 km buffer centered along the entire length of the transect. Calculated at the transect level.
Canopy_Cover: The average canopy cover calculated using a canopy densiometer at ten points for each transect segment.
Understory_Density: A principal component axis measuring the density of understory shrubs, ferns, vines, tree ferns, and palms, as measured using belt transects, for each transect segment. More negative values correspond to higher densities of each category of plant.
Tree_Size: A principal component axis measuring the density of large-diameter trees, as measured by belt transects, for each transect segment. More positive values correspond to greater densities of large-diameter trees.
Vertical_Sturcture: A measure of vertical vegetation complexity. We calculated the proportion of ten point surveys that contained vegetation in five height bands for each transect segment. We then used these proportion data to calculate the Shannon Diversity Index of vegetation complexity for each transect segment. This variable was closely correlated with canopy height at our sites.
Species abundances: The observed abundance of each species in the flock. Species names use the latin binomial.
Funding provided by: Tinker Foundation
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100006038
Award Number:
Funding provided by: Animal Behavior Society
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100009702
Award Number:
Files
Dryad_file.csv
Files
(185.3 kB)
| Name | Size | Download all |
|---|---|---|
|
md5:a75c168ce906efa23064c963d71ac152
|
185.3 kB | Preview Download |