Birds

Since 2010, Point Blue Conservation Science has conducted 1,461 bird surveys across TomKat Ranch during May and June and detected a total of 98 bird species. Each year, biologists conduct point count surveys for birds at a random sample of points chosen from a grid across the ranch, as well as at 12 points in riparian vegetation along Honsinger Creek. We analyzed this data to examine spatial patterns and trends in species richness and in grassland bird abundance across the ranch.

Updated: March 7, 2025

SMART Goals

Increase grassland breeding birds: Increase densities to an average of 4.25 birds per 10 acres.

Support riparian birds: Continue increasing riparian bird populations at current rates (Wilson’s Warbler, Swainson’s Thrush, Song Sparrow). Maintain high bird species richness in Honsinger Creek (20-50 species per point).

Average focal species abundance

The density of grassland focal species (Grasshopper Sparrow and Savannah Sparrow) varies across the ranch. We compiled bird survey data across 2010-2024 to estimate the overall average density (birds per 10 acres) of each species at each survey point across the ranch.

Choose a focal species at bottom left. Click on any of the grid cells for the density estimate.

Focal species declines

Since 2010, we have observed a slight ranch-wide decline in the density of Savannah Sparrows and Grasshopper Sparrows.

Species richness concentrated along Honsinger Creek

The shading in this map shows the estimated number of species ever detected near a bird survey station, with darker colors representing more species. Honsinger Creek is a hotspot of bird species richness, with some of the highest numbers of species, but there are also some other hotspots across the ranch.

Click on any of the points or grid cells for the number of species detected.

Decline in grassland species richness

Ranch-wide, there were initially more total species in grassland point than in riparian points. Grassland species richness was particularly sensitive to drought, with reduced species richness in years (2014-2016, 2021-2022), but increased with average rainfall in 2024.

About this page

This interactive web page was produced in R using rmarkdown and the packages leaflet and plotly. The code used to produce this web page is available on Github.