DOI: 10.57830/2315280
title: National Park Service Northeast Region Deer Spotlight Monitoring, 2024-2025 Cumulative Data Package

description: Overabundant deer have harmful effects on forests by preventing regeneration of a number of important canopy tree species, and by preferentially browsing certain native species while avoiding invasive plants. Left unchecked, the combination of deer and invasive species can eliminate forests entirely, transforming them into invasive shrub thickets. Overabundant deer are also a human health risk, through the increased risk of deer-vehicle collisions and because of increased prevalence of tick-borne illnesses. The Northeast Region of the National Park Service is working to encourage resilient forests by managing overabundant deer, removing invasive species, and taking other actions such as planting climate-resilient tree species in key areas.

An important part of this Resilient Forests Initiative is monitoring deer. Monitoring is used to determine where the populations are in need of intervention and to track the impacts of management actions. Multiple monitoring methods are possible depending on the park, including aerial forward-looking infrared surveys, camera traps, and spotlighting (with visible or infrared light). This data set represents the spotlight data collected at multiple parks in the Northeastern United States, including Gateway National Recreation Area (GATE), Marsh-Billings-Rockefeller National Historical Park (MABI), Morristown National Historical Park (MORR), Richmond National Battlefield Park (RICH), and Saratoga National Historical Park (SARA).

The methods used are based on a protocol developed by the Heartland Inventory & Monitoring Network, and they produce two types of data: 1) bearings and distances to deer seen from a vehicle driving a route through the park, and 2) visibility information denoting how far observers feel they could see deer, taken every 0.05 mile (0.13 km) along the route. Visibility in some years is collected in two separate surveys with 0.10 mi intervals, with the second survey start point offset by 0.05 mi.

Monitoring Objective: Estimate deer abundance (an index that approximates the number of deer per square mile) in the surveyed area with sufficient accuracy to support management decision-making.

This data package contains a cumulative record of all monitoring data collected at the participating parks through the most recent field season and is organized into three (3) datasets:

Deer_Locations_Cumulative_YYYY-MM-DD.csv - processed deer survey event data, including the raw data plus calculated locations of deer. Incidental observations are not included in this data set.

Deer_VisibleArea_Cumulative_YYYY-MM-DD.csv - processed visibility survey event data, including the raw data plus calculated coordinates for the limit of visibility on either side of the vehicle. The limits of visibility are used to create a polygon in a Geographic Information System to estimate the area surveyed for each monitoring season and park.

Incidental_Sightings_Cumulative_YYYY-MM-DD.csv - Incidental sightings of species other than deer that are recorded during the survey, including count, species, and observer location.

Note that the date at the end of each data file represents the date that the dataset was last updated.