Sapsucker Tree Use Across Diverse Landscapes

The goal of this project is to use a coordinated, network approach to build a biogeographically comprehensive data set of sapsucker well occurrence and abundance. Environmental data from the National Ecological Observatory Network (NEON) will be used to provide regional context.

Sapsuckers are widely distributed North American woodpeckers that primarily feed on tree sap. Their foraging leaves behind sap wells, which are small, round holes that often occur in distinctive horizontal or grid-like patterns on the trunks and large limbs of trees (as shown in the photograph on this page). These sap wells rarely harm the tree; rather, they can facilitate food resource access for over 40 other species, such as ruby-throated hummingbirds, red squirrels, and bees. For this reason, sapsuckers are often considered a keystone species – a species that has an impact on its ecosystem that is disproportionate to its abundance.

Hypotheses/Objectives: Participants may use this project to address questions at a macroecological scale such as: (1) How does urbanization affect sap well occurrence and abundance? (2) Does sap well occurrence and abundance differ among native and non-native tree species? (3) Does sap well occurrence and abundance vary with tree size and species across different ecoregions? (4) Are sap wells oriented in a preferred direction that correlates to prevailing winds or sunlight exposure? (5) How does sap well occurrence and abundance correspond to the distributions of sap-well-using species, such as the rufous hummingbird and red squirrel?

Summary of Methods: For the basic protocol, students will observe trees in their locality and record the tree species; native status; size; bark characteristics; presence, estimated quantity, location (e.g., lower trunk, upper trunk, limbs), orientation, and age or freshness of sap wells; and site attributes such as degree of urbanization and ecoregion. Environmental data from the National Ecological Observatory Network (NEON) will be used to provide regional context.

Expanded Project Info: Access background info, datasheets, and detailed protocol here.

Curriculum: This project can be the subject of a course laboratory activity lasting between 1 and 3 weeks. Access learning objectives and instructional materials for the sapsucker project here.

Other Project Materials: Assessment Materials

Publications will be linked here when available.