Managed Change to Support an Endangered Species

512x219_Jumping Mouse Habitat_Sanchez

You may have noticed recent changes to the landscape of Bosque del Apache, especially in wetlands and areas that historically held water throughout the year. These focused prescriptions were done purposefully by refuge staff to support the needs of a rare and unique creature. 

The New Mexico Meadow Jumping Mouse is a tiny mammal who hibernates seven months out of the year, awakening in mid-May to search for food and produce one or two young before October cues a return to hibernation. During its short active season, jumping mice create a day nest within their small territory: either in dense grass patches or along dry earthen banks. Each night, they emerge from their daytime hide-outs and swim across ditches and standing water to get to the seeds of tall herbaceous vegetation (such as spikerush and grasses), where they jump from plant to plant to feed.

More closely related to jerboas than to the common house mouse or deer mouse, this creature also occurs in the Sangre de Cristo, Sacramento, and Jemez mountains of New Mexico, and in three locations in Colorado and Arizona. Historically, this species was documented intermittently throughout the Rio Grande Valley from Velarde, New Mexico to Bosque del Apache National Wildlife Refuge in areas near streams and water-saturated soils.

Due to limited surface water availability and changes to the Rio Grande flood regime, the jumping mouse population within the valley has declined considerably. The population at Bosque del Apache is the last known remaining low-elevation population in New Mexico.

The Rio Grande historically experienced large flood events, which would create backwater areas, side channels, and erosive disturbances that would displace woody plants and replace vast areas with herbaceous seed-bearing plants and salt-grass meadows. Currently, the Rio Grande does not experience these dynamic disturbances; therefore, woody plant species have been able to take over and slowly progress into a late succession plant community, which is not favorable habitat for the jumping mouse. In order to mimic this historical function that enhances habitat for both waterfowl and federally listed species, the refuge annually implements disturbances using farm equipment, such as disks and mowers,

Upon federal listing of the jumping mouse in 2014, the refuge prescribed maintenance and monitoring actions to support this declining species.

Beginning in 2017, the refuge began implementing large-scale projects to create and restore habitat specifically for the jumping mouse. Efforts continue and include: removing woody vegetation from areas adjacent to occupied jumping mouse habitat; creating small channels mimicking “beaver runs” adjacent to several key refuge ditches to encourage herbaceous plant growth; strategically placing water control structures in areas to establish the appropriate plant community for nighttime feeding purposes; and converting areas of standing water into safe jumping mouse feeding habitat.

Some of these efforts can be viewed along the Auto Tour Loop. Immediately west of the Rio Viejo Trail parking area is an area that has recently undergone changes to support the restoration of New Mexico Meadow Jumping Mouse habitat.

This six-acre old rookery unit formerly held water year-round and was once a popular location for roosting wading birds. This area has since degraded as standing dead trees have succumbed to decomposition, limiting available roosting sites for wading birds. The old rookery unit also marks the southern-most extent of where the jumping mouse resides on the refuge. Since it held water year-round, it likely served as a barrier for jumping mouse habitat expansion because American bullfrogs and fish could hunt and eat jumping mice as they swam across the open water to get to nighttime feeding areas.

As part of an effort to create new jumping mouse habitat, the refuge decided to restore this ponded site to an early succession wetland unit. To accomplish this, many tons of dirt were hauled in to create a berm that separates the unit from surface water in-flows, and three small water-control structures were installed. This restoration will allow biological staff to strategically manage the water flows, providing the habitat characteristics favorable to the jumping mouse. In time, this unit will be transitioned into an herbaceous plant community exhibiting saturated soils and providing an opportunity for this imperiled species to extend its range southward along the Riverside Canal.