A Mammal Inventory of Albuquerque s Rio Grande s Bosque and Islands By: Reilly Elder, Nate Kaspi, Cory Schaefer, and Noel Underwood.

Transcription

1 Black Institute & Bosque Ecosystem Monitoring Program (BEMP) Education Office 4000 Learning Road NW Albuquerque, NM January 2013 A Mammal Inventory of Albuquerque s Rio Grande s Bosque and Islands By: Reilly Elder, Nate Kaspi, Cory Schaefer, and Noel Underwood Including: A Report of Winter and Spring 2012 Small Mammal Trapping Effort for Tawny Bellied Cotton Rat At and Near Rio Grande Nature Center State Park By: Reilly Elder, Nate Kaspi, Cory Schaefer, and Noel Underwood Meso-Carnivore Track Plate Study in the Middle Rio Grande Bosque By: Abby Anderson and Sydney Dazzo Infrared Camera Trap Study in the Middle Rio Grande Bosque By: Jesse Chavez and Sam Mackenzie Faculty Advisor: Daniel Shaw Summary We conducted an inventory of mammals within the Rio Grande s riverside forest, the bosque, and islands through the northern section of Albuquerque from fall of 2011 through spring of We gathered our own data through small mammal trapping, track plates, infrared camera traps, and recorded observations. We also included other data gathered by our teachers and colleagues at Bosque School who used the same methods. We identified 22 species of mammals including 13 previously recorded in 1996 by Campbell et al. in a study that focused primarily on small mammals and incidental observations. Of the additional nine species not recorded in 1996, three were detected through the use of small mammal trapping and the other six through observation, track plate, and/or infrared camera. The one species that we did not detect that the 1996 study recorded was the tawny-bellied cotton rat (Sigmodon fulviventer). Our inability to detect the tawny-bellied cotton rat should not be used to make any definitive statements about the presence or absence of this species in Albuquerque s bosque as our work was not comprehensive and not statistically tested. However, since 1996 there have been substantial habitat changes and a reduction of grassland habitat within Albuquerque s bosque and further study regarding this species at this location is warranted. 1

2 Introduction The riverside forest, or bosque, of the Rio Grande through Albuquerque, NM has undergone considerable habitat alteration since 1996 when the last comprehensive survey of mammals was completed (Campbell 1997). Recent landscape changes include human alterations such as: large swath mowing of vegetation; wildfire fuel load reduction and wood chipping, construction of and subsequent reduced river flow related to a new drinking water diversion dam; aggregation and degradation of the river bed due to dams, and rechanneling in the Rio Grande itself. Substantial non-human impacts include drought and large wild land fires. We wanted to inventory for mammals along the Rio Grande in order to see if the suite of mammals present has changed. This report pays particular attention to the tawny-bellied cotton rat, a diurnal habitat specialist requiring dense cover to protect it as it forages. We suspected that it would have had difficulty adapting to habitat changes that have occurred over the last 16 years within the Rio Grande s bosque and adjacent to the Rio Grande Nature Center State Park State Park (RGNCSP) area. To our knowledge, no tawny-bellied cotton rats (Sigmodon fulviventer) have been detected in Albuquerque, New Mexico at the RGNCSP and its adjacent riverside forest, the bosque, habitat since They were last detected by Chris Roberts and his associates at both the RGNC and an upland area since developed (Daniel Shaw Personal Communication). Methods We attempted to document as many species of mammals as we could using a variety of detection methods. Our primary study area was within a roughly 50 hectare portion of forest on the west side of the Rio Grande just south of the Montano Boulevard Bridge where it crosses the Rio Grande near the Bosque School campus. Other study areas included several islands between Alameda Boulevard Bridge and just south of the Central Avenue Bridge. In order to identify mammal species within these locations, we used several different methods for mammal detection including track plates, small mammal trapping with live-capture Sherman traps, infrared camera traps, and recorded observations. We also conducted small mammal trapping surveys at the RGNCSP and used recorded observations maintained by State Parks staff. For small mammal trapping, we followed Scheerer s 2011 protocol. We focused our trapping efforts at locations used by Campell et al. in and other locations where tawny-bellied cotton rats were discovered in 2005 by Roberts. In areas where tawny-bellied cotton rats had been previously found, instead of mesic conditions we generally found ground cover consisting of dense wood chips and exotic kochia (Kochia scoparia). In addition, we sought out patches of alkali sacaton (Sporobolus airoides), a preferred tawny-bellied cotton rat habitat element. However, even after extensive foot surveys between Alameda Boulevard and Interstate 40 bridges we were unable to find extensive occurrences of that grass type. 2

3 We trapped for a total of 910 trap-nights during our study. This included three sets of three consecutive night trap effort on six different islands (figures 1-3). These were supplemented by approximately 280 trap-nights by Hooper and her Bosque School students in the bosque near their campus. (Figures 1-3 depict the locations of island where small mammal trapping, infrared cameras, and track plates were deployed {photos Google Earth}). Fig. 1. One study island north of Paseo del Norte Fig. 2 Three study islands south of Montano Fig. 3 Two study islands bracketing Central Ave Infrared camera traps were set with the intent of recording carnivore presence. We did sets of three consecutive nights on the same islands where we small mammal trapped, 3

4 but not concurrently with the small mammal trapping. We positioned cameras 0.5 to 1.0 meter off the ground and baited the locations with canned herring. Additional camera traps were set up and maintained by our student colleagues Chavez and MacKenzie from January through April 2011 at three locations near the Bosque School campus. In addition to camera traps, we used meso-carnivore track boxes (Fig. 4) and plates (Fig. 5) as designed by K. Elder (2011). The elongated boxes of roughly 25x25x85cm had one opening. At the box entrance, a layer of charcoal covered the floor, followed by a section of sticky contact paper, and the back of the box was baited with cat food. In addition to our box-track plate work, our colleagues Anderson and Dazzo also conducted 192 nights of box-plate work (Fig. 6) (four consecutive nights at four locations with four boxes per location, three times). Fig.4 Track plate box Fig. 5 Interior base plate of a track plate box Fig. 6. Yellow pins showing locations of the four sets of four box-track plates used by Anderson and Dazzo along the Rio Grande bosque and major bridge crossings and Bosque School campus 4

5 Recorded observations were made by the authors, student colleagues, and Bosque Ecosystem Monitoring Program (BEMP) and Bosque School science department faculty and staff. These tended to be incidental mammal sightings made while the observer was conducting other field work. All observations were recorded in field notebooks contemporary with the sighting. Findings A summary of our findings is presented in Fig. 7. Findings from Campbell 1997 are shown for comparison. We detected 22 species of mammals in Albuquerque s bosque including two feral (domestic dog and cat) and one exotic (house mouse) species Present in 96 Present now Species Reported Sherman/large _ mammal traps, etc. Sight Sherman Live Traps Camera Trap Track Plate Pitfall Trap Not in 2011 Not in Canis familiaris (domestic dog) Canis latrans (coyote) Felis cattus (domestic cat) Spilogale gracilis (western spotted skunk) Mephitis mephitis (striped skunk) Taxidea taxus (badger) Mustela frenata(long tailed weasel) Procyon lotor (raccoon) Erethizon dorsatum (porcupine) Castor canadensis (beaver) Ondatra zibethicus (muskrat) Sylvilagus audubonii (desert cottontail) Spermophilus variegatus (rock squirrel) Sigmodon fulviventer (tawny-bellied cotton rat) Peromyscus maniculatus (deer mouse) Peromyscus leucopus (white-footed mouse) Dipodomys ordii (ord'skangaroo rat) Thomomys bottae (botta's pocket gopher) Notiosorex crawfordi (desert shrew) Perognathus flavus (silky pocket mouse) Mus musculus (house mouse) Reithrodontomys megalotis (western harvest mouse) Fig. 7. Summary of mammals recorded during 2011 and early 2012 as present in the Rio Grande bosque within Albuquerque. Species represented in red are ones found by the current study but were not found by the study in These are western spotted-skunk, badger, long-tailed weasel, porcupine, deer mouse, desert shrew, ord s kangaroo rat, and silky pocket mouse. Species in blue show any that were seen in , but not in the present study. The only species that this is true for is the tawny-bellied cotton rat. Discussion Although we detected nine more mammal species than Campbell et al. did in that is most likely due to our use of other methods that they did not deploy (infrared camera and box plate traps) and an increased number of observers. It is also important to note that our small mammal trapping involved only one quarter the number of trap night 5

6 effort that Campbell conducted, was non-randomized, and did not replicate either Campbell or the studies that preceded it. Our work was merely a presence/absence attempt. We were unable to detect tawny-bellied cotton rat though we focused our non-randomized small mammal trapping efforts to maximized capture success for that species. We did that by placing traps directly in possible grass covered runways and within other suitable habitat conditions. Even so, we were unsuccessful. Our inability to detect the tawny-bellied cotton rat should not be used to make any definitive statements about the presence or absence of this species in Albuquerque s bosque as our work was not comprehensive and not statistically tested. However, since 1996 there have been substantial habitat changes and a reduction of grassland habitat and cover within Albuquerque s bosque including the RGNC and further study regarding this species at this location is warranted. For Additional Information Daniel Shaw Faculty and Director Black Institute for Environmental Studies Bosque School, 4000 Learning Road NW, Albuquerque, NM (505) dan.shaw@bosqueschool.org Acknowledgements Bosque School Wildlife Biology and Conservation Classes including: Galen Alsobrook, Abby Anderson, Melina Baron-Deutsch, Jessie Chavez, Sydney Dazzo, Cameron Ferrante, Molly Fisher, Max Giblin, Sam Mackenzie, Enrique Pacheco, and Joe Scanlon. Bosque Ecosystem Monitoring Program (BEMP) staff and volunteers and Bosque School Faculty including: Katie Carillo, Rowan Converse, Kate Elder, Gileen Elder, Kim Fike, Livingston MacLake, Cait Rottler, Kimi Scheerer, and Daniel Shaw Bosque School middle school science classes and their teacher Sarah Hooper. Rio Grande Nature Center and State Park staff including: Beth Dillingham, David Certain, and Karen Herzenberg. References Campbell, M., Stuart, J. & Miyashiro A survey of small mammal populations in the Rio Grande Valley State Park, Albuquerque, New Mexico Bosque Environmental Consulting (Abq. Open Space contract # ) Elder, K A protocol for meso carnivore track plates. Black Institute at Bosque School Albuquerque. Scheerer, K Small mammal trapping initiative research plan Black Institute at Bosque School, Albuquerque 6