The North American Badger at West Mesa; Grasslands Preserve, City of Albuquerque Open Space, Bernalillo County, New Mexico
Introduction–Natural History of the Badger
In order to fully understand the current situation with the Gunnison’s prairie dog (Cynomys gunnisoni) and its predator, the badger (Taxidea taxus) at the Prairie Dog Primary Habitat at Grasslands Preserve, the largest City of Albuquerque Open Space, Bernalillo County, NM, one first must be informed about the natural and life history of the badger in general.
Badgers are promiscuous and have delayed implantation. The implantation of the early embryo (called the blastocyst) occurs in February and development proceeds until pups are born. Badger pups are born late March or early April in other latitudes. Litter size ranges from 1 to 5 with the most often number at 2 or 3 pups. Males that are 14 months have mature sperm already. Males are in their breeding season during the May to August period. Of the female yearlings, 38% do not release eggs from their ovaries (ovulate). About 52-72% of the females gave birth or were pregnant in Idaho.
Adult badgers are night active (that is nocturnal) while young of the year are active at dawn and dusk (that is crepuscular). Badgers do not hibernate although they do undergo a mild torpor. Badgers are solitary except during the breeding season where the sexes get together and pup-rearing season when the mother is with pups.
On average there is one badger per 2.6 square kilometers in NW Utah while there are 2 badgers every square kilometers in northwestern Wyoming.
For badgers one year old and older males have a home range of 5.8 square kilometers while females have a home range of 2.4 in northwestern Utah. In southwestern Idaho, animals older than one year old, the males had a home range of 1.4 square kilometer. Home ranges of all sex and age classes may overlap. Adult males overlap the home ranges of a number of smaller female home ranges.
There is a tendency for females to be territorial or guard their home ranges. Territorial systems are favored whereby human exploitation by trapping is minimal.
Prey of badgers includes rodents and rabbits/hares (that is lagomorphs) and occasionally birds, reptiles, and insects. Prey abundance in their diet varies according to prey availability, season-to-season, and year-to-year. Badgers have a very sturdy or robust pectoral girdle (upper body) with powerful pectoral muscles and well-developed claws for digging. Rodents which they prey upon include: the mountain pocket gopher (Thomomys talpoides), yellow-nosed pocket gopher (Pappogeomys castanops), kangaroo rats (Dipodomys spp.), pocket mice (Perognathus spp.), ground squirrels (Spermophilus spp. and Ammospermophilus spp.), northern grasshopper mice (Onychomys leucogaster), southern plains woodrat (Neotoma micropus), house mice (Mus musculus), and deer mice (Peromyscus sp.). Lagomorphs eaten include black-tailed jackrabbits (Lepus californicus) and desert cottontail rabbits (Sylvilagus audubonii). Badgers will frequent old badger dens and catch and eat cottontails and ground squirrels usurping them. Badgers will hunt ground squirrels by plugging all entrances but one, and then they will excavate it. Another strategy is to hide in their underground burrows and ambush ground squirrels. Yet another strategy is to dig open ground squirrel burrows and kill the entire family.
Badger predators include coyotes (Canis latrans), striped skunks (Mephitis mephitis), mountain lions (Puma concolor), and rarely other badgers. Humans kill badgers by accidentally striking them with vehicles, shooting them, poisoning them (sodium fluoroacetate), and trapping them.
The den is the center of daytime that is diurnal) inactivity, food storage, and birth. Dens have an elliptical entrance with a single burrow with the excavated earth piled into a mound of soil at the entrance. On average they dig 1.6 dens/ha. They generally dig new dens each day but occasionally reuse dens for more than one den. Usually for resting dens, badgers will deposit their droppings (that is scats) at the den entrance and in the burrow. Dens in which the female badger rears her young (that is natal dens) lack scat at the entrance. Females with pups may switch dens according to prey availability.
Badgers may transmit plague among rodent colonies. They have transient infections exhibiting an antibody response. In one study 72-86% of the animals sampled were seropositive. They can contract canine distemper virus.
Situation at Grasslands Preserve: Course of Events*
- “In the spring of 2006, a total of 13 badger diggings into prairie dog burrows were observed.”…the diggings were concentrated in the south release area in 2006…” (Polechla 2007).
- PJP and EU sees badger sign summer 2007 “In the spring of 2007 (18 and 29 April and 12 May) I observed only 4 badger diggings and noting two (one distinct and one indistinct) badger tracks and collected a badger scat. The diggings were concentrated in the…northern areas in 2007. Although in the long term badgers contribute to the faunal diversity they also keep populations in control, they are undesirable when trying to establish [prairie dog] populations. If badger activity persists at 2006 levels then live trapping and relocation of badgers may be necessary (Polechla 2007).”
- PJP collects dead prairie dog summer 2007, test negative for plague (Me. F, personal communication).
- PE sees dead road-kill badger on Shooting Range Road summer 2007 (PE to PJP personal communication).
- Delay on contract for fall 2007 and Spring 2008 reports due to miscommunication.
- Spring 2007 -late winter 2007-2008, No badger tracks on N-S and E-W road prompts PJP to do 6 April 2008 a perimeter/middle check of 2007 colony on the north tract of Prairie Dog Primary Habitat .
- 6 April 2008 PJP does 25% of artificial and natural prairie dog burrows excavated by badgers (feeding excavations) and photographs damage, sees tracks and fresh claw digging marks, and elliptical and dome shaped day dens (see Table 1), pull out tubes, no damage to nest box, little fresh prairie dog scat, appears to be bad. Notifies PDP, recommends badger work be done to protect prairie dogs investment of time, labor, and money. Walking survey shows about 3 Gunnison’s prairie dog above ground. A total of 8 badger scats found at entrance to diggings and associated with tracks…collected.
- 30 May 2008 EU and PE dust and count prairie dog burrows and re-photograph damage and use burrow camera to search for prairie dogs in excavated prairie dog nest box complexes, determines that out of all but “about 100” were free of prairie dogs. Reconfirms badger damage.
- EU & YB call meeting with PJP and PE, discuss badger situation.
- 11 June 2008 PJP resurveys north tract and finds no new badger sign only old (prior to 6 April 2008).
- 13 June 2008 PJP recommends meeting with City of Albuquerque to discuss badger situation.
Badgers and Prairie Dogs @ Other Sites*
- 21 February 2008. Susan K. Lentz collects badger specimen (PJP 3353) from San Juan County, NM in vicinity of Gunnison’s prairie dog colony.
- Summer 2007. DW visits Zia Pueblo from B.L.M. side of fence and sees badger damage and shot gun shells in prairie dog colony.
- 25-26 March 2006. PJP spotlight badger in Gunnison’s prairie dog colony in Aubrey Valley, Arizona.
- Winter 2005-2006 (after major prairie dog relocation from Santa Fe to Sevilleta NWR by PM, MiF, PJP, EU, YB, and others). PJP teaches MiF badger trapping techniques since badgers at Sevilleta NWR were visiting Gunnison’s prairie dog colony. MiF catches badger and relocates in on other end of refuge on the other side of Rio Grande.
- 8 November 2005. Zane Dohner collects badger specimen (PJP 3203) San Juan County, NM.
- 26 September 2005. PJP collects badger specimen (PJP 3168), near where PM relocates Zia Pueblo badger.
- 24 September 2005. PM relocates Zia Pueblo badger Sandoval County, NM.
- 1 Sept. 2005. Mike Fugagli collects badger specimen (PJP 3259) Grant County, NM
- 20 August 2005. PJP collects badger specimen (PJP 3141), Sandoval County, NM in vicinity of Gunnison’s prairie dog colony.
- 28-29 July 2005. At Zia Pueblo, Prairie Ecosystem and Prairie Dog Pals sets up all night vigil, EU sets up badger alarm system. Badger escapes in the cover of late night darkness. Later PM trap and relocate to Santa Ana Pueblo, PJP finds road kill in that vicinity.
- 17 September 2003. Diane Sewell McCash collects badger specimen (PJP 3031), Paradise Hills, Bernalillo County, NM.
- January 2001. Turner Foundation biologist talks about the Vermejo Ranch, Colfax County, NM. Badger predation is a major contributor to black-tailed prairie dog relocation (personal communication to PJP, Arizona-New Mexico Chapter of the Wildlife Society, Gallup, NM.) He recommends live trapping badger and fencing. Shier (2006) describes predation a problem with black –tailed prairie dog relocation.
- 17 May 1998-30 April 2003. PJP observes a total of 12 observations of badger tracks, dens, road kills, and diggings in kangaroo rat burrows at Bitter Lake National Wildlife Refuge and environs in Plains pocket gopher (Geomys bursarius), Mexican ground squirrel (Spermophilus spilosoma) southern plains woodrat (Neotoma micropus) habitat…within about 5 miles of black-tailed prairie dog town.
- 13 August 1998. PJP collects badger specimen (PJP 2111), Socorro County, NM.
- 19 October 1996. PJP collects badger specimen (PJP 1737), Luna County, NM.
- In late afternoon October 1996, PJP saw a badger near Punta Chueca, Sonora, Mexico in the Sonora desert near Tiburon Island.
- 2 October 1995. MiF collects badger specimen (PJP 1665), Socorro County, NM 6 mi. N. Bernardo on I-25 at Mile Marker # 170.
- 25 September 1994. PJP collects badger specimen (PJP 1624), Valencia County, 14 mi. North Sevilleta NWR Field Station on I-25.
- December 1986 K. Head collects badger specimen (PJP 1516), Franklin County, Arkansas.
- 1977-1980 PJP tracks badgers in sand on track survey Eddy County, NM in Chihuahuan desert w/ plains pocket gopher, spotted ground squirrels (Spermophilus spilosoma), kangaroo rats (Dipodomys spp.), pocket mice (Perognathus spp.), and northern grasshopper mice (Onychomys leucogaster).
- Summer1977. PJP encounters free-ranging badger before dusk near proposed W.I.P.P. site, Eddy County, New Mexico
- 19 February 1977 to 8 March 1978. PJP with Rodger Payne live-capture badger in coyote set eastern New Mexico.
- Badgers can inhabit a wide range of habitats, latitudes, and altitudes.
- Badgers and prairie dogs have co-evolved through geologic time and should be able to coexist if there is large enough prairie dog population to be able to withstand an annual predation by badgers and other predators (coyotes, ferruginous hawks, etc.) and other mortality factors.
- Badgers have a large home range and are solitaryunless breeding or with a mother and pups.
- Badgers are facultative rather than obligate predators of prairie dogs. As such they will feed on prairie dogs available and switch to other prey such as ground squirrels and kangaroo rats when prairie dogs are not available. Badgers will continue to return and forage at prairie dog colonies until they have literally eaten themselves “out of house and home.”
- Badgers at West Mesa will prey upon banner-tailed kangaroo rats (Dipodomys spectabolis) (about 3 of 30 burrow complexes (10%) had badger foraging digs in them) and possible ground squirrels, pocket gophers, other rodents, and lagomorphs.
- Badgers at West Mesa will occasionally prey upon prairie dogs during the summer, but will dig prairie dogs out of their burrows during hibernation or out families of prairie dogs when they are suckling their young. Badgers increase their capture success on prairie dogs when they are most vulnerable…at night, during hibernation, or while nursing their young.
- Badgers occur throughout Grasslands Preserve (on and off Prairie Dog Primary Habitat), Petroglyphs National Monument, throughout the West Mesa, central New Mexico, and the west bank of the Rio Grande…a vast area. As such, capturing badgers on the Prairie Dog Primary Habitat will only temporarily create a void that will be quickly filled by neighboring individuals and populations. Although, other biologists have experienced similar situations in other parts of New Mexico, few studies have been performed examining the predator-prey dynamics between prairie dogs and badgers.
- Badgers at the north tract were able to dig to prairie dog nest boxes but were not able to chew and claw through. A single badger family could have caused most of the damage. Prairie dogs initially escaped but were preyed upon or dispersed leaving them compromised at best and dead at worst. The result is that the prairie dog population plummeted and badgers sensing little lingering high pockets of concentrated prey, dispersed into adjacent areas. Little fresh badger sign indicates low badger population density. This relationship needs quantifying.
- Our goal at Grasslands Preserve should be to re-establish Gunnison’s prairie dogs by natural reproduction and recruitment.
- Hindsight is always 20/20. We as a group were “penny-wise and pound-foolish” not to be more pro-active about badgers and protect our prairie dog relocation investment. Not spending several thousand dollars to protect our six-figure (I predict about 1-2% of annual budget) investment proved to be foolish.
- At this point, prairie dog relocation will not be effective in establishing viable prairie dog population without badger relocation program.
- Monitor badger populations by walking the perimeter and middle of new north tract of Prairie Dog Primary Habitat especially during hibernation and pup suckling seasons.
- Assign Paul Polechla to feed prairie dogs once every other week during spring and summer relocation season. This is a cost-effective way of simultaneously feeding and collecting badger information.
- PJP should contact NM Game and Fish regarding permitting for badger live-trapping and removal (may have required permit or may need to apply for one).
- City of Albuquerque and PDP needs to budget for monitoring (during hibernation and prairie dog pup weaning periods), live trapping, and relocating badgers annually when necessary. Some costs include: lures ($5 for 1 oz bottle x 4), traps ($10/day x 3 weeks/year), misc. supplies $50, *infrared camera system for monitoring $500/each x 2, transportation cost, and wages.
- Live-trap and relocate badgers when badger damage is 1/16 to 1/8 (that is ¼ to ½ of the damage of 6 April 2008) of the prairie dog nest boxes and natural burrows.
- Relocation of badgers should continue annually as needed until the prairie dog colony produces a “standing crop” of prairie dogs that offset prairie dog mortality including badger predation, other predator predation, and other natural mortality.
- PDP should explore additional sources of funding to study dynamic predator-prey relationship between Gunnison’s prairie dog and its predators on West Mesa. Provisional and ultimately more sophisticated modeling of predator-prey relationship should be done.
- PJP is ideally qualified to accomplish these recommendations. He has specialized in carnivores for his Master’s thesis and Ph.D. dissertation and numerous post-doctoral studies including those on prairie dog predators including badgers.
By Paul J. Polechla Jr., Ph.D., Sr. Ecologist
Lindzey, F.G. 1978. Movement patterns of badgers in northwestern Utah. Journal of Wildlife Management 42:418-422.
Lindzey, F.G. 2003. Badger (Taxidea taxus). Pp. 683-691. In Wild mammals of North America. G.A. Feldhamer et al. (eds.) Johns Hopkins University Press, Baltimore, MD, 1216 pp.
Polechla, P.J. 1977-2008. Field notes and vertebrate catalogue. Unpaginated. 38 volumes.
Polechla, P.J. 2007. Gunnison’s prairie dog relocation project on the Grasslands Preserve of the West Mesa, Albuquerque Open Space, Bernalillo County, New Mexico. Prairie Dog Pals, Albuquerque, NM, 25 pp.
* Initials of central New Mexico prairie dog biologists, volunteers, and naturalists include: DW = Dick Westphal, EU =Ed Urbanski, MeF = Megan Friggens, MiF = Michael Friggens, PE = Paul Eilers, PJP = Paul J. Polechla, PM = Paula Martin, and YB= Yvonne Boudreaux.