Captive reproduction in Heermann's kangaroo rat, Dipodomys heermanni

Abstract

This paper summarizes 8 years of captive breeding experience with the endangered Morro Bay kangaroo rat (Dipodomys heermanni morroensis) and the nonendangered Lompoc kangaroo rat ( D . h. arenae), a related form used as a surrogate. Kangaroo rats are aggressive and must be caged individually; copulation can only take place when the female is in estrus. The estrous cyle varies, but is usually 14-17 days long; gestation averages 31 days. Data on development of the young, animal health, mortality, and longevity are presented. The productivity of this project is compared with that of another long-term kangaroo rat breeding project in terms of the number of young produced per female per year. A captive breeding program can be initiated with 40-50 reproductive animals as a founder group.

Solitary is not Asocial: Effects of Social Contact in Kangaroo Rats (Heteromyidae: Dipodomys heermanni)

“…Previous studies have established that, as the female approaches the peak of her cycle, swelling increases and perforation becomes more likely ( Wilson et al . 1985 ; Roest 1991; Yoerg 1994, 1995). In addition, the presence of a vaginal cast indicates that the cycle peak has just passed.…”

“…Dipodomys heermanni appears to maintain exclusive home ranges, and is probably territorial ( Tappe 1941; Shier 1997). In captivity, D. heermanni exhibit high levels of aggression; even when females are in peak estrus, kangaroo rats of both sexes may initiate fatal fighting ( Roest 1991; Yoerg 1994). The aim of the present study was to determine the conditions that promote or reduce agonistic behavior in D. heermanni , to increase our understanding of social interaction in this species and, as a result, to improve methods for captive breeding.…”

Some Analyses and Recommendations on Diet Formulation for Conservation Breeding of the Galapagos Rice Rat of Isla Santiago, Nesoryzomys swarthi

“…However, the list of species brought back from the brink of extinction via conservation breeding continues to grow and includes several species with fairly complex captive needs such as the black‐footed ferret, California condor, and Guam kingfishers [Grenier et al., ; Kessler and Haig, ; Walters et al., ]. Endangered rodent species have been the subject of captive breeding in several instances with good results [Alligood et al., ; Roest, ]. Other Oryzomine rodents have also bred successfully in captivity [Hamilton, ; Voss et al., ].…”

Native Small Mammal Use of an Invasive Grass: Heermann's kangaroo rats (Dipodomys heermanni) and Veldt grass (Ehrharta calycina) in Coastal California

“…The sand in each aquarium, and nest jars, were cleaned after Thompson et al (1995) and Shier and Randall (2007). Animals were given lettuce, as a source of free water, once a day throughout their time in captivity (methods follow Yoerg and Shier 1997, Shier and Yoerg 1999, Shier and Randall 2007, Thompson et al, 1995, Roest 1991. Lettuce was given as a source of free water (rather than free water itself) because these animals are adapted to very arid environments, and an excess of water is known to cause excessive urination, eventually leading to weight loss and weakness (Eisenberg 1967).…”

“…Previous research on the Lompoc kangaroo rat focused on gaining insight into Morro Bay kangaroo rats' food and habitat preferences (Stewart andRoest, 1960 andCongdon andRoest, 1975), breeding behavior and captive breeding programs (Roest, 1991), reintroductions of captive kangaroo rats into the wild (Gambs, 1986), and competitors (Gambs, 1986, reviewed in Kofron and Villablanca submitted seeds had significant effects on local plant community structure, since test plots that excluded kangaroo rats showed a significant change from desert shrubland to grassland exhibiting at least a threefold increase in tall perennial and annual grasses along with an increase in arid grassland rodents (Brown and Heske, 1990). Kerley et al (1997) merriami and D. ordii) were responsible for the grass cutting under field conditions.…”