Using exotic antigens to measure reproduction and dispersal in Peromyscus leucopus

1991 ◽  
Vol 69 (2) ◽  
pp. 528-530
Author(s):  
Gregory E. Glass ◽  
George W. Korch ◽  
James E. Gomez ◽  
James E. Childs

Free-ranging female white-footed mice, Peromyscus leucopus, were inoculated with a series of exotic (not encountered in the environment) antigens to evaluate the utility of maternally transferred antibodies in identifying offspring under field conditions. Inoculated females suffered no apparent effects from the antigens, and their survival, growth, and reproductive success did not differ from those of uninoculated, control females. Six of nine marked females produced seven offspring. These offspring dispersed an average of 64 m from their mothers' centers of activity. Recruitment rates per adult female were similar to those reported for nest box studies. The exotic antigen technique appears to be a feasible method for studying the population biology of secretive small mammals.

The Condor ◽  
2001 ◽  
Vol 103 (1) ◽  
pp. 180-183 ◽  
Author(s):  
Thomas J. Maier ◽  
Richard M. Degraaf

Abstract Small mammals, such as mice and voles, have been implicated as major egg predators of Neotropical migrant passerines by field studies using soft plasticine eggs or the very small eggs of Zebra Finch (Taeniopygia guttata). Nevertheless, the effort required to depredate these commonly used egg surrogates may be less than that required to depredate the larger, thicker-shelled eggs of most passerine species. To compare the depredation of these surrogates to that of the eggs of a mid-sized passerine by a ubiquitous small predator, we exposed dissimilar pairs of plasticine, Zebra Finch, and House Sparrow (Passer domesticus) eggs to captive white-footed mice (Peromyscus leucopus). Plasticine eggs were marked by mice more than either kind of real egg, and Zebra Finch eggs were breached more often than House Sparrow eggs. We conclude that the use of either plasticine or Zebra Finch eggs may lead to overestimation of the ability or proclivity of small mammals to actually depredate the eggs of most passerines.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah A. Boyle ◽  
Noé U. de la Sancha ◽  
Pastor Pérez ◽  
David Kabelik

AbstractSpecies that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. We extracted glucocorticoids from fur samples of 106 small mammals (rodent genera Akodon and Oligoryzomys, and marsupial genera Gracilinanus and Marmosa) from six forest fragments (2–1200 ha) in the Reserva Natural Tapytá, Caazapá Department, Paraguay. To our knowledge, this is the first publication of corticosterone and cortisol levels for three of the four sampled genera (Akodon, Oligoryzomys, and Marmosa) in this forest system. We discovered three notable results. First, as predicted, glucocorticoid levels were higher in individuals living withing small forest fragments. Second, animals captured live using restraint trapping methods (Sherman traps) had higher glucocorticoid levels than those animals captured using kill traps (Victor traps), suggesting that hair glucocorticoid measures can reflect acute stress levels in addition to long-term glucocorticoid incorporation. These acute levels are likely due to urinary steroids diffusing into the hair shaft. This finding raises a concern about the use of certain trapping techniques in association with fur hormone analysis. Finally, as expected, we also detected genus-specific differences in glucocorticoid levels, as well as cortisol/corticosterone ratios.


1987 ◽  
Vol 65 (10) ◽  
pp. 2519-2523
Author(s):  
Gregory H. Adler ◽  
Mark L. Wilson ◽  
Michael J. DeRosa

A population of Peromyscus leucopus (white-footed mouse) in northeastern Massachusetts was manipulated for 3 years to determine the effects of adults on survival and recruitment. Two experimental grids were established, from which either all adult males or all adult females were removed continually. The effects of these two manipulations were compared with demography on a control grid. Manipulations had no apparent effect on breeding intensity of young, survival rates of adults, or residency rates of adults and young. Recruitment of adult males was higher on the adult male removal grid than on the control grid. Recruitment rates of adult males and of young males and young females were lower on the adult female removal grid than on the control grid. Survival rates of young males were higher on the adult female removal grid than on the control grid; this effect may have been due to either reduced adult female residency or adult male recruitment. All differences between experimental and control grids were noted only during breeding seasons. Adult males apparently limited recruitment of adult consexuals. The effects of manipulations on other measured parameters were inconclusive because of high immigration rates of adult males onto the adult male removal grid and reduced recruitment of adult males and decreased production of young on the adult female removal grid.


1989 ◽  
Vol 67 (9) ◽  
pp. 2321-2325 ◽  
Author(s):  
David T. Krohne

The population biology of white-footed mice (Peromyscus leucopus) inhabiting a 1.4-ha naturally occurring dispersal sink was studied for 5 years in west-central Indiana and compared with that in surrounding old-growth habitat. Densities in the dispersal sink were consistently lower than in prime habitat. Autumn and winter survival were practically nil. The sink was recolonized by adults in the spring following extreme low winter densities or extinction. Summer reproductive rates and the pattern of territoriality were similar to those in prime habitat. Mice colonized elsewhere when empty prime habitat was made experimentally available. The data suggest that few dispersing mice can be accommodated by the dispersal sink.


2020 ◽  
Vol 7 (4) ◽  
pp. 194
Author(s):  
Francesca Coppola ◽  
Enrico D’Addio ◽  
Lucia Casini ◽  
Simona Sagona ◽  
Antonio Felicioli

The tiletamine-zolazepam mixture is a widely used anesthetic for chemical immobilization of wild mammals due to its short induction time, good muscle relaxation, smooth recovery with low convulsions occurrence, and minimal effect on respiration. An injection dose of 7–8 mg/kg of tiletamine-zolazepam has been proven to be an effective and safe immobilizing mixture for crested porcupines under field conditions. However, the occurrence of long immobilization and recovery times, with high excitement and convulsion during awakening, were recorded. In order to reduce such side effects after recovery, the effectiveness of a lower dosage (4–6 mg/kg) of tiletamine-zolazepam (Zoletil®) was tested. The results obtained confirm that the use of tiletamine-zolazepam in crested porcupine immobilization provides a quick induction, wide safety margin, and predictable awakening under field conditions. A smaller injection dosage of 5 mg/kg has been proven to be sufficient to ensure a short induction time (average: 7.1 min), with good muscle relaxation and little excitement of the animals during awakening. The lower dosage of tiletamine-zolazepam, while providing a shorter recovery time (average: 53.6 min), proves to be adequate for standard handling procedures. Furthermore, the smaller amount of tiletamine-zolazepam also ensures safe immobilization for pregnant individuals and porcupettes.


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