• An optimal and near-optimal strategy to selecting individuals for transfer in captive breeding programs

      Allen, S.D.; Fathi, Y.; Gross, K.; Mace, Michael E.; (2010)
      As species extinction rates continue to rise, zoos have adopted a more active role in the conservation of endangered species. A central concern is to preserve genetic diversity of zoological populations....
    • California Condor North American Studbook (Gymnogyps californianus)

      Mace, Michael E. (Diego Zoo GlobalEscondido, CA, 2014)
    • California condor North American studbook (Gymnogyps californianus)

      Mace, Michael E.; (Zoological Society of San DiegoEscondido, CA, 2010)
    • California condor studbook

      Mace, Michael E. (San Diego Zoo GlobalSan Diego: San, 2012)
    • California Condor Studbook

      Mace, Michael E. (Zoological Society of San DiegoSan Diego, 2011)
    • Patterns of mortality in free-ranging California condors (Gymnogyps californianus)

      Rideout, Bruce; Stalis, Ilse H.; Papendick, Rebecca; Pessier, Alan P.; Puschner, B.; Finkelstien, M.E.; Smith, D.R.; Johnson, M.; Mace, Michael E.; Stroud, R.; et al. (2012)
      We document causes of death in free-ranging California Condors (Gymnogyps californianus) from the inception of the reintroduction program in 1992 through December 2009 to identify current and historic mortality factors that might interfere with establishment of self-sustaining populations in the wild. A total of 135 deaths occurred from October 1992 (the first post-release death) through December 2009, from a maximum population-at-risk of 352 birds, for a cumulative crude mortality rate of 38%. A definitive cause of death was determined for 76 of the 98 submitted cases, 70%(53/76) of which were attributed to anthropogenic causes. Trash ingestion was the most important mortality factor in nestlings (proportional mortality rate [PMR] 73%; 8/11), while lead toxicosis was the most important factor in juveniles (PMR 26%; 13/50) and adults (PMR 67%; 10/15). These results demonstrate that the leading causes of death at all California Condor release sites are anthropogenic. The mortality factors thought to be important in the decline of the historic California Condor population, particularly lead poisoning, remain the most important documented mortality factors today. Without effective mitigation, these factors can be expected to have the same effects on the sustainability of the wild populations as they have in the past.
    • Sexing of mid-incubation avian embryos as a management tool for zoological breeding programs

      Jensen, Thomas; Mace, Michael E.; Durrant, Barbara S. (2012)
      …The ability to selectively incubate and hatch eggs of a desired sex represents a significant improvement in the long-term management of avian species. This study describes a successful method for in ovo sexing of embryos from stage 30 through 42 of incubation (Hamburger and Hamilton [1951] J Morphol 88:49–92).…