• Artificial propagation and neonatal care of passerines as an effective tool for in-situ species recovery programs

      Switzer, Richard A.; Cristinacce, A.; Ladkoo, A.; Goltz, T.; Ward, G.; Kuehler, Cyndi M.; Lieberman, Alan A.; Jones, C.; (2010)
    • Automated telemetry reveals post-reintroduction exploratory behavior and movement patterns of an endangered corvid, ʻAlalā (Corvus hawaiiensis) in Hawaiʻi, USA

      Smetzer, Jennifer R.; Greggor, Alison L.; Paxton, Kristina L.; Masuda, Bryce M.; Paxton, Eben H. (2021)
      Continuous movement monitoring is a powerful tool for evaluating reintroduction techniques and assessing how well reintroduced animals are adjusting to the wild. However, to date, continuous monitoring has only occurred for large-bodied species capable of carrying heavy tracking devices. In this study we used an automated VHF radio telemetry array to investigate the exploratory behavior and movement patterns of critically endangered ?Alal? (Corvus hawaiiensis), reintroduced to the Island of Hawai?i in 2017. The 11 juvenile ?Alal? we tracked exhibited high site fidelity and initial survival. Over time the birds showed decreased time spent at the supplemental feeders, and transitioned to more focused use of the landscape, suggesting increased foraging on wild food items. Birds with seemingly less spatial neophobia at release also made larger post-release exploratory movements. This study provides the first evidence that 1) supplemental feeding can support site fidelity for reintroduced ?Alal? without restricting a transition to independent foraging, and 2) that pre-release personality metrics may be useful predictors for predicting post-release movements of ?Alal?. Our work is the first to demonstrate the utility and power of automated telemetry for monitoring the reintroduction of small species.
    • Conservation implications of inaccurate estimation of cryptic population size: Inaccurate estimation of cryptic population size

      Katzner, T. E.; Ivy, Jamie A.; Bragin, E. A.; Milner-Gulland, E.J.; DeWoody, J. A. (2011)
      ...Estimating population size is central to species‐oriented conservation and management. However, in spite of recent development in monitoring protocols, there are gaps in our ability to accurately and quickly estimate numbers of individuals present, especially for the cryptic and often non‐breeding components of structured vertebrate populations. Yet knowing the size and growth trajectory of all stage classes of a population is critical for species conservation. Here we use data from 2 years of non‐invasive genetic sample collection from the cryptic, non‐breeding component of an endangered bird of prey population to evaluate the impact of variability in population estimates on demographic models that underpin conservation efforts....
    • Disorders of sexual development in wild and captive exotic animals

      Mastromonaco, G. F.; Houck, Marlys L.; Bergfelt, D. R. (2012)
      ...Compared to the wealth of information available on humans and domestic species, a better understanding of the factors influencing sexual development in wildlife is essential for developing and improving population management or conservation plans. This review attempts to bring together the different facets of DSDs as studied in the fields of reproductive physiology, endocrinology, ecotoxicology, wildlife biology, and environmental health.
    • Epidemiology of tuberculosis in multi-host wildlife systems: Implications for black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros

      Dwyer, Rebecca A.; Witte, Carmel L.; Buss, Peter; Goosen, Wynand J.; Miller, Michele (2020)
      Cases of tuberculosis (TB) resulting from infection with Mycobacterium tuberculosis complex (MTBC) have been recorded in captive white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros. More recently, cases have been documented in free-ranging populations of both species in bovine tuberculosis (bTB) endemic areas of South Africa. There is limited information on risk factors and transmission patterns for MTBC infections in African rhinoceros, however, extrapolation from literature on MTBC infections in other species and multi-host systems provides a foundation for understanding TB epidemiology in rhinoceros species. Current diagnostic tests include blood-based immunoassays but distinguishing between subclinical and active infections remains challenging due to the lack of diagnostic techniques. In other species, demographic risk factors for MTBC infection include sex and age, where males and adults are generally at higher risk than females and younger individuals. Limited available historical information reflects similar age- and sex-associated patterns for TB in captive black and white rhinoceros, with more reports of MTBC-associated disease in black rhinoceros than in white rhinoceros. The degree of MTBC exposure in susceptible wildlife depends on their level of interaction, either directly with other infected individuals or indirectly through MTBC contaminated environments, which is dependent on the presence and abundance of infected reservoir hosts and the amount of MTBC shed in their excreta. Captive African rhinoceros have shown evidence of MTBC shedding, and although infection levels are low in free-ranging rhinoceros, there is a risk for intraspecies transmission. Free-ranging rhinoceros in bTB endemic areas may be exposed to MTBC from other infected host species, such as the African buffalo (Syncerus caffer) and greater kudu (Tragelaphus strepsiceros), through shared environmental niches, and resource co-utilization. This review describes current knowledge and information gaps regarding the epidemiology of TB in African rhinoceros.
    • Hormones and reproductive cycles in Crocodilians

      Milnes, Matthew R.; Norris, D.O.; Lopez, K.H. (ElsevierSan Diego, CA, 2011)
      During embryonic development, hormonal influence upon sexual differentiation in crocodilians begins and continues for years until sexual maturation is attained. Shortly after sex determination, estrogen production in the embryonic ovary increases and promotes proliferation of the Müsllerian ducts, whereas the testis produces anti-Müllerian hormone, which results in its regression....
    • Human and great ape red blood cells differ in plasmalogen levels and composition

      Moser, A.B.; Steinberg, S.J.; Watkins, P.A.; Moser, H.W.; Ramaswamy, K.; Siegmund, K.D.; Lee, D.R.; Ely, J.J.; Ryder, Oliver A.; Hacia, J.G. (2011)
      Plasmalogens are ether phospholipids required for normal mammalian developmental, physiological, and cognitive functions. They have been proposed to act as membrane antioxidants and reservoirs of polyunsaturated fatty acids as well as influence intracellular signaling and membrane dynamics. Plasmalogens are particularly enriched in cells and tissues of the human nervous, immune, and cardiovascular systems. Humans with severely reduced plasmalogen levels have reduced life spans, abnormal neurological development, skeletal dysplasia, impaired respiration, and cataracts. Plasmalogen deficiency is also found in the brain tissue of individuals with Alzheimer disease.
    • Sex-specific epigenetic profile of inner cell mass of mice conceived in vivo or by IVF

      Ruggeri, Elena; Lira-Albarrán, Saúl; Grow, Edward J; Liu, Xiaowei; Harner, Royce; Maltepe, Emin; Ramalho-Santos, Miguel; Donjacour, Annemarie; Rinaudo, Paolo (2020)
      …Animal studies indicate that IVF offspring display metabolic alterations, including hypertension, glucose intolerance and cardiac hypertrophy, often in a sexual dimorphic fashion. The detailed nature of epigenetic changes following in-vitro culture is, however, unknown. This study was performed to evaluate the epigenetic (using whole-genome bisulfite sequencing (WGBS) and assay for transposase-accessible chromatin using sequencing (ATAC-seq)) and transcriptomic changes (using RNA-seq) occurring in the inner cell mass (ICM) of male or female mouse embryos generated in vivo or by IVF....
    • Social context mediates testosterone's effect on snort acoustics in male hyrax songs

      Weissman, Yishai A.; Demartsev, Vlad; Ilany, Amiyaal; Barocas, Adi; Bar-Ziv, Einat; Geffen, Eli; Koren, Lee (2019)
      Testosterone affects physical and motivational states, both of which may strongly influence vocalization structure and acoustics. The loud complex calls (i.e., songs) of male rock hyraxes (Procavia capensis) are used as honest signals for advertising physical and social states. The snort, a low frequency, noisy element of the song, encodes information on the singer's age and social rank via harshness, as measured by jitter (i.e., acoustic frequency stability) and duration; suggesting that the snort concomitantly advertises both vocal stability and aggression. Our past findings revealed that testosterone levels are related to both vocal elements and social status of male hyraxes, suggesting that hormonal mechanisms mediate the motivation for aggressive and courtship behaviors. Here we examined whether long-term androgen levels are related to snort acoustics and song structure by comparing levels of testosterone in hair with acoustic and structural parameters. We found that songs performed by individuals with higher testosterone levels include more singing bouts and longer, smoother snorts, but only in those songs induced by external triggers. It is possible that hyraxes with higher levels of testosterone possess the ability to perform higher-quality singing, but only invest in situations of high social arousal and potential benefit. Surprisingly, in spontaneous songs, hyraxes with high testosterone were found to snort more harshly than low-testosterone males. The context dependent effects of high testosterone on snort acoustics suggest that the aggressive emotional arousal associated with testosterone is naturally reflected in the jittery hyrax snort, but that it can be masked by high-quality performance.