Fossil Rim Wildlife Center Research Articles

DETECTION AND DIFFERENTIATION OF TRICHURIS IN GIRAFFE (GIRAFFA CAMELOPARDALIS) UNDER HUMAN CARE.

Trichuris spp. are nematode parasites infecting many species, including domestic and wild ruminants in zoological and wildlife parks worldwide. These nematodes cause significant morbidity in giraffes (Giraffa camelopardalis) and other hoofstock. Parasite transmission between ruminant species is well reported; however, relative to domestic species, little is known about Trichuris infections in giraffes under human care. We hypothesized that Trichuris spp. differ between individual giraffes in different US regions, suggesting giraffes are susceptible to Trichuris from other ruminant hosts. The study sites used to assess this hypothesis included The Wilds in Cumberland, Ohio; Fossil Rim Wildlife Center in Glen Rose, Texas; White Oak Conservation in Yulee, Florida; and Binder Park Zoo in Battle Creek, Michigan. Trichuris eggs were collected from the feces of 14 individual giraffes located at the four different study sites and from soil samples from the enclosures where Trichuris-positive giraffes were housed. The eggs were isolated and their genes were amplified by PCR and compared at the molecular level. Trichuris samples from four giraffe hosts and one soil site were sequenced and portions of the cox1 and 18S genes compared. This study found that >12 eggs per gram of fecal-derived Trichuris eggs must be present to amplify Trichuris-specific DNA. The Trichuris spp. found in the majority of giraffes in this study were most similar to T. ovis and T. discolor, and one giraffe sample had greater similarity to T. skrjabini and T. leporis.

Survey of Reticuloendotheliosis Virus in Wild Turkeys (Meleagris gallopavo) in Texas, USA.

Reticuloendotheliosis virus (REV) is an immunosuppressive and sometimes oncogenic avian retrovirus that establishes lifelong infection in a wide range of avian species. REV-infected wild birds roaming near at-risk captive flocks, such as is the case for the highly endangered Attwater's Prairie Chicken (APC; Tympanuchus cupido attwateri), could act as a reservoir for viral transmission. In wild birds, prevalence rates of REV are low and appearance of associated disease is uncommon. During 2016-17, nearly half of all captive adult APC mortality at Fossil Rim Wildlife Center captive breeding facility in Glen Rose, Texas, US was attributed to REV infection. The unusually high REV prevalence rate prompted us to survey for this virus in wild galliforms throughout the region. From 2016-17, 393 blood samples collected from two subspecies of Wild Turkeys (Meleagris gallopavo) were tested for REV proviral DNA through amplification of the viral 3' long terminal repeat and segments of the viral pol gene. In REV-affected counties, 5% (5/98) of native Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) were identified as REV-positive. In addition, we detected REV in one of 62 Eastern Wild Turkeys (Meleagris gallopavo silvestris) that had been imported during conservation efforts. To better determine protective measures, continued surveillance, including collection and genetic analysis of REV-infected samples, is necessary to identify sources of REV outbreaks in captive APC flocks.

FECAL CORTISOL LEVELS IN SCIMITAR-HORNED ORYX, ORYX DAMMAH, REVEALS DIFFERENCES BETWEEN CAPTIVE ENVIRONMENTS.

Due to the intensive management of the scimitar-horned oryx, Oryx dammah, involving both captivity and reintroductions, understanding the stress associated with environmental situations this endangered species might experience would be particularly helpful. Fecal cortisol levels were measured across seasons, between captive management programs, and among varying reproductive states in animals held at Fossil Rim Wildlife Center (FRWC) and Kansas City Zoo (KCZ). A total of 72 samples were collected from FRWC and 69 samples were collected from KCZ. The herd size and sex ratio changed for both locations in the middle of sampling due to translocations and birth. The herd sizes ranged from 25 to 28 individuals at FRWC and 22 to 24 individuals at KCZ. An ELISA was optimized and utilized to investigate fecal cortisol variances across seasons, captive management programs, and among varying reproductive states. Fecal cortisol levels ranged from 68.9 to 668.7 pg/g throughout this study, but key differences were found in response to reproductive status, environmental conditions, and social status. The highest level of fecal cortisol measured (668.7 pg/g) was in a pregnant female 9 days prior to parturition. During winter months, an increase in fecal cortisol levels occurred in both herds (FRWC 160.3 pg/g to 335.1 pg/g and KCZ 118.8 pg/g to 505.0 pg/g). In addition, when intact males were held together in an enclosure, the dominant males had lower fecal cortisol levels compared with submissive males during three of the four sampling periods. Understanding how these data relate to the physiologic stress response will require further study, but these results can be utilized to help establish expected fecal cortisol ranges in multiple environments and can aid current captive scimitar-horned oryx management programs, as well as future reintroduction efforts.

Fecal parasite identification by microscopy and PCR in scimitar-horned oryx, Oryx dammah, managed at two sites.

The scimitar-horned oryx, Oryx dammah, an endangered species extinct in the wild, is managed in various captive management programs and is the focus of reintroduction efforts. Management variability can contribute to substantial parasite load differences, which can affect deworming programs and potentially transfer parasites to different regions with translocations. Parasite studies in O. dammah are lacking. In this study, we determined fecal egg/oocyst counts of O. dammah in two captive herds, Fossil Rim Wildlife Center (FRWC) and Kansas City Zoo (KCZ). Fecal egg counts (FEC) were performed on O. dammah feces collected seasonally using the modified McMaster method, and microscopy provided additional identification of parasite genera ova and oocysts. To identify parasites to species level, homogenized fecals provided DNA subjected to the polymerase chain reaction (PCR) using genus specific primers. Microscopy and sequencing results indicated the presence of Strongylus (Strongylus vulgaris, Angiostrongylus cantonensis), Trichostrongylus (Haemonchus contortus, Camelostrongylus mentulatus), Trichuris (T. leporis, T. ovis, and T. discolor), Isospora (Isospora gryphoni) and Eimeria (E. zuernii and E. bovis), with Strongylus being the most common. Nematodirus was identified through microscopy at FRWC. Fecal egg counts were significantly higher in (FRWC) than in (KCZ) in all samplings (P = <0.001). No significant difference was seen between parasite load and seasons (P = 0.103), nor site and season (P = 0.51). Both study sites maintained most animals within commonly accepted FEC levels found in domestic livestock. Individuals with high numbers of EPG or OPG were subordinate males, pregnant females, or neonates. Several significant interactions were found between genera of parasites, age, sex, season, and pregnancy status in the FRWC herd. Sampling limitations prevented further analysis of the KCZ herd. Understanding interactions between parasite loads and physiological, environmental, and regional differences can help determine inter-specific transfer of parasites, and establish appropriate anthelmintic programs for O. dammah herds.

Spatial and temporal distributions of the Spinose Ear Tick,Otobius megnini, within animal shelters at Fossil Rim Wildlife Center

Spinose ear ticks, Otobius megnini, are monoxenous parasites that feed within the ear of ungulates, subjecting them to debilitating conditions. Little is known about the spatial dispersion of spinose ticks in animal shelters or the temporal variation in their abundance. Therefore, the objectives of this study were to: 1) determine the temporal distribution of spinose ear tick abundance within animal shelters, 2) determine the spatial distribution of larvae and adults within animal shelters, and 3) examine the effects of climatic variables on tick abundance. No temporal trend was identified for larval or adult ticks. Larval abundance was highest in quadrats located against the shelter wall while no spatial difference was found in adult abundance. Mean larval tick abundance was significantly correlated with mean temperature while mean adult tick abundance was significantly correlated with mean relative humidity.

Nocturnal peace at a Conservation Center for Species Survival?

E.O. Wilson suggested that the natural world is the most information-rich acoustic environment, especially for animals and indigenous peoples, and that is directly and indirectly essential to their survival (Wilson, 1984, Biophilia, Harvard University Press). Agriculturalists still value and constantly monitor their soundscape since it provides invaluable cues that may lead to success or failure. Krause reports that healthy natural soundscapes comprise a myriad of biophony, and indeed the ecological health of a region can be measured by its diverse voices (Krause, 1987, “Bio-acoustics: Habitat ambience & ecological balance,” Whole Earth Rev.). But do such soundscapes fall silent for much of the night? And are there extensive periods of silence at a highly successful Conservation Center for Species Survival? This study analyzes the soundscape continuously recorded at Fossil Rim Wildlife Center in Texas for a week during Fall 2013, to determine the prevalence of quiet periods and the acoustic environment in which such periods appeared to occur.

What comprises a healthy soundscape for the captive Southern White Rhinoceros (Ceratotherium simum simum)?

Many creatures, including the myopic rhinoceros, depend upon hearing and smell to determine their environment. Nature is dominated by meaningful biophonic and geophonic information quickly absorbed by soil and vegetation, while anthrophonic urban soundscapes exhibit vastly different physical and semantic characteristics, sound repeatedly reflecting off hard geometric surfaces, distorting and reverberating, and becoming noise. Noise damages humans physiologically, including reproductively, and likely damages other mammals. Rhinos vocalize sonically and infrasonically, but audiograms are unavailable. They generally breed poorly in urban zoos, where infrasonic noise can be chronic. Biological and social factors are studied, but little attention if any is paid to soundscape. We present a methodology to analyze the soundscapes of captive animals according to their hearing range. Sound metrics determined from recordings at various institutions can then be compared and correlations with the health and wellbeing of their animals can be sought. To develop this methodology we studied the sonic, infrasonic, and seismic soundscape experienced by the white rhinos at Fossil Rim Wildlife Center, one of the few U.S. facilities to successfully breed this species in recent years. Future analysis can seek particular parameters known to be injurious to human mammals, plus parameters known to invoke response in animals.

Measuring the sonic, infrasonic and seismic soundscape of the Southern White Rhinoceros (Ceratotherium simum simum) at a wildlife park conservation center

Many creatures, including the myopic rhinoceros, depend upon hearing and smell to determine their environment. Nature is dominated by biophonic and geophonic sounds quickly absorbed by soil and vegetation, while anthrophonic urban soundscapes exhibit vastly different physical and semantic characteristics, reflecting off hard geometric surfaces, distorting and reverberating, and becoming noise. Noise damages human physiologically, including reproductively, and likely damages other mammals. Rhinos vocalize sonically and infrasonically but audiograms are unavailable. They generally breed poorly in urban zoos, where infrasonic noise tends to be chronic. Biological and social factors have been studied but little attention if any has been paid to soundscape. To comprehensively describe the rhinos’ sonic, infrasonic and seismic environment at Fossil Rim Wildlife Center, one of the few U.S. facilities to successfully breed white rhinos in recent years, I began by comparing the sound metrics at different times of day in categories, for example, during visitation hours versus park closure. Further analysis will seek particular parameters known to be injurious to humans, plus those already known to impact animals. Later, the soundscapes of other facilities could be compared to seek correlations between their soundscapes and the health and well-being of the rhinos within their care.

The soundscape experienced by the Southern White rhinoceros (Ceratotherium simum simum) at a wildlife park conservation center

Many creatures, including the myopic rhinoceros, depend on hearing and smell even more than on their sight. Noise impacts human health and reproduction, and may impact these other mammals similarly, or even more. Rhinos have been recorded vocalizing infrasonically and sonically. They have a poor breeding record in urban zoos, in which infrasonic noise tends to be chronic. Herd size and composition, the age of potential mates, substrate, enclosure design, and other factors have been studied but little attention if any has been paid to soundscape. As a first step to comparing the soundscapes of facilities in which rhinos have and have not bred successfully, this project recorded and analyzed the soundscape of white rhinos at Fossil Rim Wildlife Center in Texas, one of five Conservation Centers for Species Survival, and one of the few U.S. facilities to successfully breed this species in recent years. Animal responses to sound have been shown to depend on sound level, rate of onset, duration, number of events, spectral distribution of the sound energy, presence of pure tones, the relative level of background noise, and semantics. Similar parameters were analyzed for the data recorded at Fossil Rim and will be presented here.

Off-Host Collection Methods of theOtobius megnini(Acari: Argasidae)

Otobius megnini (Dugès), often referred to as the spinose ear tick, is a one-host tick infesting the ear canal of a variety of ungulate species. The objective of this study was to develop sampling methods for collecting free-living stages of O. megnini and to collect preliminary data on habitat distribution. Sampling occurred during 2010 and 2011 at Fossil Rim Wildlife Center (FRWC) near Glen Rose, TX, where tick presence has been observed in the ears of a variety of ungulates. To sample for nonfeeding adult stage presence, a debris-filtering method was developed using screens of varying gauges. To sample host-seeking larval-stage tick presence, a carbon dioxide (CO2) trap was developed using compressed CO2 released through tubing along with cotton fabric used for tick attachment. Both methods proved successful with adults and larvae collected from animal shelters, with larvae also collected from oak leaf litter away from any structure. Locating both life stages off the host is the first crucial step toward the management of this tick species at facilities such as FRWC.

A Suite of Microsatellite Markers Optimized for Amplification of DNA From Addax (Addax nasomaculatus) Blood Preserved on FTA Cards

The addax (Addax nasomaculatus) is a critically endangered antelope that is currently maintained in zoos through regional, conservation breeding programs. As for many captive species, incomplete pedigree data currently impedes the ability of addax breeding programs to confidently manage the genetics of captive populations and to select appropriate animals for reintroduction. Molecular markers are often used to improve pedigree resolution, thereby improving the long-term effectiveness of genetic management. When developing a suite of molecular markers, it is important to consider the source of DNA, as the utility of markers may vary across DNA sources. In this study, we optimized a suite of microsatellite markers for use in genotyping captive addax blood samples collected on FTA cards. We amplified 66 microsatellite loci previously described in other Artiodactyls. Sixteen markers amplified a single product in addax, but only 5 of these were found to be polymorphic in a sample of 37 addax sampled from a captive herd at Fossil Rim Wildlife Center in the US. The suite of microsatellite markers developed in this study provides a new tool for the genetic management of captive addax, and demonstrates that FTA cards can be a useful means of sample storage, provided appropriate loci are used in downstream analyses.

Twenty-four hour activity budgets and patterns of behavior in captive ocelots ( Leopardus pardalis)

Activity budgets of captive ocelots ( Leopardus pardalis) were assessed from over 547 h of observational data obtained from six ocelots; two females at the Dallas Zoo (Dallas, TX), two females at the Caldwell Zoo (Tyler, TX) and a male and female at the Fossil Rim Wildlife Center (Glen Rose, TX). Data were examined for the percentage of active behaviors exhibited during the day and nighttime hours; temporal patterns of active, pace, exploratory and marking behavior, and for significance in pacing behavior between pre- and post-feeding times. The captive cats had a bimodal pattern of active behavior similar to field studies of wild ocelots, except that the timing of the active peaks were closer to the diurnal hours for the captive cats. The captive ocelots were less active than wild ocelots, and more diurnal. Also, the captive cats exhibited stereotypic pacing. When the percentage of time of active behavior was assessed for each cat, a strong variation between individuals and institution was not seen. Pacing behavior was highest prior to the feeding times for the cats. In assessing patterns of behavior, peaks in marking and exploratory behavior in the cats did not occur at the same time as the peaks in active behavior. However, we did see institutional differences in the pattern of exploratory and marking behavior, which may have been influenced by differing management practices.

Behavioral changes associated with introductions of male maned wolves (Chrysocyon brachyurus) to females with pups

Three male maned wolves were successfully introduced to their mates and 7- to 12-week-old pups at the Houston Zoological Gardens and Fossil Rim Wildlife Center in 1994 and 1995. The introductions took 3–7 weeks and had three stages: 1) allowing the male to see the female and pups through a chain-link panel or a full chain-link fence, 2) introducing the male and female without the pups present, and 3) introducing the male to the pups. For 7 days before Stage 2 and 7 days during Stage 3, the adults were observed for 150 hr. The amount of time they spent active and the amount of time they spent near the pups were recorded, as well as all behaviors they directed to the pups. After the males were introduced, the females' activity decreased, and the males' activity increased. The females spent less time near the pups after the introduction. The introduction did not affect the females' rates of affiliative or aggressive behaviors to the pups, and there was no difference between males' and females' rates of affiliative or aggressive behaviors. This introduction procedure offers an alternative to leaving the male with the pups from the time they are born. The adults' behavioral changes after the introduction show the benefits that occur when captive male maned wolves are allowed to help rear their pups. Zoo Biol 18:189–197, 1999. © 1999 Wiley-Liss, Inc.