bluuebunny/crossref_metadata_2025 huggingface dataset:
Early events following maternal exposure to 5‐fluorouracil lead to dysmorphology in cultured embryonic tissues
Authors: Shuey D. L. , Buckalew A. R. , Wilke T. S. , Rogers J. M. , Abbott B. D.
Published: June 2005

The chemotherapeutic agent 5‐fluorouracil (5‐FU) is teratogenic in a number of species, yet the mechanism(s) of its developmental toxicity are not fully understood. Administration of 5‐FU to the pregnant CD rat on day 14 of gestation results in dose‐dependent growth retardation and numerous malformations in near‐term fetuses, including hindlimb defects and cleft palate. Following treatment, a number of rapid biochemical and cellular alterations are detectable in embryonic hindlimbs, craniofacial and other tissues, which include thymidylate synthetase (TS) inhibition and altered cell cycle progression. In order to assess the importance of these early events in 5‐FU‐induced dysmorphogenesis, embryonic mid‐facial tissues and hindlimbs were dissected 3 or 6 hr after administration of 5‐FU to the dam and placed in explant culture. After 5 days in culture, craniofacial explants were evaluated morphologically for palatal closure and growth was assessed by measuring total protein and DNA content. Hindlimb explants were stained for cartilage using alcian blue to evaluate development of the digits. Craniofacial explants cultured at either 3 or 6 hr after exposure exhibited dose‐dependent growth retardation and defects of palatal fusion at the end of the culture period. Deficits in protein and DNA content were similar to those in craniofacial tissues that continued to develop in utero after treatment, although morphological defects in cultured explants did not correlate well with the incidence of cleft palate in vivo. Dose‐dependent deficits in metatarsal and phalanx development were observed in hindlimb explants dissected either 3 or 6 hr after maternal treatment. These results suggest that events sufficient to produce growth retardation and dysmorphogenesis occur within 3 hr of 5‐FU administration, and support the hypothesis that direct, rapid, and short‐lived biochemical and cellular changes in embryonic target tissues (i.e., TS inhibition, cell cycle alterations, and/or as yet unidentified events) are the critical mechanistic events in 5‐FU developmental toxicity. © Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Growth Profiles of human autosomal trisomies at midgestation
Authors: Barr Mason
Published: June 2005

Somatic and visceral growth profiles of midgestation human fetuses with trisomy 21, 18, or 13 demonstrate that each disorder has a characteristic pattern of growth aberration. The most striking deviations are short limbs in trisomy 21, subnormal adrenal and lung weights in trisomy 18, and supranormal spleen and kidney weights in trisomy 13. © 1994 Wiley‐Liss, Inc.
Axial rotation in rat embryos: Morphological analysis and microsurgical study on the role of the allantois
Authors: Fujinaga Masahiko , Hoffman Brian B. , Baden Jeffrey M.
Published: June 2005

In mouse and rat embryos, the embryonic disc develops within a cup‐shaped “egg cylinder” and consists of an inner layer of ectoderm and an outer layer of endoderm. Because of this configuration, the embryo first develops in a dorsally flexed position and then undergoes “axial rotation” to a ventrally flexed position. In the present study, we first analyzed the morphological process of axial rotation in rat embryos using novel reference axes set in the egg cylinder that remained invariant during the process. Our new perspective allowed us to demonstrate that the process consists of three movement which start at different stages of development: twisting of the upper body at stage 12/s7–8, twisting of the middle body at stage 13/s11–12, and twisting of the lower body (so called “tail”) at stage 14/s15–16. Axial rotation is an interesting developmental event not only because it is such a dynamic process but also because it is one of the earliest morphological sings of body asymmetry. This asymmetry is strongly biased in that tail almost always finishes up on the right side of the embryo for reasons that are still unknown. In the second part of the study, we preformed microsurgical experiments to extend our previous finding that removal of the allantois results in random determination of tail sidedness. We demonstrated that an allantois transplanted from another embryo can prevent this abnormal sidedness in an embryos whose allantois had been removed and that transecting the allantois did not lead to abnormal tail sidedness. A possible explanation is that the allantois produces a chemical factorthat controls tail sidedness. © 1995 Wiley‐Liss, Inc.
Interactions of Wnt‐1 and Wnt‐3a are essential for neural tube patterning
Authors: Augustine Karen A. , Liu Edison T. , Sadler T. W.
Published: June 2005

Wnt‐1 and Wnt‐3a have been postulated to share functional redundancy in spinal cord morphogenesis due to their homologies in protein structure and overlapping expression patterns. In this study, antisense oligonucleotides and a murine whole embryoculture system were used to examine functional interactions of Wnt‐1 and Wnt‐3a in late gastrulation and neurulation. Early somite mouse embryos were injected with combinations of Wnt‐1 and Wnt‐3a antisense oligonucleotides and then grown in vitro for up to 48 hr. Simultaneous inhibition of Wnt‐1and Wnt‐3a expression resulted in pattern loss in the presumptive spinal cord, which was apparent within 4 hr following antisense treatment. The neural tube was wavy, there was a reduction in the number of nuclear layers in the walls of the neural tube, and evidence of decreased cell adhesion between neuroepithelial cells by 12 hr postinjection. In addition, notochord and primitive streak abnormalities accompanied neural tube abnormalities. The existence of regulatory interactions between Wnt‐1, Wnt‐3a, and engrailed genes was also examined in this study. Antisense inhibition of Wnt‐1 or Wnt‐3a expression resulted in reduction of engrailed protein levels in the brain, somites, and spinal cord. However, simultaneous inhibition of both Wnt genes resulted in more complete loss of engrailed protein in these regions. Herein, we present data suggesting functional redundancy of Wnt‐1 and Wnt‐3a in neural tube patterning and in regulation Of engrailed expression. © 1995 Wiley‐Liss, Inc.
Development of the olfactory nerve: Its relationship to the craniofacies
Authors: Braddock Stephen R. , Grafe Marjorie R. , Jones Kenneth L.
Published: June 2005

Although absence of the olfactory bulbs is a relatively common occurrence seen in holoprosencephaly, in Kallman syndrome, and in a number of malformation syndromes, the extent to which it determines olfactory nerve development, as well as the part it plays in the morphogenesis of the nasal structures, is unknown. Cases of arhinencephaly ascertained at autopsy were studied in an effort to better understand the relationships between the olfactory nerve, bulb, and facies. Based on these studies, it is concluded that both olfactory receptor cells and olfactory nerves are present in arhinencephaly, that the olfactory nerves did not make contact with the brain in these cases, that the presence of olfactory nerves is independent of the severity of the central nervous system malformation, and that the shape of the nasal sturctures is not dependent on the presence of the olfactory nerve. © 1995 WiIey‐Liss, Inc. © 1995 Wiley‐Liss, Inc.
Cellular adaptation to chronic cadmium exposure: Intracellular localization of metallothionein protein in human trophoblast cells (JAr)
Authors: Breen John G. , Nelson Eric , Miller Richard K.
Published: June 2005

Trophoblast cells are the first embryonic cells that modulate the transfer of a variety of compounds (oxygen, amino acids, xenobiotics, metals) from the maternal to the fetal circulation in the human placenta. Human placental exposure to the toxic metal, cadmium (Cd) results in a decrease in the production of human chorionic gonadotropin (hCG), a decrease in the maternal to fetal transport of zinc (Zn), and trophoblastic necrosis. Thus, the ability of trophoblast cells to adapt to exposure to the toxic metal Cd has been considered crucial. In this study, the expression and intracellular localization of metallothionein (MT), a small molecular weight, metal binding protein, was examined in trophoblast cells (JAr) grown in normal media and in cells exposed chronically (6 months) to 2 μM CdCl2. Conventional and confocal fluorescence microscopy were used to examine the intracellular localization of MT protein in control cells and cells grown chronically in Cd. In unexposed trophoblast cells, MT protein was primarily perinuclear with low level, punctate expression in the cytosol. Following both chronic and 24 hour exposure to Cd, MT protein levels were increased (at least 3‐fold in both chronic and acute exposures) and the protein was now concentrated inside the nucleus with a lacy, cytoskeletal pattern of expression in the cytosol. To determine if the nuclear accumulation of MT protein was dependent on new protein synthesis, control cells were exposed to CdCl2(2 μM) and cycloheximide (2 μg/ml) for 24 hours. Following this exposure to Cd and cycloheximide, MT protein was perinuclear, suggesting that it was high levels of newly synthesized MT protein that accumulated in the nucleus of Cd treated cells. Cd exposed cells were also treated with colchicine (10 μM) to disrupt the cytoskeleton. Cytosolic MT protein expression in these cells was different from cells treated with Cd alone, suggesting that MT protein is associated with elements of the cytoskeleton. Thus, human trophoblast cells (JAr) exposed chronically will modulate cellular defense mechanisms to adapt to Cd. The specific redistribution of MT protein to the nucleus and to the cytoskeleton of challenged cells may be an important mechanism for cell defense against Cd and other toxicants. © 1995 Wiley‐Liss, Inc.
Role of formate in methanol‐induced exencephaly in CD‐1 mice
Authors: Dorman David C. , Bolon Brad , Struve Melanie F. , LaPerle Krista M. D. , Wong Brian A. , Elswick Barbara , Welsch Frank
Published: June 2005

Mouse embryos develop exencephaly when dams are exposed by inhalation to high concentrations (⩾10,000 ppm) of methanol on gestational day 8 (GD8; copulation plug = GD0). The present study examined the role of formate, an oxidative metabolite of methanol, in the development of methanol‐induced exencephaly in CD‐1 mice and cultured mouse embryos. The pharmacokinetics and developmental toxicity of sodium formate (750 mg/kg by gavage), a 6‐hr methanol inhalation (10,000 or 15,000 ppm), or methanol gavage (1.5 g/kg) in pregnant CD‐1 mice on GD8 were determined. Gross morphological evaluations for neural tube closure status in embryos or exencephaly in near‐term fetuses were performed. Decidual swellings and maternal plasma were analyzed for methanol and formate. The mean (± S.E.M.) end‐of‐exposure plasma methanol concentration was 223 ± 23 mM following the 6‐hr, 15,000 ppm methanol inhalation. There were no changes in blood or decidual swelling formate concentrations under any of the methanol exposure conditions. Peak formate levels in plasma (1.05 ± 0.2 mM; control 0.5 ± 0.3 mM) and decidual swelling (2.0 ± 0.2 mM; control 1.1 ± 0.2 mM) from pregnant mice (GD8) given sodium formate (750 mg/kg, po) were similar to those observed following a 6‐hr methanol inhalation of 15,000 ppm (plasma = 0.75 ± 0.1 mM; decidual swelling = 2.2 ± 0.3 mM) but did not result in exencephaly. In cultures of neurulating mouse embryos explanted on GD 8, the incidence of cephalic dysraphism observed on GD 9 + 6 hr was significantly increased relative to appropriate controls after a 12‐hr exposure to 375 mM methanol or to formate concentrations (40 mM) that exceeded those observed in vivo. These results suggest that exencephaly is a direct result of the effects of the parent compound methanol, administered at high concentrations, rather than the accumulation of formate. © 1995 Wiley‐Liss, Inc.
Physiologically based pharmacokinetics of methoxyacetic acid: Dose–effect considerations in C57BL/6 mice
Authors: O'flaherty Ellen J. , Nau Heinz , McCandless David , Beliles Robert P. , Schreiner Claire M. , Scott William J.
Published: June 2005

Methoxyacetic acid (MAA), a weak acid with a pKa of 3.57, was used to test the broad hypothesis that distribution of weak acids in maternal and fetal tissues is determined principally by the pKa of the acid and the pH values of tissue and fluid compartments and to examine tissue dose–teratogenesis relationships, as well as administered dose–teratogenesis relationships. Five related experimental studies were conducted in pregnant C57BL/6CrlBR mice: a conventional dose–response study of developmental toxicity and transplacental pharmacokinetics in mice, a second dose–response study in which reproductive outcomes in litters from individual dams were related to individual pharmacokinetic behavior, a protein‐binding experiment, an embryo tissue localization study, and determination of pH in maternal and embryonic compartments after exposure to MAA. MAA was administered intraperitoneally at 9:00 a.m. on day 10 of gestation, at doses ranging from 88 to 164 mg/kg. Localization within the forelimb bud of the embryo, an MAA target site, was determined by computerized image analysis of the distribution of radiolabeled MAA. The kinetic predictions of a physiologically based model incorporating tissue pH values and MAA pKa agreed well with observed concentrations at the lowest dose However, at intermediate and higher doses, concentrations in both maternal and embryonic tissues were consistently underestimated. MAA was bound neither to maternal plasma proteins nor to embryonic proteins. Intermediate and higher doses of MAA caused dose‐dependent transient depressions in tissue pH, but these were not of sufficient duration to bring predicted tissue concentrations into congruence with the concentrations observed. Distribution of MAA within the forelimb bud was broadly consistent with the pH hypothesis, but MAA concentration was not increased in the distal postaxial sector that is the site of the precursor cells of the missing digits. Internal exposure to MAA, defined as the area under the maternal plasma or embryo concentration curve (AUC), was not proportional to administered dose, but AUC‐response relationships generated by the group and individual dose–response studies were comparable. While AUC may be a useful measure of effective MAA dose, it cannot be accurately predicted at teratogenic doses of this agent by the model as it is presently structured. © 1995 Wiley‐Liss, Inc.
Does concurrent or prior nicotine exposure interact with neonatal hypoxia to produce cardiac cell damage?
Authors: Tolson C. M. , Seidler F. J. , McCook E. C. , Slotkin T. A.
Published: June 2005

Cigarette smoking during pregnancy exposes the fetus to both nicotine and hypoxia/ischemia; postnatal exposure to second‐hand smoke also involves substances that cause hypoxia (CO, HCN). Although developing cardiac cells are more resistant to hypoxia‐induced damage than are mature cells, we examined whether nicotine affects this resistance, either when exposure is concurrent with hypoxia, or when animals are exposed to nicotine prenatally and receive subsequent hypoxic exposure. One, 8‐, or 15‐day‐old rats exposed to 7% O2 for 2 hr all showed inhibition of cardiac DNA synthesis. By contrast, administration of nicotine at either low (0.3 mg/kg) or high (3 mg/kg) doses failed to alter DNA synthesis. To examine effects on cells that were not undergoing mitosis, we examined ornithine decarboxylase (ODC), an enzymatic marker for cell damage. One day old rats showed inhibition of ODC by hypoxia, a response that represents preservation of cell integrity; by 8 days of age, ODC was increased by hypoxia, evidence of cell damage. The high dose of nicotine evoked an increase in ODC at all ages and the low dose exacerbated the effects of hypoxia at 8 days of age. Prenatal nicotine exposure caused a transient inhibition of cardiac DNA synthesis but did not produce evidence of cell damage (ODC, protein synthesis markers) by itself, nor did it alter the effect of a subsequent postnatal exposure to hypoxia. These results suggest that cardiac cell damage could emerge as a consequence of concurrent, repeated exposures to nicotine and hypoxia. Such effects could contribute to the elevated incidence of perinatal morbidity/mortality and Sudden Infant Death Syndrome associated with smoking. © 1995 Wiley‐Liss, Inc.
Effect of treatment with phenobarbital and stiripentol on carbamazepine‐induced teratogenicity and reactive metabolite formation
Authors: Finnell Richard H. , Bennett Gregory D. , Slattery John T. , Amore Benny M. , Bajpai Manoj , Levy René H.
Published: June 2005

A model using SWV mice was developed to investigate the mechanistic basis of carbamazepine (CBZ)‐related fetotoxicity. Drug administration was initiated prior to conception and continued until day 18 of gestation. The incidence of malformation was 33% following CBZ exposure (1,500 mg/kg/day), compared with a 5% incidence in pair‐fed control animals (P< 0.05). Coadministration of nonteratogenic doses of phenobarbital (PB; a cytochrome P‐450 inducer) (45 mg/kg/day) and CBZ (1,000 mg/kg/day) increased the frequency of malformation from 10% to 26% (P<0.05), compared with mice dosed with CBZ alone (1,000 mg/kg/day). Coadministration of stiripentol (STP; a cytochrome P‐450 inhibitor) (300 mg/kg/day) decreased the incidence of malformations produced by CBZ (1,500 mg/kg/day) from 33% to 16.7% (P<0.05). The effect of PB administration on the binding of 14C in maternal and fetal tissue was assessed in dams that received CBZ (1,000 mg/kg/day) with or without PB (45 mg/kg/day) or STP (300 mg/kg/day) chronically and a single i.p. dose of 14C‐CBZ on day 12 of gestation. In all instances, binding was greatest in maternal liver, then in the placenta, fetal head and body, and maternal thigh muscle. In all tissues, PB caused a two‐ to threefold increase in binding, compared with binding in mice exposed to CBZ alone. STP administration decreased protein adduct formation only in maternal liver. The binding of 14C was also assessed in hepatic microsomes prepared from female mice exposed to CBZ and PB or STP as in the in vivo study of 14C binding. The extent of irreversible binding was 67% greater in microsomes prepared from mice pretreated with PB and CBZ than with CBZ alone, while STP resulted in only 21% inhibition of 14C adduct formation (P<0.05). The results are consistent with the formation of a chemically reactive teratogenic metabolite of CBZ in mice by cytochrome(s) P‐450. © 1996 Wiley‐Liss, Inc.
Atypical aortic coarctation and innominate artery stenosis associated with clubfoot and lower leg ischemia in an infant
Authors: Smith J. Clinton , Joransen James A. , Heath Bobby , Allen Bret C.
Published: June 2005

We report findings in a male infant born with talipes equinovarus and ischemic necrosis of the left lower leg and foot associated with atypical coarctation of the ascending aorta and stenosis and hypoplasia of the proximal innominate artery. We hypothesize that a vasculopathy of unknown etiology occurred in utero that resulted in ascending aortic arch coarctation and innominate artery stenosis. The presence of a thrombus in the coarcted segment suggests that one or more emboli could have been resposible for vascular compromise and subsequent clubfoot deformity and lower leg ischemia. Alternatively, a vasculopathy similar to that hypothesized as occurring in the aorta might also have occurred in the left anterior tibial artery, causing structural deformity and soft tissue ischemia of the left lower leg and foot. We believe that this is the first report of this association of findings. © 1996 Wiley‐Liss, Inc.
A captive behavioral enrichment study with Asian small‐clawed river otters (Aonyx cinerea)
Authors: Foster‐Turley Pat , Markowitz Hal
Published: June 2005

Asian small‐clawed river otters (Aonyx cinerea) were given the opportunity to hunt for and capture live crickets (Acheta domestica) in a public interactive display. The otters learned the experimental routine during the first day of exposure. Different response levels were recorded at each of three capture sites, A, B, and C. The animals showed continued motivation for hunting despite the fact that there was no deprivation and the crickets represented an insignificant part of the diet. Besides live crickets, other items—cat food, dead crickets, and gelatin capsules—were introduced for five days each. The otters made the most captures per opportunity for live crickets, followed, in order of preference, by dead crickets, cat food, and gelatin capsules. Although gelatin capsules were found to be the least motivating prey item, the otters hunted for them whenever they were offered. Thus, any active opportunity to produce a change in their environment was rewarding to the otters.
Observations on the behavior of captive sitatunga (Tragelaphus spekei)
Authors: Popp James W.
Published: June 2005

Little is known about the behavior of the sitatunga. In order to learn more about their behavior, a group of sitatunga was studied at the Audubon Park and Zoological Garden. Courtship in the sitatunga begins with a male pursuing the female. The female occasionally stops, allowing the male to approach in the “low stretch” posture. If the female does not move away the male rests his chin on the female's rump and then mounts her. Males commonly horn branches, sticks, and turf. The possible functions of horning are discussed. Males also engage in sparring or “play‐fighting.” Mutual grooming, vocalizations, and mother‐young interactions of the sitatunga are described. The behavior of sitatunga is compared to that of other Tragelaphines.
Evaluation of two computerized data collection devices for research in zoos
Authors: Gerth Jeffrey M. , Lewis Charles M. , Stine Wm. Wren , Maple Terry L.
Published: June 2005

Computerized data collection devices can aid research in zoos if applied carefully to the research study. This article provides guidelines for use of two models of a representative data collection device, the Datamyte. The general features of each model are presented and compared in two hypothetical zoo studies. In addition, a human engineering analysis of the placement of keys and the physical enclosure was conducted at our laboratories. Procedures to overcome minor flaws in construction and design are discussed. The Datamyte 801 is less complicated, has limited data storage capacity, and is easier for use by novice observers than the Datamyte 1000. Therefore the Datamyte 801 is recommended for limited, short‐term focal animal studies. The Datamyte 1000 is capable of complicated coding schemes at the expense of field analysis of the data, and simplicity in its basic operation.
Demographic trends in a captive population of red pandas (Ailurus fulgens)
Authors: Roberts Miles
Published: June 2005

Birth and survivorship data based upon 39 litters born over a ten‐year period are examined and discussed. Reproduction in red pandas is characterized by seasonal breeding, small mean litter size, and relatively high survivorship of young, and in general follows a typical “K‐selected” life‐history strategy.

The mean litter size was two, and the sex ratio at birth was approximately 1 male to 1.11 females. Higher male mortality in the early age classes resulted in a sex ratio in favor of females. Mortality was not correlated with age or experience of the mother but was found to be highly positively correlated with an increase in the inbreeding coefficient of the young. There was no significant difference in mortality among the different litter‐size classes, and in general mortality decreased with age.

Recommendations concerning future management for the study population are given.
Selected aspects of Lemur variegatus reproductive biology
Authors: Shideler Susan E. , Lindburg Donald G.
Published: June 2005

Results from data collected during the 1978–1979 breeding season on the reproduction of Lemur variegatus at the San Diego Zoo provide information which generally supports previously published reports on this species. Comparison of selected results from these data to a larger data base of which they are a part makes it possible to resolve some of the discrepancies between reports. Certain aspects of the reproductive biology of this species may then be generally characterized with confidence: The onset of seasonal breeding as evidenced by estrous behavior begins as early as mid‐December in the northern hemisphere and may continue through March; genital changes associated with estrus in females last 9.85 ± 1.67 days (± SD); female receptivity occurs 7.0 ± 1.53 days after the onset of these genital changes and lasts 12‐24 hours, during which breeding occurs; gestation averages 99.47 ± 4.19 days; the peak birth season is April–May; litters normally contain two to three offspring, with full‐term neonates weighing an average of 104.63 ± 19.10 grams. In addition, L variegatus appears to be highly resistant to the impact of captivity on both its reproductive physiology and behavior, as indicated by the 100% breeding success of the diversely reared and managed groups of study animals.
Fecundity in the captive howler monkey, Alouatta caraya
Authors: Shoemaker Alan H.
Published: June 2005

Seven female Black howler monkeys, Alouatta caraya, from both wild‐ and captive‐born origins have reproduced at Riverbanks Zoological Park. Three of the five wild‐born females arrived as juveniles and grew to maturity; the other two were already mature upon arrival and reproduced shortly therafter. Two females which were born within the park's collection have since reached maturity and also reproduced. The interval between the first and second young of wild‐born howlers is longer than between subsequent birth intervals. Subsequent young are also more precocious than their preceding siblings. In at least one case, a socially inferior female did not reproduce until placed within a different troop situation which elevated her social status. Females born in captivity conceived when 42 and 35 months old, the former situation being linked to low social status. Young born to females housed under both seasonal and regulated conditions of photoperiod demonstrated no difference in breeding intervals and seasonality of birth does not appear to be a factor in howler monkey reproduction.
Chromosome studies in the orangutan (Pongo pygmaeus): Practical applications for breeding and conservation
Authors: Seuánez Héctor N.
Published: June 2005

The unequivocal identification of Bornean, Sumatran, and first‐generation hybrid orangutans can be carried out by chromosome analysis, a procedure that is more reliable than any other so far used to distinguish between orangutan subspecies. Chromosome differences between subspecies have been compared with protein and DNA studies, and these have shown that Bornean and Sumatran orangutans are more different from each other than we originally thought. Chromosome studies in the orangutan have shown variant chromosome types that are not subspecies‐specific. One of these variant types is a product of a complex double inversion rearrangement and is a polymorphic trait in both subspecies. In view of our findings, specific guidelines have been recommended for evaluating the fertility of hybrid specimens and maintaining purebred orangutan stocks.
Tool use by captive chimpanzees at an artificial termite mound
Authors: Nash Victoria J.
Published: June 2005

This study examines tool use by a colony of captive chimpanzees at an artificial termite mound. The mound, constructed of concrete, simulates the termite mounds which are used as food sources by wild chimpanzees who extract the termites using grass or twig‐type tools. In the present study, tool availability was manipulated, specifically the type of tool, and the distance of tool material from the mound. The type of food available in the mound was also varied. Tool‐making and tool‐using behavior was examined in relation to individual, age, and sex differences.

The artificial mound proved to be a viable simulation of the naturally occurring mounds, with most of the chimpanzees exploiting the food in the mound by using tools over the period of study. Interesting individual differences emerged in the way that the chimpanzees selected and used tools, some preferring to move some distance from the mound to collect “off‐the‐peg” tools, others preferring to sit and fashion a tool from material available nearer the mound. Also, some chimpanzees used both ends of a tool, while others used only one end. There were significant age differences in activity at the mound, the younger chimpanzees spending more time at the mound, using tools previously used by others, and manipulating the mound holes manually. Sex differences, although not significant, were apparent. The artificial mound provides the chimpanzees with a stimulating and rewarding activity, interest and enjoyment for the public, and an opportunity for researchers to study tool use under more controlled conditions than are possible in the field.
Observations on the reproductive biology of the land tortoises Geochelone emys and Geochelone yniphora in the Honolulu Zoo
Authors: McKeown S. , Juvik J. O. , Meier D. E.
Published: June 2005

Captive reproduction of the Burmese brown tortoise (Geochelone emys) has occurred repeatedly over a five‐year period in the Honolulu Zoo. Maximum clutch size (51 eggs) exceeds that reported for other members of the Testudinidae. Nesting behavior in G emys includes construction of a large leaf‐litter mound. Collection of nest‐building material is accomplished by “back‐sweeping” of ground litter within a distance of up to 4 m from the nest site. The nesting female assumes a “nest‐guarding” behavior for a period of 2–3 days following egg laying. Eggs incubated artificially hatched in 63–84 days, with egg fertility at 78–84%. One hundred and three G emys were successfully hatched and reared during the period 1978–82.

A colony of endangered Madagascar angulated tortoises (Geochelone yniphora) have been maintained at the Honolulu Zoo since 1971. Courtship and mating behavior is similar to that described for the consubgeneric G radiata. Distinctive male “hooking” behavior during courtship in G yniphora is related to the exaggerated epiplastron development in this species. Egg laying has occurred repeatedly in the G yniphora colony since 1979 (mean clutch size = 4.2; N = 6) although no eggs have yet proved fertile.
Hand‐rearing infant stumptailed macaques
Authors: Chamove Arnold S. , Anderson James R.
Published: June 2005

Fifty‐four infant macaques (Macaca arctoides) were separated from their mothers between 1 and 10 days of age. Simple training led to them learning to self‐feed by about 30 hours, in some cases much earlier. Supplementary feeding of the infant before separation facilitated the establishment of self‐feeding. The greater weight of adult stumptailed macaques compared to rhesus may begin during the first months of life.
Species decline: A perspective on extinction, recovery, and propagation
Authors: Carpenter James W.
Published: June 2005

This keynote address was presented at the Conference on the Conservation of Endangered Species in Zoological Parks and Aquariums on April 18, 1982 at the National Aquarium in Baltimore. It outlines 1) future trends in the world's environment, resources, and population; 2) factors affecting species decline; 3) reasons for preserving life forms; and 4) techniques, with emphasis on captive propagation, used to assist in species recovery.
Crane reproductive physiology and conservation
Authors: Gee George F.
Published: June 2005

Some unique features of crane reproduction, management, and conservation are described. Because cranes are sexually monomorphic, sexing is difficult and must be accomplished using behavior, laparoscopy, cloacal examination, genetic techniques, or fecal steroid analysis. Although husbandry techniques for cranes are similar to those used with other nondomestic birds, a number of basic characteristics, such as extreme aggressiveness, imprinting by the crane chick on man, a delayed molt in the immature crane, delayed sexual maturity, and infertility, pose special problems for the propagator. Artificial insemination is a practical solution to crane infertility. Vigorous captive management and propagation efforts must become increasingly important if several endangered crane species are to survive the continuing decline in wild populations. The ultimate goal is the restoration of suitable habitat and sustainable native populations.
Observations of maternal‐infant interactions in a captive herd of sable antelope (Hippotragus niger)
Authors: Murdock Gwendolyn K. , Stine William Wren , Maple Terry L.
Published: June 2005

The New York Zoological Society's captive‐breeding program on St Catherine's Island, Georgia, includes a herd of sable antelope (Hippotragus niger). Two aspects of mother‐infant interactions, nursing and hiding, are described herein. Three younger calves, up to 6 d of age, and three older calves, 8 to 50 d of age, were the subjects of focal‐animal and continuous observations and instantaneous time‐point samples. Two of the younger calves were born to multiparous cows. One cow was primiparous. Between the three calves, quantitative differences in nursing episodes were found in the mean duration (1.7–3.6 min), mean number per d (1.0–8.6 episodes), and mean total time per d (2.6–14.6 min). Despite these differences, all calves thrived. The multiparous cows exhibited a pattern described in captive and wild ungulates: approaching their calves prior to nursing before the calves emitted any response; and nursing their calves early and late in the day. The cows also exhibited nursing‐time synchrony. Three instances of calves suckling younger calves' mothers are also described. Two new interpretations of the function of hiding behavior are offered: (1) If older calves exploit the inexperience of newborn calves by nursing from their mothers, then younger calves may benefit by hiding out of the view of other herd members. Hiding behavior may result from intercalf competition; and (2) if newborns vacillate between arousal‐increasing and arousal‐reducing activities, then “hider” species may hide to attain arousal‐reduction.
Diagnosis and treatment of infertility in male great apes
Authors: Gould K. G.
Published: June 2005

Increased concern for maintenance of endangered species in captivity has prompted increased interest in monitoring the fertility of captive animals. This paper outlines methods for discrimination between lack of reproduction and infertility, and provides guidelines for identification of physiological causes of infertility. The role of environment in infertility is discussed, and suggestions are made for correction of environmental deficiencies. A brief review of the potential for infectious infertility is followed by an outline of appropriate treatments. It appears that a primary cause of physiological infertility in the gorilla is spermatogenic arrest, and it also appears possible that this defect may be corrected by alterations in environment and management. In summary, the outlook for continued breeding of great apes in captivity is bright, and efforts in the past few years to identify and alleviate potential causes for infertility and nonreproduction are beginning to yield good results.
Research on reproductive biology of gorillas
Authors: Nadler Ronald D. , Collins Delwood C.
Published: June 2005

Laboratory research has implicated several variables which contribute to the regulation of reproductive behaviour of captive gorillas. Females were found to be increasingly attractive to males during the follicular phase of the menstrual cycle when estrogen and testosterone concentrations in the female were increasing. Females solicited mating from the males primarily at midcycle, about the time when the concentration of testosterone was maximal. No mating occurred during the mid‐ to late luteal phase after progesterone concentrations were elevated. Both males and females initiated mating during the midcycle, periovulatory period, but male initiative accounted for most mating that was temporally dissociated from that period. Individual differences between males and among females contributed to the variability in results. Confinement of a male and female in relatively small quarters appears to interact with certain aspects of species‐typical behaviour to distort patterns of mating in laboratory tests. Data on behaviour of gorillas in the wild contributed to interpretation of the laboratory results and suggest an enlightened approach to the captive maintenance and breeding of gorillas. An important consideration in promoting captive breeding of gorillas seems to be the provision of options to the female for regulating the frequency and distribution of mating in the cycle.
Freeze‐branding beaver tails
Authors: Pfeifer Sharon , Wright Frank H. , DonCarlos Mike
Published: June 2005

Freeze‐branding has proven useful in managing and researching a captive group of beaver (Castor canadensis) at the Minnesota Zoological Garden. Over 24 mo, 13 freeze‐brands were applied to the tails of 11 beaver for varying application times. Permanence of brands increased with increasing distance from tail base. Because permanence of freeze‐brands on cattle is influenced by skin thickness, the tail of a male beaver was horizontally sectioned into nine roughly equidistant segments, photographed to scale, and the epidermal/dermal thickness of the dorsal side of each section was measured to determine if skin thickness affected freeze‐branding success in beaver. Thickness of the epidermal and dermal layers of the dorsal tail surface decreased 14‐fold from tail base to tip. Based on our preliminary finding that freeze‐brand permanence improved with decreased thickness of the epidermal/dermal layers of the tail, we recommend that beaver be freeze‐branded for 25 s on the lower half of the tail for best results.
Excretion of radiolabeled estradiol in the cat (Felis catus, L): A preliminary report
Authors: Shille V. M. , Wing A. E. , Lasley B. L. , Banks J. A.
Published: June 2005

The time course and end products of estradiol metabolism were studied in the domestic cat, which has been chosen as a model for steroid metabolism studies in nondomestic felidae. Radiolabeled estradiol was injected intravenously into three adult female cats; one had a spontaneous estrus, one was induced with follicle‐stimulating hormone, and one had been ovariohysterectomized; feces, urine, and blood were collected daily, and the radioactivity content was determined. Feces and urine contained 47 and 1% of the injected dose (0.33 μCi), respectively. Metabolites appeared earlier in the urine than in feces (d 1 vs d 2 postinjection), and excretion was completed on d 5; no radioactivity was detected in plasma 24 h postinjection. Estradiol metabolites were excreted as unconjugated estrogens (22%) and as conjugates hydrolyzable with β‐glucuronidase and acid solvolysis (7 and 50%, respectively); the remaining 14% were not recoverable with any of the above methods. The major portion of the conjugates was estradiol‐17β (64–80%) while 11–16% appeared as estrone. Endogenous cycles related to the spontaneous and induced ovarian activity were monitored by observation of estrous behavior, vaginal epithelium cornification, and plasma estradiol determination. The reproductive state of each animal had no effect on the time course or type of metabolite excreted.

We found low proportions of injected radioactivity excreted in the urine and high residual levels remaining after hydrolysis and extraction in the feces. These findings suggest that although feces are an abundant source of estradiol metabolite in the cat, and probably in the exotic felidae, development of noninvasive methods for monitoring ovarian cycles in these species will depend on more efficient methods for urine hydrolysis, on the resolution of problems encountered in fecal steroid analysis, or on the identification of metabolites which may be measured directly in the urine without hydrolysis or extraction.
The frozen zoo concept
Authors: Benirschke Kurt
Published: June 2005

Biologic material from exotic species is difficult to obtain for scientists. Yet much depends on the availability of such materials for a better understanding of evolutionary relationships and genetics of animals. Zoos have an obligation to participate in the safeguarding of some of these tissues by preserving cells, serum, and organs under optimal conditions. This paper describes the state of the frozen tissue‐cell bank at San Diego Zoo and examines possible future directions for the collection of essential materials.
Reproductive studies unit of the New York Zoological Society
Authors: Stover Janet , Westrom Wendy K.
Published: June 2005

The Reproductive Studies Unit of the New York Zoological Society addresses several areas of exotic animal reproduction. These include semen collection and freezing, embryo transfer in the gaur, study of normal reproductive anatomy, urinary hormone analysis of cycling and pregnant females, and postmortem collection and freezing of oocytes. The primary goal is development of exotic species gene banks.
Observations of daily activity patterns in two captive short‐nosed echidnas, Tachyglossus aculeatus
Authors: Brannian John , Cloak Connie
Published: June 2005

Daily activity patterns of a pair of short‐nosed echidnas, Tachyglossus aculeatus, at the Topeka Zoo were observed once monthly for 1 year. These echidnas remained primarily nocturnal throughout the year. In observations when both echidnas exhibited extended periods of activity (5 hours or more) there was a high correlation in times activity began between the two animals.

Activity patterns varied throughout the year possibly associated with changes in temperature and/or photoperiod. Diel temperature changes and noise levels did not appear to be major factors influencing activity in this study.
The status of north american captive herds of the banteng,Bos javanicusd'Alton
Authors: Davis Scott , Read Bruce
Published: June 2005

The genetic purity of captive banteng herds has often been questioned because banteng have the ability to hybridize with domestic cattle breeds. An electrophoretic survey of North American captive herds of the Javanese banteng,Bos javanicus javanicusd'Alton, was carried out to determine if contamination could be detected. The animals examined represented descendants from five separate importations. Of the 21 loci examined, four proved to be informative. An analysis of these loci failed to indicate a single case of potential genetic contamination, although sample sizes were small. Bull color, which has been suggested as an indicator of genetic purity, was found to relate to the geographic origin of the banteng lineage. Since the North American herd is uncontaminated at the present time, great care should be taken to determine the suitability of new import animals.
Orangutans' color preference for food items
Authors: Barbiers Robyn B.
Published: June 2005

The effects of the addition of color to a dry primate diet on the feeding behavior of orangutans were studied. Purina Monkey Chow was dipped in food coloring (red, green, blue, orange). Colored and plain chow was offered to the subjects, three adults, and two juveniles. Time to eat or lose interest in feeding, quantity, and color of pieces of chow handled and eaten were recorded for each group. The juveniles' consumption of chow increased when offered colored chow, and adults required less time to consume their food. One juvenile showed a significant preference for red monkey chow.
Duration of strike‐induced chemosensory searching in long‐term captive rattlesnakes at national zoo, audubon zoo, and San Diego Zoo
Authors: Chiszar David , O'Connell Barbara , Greenlee Robin , Demeter Bela , Walsh Trooper , Chiszar Joan , Moran Katy , Smith Hobart M.
Published: June 2005

Rattlesnakes typically strike and release adult rodent prey. Striking is followed by a sustained, high rate of tongue flicking that guides the snake to the envenomated, dead prey. Wild‐caught rattlesnakes exhibited this chemosensory searching for about 2.5 h, and the present study demonstrated that long‐term captive rattlesnakes (Crotalus atrox, C durissus, C horridus, C vegrandis, C unicolor) at three zoos did the same. Because these zoo‐raised snakes had always been offered dead rodents and because the snakes had become accustomed to ingesting them without striking, the present snakes had rarely exercised their innate predatory repertoires. The duration of chemosensory searching in these snakes indicates that this important aspect of the predatory repertoire had not been degraded as a consequence of long‐term captive husbandry.
Pregnancy detection in tapirs by direct urinary estrone sulfate analysis
Authors: Kasman L. H. , McCowan B. , Lasley B. L.
Published: June 2005

Urinary levels of estrone sulfate (ES), indexed by creatinine (CR), were evaluated by a direct radioimmunoassay of four Malayan (Tapirus indicus) and one Brazillian (Tapirus terrestris) tapir pregnancies. Levels rose above baseline ES values of 20 ± 1.2 ng/mg CR (n = 200) in the Brazilian animal and 25 ± 1.3 ng/mg CR (n = 105) in the Malayan animals at approximately 7 months prior to parturition and continued to rise in both species until just before parturition. Quantitatively, levels rose 10‐fold higher in the Brazillian animal than in the Malayan animals through approximately 1 month prior to parturition in both species. These findings indicate that routine urinary monitoring provides an accurate means for detecting pregnancy in tapirs and suggests differences in estrogen excretion patterns between tapir species and with other perissodactyls.
Killer whale shares food with gulls at the Vancouver Public Aquarium
Authors: Nordquist Charles , Hutchins Michael
Published: June 2005

A 6‐ to 9‐year‐old female killer whale (Orcinus orca) was observed sharing food with gulls at the Vancouver Public Aquarium. Hypotheses regarding the origin of this apparently learned behavior are discussed and evaluated. The behavior can be explained by an operant model, but there is evidence that social mimicry or observational learning may also be involved.
Maternal and paternal care in the rock cavy,Kerodon rupestris, a South American hystricomorph rodent
Authors: Tasse Judy
Published: June 2005

The maternal and paternal behavior ofKerodon rupestriswas examined. Quantitative differences between fathers and mothers and between mothers raising young with fathers present and with fathers absent were assessed. Growth rates of young raised by paired females and by lone females were compared.

The male provides direct paternal care to the young by engaging in allogrooming, sniffing, and huddling. There is no significant difference between the sexes in the amount of contact promoting behavior given to the offspring, nor are the sexes significantly different in the amount of exploratory sniffing of the offspring. When the male is absent, the female spends a greater amount of time in contact with the young. Young raised by lone females gained significantly more weight than young raised by paired females.

The suggestion that indirect paternal care acts to reduce female aggression to the young and relieve the energy expenditure burden of the female is discussed. The results indicate that social experience is gained at the expense of physical nurturing when the male is present.
Giraffe squeeze cage procedure
Authors: Wienker Wendy R.
Published: June 2005

A squeeze cage at Woodland Park Zoo has become a valuable tool in giraffe management. The cage has been used 63 times in 4 years with no serious injuries to animals or personnel. Conditioning the giraffes to the cage is of foremost importance in planning a successful restraining procedure. Individual giraffes react differently to the stress of being confined, so careful monitoring of behavior throughout is imperative to anticipate and prevent potential problems. Staff should be fully trained in the use of the equipment and familiar with the temperament of the giraffe. The cage is used for hoof trimming and routine medical examinations, including blood collection, X‐rays, and giving injections.