Disease risk and inter‐institutional transfer of specimens in cooperative breeding programs: Herpes and the elephant species survival plans

Managers of cooperative breeding programs and re‐introduction projects are increasingly concerned with the risk of disease transmission when specimens are transferred among facilities or between facilities and the natural environment. We used data maintained in North American studbooks to estimate the potential risks of disease transmission by direct and indirect contact of specimens in the American Zoo and Aquarium Association’s Elephant Species Survival Plan. Histological evidence for a novel herpesvirus disease transmitted between and within elephant species housed in North American facilities prompted an examination of the scope of possible transmission routes within the captive population. We found that, compared with other species managed through Species Survival Plans, elephants experience relatively few transfers between zoos. Nevertheless, the number of direct contacts with other elephants born during the study period of 1983–1996 (excluding stillbirths) was much higher than we had anticipated (μ = 25 ± 27; N = 59) and the number of potential indirect contacts was surprisingly large (μ = 143 ± 92; N = 59). Although these high rates of potential contacts complicate exact identification of infection pathways for herpesvirus, we were able to propose potential routes of transmission for the histologically identified cases. Furthermore, the extraction of data from studbooks allowed us to readily identify other specimens that did not succumb to the disease despite similar exposure. Moreover, we were able to identify other possible cases to recommend for histological examination. Herein we reveal the possibilities of multiple disease transmission pathways and demonstrate how complex the patterns of transmission can be, confounded by the unknown latency of this novel herpesvirus. This emphasizes the need for zoo veterinarians and cooperative breeding programs to consider the full potential for disease transmission associated with each and every inter‐zoo transfer of specimens. Zoo Biol 20:89–101, 2001. © 2001 Wiley‐Liss, Inc.     

One year later: evaluation of PMC‐recommended births and transfers

To meet their exhibition, conservation, education, and scientific goals, members of the American Zoo and Aquarium Association (AZA) collaborate to manage their living collections as single species populations. These cooperative population management programs, Species Survival Plans^® (SSP) and Population Management Plans (PMP), issue specimen‐by‐specimen recommendations aimed at perpetuating captive populations by maintaining genetic diversity and demographic stability. Species Survival Plans and PMPs differ in that SSP participants agree to complete recommendations, whereas PMP participants need only take recommendations under advisement. We evaluated the effect of program type and the number of participating institutions on the success of actions recommended by the Population Management Center (PMC): transfers of specimens between institutions, breeding, and target number of offspring. We analyzed AZA studbook databases for the occurrence of recommended or unrecommended transfers and births during the 1‐year period after the distribution of standard AZA Breeding‐and‐Transfer Plans. We had three major findings: 1) on average, both SSPs and PMPs fell about 25% short of their target; however, as the number of participating institutions increased so too did the likelihood that programs met or exceeded their target; 2) SSPs exhibited significantly greater transfer success than PMPs, although transfer success for both program types was below 50%; and 3) SSPs exhibited significantly greater breeding success than PMPs, although breeding success for both program types was below 20%. Together, these results indicate that the science and sophistication behind genetic and demographic management of captive populations may be compromised by the challenges of implementation. Zoo Biol 0:1–11, 2006. © 2006 Wiley‐Liss, Inc.     

A system for monitoring and improving animal visibility and its implications for zoological parks

With the growing trend in zoos to build complex, naturalistic exhibits comes the potential for exhibits to be so densely vegetated or complex that animals are not easily seen by zoo visitors. This can negatively impact the visitor's visiting experience and the zoo's ability to communicate conservation and education messages. Over the past 9 years, Disney's Animal Kingdom^® has developed a process for monitoring and improving the visibility of animals on display to the public. This animal visibility process utilizes a data collection system whereby systematic observations are collected each week. The percentage of observations where at least one animal was visible is recorded for each species and compared to an 80% visibility criterion. Species that do not reach this criterion for 4 consecutive weeks are discussed at animal management meetings. If the problems associated with animal visibility cannot be easily solved, the animal‐care teams partner with the research team to conduct a second process, called the Visibility Issues Process. This process provides additional information for the animal‐care team to utilize in developing a plan to improve visibility. Although the processes described here are specific to the infrastructure at Disney's Animal Kingdom^®, the basic concepts of (1) a formalized visibility data collection process, (2) a visibility criterion to which managers of species are held accountable, and (3) a process for planning to improve animal visibility without negatively impacting animal welfare are fundamental concepts that can be developed at individual institutions and incorporated into that zoo's existing infrastructure. Zoo Biol 29:68–79, 2010. © 2009 Wiley‐Liss, Inc.     

Taxonomic and Distributional Databases of Fishes in Taiwan

The fishes of Taiwan comprise total 2450 species in 250 families, about 1/10 of the world's fishes. Curatorial and distributional data of Taiwanese fish have been integrated into a database that can be accessed interactively on the Internet at http://fishdb.sinica.edu.tw. The database includes the following items: basic information and specimen photo of each species, distributional database, bibliographic database, curatorial database, inquiring system for Chinese fish names of the world fishes, and new version of erratum of Fishes of Taiwan. The above regional database of Taiwanese fishes provides hyperlinks to fish data for each species in the global fish data, FishBase, of ICLARM (http://www.fishbase.org). Through the collaboration with FishBase and other global networks for taxonomic purposes, like Species 2000, BioNet, or GBIF (Global Biodiversity Information Facilities), users in the world can also obtain updated data provided by Taiwan. We hope our experience with database establishment can be used as a model to help other countries to develop their own regional fish databases or even to build up databases of other groups of organisms. There should be one good approach for all people in the world for sharing complete and updated biodiversity information via the Internet.     

Creating,curating and evaluating a mitogenomic reference database to improve regional species identification using environmental DNA

Species detection using eDNA is revolutionizing global capacity to monitor biodiversity. However, the lack of regional, vouchered, genomic sequence information—especially sequence information that includes intraspecific variation—creates a bottleneck for management agencies wanting to harness the complete power of eDNA to monitor taxa and implement eDNA analyses. eDNA studies depend upon regional databases of mitogenomic sequence information to evaluate the effectiveness of such data to detect and identify taxa. We created the Oregon Biodiversity Genome Project to create a database of complete, nearly error-free mitogenomic sequences for all of Oregon's fishes. We have successfully assembled the complete mitogenomes of 313 specimens of freshwater, anadromous and estuarine fishes representing 24 families, 55 genera and 129 species and lineages. Comparative analyses of these sequences illustrate that many regions of the mitogenome are taxonomically informative, that the short (~150 bp) mitochondrial ‘barcode’ regions typically used for eDNA assays do not consistently diagnose for species and that complete single or multiple genes of the mitogenome are preferable for identifying Oregon's fishes. This project provides a blueprint for other researchers to follow as they build regional databases, illustrates the taxonomic value and limits of complete mitogenomic sequences and offers clues as to how current eDNA assays and environmental genomics methods of the future can best leverage this information.     

Extinction risk assessment for the species survival plan (SSP®) population of the Bali mynah (Leucopsar rothschildi)

The Bali mynah Species Survival Plan (SSP^®), an Association of Zoos and Aquariums program, strives to maintain the genetic and demographic health of its population, avoid unplanned changes in size, and minimize the risk of population extinction. The SSP population meets current demographic and genetic objectives with a population size of 209 birds at 61 institutions and 96% genetic diversity (GD) retained from the source population. However, participating institutions have expressed concerns regarding space allocation, target population size (TPS), breeding restrictions, inbreeding depression, and harvest in relation to future population availability and viability. Based on these factors, we assess five questions with a quantitative risk assessment, specifically a population viability analysis (PVA) using ZooRisk software. Using an individual-based stochastic model, we project potential population changes under different conditions (e.g. changes in TPS and genetic management) to identify the most effective management actions. Our projections indicate that under current management conditions, population decline and extinction are unlikely and that although GD will decline over 100 years the projected loss does not exceed levels acceptable to population managers (less than 90% GD retained). Model simulations indicate that the combination of two genetic management strategies (i.e. priority breeding based on mean kinship and inbreeding avoidance) benefits the retention of GD and reduces the accumulation of inbreeding. The current TPS (250) is greater than necessary to minimize the risk of extinction for the SSP population but any reduction in TPS must be accompanied by continued application of genetic management. If carefully planned, birds can be harvested for transfer to Bali for a reintroduction program without jeopardizing the SSP population. Zoo Biol 28:230–252, 2009. © 2009 Wiley-Liss, Inc.     

GB Non-native Species Information Portal: documenting the arrival of non-native species in Britain

Information on non-native species (NNS) is often scattered among a multitude of sources, such as regional and national databases, peer-reviewed and grey literature, unpublished research projects, institutional datasets and with taxonomic experts. Here we report on the development of a database designed for the collation of information in Britain. The project involved working with volunteer experts to populate a database of NNS (hereafter called “the species register”). Each species occupies a row within the database with information on aspects of the species’ biology such as environment (marine, freshwater, terrestrial etc.), functional type (predator, parasite etc.), habitats occupied in the invaded range (using EUNIS classification), invasion pathways, establishment status in Britain and impacts. The information is delivered through the Great Britain Non-Native Species Information Portal hosted by the Non-Native Species Secretariat. By the end of 2011 there were 1958 established NNS in Britain. There has been a dramatic increase over time in the rate of NNS arriving in Britain and those becoming established. The majority of established NNS are higher plants (1,376 species). Insects are the next most numerous group (344 species) followed by non-insect invertebrates (158 species), vertebrates (50 species), algae (24 species) and lower plants (6 species). Inventories of NNS are seen as an essential tool in the management of biological invasions. The use of such lists is diverse and far-reaching. However, the increasing number of new arrivals highlights both the dynamic nature of invasions and the importance of updating NNS inventories.     

七种圈养鹤的部分血液生化指标分析

为探索圈养鹤类的血液生化指标差异,本研究对白鹤(Grus leucogeranus)、丹顶鹤(G.japonensis)、黑冠鹤(Balearica pavonina)、黑颈鹤(G.nigricollis)、灰冠鹤(B.regulorum)、蓝鹤(Anthropoides paradiseus)和白枕鹤(G.vipio)的10项血液生化指标(总胆固醇、甘油三酯、总蛋白、白蛋白、球蛋白等)进行统计分析,并与国际物种信息系统(ISIS)提供的数据进行比较。结果表明,1)不同鹤类之间总胆固醇差异显著,而甘油三酯和血糖没有显著性差异,除了黑冠鹤和灰冠鹤的总胆固醇以及蓝鹤的血糖外,其余鹤类的常值均高于ISIS的平均值。2)不同鹤类之间的总蛋白、球蛋白和白蛋白的浓度差异显著,但总蛋白、球蛋白和白蛋白均在ISIS的正常范围内。3)不同鹤类间肌酐和尿酸不具有显著性差异,其中尿酸低于ISIS平均值,但仅尿素氮差异显著。不同鹤类之间血液生化指标存在差异,与圈养鹤的营养水平和环境有关。因此血液生化指标对于圈养鹤类营养状态和健康情况的判断具有重要参考价值,对圈养动物饲养管理具有重要的指导作用。     

Marsupials and monotremes: A case study in regional collection planning

Cooperative collection planning is critical to the future of zoological parks and aquariums, yet few published models currently exist for collection plan development and implementation. In particular, there has been little discussion about the relationship between regional and institutional collection planning or about what defines a quality regional collection plan (RCP). This article documents the regional collection planning process adopted by the AZA Marsupial and Monotreme Taxon Advisory Group (TAG). More specifically, it outlines the philosophical foundation of the North American RCP for Marsupials and Monotremes, the organizational structure developed by the TAG to facilitate communication, evaluation and institutional participation, and other important details of the planning process. It also documents how the RCP was used by one institution (Los Angeles Zoo) to formulate its Institutional Collection Plan (ICP). Zoo Biol 17:433–451, 1998. © 1998 Wiley-Liss, Inc.     

全球外来入侵生物与植物有害生物数据库的比较评价

[目的]为了明确全球生物安全与植物保护领域内数据库建设进展和我国数据库的建设成效,对全球重要的外来入侵生物与植物有害生物数据库进行分类介绍和比较评价研究.[方法]根据数据库收录物种的地理范围、类群及数据库特色功能,对数据库进行分类.对重要数据库的主要功能进行简要介绍,设立多指标评价体系将我国数据库与国际优质数据库进行比...     

Use of population viability analysis models for Atlantic and Pacific salmon recovery planning

Uncertainty and risk abound in making natural resource management decisions. Population viability analysis (PVA) includes a variety of qualitative or quantitative analyses to predict the future status of a population or collection of populations and to predict the risk of extinction (or quasi-extinction) over time given some assumptions of the factors driving population dynamics. In this paper, we review the various PVA models applied to Atlantic and Pacific salmon for determination of listing under the Endangered Species Act and in planning recovery actions. We also review the numerous cautions involved in developing PVA models and in interpreting their results. There have been a larger number of PVA models applied to Pacific salmon compared to Atlantic salmon due to the greater geographic range and number of species of Pacific salmon. Models for both Atlantic and Pacific salmon have ranged from simple models that view populations as simply a number of organisms to complex age- or stage-structured models depending on the purpose of the model and available data for model parameterization. The real value of PVA models to salmon conservation is not in making absolute predictions of the risk of extinction, but rather in evaluating relative effects of management alternatives on extinction risk and informing decision making within an adaptive management framework. As computing power, quantitative techniques, and knowledge of mechanistic linkages between terrestrial, freshwater, and marine environments advance, PVA models will become an even more powerful tool in conservation planning for salmon species.     

Survival on the ark: life history trends in captive parrots

Members of the order Psittaciformes (parrots and cockatoos) are among the most long-lived and endangered avian species. Comprehensive data on lifespan and breeding are critical to setting conservation priorities, parameterizing population viability models, and managing captive and wild populations. To meet these needs, we analyzed 83, 212 life history records of captive birds from the International Species Information System and calculated lifespan and breeding parameters for 260 species of parrots (71% of extant species). Species varied widely in lifespan, with larger species generally living longer than smaller ones. The highest maximum lifespan recorded was 92 years in Cacatua moluccensis, but only 11 other species had a maximum lifespan over 50 years. Our data indicate that while some captive individuals are capable of reaching extraordinary ages, median lifespans are generally shorter than widely assumed, albeit with some increase seen in birds presently held in zoos. Species that lived longer and bred later in life tended to be more threatened according to IUCN classifications. We documented several individuals of multiple species that were able to breed for more than two decades, but the majority of clades examined had much shorter active reproduction periods. Post-breeding periods were surprisingly long and in many cases surpassed the duration of active breeding. Our results demonstrate the value of the ISIS database to estimate life history data for an at-risk taxon that is difficult to study in the wild, and provide life history data that is crucial for predictive modeling of future species endangerment and proactively managing captive populations of parrots.     

Putting the Spotlight on Internally Displaced Animals (IDAs): A Survey of Primate Sanctuaries in Africa,Asia, and the Americas

As anthropogenic activity makes deeper incursions into forests, fragmenting habitat, wildlife is forced into closer proximity to humans leading to increased incidences of human–wildlife conflict and wildlife displacement. These same incursions facilitate poaching for the commercial trade in dead and live animals. As a direct result, the number of sanctuaries and internally displaced animals (IDAs) in need of sanctuary placement and rehabilitation are increasing. We focus on internally displaced primates given the prevalence of primate‐focused facilities and anthropomorphic considerations surrounding this taxonomic group. Surveys were distributed globally to map the extent and range of native primate sanctuaries and species. Over 70 facilities care for more than 6,000 native primates comprising 64 species, with almost half listed as endangered or critically endangered. As not all sanctuaries were identified at the time of the survey distribution, we estimate that the actual number of facilities is closer to double this number with a captive population in excess of 10,000 individual primates. Native primate sanctuaries hold significant numbers of primates in long‐term captive care, with less than half (37%) identified as candidates for release. The surveyed sanctuary population accounts for 35% of the world's captive primates, as compared to ISIS‐registered (where ISIS is International Species Information System) zoological facilities, although we estimate that the actual population is closer to 58%. For some species, the sanctuary population represents the only population in captivity. We discuss the prevalence of range‐state sanctuaries and their primate populations, and issues surrounding their future development and management. Am. J. Primatol. 75:116‐134, 2013. © 2012 Wiley Periodicals, Inc.     

The use of long acting subcutaneous levonorgestrel (LNG) gel depot as an effective contraceptive option for cotton-top tamarins (Saguinus oedipus)

Cotton‐top tamarins (Saguinus oedipus) are a critically endangered species that have been bred successfully in captivity for many years. For two decades, the Cotton‐top Tamarin SSP^© has been challenged with a high rate of reproduction combined with a history of contraceptive failures and nonrecommended births using the current Depo Provera^® (medroxyprogesterone acetate) injection followed by MGA (melengestrol acetate) implant contraception combination. To address these issues we have developed and tested the use of levonorgestrel (LNG) as an effective contraception option for cotton‐top tamarins. LNG was delivered in an injectable, gel matrix consisting of polylactic‐co‐glycolic acid, triethyl citrate and N‐methylpyrrolidone. This gel matrix forms a biodegradable depot at the subcutaneous injection site providing slow release of the active ingredient. Gel matrix composition and LNG concentration were adjusted in four gel formulations to maximize the duration of contraceptive efficacy while minimizing immediate post‐injection increases in fecal LNG concentration. LNG treatment (68.44±8.61 mg/kg) successfully eliminated ovarian cycles (fecal pregnanediol‐3‐glucuronide (PdG) and estrone conjugates (E₁C)) for 198.8±70.3 days (formulation four; range 19–50 weeks). It was demonstrated that subcutaneous LNG depot injection was an effective, reversible contraceptive option for the management of cotton‐top tamarins in captivity. Zoo Biol 30:498–522, 2011. © 2010 Wiley Periodicals, Inc.     

Population Fluctuations and Synchrony of Grassland Butterflies in Relation to Species Traits

Population fluctuations and synchrony influence population persistence; species with larger fluctuations and more synchronised population fluctuations face higher extinction risks. Here, we analyse the effect of diet specialisation, mobility, length of the flight period, and distance to the northern edge of the species’ distribution in relation to between-year population fluctuations and synchrony of butterfly species. All butterfly species associated with grasslands were surveyed over five successive years at 19 grassland sites in a forest-dominated landscape (50 km²) in southern Sweden. At both the local and regional level, we found larger population fluctuations in species with longer flight periods. Population fluctuations were more synchronous among localities in diet specialists. Species with a long flight period might move more to track nectar resources compared to species with shorter flight period, and if nectar sources vary widely between years and localities it may explain that population fluctuations increase with increasing flight length. Diet generalists can use different resources (in this case host plants) at different localities and this can explain the lower synchrony in population fluctuations among generalist species. Higher degree of synchrony is one possible explanation for the higher extinction risks that have been observed for more specialised species. Therefore, diet specialists are more often threatened and require more conservation efforts than generalists.     

Regional collection planning for speciose taxonomic groups

Regional collection planning and implementation are essential if professional zoological parks and aquariums are to achieve their collective conservation and animal management goals. Several regional associations currently have taxon advisory groups (TAGs) in place whose primary role is to develop taxon‐specific collection plans. During their planning process, TAGs review all known taxa of interest and evaluate them based on relevant criteria. TAGs also evaluate the total amount of captive space available to determine the number of priority taxa that can be maintained. In addition, some TAGs heighten their impact on conservation by producing an action plan of select conservation and research projects to be supported by participating institutions. Although current guidelines for regional collection plan (RCP) development are extremely useful for some TAGs, such as those for most mammalian taxa, they do not address the needs of other more speciose TAGs, such as those for fish, invertebrates, and amphibians. These TAGs, characterized by their numerous taxa and more flexible space requirements, still need to develop plans for the species they manage. We recommend that highly speciose TAGs make development of an action plan their highest priority and use it to direct the RCP process. This will limit the number of taxa they need to consider, while ensuring that their RCPs are directly relevant to conservation. Once their action plans have been developed, speciose TAGs can then determine which species are most important to zoological collections and at what level they should be managed. This strategy represents a departure from the current processes used to develop RCPs for many mammalian and avian species and, as such, has not yet been addressed. An action plan‐driven approach will result in more practical and relevant planning for speciose TAGs. Zoo Biol 21:313–320, 2002. © 2002 Wiley‐Liss, Inc.     

Semen collection and evaluation in free‐ranging Brazilian rattlesnakes (Crotalus durissus terrificus)

Two hundred‐ninety species of reptiles are estimated to need urgent action for conservation, with at least 113 threatened species worldwide. The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species includes 80 species of snakes, with six native Brazilian species, a number likely to be an underestimation. Some authors believe that assisted reproduction would be an important tool to improve reproduction in captivity of some reptiles. An efficient technique for semen collection and evaluation is an important step in development of protocols for cryopreservation of semen or artificial insemination in snakes, contributing to the conservation of endangered species. Although these techniques are important, some basic semen parameters are described for four of the ～2,900 snake species in the world. The Brazilian rattlesnake (Crotalus durissus terrificus) was chosen as a model for semen collection in snakes because it is found quite often in Sao Paulo State. Semen was collected once from each animal by the same investigator during the mating season of this species in Brazil. After antiseptic cleansing of the skin around the cloaca, the snakes were injected subcutaneously with a dose of 15 mg/kg of 1% solution of lidocaine around the cloaca. Semen was collected with ventral massages after cloacal relaxation and directly from genital papilla inside the cloaca. A total of 28 ejaculates from 39 animals were obtained, representing collection efficiency of 71.80%. Semen volume and concentration in Brazilian rattlesnakes ranged from 3–70 µl and from 0.94–2.23 × 10⁹ spermatozoa/ml, respectively. Zoo Biol 0:1–6, 2007. © 2007 Wiley‐Liss, Inc.     

海洋生物多样性信息资源

海洋生物多样性甚高, 但却饱受人为的破坏及干扰。目前全球最大的含点位数据的在线开放性数据库是海洋生物地理信息系统(OBIS), 共约12万种3,700万笔资料; 另一个较大的数据库世界海洋生物物种登录(WoRMS)已收集全球22万种海洋生物之物种分类信息。除此之外, 以海洋生物为主的单一类群的数据库只有鱼库(FishBase)、藻库(AlgaeBase)及世界六放珊瑚(Hexacorallians of the World)3个。跨类群及跨陆海域的全球性物种数据库则甚多, 如网络生命大百科(EOL)、全球生物物种名录(CoL)、整合分类信息系统(ITIS)、维基物种(Wikispecies)、ETI生物信息(ETI Bioinformatics)、生命条形码(BOL)、基因库(GenBank)、生物多样性历史文献图书馆(BHL)、海洋生物库(SeaLifeBase); 海洋物种鉴定入口网(Marine Species Identification Portal)、FAO渔业及水产养殖概要(FAO Fisheries and Aquaculture Fact Sheets)等可查询以分类或物种解说为主的数据库。全球生物多样性信息网络(GBIF)、发现生命(Discover Life)、水生物图库(AquaMaps)等则是以生态分布数据为主, 且可作地理分布图并提供下载功能, 甚至于可以改变水温、盐度等环境因子的参数值, 利用既定的模式作参数改变后之物种分布预测。谷歌地球(Google Earth)及国家地理(National Geographic)网站中的海洋子网页, 以及珊瑚礁库(ReefBase)等官方机构或非政府组织之网站, 则大多以海洋保育的教育倡导为主, 所提供的信息及素材可谓包罗万象, 令人目不暇给。更令用户感到方便的是上述许多网站或数据库彼此间均已可交互链接及查询。另外, 属于搜索引擎的谷歌图片(Google Images)与谷歌学术(Google Scholar)透过海洋生物数据库所提供的直接链接, 在充实物种生态图片与学术论文上亦发挥极大帮助, 让用户获得丰富多样的信息。为了保育之目的, 生物多样性数据库除了整合与公开分享外, 还应鼓励并推荐大家来使用。本文乃举Rainer Froese在巴黎演讲之内容为例, 介绍如何使用海洋生物多样性之数据来预测气候变迁对鱼类分布的影响。最后就中国大陆与台湾目前海洋生物多样性数据库的现况、两岸的合作及如何与国际接轨作介绍。     

Measurements of birth defect prevalence: Which is most useful as a comparator group for pharmaceutical pregnancy registries?

Pharmaceutical pregnancy registries document birth defects and other complications reported in pregnancies exposed to specific medications or diseases. A baseline estimate of birth defect prevalence is necessary for comparison. To identify potential teratogenic signals, the pregnancy registry must have a comparator that most closely matches the exposed population and data collection methodology, which are characteristics that vary among the multiplicity of birth defect surveillance systems. The system that yields the most accurate prevalence data may be different from that most closely matching the pregnancy registry methods. State public health programs have highly accurate and precise statistics, but their populations are broader than those of a pharmaceutical pregnancy registry. Large collaborative databases may have a more useful covered population, but there are secondary problems related to data precision. Health care databases enroll large numbers of patients and have good information about exposures and health problems, but the data can be difficult to access and lack useful detail. Exposure‐related databases are closer in population definition and collection methods, though the presence of different diseases and exposures can be problematic. Internal comparators are likely to be most useful in formal statistical analysis, but added cost and management burden and may require significantly increased registry enrollment. There is no ideal comparator, and this must be taken into account when planning a single‐exposure or single‐disease pregnancy registry. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.