Amy B. Plowman

Population size and habitat quality affect genetic diversity and fitness in the clonal herb Cirsium dissectum

Remaining populations of plant species in fragmented landscapes are threatened by declining habitat quality and reduced genetic diversity, but the interactions of these major factors are rarely studied together for species conservation. In this study, the interactions between population size, habitat quality, genetic diversity and fitness were investigated in 22 populations of the clonal herb Cirsium dissectum throughout the British Isles. Regression analysis was used to identify significant factors, and a structural equation model was developed to illustrate and integrate these interactions. It was found that smaller populations (measured as the total number of plants) had lower genetic diversity (proportion of polymorphic loci), and that reduced genetic diversity (allelic richness) had a negative impact on the survival of seedlings grown under standard conditions. Habitat quality also had a large effect on C. dissectum. Unmanaged sites with tall vegetation, no bare soil and higher nutrient levels had smaller populations of C. dissectum, but flowering was promoted. Flowering was suppressed in heavily grazed sites with short vegetation. Higher levels of bare soil and phosphorus both had a positive relationship with genetic diversity, but probably for distinctly different reasons: bare soil provides safe sites for establishment, whilst phosphorus may promote flowering and improve seed germination. In order to conserve C. dissectum, management needs to maintain site heterogeneity so that C. dissectum can flower and establishment gaps are still available for seedlings; when either component is reduced, negative feedbacks through reduced genetic diversity and individual fitness can be expected. This study therefore highlights the importance of considering both conservation genetics and habitat quality in the conservation of plant species.

Genetic testing of dung identification for antelope surveys in the Udzungwa Mountains, Tanzania

Dung counts are frequently employed to infer abundance of antelope species in African forests, but the accuracy of dung identification has rarely been tested. We used non-invasive genetic methods to test the accuracy of both field identification and morphometrics for identifying dung samples collected in the Udzungwa Mountains, Tanzania. Species identity was established by sequencing part of the mitochondrial control region from faecal DNA. Field identification was found to be correct in only 58–76% of cases depending on the observer. Discriminant analysis of dung pellet length correctly classified 80% of samples but a larger reference sample size is needed before using this method to classify dung of unknown origin. The results of this study illustrate the potential inaccuracy of dung counts as a monitoring tool for sympatric forest antelope species when the probability of correct identification is unknown. We recommend molecular testing of species identity during forest antelope surveys before conclusions are drawn on the basis of other identification methods.

BIAZA Statistics Guidelines: Toward a Common Application of Statistical Tests for Zoo Research

Zoo research presents many statistical challenges, mostly arising from the need to work with small sample sizes. Efforts to overcome these often lead to the misuse of statistics including pseudoreplication, inappropriate pooling, assumption violation or excessive Type II errors because of using tests with low power to avoid assumption violation. To tackle these issues and make some general statistical recommendations for zoo researchers, the Research Group of the British and Irish Association of Zoos and Aquariums (BIAZA) conducted a workshop. Participants included zoo-based researchers, university academics with zoo interests and three statistical experts. The result was a BIAZA publication Zoo Research Guidelines: Statistics for Typical Zoo Datasets (Plowman [2006] Zoo research guidelines: statistics for zoo datasets. London: BIAZA), which provides advice for zoo researchers on study design and analysis to ensure appropriate and rigorous use of statistics. The main recommendations are: (1) that many typical zoo investigations should be conducted as single case/small N randomized designs, analyzed with randomization tests, (2) that when comparing complete time budgets across conditions in behavioral studies, G tests and their derivatives are the most appropriate statistical tests and (3) that in studies involving multiple dependent and independent variables there are usually no satisfactory alternatives to traditional parametric tests and, despite some assumption violations, it is better to use these tests with careful interpretation, than to lose information through not testing at all. The BIAZA guidelines were recommended by American Association of Zoos and Aquariums (AZA) researchers at the AZA Annual Conference in Tampa, FL, September 2006, and are free to download from www.biaza.org.uk.

Fluid and particle passage in three duiker species

Ruminants are characterised by two different types of reticulorumen (RR) physiology. ‘Cattle-type’ ruminants have, amongst other features such as RR contents stratification and a heterogenous intraruminal papillation, a distinct difference between the mean retention time (MRT) of small particles and fluids (the ratio is called the selectivity factor, SF). ‘Moose-type’ ruminants have RR contents that are less stratified, a more homogenous intraruminal papillation and low SFs, indicating less difference in the MRT of small particles and fluids. To date, physiological data indicating a ‘moose-type’ physiology have only been measured in giraffids and Odocoilean cervids, raising the question whether it is limited to these taxonomic groups only. Here, we measured MRTs of fluids and particles in five duikers (Bovidae, Cephalophinae) from three species (Sylvicapra grimmia, Cephalophus monticola and Cephalophus sylvicultor) and found SFs in the RR of 1.27 ± 0.18—well within the range of these other browsers. These results are the first physiological indication that a ‘moose-type’ physiology may also occur in bovid species and thus might represent a true convergent adaptation.

A new population of the Critically Endangered Aders’ duiker Cephalophus adersi confirmed from northern coastal Kenya

Aders’ duiker Cephalophus adersi is a small antelope endemic to the coastal forests of east Africa. Threatened by habitat loss and hunting, the species is categorized as Critically Endangered on the IUCN Red List. Until recently Aders’ duiker was known to persist only on Zanzibar, Tanzania, and in the Arabuko-Sokoke Forest National Reserve, Kenya. However, in 2004 a sighting of a single individual was reported from the Dodori forest in northern coastal Kenya, raising the possibility that the species survives elsewhere. Subsequently, an opportunistic camera-trap survey was conducted in September and October 2008 to establish the occurrence of Aders’ duiker in Kenyan coastal forests north of the Tana River. One hundred and fifty six images of Aders’ duikers were obtained from 12 of 28 camera-trap sites (46 of 358 camera-trap days), confirming the existence of a population of Aders’ duiker in the Boni–Dodori forest both inside and outside the National Reserves. In addition, we sighted individuals of the species on three occasions. The relatively high encounter rates per unit effort compared to similar data from Arabuko-Sokoke forest suggest the Boni–Dodori population is significant. Initial surveys of the local Awer community revealed that Aders’ duiker is well known by the name guno . These findings significantly improve the conservation prospects for Aders’ duiker and highlight the need for greater research and management efforts in the poorly known Boni–Dodori forest.

Feeding Asian pangolins: An assessment of current diets fed in institutions worldwide

Pangolins are ant specialists which are under intense threat from the illegal wildlife trade. Nutrition has notoriously been their downfall in captivity and is still an issue in regards to rescue and rehabilitation. We analyzed the nutrient content of diets used by institutions that are successfully keeping Asian pangolins and to assess the variety of the ingredients and nutrients, compared these with the nutritional requirements of potential nutritional model species. We performed intake studies at five institutions and also had data from three other institutions. We also analyzed five different wild food items to use as a proxy of wild diet. We observed two categories of captive diets: those mostly or completely composed of insects and those high in commercial feeds or animal meat. Nutrient values were broad and there was no clear rule. The non-protein energy to protein energy ratio of the diets were much higher than the wild food items, more so for those which receive less insects. The average contribution of carbohydrate, fat, and protein energy were also further away from the wild samples the less insects they contained. The previously suggested nutritional model for pangolins is the domestic dog which is supported by our relatively large nutrient ranges of apparently successful diets, however, due to their highly carnivorous nature; the upper most nutrient intake data are not consistent with this and favor the feline nutrient recommendations. We are unable to render a conclusion of what model is more appropriate based on our data collected.

Identification of possible nutritional and stress risk factors in the development of marmoset wasting syndrome

Marmoset wasting syndrome (MWS) describes a series of symptoms in callitrichids that lead to general weakness and a failure to thrive in captive conditions such as zoological institutions. Though the cause of MWS has not been identified, the majority of hypotheses are linked to deficiencies of specific nutrients and increased stress levels. Questionnaires were sent to zoos requesting information on diets and housing of currently living and dead callitrichids before their deaths, as well as their postmortem reports. Risk factors for development and occurrence of MWS include close proximity of predator enclosures and high levels of dietary magnesium and zinc. Variables with effects which may protect against the development of MWS included provision of a nest box, natural trees within enclosure, reduced visibility to visitors, as well as dietary factors such as higher concentrations of potassium and fiber fractions. The protective effects of limited concentrate feeds and increased total dietary fiber may help reduce the risks of developing MWS. The minerals may not have biological implications in MWS per se, however, they may be reflective of diets too high in concentrates and too low in plant matter. Habitat designs that are less naturalistic and those which provide insufficient privacy or hide areas may increase chronic stress for callitrichid species, possibly because of visitor-related stress. Other causes of chronic stress in captive zoo populations should be the topic of further research to reduce occurrence of MWS.

Genetic Patterns in Forest Antelope Populations in the Udzungwa Mountains, Tanzania, as Inferred from Non-Invasive Sampling

ABSTRACT As for many tropical regions, the evolutionary and demographic status of antelope populations in the Udzungwa Mountains, Tanzania, are poorly resolved. We employed genetic information from 618 faecal samples to assess the status of forest antelope species in terms of their distribution, intraspecific diversity and population subdivision within the Udzungwa landscape. Most species were detected in the majority of forest fragments, except for Philantomba monticola. Phylogenetic analyses were consistent with traditional taxonomy with the exception of Cephalophus harveyi which was paraphyletic with respect to C. natalensis. There was strong support for three C. harveyi mtDNA clades within the Udzungwa Mountains although nuclear genetic variation did not partition strongly with these maternal lineages. Significant partitioning of genetic variation between sampling areas was detected for all species except the endangered C. spadix. Overall, our results demonstrate the value of non-invasive genetic sampling in studying the distribution and evolution of rarely observed species.