Individual identification and genetic variation of lions (Panthera leo) from two protected areas in Nigeria.

This survey was conducted in two protected areas in Nigeria to genetically identify individual lions and to determine the genetic variation within and between the populations. We used faecal sample DNA, a non-invasive alternative to the risky and laborious task of taking samples directly from the animals, often preceded by catching and immobilization. Data collection in Yankari Game Reserve (YGR) spanned through a period of five years (2008 -2012), whereas data in Kainji Lake National Park (KLNP) was gathered for a period of three years (2009, 2010 and 2012). We identified a minimum of eight individuals (2 males, 3 females, 3 unknown) from YGR and a minimum of ten individuals (7 males, 3 females) from KLNP. The two populations were found to be genetically distinct as shown by the relatively high fixation index (FST  = 0.17) with each population exhibiting signs of inbreeding (YGR FIS  = 0.49, KLNP FIS  = 0.38). The genetic differentiation between the Yankari and Kainji lions is assumed to result from large spatial geographic distance and physical barriers reducing gene flow between these two remaining wild lion populations in Nigeria. To mitigate the probable inbreeding depression in the lion populations within Nigeria it might be important to transfer lions between parks or reserves or to reintroduce lions from the zoos back to the wild

Isotope signatures in winter moulted feathers predict malaria prevalence in a breeding avian host

It is widely accepted that animal distribution and migration strategy might have co-evolved in relation to selection pressures exerted by parasites. Here, we first determined the prevalence and types of malaria blood parasites in a breeding population of great reed warblers Acrocephalus arundinaceus using PCR. Secondly, we tested for differences in individual feather stable isotope signatures (delta C-13, delta N-15, delta D and delta S-34) to investigate whether malaria infected and non-infected birds had occupied different areas in winter. We show that birds moulting in Afro-tropical habitats with significantly higher delta C-13 and delta N-15 but lower delta D and delta S-34 values were more frequently infected with malaria parasites. Based on established patterns of isotopic distributions, our results indicate that moulting sites with higher incidence of malaria are generally drier and situated further to the north in West Africa than sites with lower incidence of malaria. Our findings are pertinent to the general hypothesis that animal distribution and particularly avian migration strategy might evolve in response to selection pressures exerted by parasites at different geographic scales. Tradeoffs between investment in energy demanding life history traits (e.g. migration and winter moult) and immune function are suggested to contribute to the particular choice of habitat during migration and at wintering sites

MAGNETIC RESONANCE IMAGING FOR NONINVASIVE ANALYSIS OF FAT STORAGE IN MIGRATORY BIRDS

Many bird species migrate long distances without any food intake and must optimize storage of energy with respect to minimization of aerodynamic drag. To contribute to the understanding of this issue, we investigated, by magnetic resonance imaging (MRI), spatial distributions of body fat during the accumulation process before migration. We collected data from 12 Lesser Whitethroats (Sylvia curruca), 9 European Robins (Erithacus rubecula), 8 Blackcaps (Sylvia atricapilla), and 5 Willow Warblers (Phylloscopus trochilus). On average, each bird was examined 3.2 times. Adipose tissue was Visualized using T1-weighted spin-echo MRI at 1.5 T. Fat-containing pixels were identified by an image-segmentation procedure. Data were analyzed with respect to (1) fat distribution within the body, (2) relationship between frontal surface area and fat mass increase, (3) fat mass increase in comparison with increase in total body mass, and (4) fat mass in relation to standardized visual classification of fat deposits. Fat increase was reflected by a larger frontal area, though adipose tissue was not deposited equally along the length of the bird. Slices with largest frontal area showed relatively low fractions of fat. Frontal area increased less than expected from conventional geometrical models, which indicates that the body shape is altered. The increase in total body mass was generally higher than the total fat mass increase, which indicates that other tissue, most likely flight muscle, can metabolize rapidly in correlation with fat accumulation. In Blackcap, total fat mass was not linearly related to standardized fat-deposit classes. Received 31 August 2007, accepted 7 June 2008