No evidence for Galapagos Plasmodium lineage arriving via Humboldt Current seabirds.

2014 ◽  
Vol 20 (1) ◽  
pp. 37 ◽  
Author(s):  
Iris I Levin ◽  
Michael J Adkesson ◽  
Maranda Evans ◽  
Cindee K Rettke ◽  
Patricia G Parker

Avian malaria, caused by parasites in the genus Plasmodium, has recently been detected in the endangered Galapagos penguin (Spheniscus mendiculus). Understanding possible routes of parasite and pathogen introduction is important for management of small and isolated populations, because island populations can be at higher risk of adverse effects due to lower immunity. One possible means of introduction could be through contact with pelagic birds from coastal South America. In order to better understand the origins of Plasmodium in Galapagos penguins, we used a PCR protocol to test for haemosporidian parasites in Humboldt penguins (Spheniscus humboldti), the sister species of Galapagos penguins, and two other Humboldt Current endemics, the guanay cormorant (Phalacrocorax bougainvillii) and the Peruvian pelican (Pelecanus thagus). None of these seabirds, all sampled at Punta San Juan, Peru, tested positive for haemosporidian parasites. Although the strong Humboldt Current flows from Antarctica up the South American coast and towards Galapagos at the equator, contact rates between these Humboldt endemics and Galapagos birds might still be rare. Despite negative results, this information is important for furthering our knowledge of Plasmodium in Galapagos and in our efforts to effectively manage wildlife diseases.


The Auk ◽  
1983 ◽  
Vol 100 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Dennis M. Power

Abstract Coefficients of variation and generalized variances are compared for nine morphological characters from five mainland and four island populations of the House Finch (Carpodacus mexicanus). The purpose is to test the idea that variability is reduced in isolated populations and that there is a "population variation parameter" that determines the level of variation in most characters. Variability is greater in bill characters for Guadalupe and San Benito Islands than for mainland and other island populations. There are no consistent differences among samples in variability of wing, tail, or hind-limb characters, except for a tendency toward increased tarsus-length variability in a southern Baja California population and reduced variability in this character in San Clemente Island and Guadalupe Island populations. In bill characters, increased variability is found in the most divergent populations. The results do not support the generalization that geographic (= genetic) isolation per se causes much of a change in variability in island populations of birds, nor is there support for the idea of a pervasive quality of the gene pool that determines the level of variability in most characters.



2014 ◽  
Vol 41 (1) ◽  
pp. 1 ◽  
Author(s):  
Giovanna Massei ◽  
Dave Cowan

As human populations grow, conflicts with wildlife increase. Concurrently, concerns about the welfare, safety and environmental impacts of conventional lethal methods of wildlife management restrict the options available for conflict mitigation. In parallel, there is increasing interest in using fertility control to manage wildlife. The present review aimed at analysing trends in research on fertility control for wildlife, illustrating developments in fertility-control technologies and delivery methods of fertility-control agents, summarising the conclusions of empirical and theoretical studies of fertility control applied at the population level and offering criteria to guide decisions regarding the suitability of fertility control to mitigate human–wildlife conflicts. The review highlighted a growing interest in fertility control for wildlife, underpinned by increasing numbers of scientific studies. Most current practical applications of fertility control for wild mammals use injectable single-dose immunocontraceptive vaccines mainly aimed at sterilising females, although many of these vaccines are not yet commercially available. One oral avian contraceptive, nicarbazin, is commercially available in some countries. Potential new methods of remote contraceptive delivery include bacterial ghosts, virus-like particles and genetically modified transmissible and non-transmissible organisms, although none of these have yet progressed to field testing. In parallel, new species-specific delivery systems have been developed. The results of population-level studies of fertility control indicated that this approach may increase survival and affect social and spatial behaviour of treated animals, although the effects are species- and context-specific. The present studies suggested that a substantial initial effort is generally required to reduce population growth if fertility control is the sole wildlife management method. However, several empirical and field studies have demonstrated that fertility control, particularly of isolated populations, can be successfully used to limit population growth and reduce human–wildlife conflicts. In parallel, there is growing recognition of the possible synergy between fertility control and disease vaccination to optimise the maintenance of herd immunity in the management of wildlife diseases. The review provides a decision tree that can be used to determine whether fertility control should be employed to resolve specific human–wildlife conflicts. These criteria encompass public consultation, considerations about animal welfare and feasibility, evaluation of population responses, costs and sustainability.



1990 ◽  
Vol 55 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Dave D. Davis ◽  
R. Christopher Goodwin

Origin stories collected among the indigenous peoples in the Windward Islands during the early colonial period have been interpreted as indicating a mainland Carib affiliation for the islanders. This interpretation gave rise to efforts in the present century to identify the archaeological correlate of the presumed late prehistoric or protohistoric migration of Cariban speakers into the Lesser Antilles. Recent debate centers around two models. One of these associates the supposed migration of mainland Caribs into the Lesser Antilles with the advent of the Suazey ceramic complex in the twelfth century; the other implies either a protohistoric migration or an episode of rapid acculturation of island populations to South American mainland Carib culture in the fifteenth or sixteenth centuries. A review of relevant archaeological, historical, and linguistic evidence provides little support for either of these models. Instead, the so-called “Island Caribs” were Arawakan speakers, probably longtime residents of the Windward Islands whose cultural and linguistic connections with the mainland Caribs probably were the products of contacts related to trade and alliance.



2019 ◽  
Vol 28 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Otavio Luiz Fidelis Junior ◽  
Paulo Henrique Sampaio ◽  
Luiz Ricardo Gonçalves ◽  
Marcos Rogério André ◽  
Rosangela Zacarias Machado ◽  
...  

Abstract Livestock infections by Trypanosoma vivax have been occurring with increasing frequency, mainly due to the presence of animals with subclinical infections and without apparent parasitaemia, making diagnosis challenging. The aim of the present study was to evaluate several techniques used for T. vivax diagnosis in order to assess the best way of using them during the course of the disease. Molecular methods demonstrated higher rates of detection than parasitological methods, detecting 33 of the 54 (61.1%) known positive samples, while the hematocrit centrifugation technique (best parasitological test) detected only 44.4%. The serological methods, IFAT and ELISA, detected seropositivity in 51 of the 54 (94.4%) and 49 of the 54 (90.7%) known positive samples, respectively. Despite being highly sensitive, the latter only demonstrates exposure to the infectious agent and does not indicate whether the infection is active. The present study was the first to use the qPCR for a South American isolate, improving disease detection and quantification. Furthermore, the analyses revealed that the patent phase of the disease may extend up to 42 days, longer than previously reported. The combination of several diagnostic techniques can lower the frequency of false negative results and contributes toward better disease control.



The Auk ◽  
2005 ◽  
Vol 122 (4) ◽  
pp. 1210-1224 ◽  
Author(s):  
Jennifer L. Bollmer ◽  
Noah K. Whiteman ◽  
Michelle D. Cannon ◽  
James C. Bednarz ◽  
Tjitte de Vries ◽  
...  

Abstract Because of their smaller size and isolation, island populations tend to be more divergent and less genetically variable than mainland populations. We collected DNA samples from nine Galápagos Hawk (Buteo galapagoensis) island populations, covering the species’ entire range. Neutral minisatellite DNA markers were used to calculate within-island genetic diversity and between-island genetic differentiation (FST). Typically, these markers mutate too quickly to be informative in such studies. However, in very small, isolated populations, concerns about high mutational rate are obviated by the relative force of genetic drift. Individuals within islands had the highest levels of reported genetic uniformity of any natural bird population, with mean within-population band-sharing similarity values ranging from 0.693 to 0.956, increasing with decreasing island size. Galápagos Hawks exhibit cooperative polyandry to varying degrees across islands; however, we did not find an association between degree of polyandry and genetic variability. Between-island FST values ranged from 0.017 to 0.896, with an overall archipelago value of 0.538; thus, most populations were genetically distinct. Also, we documented higher levels of genetic similarity between nearby populations. Our results indicated negligible gene flow among most Galápagos Hawk populations, and genetic drift has played a strong role in determining structure at these minisatellite loci. Genética de Poblaciones de Buteo galapagoensis: Monomorfismo Genético dentro de Poblaciones Aisladas



1991 ◽  
Vol 18 (5) ◽  
pp. 625 ◽  
Author(s):  
WE Poole ◽  
JT Wood ◽  
NG Simms

Apparently once widespread throughout dense thickets in south-western Australia, the tammar is now much restricted in its distribution. On mainland Australia, isolated populations still persist in Western Australia, but in South Australia, where there is little remaining evidence to confirm that it extended beyond Eyre Peninsula, the wallaby is probably close to extinction. All originally recorded populations on five islands in Western Australia remain, but in South Australia all natural island populations, other than those on Kangaroo I., appear to be extinct. Morphometric analyses of crania representative of most known populations provide a means of assessing their relationships. Canonical variate analysis, the derivation of Mahalanobis distances and subsequent calculation of minimum spanning trees supported the existence of affinities within three major regional groups-a group predominantly from Western Australia, a group from Kangaroo and Greenly Is, South Australia, and a group from New Zealand-all apparently related via a population from Eyre Peninsula, presumably representative of a former widespread mainland population. By cranial criteria, feral tammars established in New Zealand are South Australian in origin although probably not introduced from Kangaroo I.



2005 ◽  
Vol 83 (11) ◽  
pp. 1478-1487 ◽  
Author(s):  
K. Ritland ◽  
L.D. Meagher ◽  
D.G.W. Edwards ◽  
Y.A. El-Kassaby

Garry oak ( Quercus garryana Dougl. ex Hook) has a long north–south distribution along the inland Pacific coast. In British Columbia, it is a keystone species in a unique and endangered “Garry oak meadow” ecosystem. Here, we apply isozyme markers to address issues in the conservation and phylogeography of Garry oak. Among 42 populations and 23 gene loci, gene diversity (expected heterozygosity) averaged 0.17, and number of alleles per locus averaged 1.84. These values are about one-half of those found in other white oak species. Using progeny arrays, we found outcrossing rates in two Vancouver Island populations to average 0.96, with no detectable biparental inbreeding; also inbreeding coefficients of the 42 populations averaged near zero (0.025); thus inbreeding is not a significant concern. Cluster analysis of genetic distances identified two major groups of populations: southern Washington – Oregon and Vancouver Island – Gulf Islands; populations within the island region were particularly homogenous. An isolated mainland British Columbia population near Sumas, British Columbia, perhaps of anthropogenic origin, showed the least genetic variability and greatest genetic distance. Generally, geographically isolated populations were more genetically depauperate, which may place handicaps on their survival, but also more genetically distinct, providing a greater evolutionary legacy to the species.



2010 ◽  
Vol 278 (1709) ◽  
pp. 1195-1202 ◽  
Author(s):  
Penelope R. Whitehorn ◽  
Matthew C. Tinsley ◽  
Mark J. F. Brown ◽  
Ben Darvill ◽  
Dave Goulson

Inbreeding and a consequent loss of genetic diversity threaten small, isolated populations. One mechanism by which genetically impoverished populations may become extinct is through decreased immunocompetence and higher susceptibility to parasites. Here, we investigate the relationship between immunity and inbreeding in bumblebees, using Hebridean island populations of Bombus muscorum . We sampled nine populations and recorded parasite prevalence and measured two aspects of immunity: the encapsulation response and levels of phenoloxidase (PO). We found that prevalence of the gut parasite Crithidia bombi was higher in populations with lower genetic diversity. Neither measure of immune activity was correlated with genetic diversity. However, levels of PO declined with age and were also negatively correlated with parasite abundance. Our results suggest that as insect populations lose heterozygosity, the impact of parasitism will increase, pushing threatened populations closer to extinction.



1976 ◽  
Vol 25 (1) ◽  
pp. 29-35 ◽  
Author(s):  
A.W. Eriksson ◽  
M.R. Eskola ◽  
J.O. Fellman

The rates of human multiple maternities in the Nordic countries were studied from continuous series of data. In the Åland and Åboland archipelagos the parish records for births and baptisms since the 1650's were used. Various sources, some unpublished, in the archives of statistics were used for Sweden (since 1749) and Finland (since 1859) as a whole. Until recently, the rates of multizygotic multiple maternities in isolated island populations in the Åland and Åboland archipelagos have been some of the highest known among Whites (15-20‰). Highly significant temporal fluctuations in the twinning rates were noted. In Sweden, the twinning rate during the last part of 18th century was about twice as high as it was in 1966-70. The triplet and quadruplet rates were about three to four times as high as they are nowadays. There has been a secular decline in DZ twinning. This downward trend set in first in the isolated populations. In Sweden, it started in the 1930's, but in Finland, not until the 1960's. The steep downward trend in the twinning rates is shown to set in about one generation after the break-up of isolation. This can be interpreted as evidence that the changes in matrimonial migration patterns have affected the rates of DZ twinning.



2018 ◽  
Author(s):  
Christina M. Bergey ◽  
Martin Lukindu ◽  
Rachel M. Wiltshire ◽  
Michael C. Fontaine ◽  
Jonathan K. Kayondo ◽  
...  

AbstractDocumenting isolation is notoriously difficult for species with vast polymorphic populations. High proportions of shared variation impede estimation of connectivity, even despite leveraging information from many genetic markers. We overcome these impediments by combining classical analysis of neutral variation with assays of the structure of selected variation, demonstrated using populations of the principal African malaria vector Anopheles gambiae. Accurate estimation of mosquito migration is crucial for efforts to combat malaria. Modeling and cage experiments suggest that mosquito gene drive systems will enable malaria eradication, but establishing safety and efficacy requires identification of isolated populations in which to conduct field-testing. We assess Lake Victoria islands as candidate sites, finding one island 30 kilometers offshore is as differentiated from mainland samples as populations from across the continent. Collectively, our results suggest sufficient contemporary isolation of these islands to warrant consideration as field-testing locations and illustrate shared adaptive variation as a useful proxy for connectivity in highly polymorphic species.



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