Santiago-Alarcon D.,Albert Ludwigs University of Freiburg |
Santiago-Alarcon D.,Institute Of Ecologia Ac |
Mettler R.,Albert Ludwigs University of Freiburg |
Segelbacher G.,Albert Ludwigs University of Freiburg |
Schaefer H.M.,Albert Ludwigs University of Freiburg
Journal of Avian Biology | Year: 2013
Parasites can exert strong selection on hosts. Throughout the year migrants are exposed to different sets of parasites, which may affect life history traits such as migratory schedules. Here, we studied the relationship between parasite infection and arrival date of blackcaps Sylvia atricapilla to their breeding grounds in Germany throughout a period of six years (2007-2012). We used two data sets, one that included all blackcaps and one that included only recaptured birds. We assesed whether parasites influence spring arrival to breeding grounds, and for the recaptured data set, we analysed temporal variation in parasitism (i.e. infection status and parasitaemia) throughout the breeding season. We used both microscopy and PCR (a fragment of ̃ 479 bp of the mtDNA cyt b) to determine haemosporidian infection. Blackcaps were mostly infected with Haemoproteus parabelopolskyi (lineages SYAT01 and SYAT02). Infection status, but not parasitaemia, was constant through time for individual birds; meaning that once a bird is infected, it most likely will retain the infection for life. We found that infection by haemosporidian parasites has no relationship to arrival date in this blackcap population; however, infection by H. parabelopolskyi has a marginally significant effect on arrival date of recaptured blackcaps, somewhat delaying their arrival to breeding grounds. Birds captured later in the season were more likely to be infected than those from early spring, and parasitaemia was frequently lower in birds captured earlier in the season compared to those captured later (summer). © 2013 The Authors.
Elvira S.,University of Pamplona |
Ibargutxi M.A.,University of Pamplona |
Gorria N.,University of Pamplona |
Munoz D.,University of Pamplona |
And 3 more authors.
Journal of Economic Entomology | Year: 2013
The insecticidal characteristics of two Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) strains produced on two different S. exigua colonies were measured using the same two host colonies. These strains constitute the active ingredients of the biological insecticides Vir-ex and Spexit and were produced on insect colonies from Spain and Switzerland. Demographic characteristics of insects from each colony were examined before infection. Larval developmental time, larval survival, and adult sex ratio did not differ between the colonies, whereas mean pupal weight was significantly higher in the Spanish colony insects. After infection, susceptibility to virus occlusion bodies (OBs), time to death, larval weight at death, and total production of OBs/larva varied significantly depending on virus strain and the colony used. Vir-ex OBs produced in Spanish colony larvae had improved insecticidal characteristics in terms in lethal dose and speed of kill metrics than other strain-colony combinations. OB production was significantly higher in Spanish colony insects infected with Spexit compared with Vir-ex infected insects from the Swiss colony, with intermediate values for the other two strain-colony combinations. Virus strain and host colony origin were highly influential in determining the insecticidal characteristics of OBs and should be considered as key parameters that require optimization during the production of SeMNPV-based insecticides. © 2013 Entomological Society of America.
Ruiz-Sanchez A.,National Autonomous University of Mexico |
Renton K.,National Autonomous University of Mexico |
Landgrave-Ramirez R.,Institute Of Ecologia Ac |
Mora-Aguilar E.F.,University of Xalapas |
Rojas-Soto O.,Institute Of Ecologia
Journal of Avian Biology | Year: 2015
Wilson's warbler comprises three subspecies separated into two geographic groups: C. p. pusilla that breeds in eastern North America; and C. p. pileolata and C. p. chryseola that breed in western North America. Given the differences between the groups in genetics, morphology, habitat use, and population decline, we tested for ecological niche similarity in both their breeding and wintering distribution using niche modeling based on temperature and precipitation data. We first conducted an inter-prediction approach considering the percent of summer and winter localities of one group that are predicted by the potential distribution of the alternate group. We also applied a null model approach that compares self-predictions and pseudoreplicates of each group to indicate similarity, divergence, or indeterminate niche overlap. Finally, we compared ecological distances between and within groups using the Gower similarity equation. We found that the western group had an ecological niche of broader climatic conditions, while the eastern group had a narrower ecological niche. The inter-prediction approach showed that, for both summering and wintering ranges, ecological niche models of the western group predicted ∼50% of the observed distribution of the eastern group, whereas eastern group models predicted < 18% of the western group distribution. The null model approach found that similarity in ecological niches was indeterminate, possibly due to the large area occupied by the two groups; but it suggests a more restricted set of climatic conditions of the eastern group distribution. However, the Gower coefficients demonstrated that the ecological distance between the two geographic groups was larger than the ecological distance within groups, indicating distinct ecological niches. Overall, our results support the hypothesis that the eastern and western groups of Wilson's warbler are two cryptic species; this should be taken into consideration for future analyses, particularly with respect to vulnerability categorization and conservation efforts. © 2015 Nordic Society Oikos.
Loera I.,Institute Of Ecologia Ac |
Ickert-Bond S.M.,University of Alaska Fairbanks |
Sosa V.,Institute Of Ecologia Ac
Ecography | Year: 2015
In this study we selected the New World species of Ephedra to understand the ecological consequences of different dispersal syndromes. The twenty-three species of Ephedra in the New World have a disjunct distribution in North and South American arid and semi-arid habitats, exhibiting three dispersal syndromes related to dispersal by birds, wind and rodents. Using DNA sequence data we inferred phylogenetic relationships and lineage divergence times, and used these estimates to test different ecological assumptions. Using comparative methods we tested for correlations between dispersal syndromes and a set of ecological variables (niche breadth, niche evolution, distributional ranges and niche position). We found that speciation events in the New World coincided with the expansion of arid habitats in this region. We suggest that the bird dispersal syndrome is related with higher rates of climatic niche evolution for all variables used, including aridity index, mean annual temperature and mean annual precipitation. Distribution ranges were correlated with niche breadth, they were however not significantly different between dispersal syndromes. Species inhabiting the extremely arid regions on niche axes had narrower niche breadths. We conclude that species whose seeds are dispersed by birds have colonized a broader set of habitats and that those with wind and rodent dispersal syndromes might have promoted the colonization of more arid environments. Ecography © 2015 Nordic Society Oikos.
Ferrer M.M.,Institute Of Ecologia Ac |
Ferrer M.M.,Autonomous University of Yucatán |
Montana C.,Institute Of Ecologia Ac |
Franco M.,University of Plymouth
Ecography | Year: 2015
The occurrence of a species in habitats of varying quality connected through migration can only be understood by detailed investigation of itsdemography. In the Chihuahuan Desert, the common shrub Flourensia cernua is found in both productive and unproductive areas. In the former, both growing and senescent populations are regularly found, while in the latter a low density scattered population persists indefinitely. While precipitation (and its annual stochastic variation) is the same in both habitats, their geomorphological differences produce a sharp difference in the availability of the limiting resource, water. This produces different population dynamics in F. cernua, but also radically different plant communities. Counterintuitively, the low-resource habitat (LR) supports a scattered, slightly increasing or stable population that coexists with its neighbors and acts as exporter of seeds (source population). In contrast, the high-resource habitat (HR) allows sporadic recruitment of locally dense patches that tend towards extinction (sink population). The latter is accounted for by the increasing dominance of the grass Pleuraphys mutica. The different dynamics and regulatory mechanisms in each habitat allow the species to occupy a wider distribution than it would have in their absence. The higher abundance of F. cernua in the sink habitat, together with its consequences on community composition and dynamics, questions the idea proposed in the literature that a sink population lives outside its fundamental niche. The study provides support to the notion that the ecological niche of a species cannot be completely characterized by its requirements (e.g. as they relate to physiology), but must also include the complex demographic responses to a spatially and temporally variable environment, which may often include substandard conditions. For the niche concept to retain its usefulness, it must incorporate the demographic response of populations to spatially and temporallyvariable resource supply. © 2015 Nordic Society Oikos.
Minimally invasive blood sampling method for genetic studies on Gopherus tortoises [Método de extracción de sangre mínimamente invasivo para estudios genéticos en tortugas terrestres del género Gopherus]
Garcia-Feria L.M.,Institute Of Ecologia A C |
Urena-Aranda C.A.,Institute Of Ecologia Ac |
Espinosa de los Monteros A.,Institute Of Ecologia Ac
Animal Biodiversity and Conservation | Year: 2015
Obtaining good quality tissue samples is the first hurdle in any molecular study. This is especially true for studies involving management and conservation of wild fauna. In the case of tortoises, the most common sources of DNA are blood samples. However, only a minimal amount of blood is required for PCR assays. Samples are obtained mainly from the brachial and jugular vein after restraining the animal chemically, or from conscious individuals by severe handling methods and clamping. Herein, we present a minimally invasive technique that has proven effective for extracting small quantities of blood, suitable for genetic analyses. Furthermore, the samples obtained yielded better DNA amplification than other cell sources, such as cloacal epithelium cells. After two years of use on wild tortoises, this technique has shown to be harmless. We suggest that sampling a small amount of blood could also be useful for other types of analyses, such as physiologic and medical monitoring. © 2015 Museu de Ciències Naturals de Barcelona.
PubMed | University of Veracruz and Institute Of Ecologia Ac
Type: Comparative Study | Journal: International journal of medicinal mushrooms | Year: 2014
The chemical composition of the aroma of fresh fruiting bodies of the cultivated mushroom Lentinus boryanus is described here and compared with medicinal shiitake mushroom L. edodes. Volatile compounds were analyzed through headspace sampling coupled with gas chromatography-mass spectrometry. The mushrooms under study were grown on different substrates based on barley straw, sugarcane bagasse, oak wood sawdust, and beech leaf litter. It was determined that L. boryanus as well as L. edodes contain an abundant amount of a volatile compound identified as 3-octanone with a sweet fruity aroma. On the other hand, only L. boryanus produced 3-octanol a characteristic aroma of cod liver oil. In total, 10 aromatic compounds were identified, some of which were obtained exclusively in one species or substrate.