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Your search keyword '"Zeller, K.A."' showing total 4 results
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4 results on '"Zeller, K.A."'

1. Modelling jaguar gene flow in fragmented landscapes offers insights into functional population connectivity

Author

Calderón, Ana Patricia, Landaverde-Gonzalez, P., Wultsch, C., Foster, R., Harmsen, B., Figueroa, O., Garcia-Anleu, R., Castañeda, F., Amato, G., Grimm, Volker, Kramer-Schadt, S., Zeller, K.A., Calderón, Ana Patricia, Landaverde-Gonzalez, P., Wultsch, C., Foster, R., Harmsen, B., Figueroa, O., Garcia-Anleu, R., Castañeda, F., Amato, G., Grimm, Volker, Kramer-Schadt, S., and Zeller, K.A.

Abstract

Context Preserving functional connectivity is a conservation priority to secure the long-term viability of geographically dispersed subpopulations, such as the jaguar (Panthera onca) populations in Central America. However, managing connectivity in this region is limited due to the scarcity of local assessments of the connectivity between existing populations, some of which exhibit low levels of gene flow and genetic admixture. Objectives We selected the jaguar as a model species to understand how gene flow of large carnivores is shaped in a heavily human-impacted landscape in the Neotropics. We assessed the impact of landscape features and spatial scale on jaguar gene flow across northern Central America, predicted synoptic, landscape-wide functional connectivity across the region; and compared connectivity predictions based on models of gene flow, habitat suitability, and expert knowledge. Methods We employed genetic data based on 335 faecal samples collected from 72 individual jaguars. We parameterized gene flow resistance surfaces using linear mixed effects models and the maximum likelihood population-effects method. We evaluated nine landscape variables at six spatial scales, selecting the optimal scale and transformation for each variable according to univariate models and AIC. To predict jaguar gene flow, we developed multivariate models and implemented resistant kernels to forecast functional connectivity between jaguar populations across the study region under three dispersal distance scenarios. Furthermore, we compared the connectivity estimates based on gene flow against those based on habitat suitability and the corridors delineated by expert knowledge in the region. Results Low resistance to jaguar gene flow was associated with greater tree cover and vegetation, lower areas of built-up, and intermediate distances from water bodies. Notably, tree cover affected jaguar gene flow on a smaller scale compared to the rest of variables. Highe

Published
2024

2. Comment on Functional landscape connectivity for a select few: Linkages do not consistently predict wildlife movement or occupancy. Autumn R. Iverson, David Waetjen, Fraser Shilling

Author

Keeley, A.T.H., Beier, P., Belote, R.T., Clark, M., Clevenger, A.P., Creech, T.G., Ehlers, L., Faselt, J., Gogol-Prokurat, M., Hall, K.R., Hardy, M.A., Hilty, J.A., Jones, A., Nuñez, T.A., Penrod, K., Poor, E.E., Schloss, C., Theobald, D.M., Smith, T., Spencer, W.D., Sutherland, R., Tabor, G.M., and Zeller, K.A.

Published
2025
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3. Fragmentation effects on woodlark habitat selection depend on habitat amount and spatial scale

Author

Bosco, L., Cushman, S.A., Wan, H.Y., Zeller, K.A., Arlettaz, R., and Jacot, A.

Subjects
fungi, 590 Animals (Zoology)
Abstract

Habitat loss and fragmentation are key drivers of biodiversity loss. However, they are usually confounded, making it difficult to separate fragmentation effects from those of habitat loss. In addition, it has been shown that often fragmentation negatively affects biodiversity only below a certain threshold of habitat amount. We investigated the separate and interactive effects of habitat amount and fragmentation on habitat selection of the woodlark at 10 spatial scales. In southern Switzerlandthis passerine mainly breeds in ground-vegetated vineyards, which therefore represent the focal habitat type in this study. Additionally, we investigated land cover, topographic and climatic variables at the same 10 scales to obtain a holistic picture of species-habitat associations. Habitat selection was analyzed at two hierarchical levels: home range selection within the study area and habitat use within home ranges. Home range selection was strongly driven by an interactive effect of habitat amount and fragmentation: woodlarks avoided fragmented areas if habitat amount was below 20% but exhibited a preference for fragmented areas if habitat amount exceeded this threshold. Both habitat amount and fragmentation most strongly affected habitat use at the 100 m scale. We did not find such interactive effects for habitat use within home ranges. At this level, habitat amount at a 50 m scale influenced woodlark presence positively with no significant effects of fragmentation. Furthermore, woodlarks preferred evenly sloped landscape mosaics interspersed with steppes and groves. Two main insights emerge from our study. First, these results highlight the necessity of studying scale explicit and interactive effects of habitat amount and fragmentation when addressing ecological questions, such as habitat selection in birds. Second, we provide management recommendations for farmers: more vineyards should be vegetated and arranged as disjunct patches where their surface covers more than 20% of the landscape but be aggregated where vegetated area is lower.

Published
2021
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4. A genetic map of Gibberella zeae (Fusarium graminearum)

Author

Jurgenson, J.E., Bowden, R.L., Zeller, K.A., Leslie, J.F., Alexander, N.J., and Plattner, R.D.

Subjects
Fusarium -- Genetic aspects, Linkage (Genetics) -- Research, Biological sciences
Abstract

We constructed a genetic linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate-nonutilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine linkage groups. The total map length is ~1300 cM with an average interval of 2.8 map units between loci. Three of the nine linkage groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two linkage groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on linkage groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.

Published
2002

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