| 1. |
- Kaiser, Kristine, et al.
(author)
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When sounds collide : the effect of anthropogenic noise on a breeding assemblage of frogs in Belize, Central America
- 2011
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In: Behaviour. - 0005-7959 .- 1568-539X. ; 148:2, s. 215-232
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Journal article (peer-reviewed)abstract
- Many organisms depend on acoustic communication for myriad functions, and have evolved behaviours to minimize effects of naturally occurring acoustic interference. However, as habitats are subject to increased alteration, anthropogenic noise becomes unavoidable, and how animals overcome such interference is not well understood. In most ecosystems, only a subset of frog species is associated with disturbed habitats; the ability of these species to overcome exogenous noise suggests that habitat associations may be related to species' response to noise. We tested the hypothesis that frogs associated with largely undisturbed forest habitat would be less likely to increase call output in response to exogenous noise than would those associated with disturbed or open habitat. While this relationship was not significant, we found a slight trend supporting the hypothesis. We then asked whether anthropogenic noise affects chorus tenure at individual- or at chorus-levels. Male frogs exposed to anthropogenic noise decreased both the number of days present at the chorus and the nightly chorus duration relative to controls. Because females generally join choruses late at night to breed, the effects of noise shown here are likely to substantially decrease frog reproductive success; thus, the acoustic environment may play an important role in shaping population dynamics and in amphibian declines.
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| 2. |
- Mortellaro, Steve, et al.
(author)
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Coefficients of Conservatism Values and the Floristic Quality Index for the vascular plants of south Florida
- 2012
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In: Southeastern naturalist (Steuben, Me.). - : Humboldt Field Research Institute. - 1528-7092 .- 1938-5412. ; 11:mo3, s. 1-62
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Journal article (peer-reviewed)abstract
- Since pre-European settlement, major alterations to the native landscape have been made, due largely to urban and agricultural developments. In south Florida, these activities have caused extensive degradation to native plant communities leaving remnant native lands. Therefore, the floristic quality of these native lands is changing, and a tool to assess their quality is needed. Assignment of coefficient of conservatism (C) values (ranging from 0 to 10) to each native plant within south Florida allows for the use of the floristic quality index (FQI), a tool to assess the quality of natural or remnant native plant communities. The coefficient of conservatism concept is based on two factors: 1) plants have various degrees of fidelity to specific habitats and their quality, and 2) plants have varying tolerances to disturbances and respond in various degrees. The establishment of C values and the use of the FQI eliminate subjectivity and provide a standardized method to evaluate the floristic condition of a site, which allows for comparisons between different sites and monitoring of sites over time. Non-native plants are not assigned conservatism coefficients values because they did not evolve in the native landscape. In south Florida (Florida Keys excluded), there are approximately 2226 plants, of which 64% (1434) are considered native and 36% (792) are considered non-native. Of the 1434 plants examined, only 94 native plants remained unranked, because the team did not have enough experience with the plant to confidently assign a C value. Approximately 33% of plants ranked fell into the ruderal categories (0–4), whereas 67% fell into obligate to natural areas categories (5–10). Once a thorough inventory of a site has been completed, a mean C value and FQI can be calculated.
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| 3. |
- Nystedt, Björn, et al.
(author)
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The Norway spruce genome sequence and conifer genome evolution
- 2013
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In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 497:7451, s. 579-584
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Journal article (peer-reviewed)abstract
- Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinus sylvestris, Abies sibirica, Juniperus communis, Taxus baccata and Gnetum gnemon reveals that the transposable element diversity is shared among extant conifers. Expression of 24-nucleotide small RNAs, previously implicated in transposable element silencing, is tissue-specific and much lower than in other plants. We further identify numerous long (>10,000 base pairs) introns, gene-like fragments, uncharacterized long non-coding RNAs and short RNAs. This opens up new genomic avenues for conifer forestry and breeding.
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| 4. |
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| 5. |
- Scofield, Douglas G., et al.
(author)
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Foraging patterns of acorn woodpeckers (Melanerpes formicivorus) on valley oak (Quercus lobata N,e) in two California oak savanna-woodlands
- 2011
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In: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 166:1, s. 187-196
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Journal article (peer-reviewed)abstract
- Landscape characteristics and social behavior can affect the foraging patterns of seed-dependent animals. We examine the movement of acorns from valley oak (Quercus lobata) trees to granaries maintained by acorn woodpeckers (Melanerpes formicivorus) in two California oak savanna-woodlands differing in the distribution of Q. lobata within each site. In 2004, we sampled Q. lobata acorns from 16 granaries at Sedgwick Reserve in Santa Barbara County and 18 granaries at Hastings Reserve in Monterey County. Sedgwick has lower site-wide density of Q. lobata than Hastings as well as different frequencies of otherQuercus species common to both sites. We found acorn woodpeckers foraged from fewer Q. lobata seed source trees (K g = 4.1 ± 0.5) at Sedgwick than at Hastings (K g = 7.6 ± 0.6) and from fewer effective seed sources (N em* = 2.00 and 5.78, respectively). The differences between sites are due to a greater number of incidental seed sources used per granary at Hastings than at Sedgwick. We also found very low levels of seed source sharing between adjacent granaries, indicating that territoriality is strong at both sites and that each social group forages on its own subset of trees. We discovered an interesting spatial pattern in the location of granaries. At Sedgwick, acorn woodpeckers situated their granaries within areas of higher-than-average tree density, while at Hastings, they placed them within areas of lower-than-average tree density, with the outcome that granaries at the two sites were located in areas of similar valley oak density. Our results illustrate that landscape characteristics might influence the number of trees visited by acorn woodpeckers and the locations of territories, while woodpecker social behavior, such as territoriality, shapes which trees are visited and whether they are shared with other social groups.
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| 6. |
- Scofield, Douglas G., et al.
(author)
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Influence of acorn woodpecker social behaviour on transport of coast live oak (Quercus agrifolia) acorns in a southern California oak savanna
- 2010
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In: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 98:3, s. 561-572
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Journal article (peer-reviewed)abstract
- 1. Many plant species depend upon animals for seed dispersal, yet animals disperse seeds in pursuit of their own social and behavioural agendas. Animal social behaviour affects where and how they forage, so it must also shape patterns of seed dispersal.2. At Sedgwick Reserve, California, USA, we established a study population of Quercus agrifolia to determine patterns of acorn foraging by the acorn woodpecker (Melanerpes formicivorous). This cooperative breeder lives in social groups that defend territories surrounding arboreal seed caches (granaries), foraging communally within these territories.3. We genotyped pericarp tissue of 568 acorns, as well as 285 adult Q. agrifolia trees, including all adults within 150 m of 16 focal granaries. After quantifying genotyping error, we identified a genetically reliable subset of 524 acorns. We assigned a source tree to each acorn and estimated the number of seed sources per granary and seed source sharing among granaries.4. We found one to eight distinct seed-source genotypes per granary, and an effective source diversity ranging from 1.0 to 6.6 seed sources. Of all transport events, 96.5% involve source trees within 150 m of the granaries. For one granary, all sampled acorns were transported from five trees located more than 1.3 km away, with all source trees within 90 m of each other. No measure of seed-source diversity was associated with density of potential seed sources, and the pattern of acorn movement fits three traditional dispersal curves poorly.5. Woodpecker groups rarely collected acorns from overlapping sets of maternal sources. Some pairs of neighbouring granaries shared maternal sources, and we identify those that were probably maintained by the same woodpecker group.6.Synthesis. Territoriality of woodpecker groups restricts both the spatial area of foraging and the sharing of seed sources. This foraging behaviour limits distances and directions of acorn transport from oaks located within woodpecker territories. Dispersal agents with this type of social structure will create a high degree of local genetic structure. Extreme behavioural variations may result in anomalous long-distance dispersal events that increase genetic connectivity, but are likely to do so in an episodic and erratic fashion.
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| 7. |
- Smouse, Peter E., et al.
(author)
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Using Seedling and Pericarp Tissues to Determine Maternal Parentage of Dispersed Valley Oak Recruits
- 2012
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In: Journal of Heredity. - : Oxford University Press (OUP). - 0022-1503 .- 1465-7333. ; 103:2, s. 250-259
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Journal article (peer-reviewed)abstract
- The spatial pattern of established seedlings yields valuable information about variation in fecundity, dispersal, and spatial structure of distributed recruits, but separating maternal and paternal contributions in monoecious species has been hampered by the “2 parent” problem. It is now possible to determine the maternal parentage of established recruits with genetic assay of maternally derived tissues of the seed or fruit, but the DNA of weathered maternal tissues often yields unreliable genotypes, reducing the practical range of such assay. We develop a mixed assay of seedling and seed (pericarp) tissues and illustrate it with distributed recruits of California valley oak (Quercus lobata Née). Detailed analysis indicates correct maternal assignment rates of canopy patch recruits of 56% (seedling assay only) versus 94% (mixed assay). For open patch recruits, maternal assignment rates were less than 50% (seedling assay only) versus 91% (mixed assay). The strategy of choice is to use seedling genotypes to identify a small set of credible parental candidates and then deploy 3–4 well-chosen pericarp/endocarp loci to reduce that list to a single obvious maternal candidate. The increase in the number of recruits available for subsequent analysis is pronounced, increasing precision and statistical power for subsequent inference.
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| 8. |
- Thompson, Pamela G., et al.
(author)
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What seeds tell us about birds : A multi-year analysis of acorn woodpecker foraging movements
- 2014
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In: Movement Ecology. - : Springer Science and Business Media LLC. - 2051-3933. ; 2, s. 12-
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Journal article (peer-reviewed)abstract
- Background: Foraging movements of animals shape their efficiency in finding food and their exposure to the environment while doing so. Our goal was to test the optimal foraging theory prediction that territorial acorn woodpeckers (Melanerpes formicivorus) should forage closer to their ‘central place’ in years of high resource availability and further afield when resources are less available. We used genetic data on acorns stored in caching sites (granaries) and adult trees for two oak species (Quercus lobata and Quercus agrifolia) to track acorn movements across oak savanna habitat in central California. We also compared the patterns of trees these territorial bird groups foraged upon, examining the effective numbers of source trees represented within single granaries (α), the effective number of granaries (β), the diversity across all granaries (γ), and the overlap (ω) in source trees among different granaries, both within and across years.Results: In line with optimal foraging theory predictions, most bird groups foraged shorter distances in years with higher acorn abundance, although we found some exceptionally long distance foraging movements in high acorn crop years. The α-diversity values were significantly higher for Quercus lobata, but not for Quercus agrifolia, in years of high acorn production. We also found that different woodpecker family groups visited almost completely non-overlapping sets of source trees, and each particular group visited largely the same set of source trees from year to year, indicating strong territorial site fidelity.Conclusions: Acorn woodpeckers forage in a pattern consistent with optimal foraging theory, with a few fascinating exceptions of long distance movement. The number of trees they visit increases in years of high acorn availability, but the extra trees visited are mostly local. The territorial social behavior of the birds also restricts their movement patterns to a minimally overlapping subsets of trees, but the median movement distance appears to be shaped more by the availability of trees with acorns than by rigid territorial boundaries.
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