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opencc-zeroDec 2016View details →

Data from: How shrub encroachment under climate change could threaten pollination services for alpine wildflowers: a case study using the alpine skypilot, Polemonium viscosum

Under climate change, shrubs encroaching into high altitude plant communities disrupt ecosystem processes. Yet effects of encroachment on pollination mutualisms are poorly understood. Here, we probe potential fitness impacts of interference from encroaching Salix (willows) on pollination quality of the alpine skypilot, Polemonium viscosum. Overlap in flowering time of Salix and Polemonium is a precondition for interference and was surveyed in four extant and 25 historic contact zones. Pollinator sharing was ascertained from observations of willow pollen on bumble bees visiting Polemonium flowers and on Polemonium pistils. We probed fitness effects of pollinator sharing by measuring the correlation between Salix pollen contamination and seed set in naturally pollinated Polemonium. To ascertain whether Salix interference occurred during or after pollination, we compared seed set under natural pollination, conspecific pollen addition, and Salix pollen addition. In current and past contact zones Polemonium and Salix overlapped in flowering time. After accounting for variance in flowering date due to latitude, Salix and Polemonium showed similar advances in flowering under warmer summers. This trend supports the idea that sensitivity to temperature promotes reproductive synchrony in both species. Salix pollen is carried by bumble bees when visiting Polemonium flowers and accounts for up to 25% of the grains on Polemonium pistils. Salix contamination correlates with reduced seed set in nature and when applied experimentally. Postpollination processes likely mediate these deleterious effects as seed set in nature was not limited by pollen delivery. Synthesis: As willows move higher with climate change, we predict that they will drive postpollination interference, reducing the fitness benefits of pollinator visitation for Polemonium and selecting for traits that reduce pollinator sharing.

opencc-zeroDec 2015View details →

Data from: Using citizen-collected wildlife sightings to predict traffic strike hotspots for threatened species: a case study on the southern cassowary

Assessing the causal factors underpinning the distribution and abundance of wildlife road-induced mortality can be challenging. This is particularly ubiquitous for rare or elusive species, because traffic strikes occur infrequently for these populations and information about localized abundance, distribution, and movements are generally lacking. Here we assessed if citizen-collected sightings data may serve as a low cost and efficient means of gathering long-term animal road-side presence and road crossing information, which could then be used to assess the causative factors and direct mitigation actions aimed at reducing wildlife traffic strike frequency. We explored this principle using two decades of traffic strike records and citizen-collected sightings of the southern cassowary Casuarius casuarius johnsonii. Roads have bisected the cassowaries' rainforest habitat and despite considerable investment into mitigation strategies for this species, road-induced mortality is considered one of the primary threatening processes affecting the population. Using a Bayesian approach and controlling for spatial autocorrelation with conditional autoregressive (CAR) models, we demonstrate that traffic strikes are primarily a density-dependent process in the southern cassowary. That is, traffic strike clusters occurred along stretches of road where cassowaries were most frequently sighted. There were, however, road stretches where traffic strike frequency was greater than predicted by the number of road-side sightings, illustrating when and where density-independent processes increased the mortality potential for a road-crossing cassowary. Synthesis and applications. This is the first time that citizen-collected sightings data have been used to systematically inform upon the abundance and distribution of wildlife traffic strike. The technique not only predicts where incidents are likely to occur but also helps us to understand the factors responsible for strike clustering. While not a replacement for systematic surveys, we highlight citizen-collected sightings data as a low-cost option when assessing contributing factors to vehicle-induced mortality. Accounting for density-dependent and independent processes will ensure the most effective allocation of resources when implementing wildlife traffic strike mitigation.

opencc-zeroDec 2013View details →

Data from: Fractured genetic connectivity threatens a southern California puma (Puma concolor) population

Pumas (Puma concolor; also known as mountain lions and cougars) in southern California live among a burgeoning human population of roughly 20 million people. Yet little is known of the consequences of attendant habitat loss and fragmentation, and human-caused puma mortality to puma population viability and genetic diversity. We examined genetic status of pumas in coastal mountains within the Peninsular Ranges south of Los Angeles, in San Diego, Riverside, and Orange counties. The Santa Ana Mountains are bounded by urbanization to the west, north, and east, and are separated from the eastern Peninsular Ranges to the southeast by a ten lane interstate highway (I-15). We analyzed DNA samples from 97 pumas sampled between 2001 and 2012. Genotypic data for forty-six microsatellite loci revealed that pumas sampled in the Santa Ana Mountains (n = 42) displayed lower genetic diversity than pumas from nearly every other region in California tested (n = 257), including those living in the Peninsular Ranges immediately to the east across I-15 (n = 55). Santa Ana Mountains pumas had high average pairwise relatedness, high individual internal relatedness, a low estimated effective population size, and strong evidence of a bottleneck and isolation from other populations in California. These and ecological findings provide clear evidence that Santa Ana Mountains pumas have been experiencing genetic impacts related to barriers to gene flow, and are a warning signal to wildlife managers and land use planners that mitigation efforts will be needed to stem further genetic and demographic decay in the Santa Ana Mountains puma population.

opencc-zeroDec 2017View details →

Data from: The importance of core habitat for a threatened species in changing landscapes

1. Habitat loss, fragmentation and alteration of the landscape matrix are interdependent processes, collectively responsible for most recent species extinctions. Thus, determining the extent to which these landscape processes affect animals is critical for conservation. However, researchers have often assumed that interdependent effects are independently related to animals' responses, underestimating the importance of one or several landscape processes in driving species declines. 2. We demonstrate how to disentangle the interdependent effects of habitat area, fragmentation, and edge context on population size by assessing abundance of a rapidly-declining grassland songbird species (Grasshopper Sparrow, Ammodramus savannarum) in eastern Kansas (USA). We conducted > 7,000 point-count bird surveys at > 2,000 sites over two breeding seasons, then modelled the direct, interactive, and indirect effects of landscape factors on abundance within spatial scales (200-, 400-, 800-, 1600-m radii) relevant to our focal species' dispersal behavior. 3. Sparrow abundance correlated most strongly with landscape structure within 400-m radii, increasing non-linearly with grassland area and decreasing with the proportion of grassland near cropland or woody edges. Sparrows' negative response to cropland edges was mostly an added, indirect consequence of reduced grassland area, whereas sparrows' stronger negative response to woody edges was not attributable to variation in grassland area. Fragmentation and edge context mattered most in landscapes comprising ~ 50–80% grassland. 4. Synthesis and applications. Abundance of a threatened grassland songbird was influenced more by core grassland area (a function of total grassland area, fragmentation, and edge context) than total grassland area per se. Moreover, a local extinction threshold of ~ 50% grassland indicated that small amounts of habitat were unsuitable for our focal species regardless of habitat configuration or matrix type. Local extinction thresholds in response to habitat area provide clear baseline targets for land managers; above those thresholds, configuration and the matrix can be modified to increase abundance of edge-sensitive animals. Conflicting evidence in the literature regarding the importance of fragmentation and matrix features could be partially explained by species-level traits, or methodological issues such as defining landscapes at ecologically-arbitrary spatial scales, assessing landscape quality using species richness, and ignoring interactive and indirect effects.

opencc-zeroDec 2017View details →

Data from: Anthropogenic disturbance of tropical forests threatens pollination services to açaí palm in the Amazon river delta

The açaí palm Euterpe oleracea Mart. in the Amazon river delta has seen rapid expansion to meet increased demand for its fruit. This has been achieved by transforming lowland forest habitats (floodplains) into simplified agroforests and intensive plantation in upland areas. As açaí palm makes an important contribution to the economy and food security of local communities, identifying management approaches that support biodiversity and ecosystem processes that underpin fruit production on açaí farms is essential. We compared flower-visitor communities and açaí fruit production in floodplain forests and upland plantations, across gradients of local management intensity (i.e. açaí density per ha) and surrounding forest cover. The relative contribution of biotic pollination and degree of pollen limitation were assessed using insect exclusion and hand-pollination experiments. We found that açaí flower visitors are highly diverse (c. 200 distinct taxa) and had variable responses to disturbance. Bee visitation was higher in floodplains and positively related to surrounding forest cover, but other flower visitors, including specialised curculionid beetles, were unresponsive to changes in surrounding forest cover. However, intensive management practices (i.e. high açaí palm densities) in floodplains and uplands had contrasting effects on flower-visitor communities, with flower-visitor richness being lower on intensively managed floodplain farms and ant densities being higher on intensive upland farms. Pollination experiments revealed açaí palm to be highly dependent on biotic pollination. Fruit set in open-pollinated inflorescences was positively related to flower-visitor richness and specialised curculionid beetle visitation, whereas the presence of ants on inflorescences had a negative effect. Synthesis and applications. Our study shows that pollinators are essential for açaí fruit production, but that intensive farming practices have eroded the relationship between surrounding forest cover and ecosystem function in floodplains (i.e. conversion of native forest into simplified agroforests) and increased the frequency of antagonistic interactions in uplands (e.g. high ant densities). These findings underline the value of extensive management practices, such as the maintenance of other tree species within farms and adjacent unmanaged forest patches, to ensure the long-term sustainability of açaí fruit production in the Amazon river delta.

opencc-zeroDec 2012View details →

Data from: Variation in the transcriptional response of threatened coral larvae to elevated temperatures

Coral populations have declined worldwide largely due to increased sea surface temperatures. Recovery of coral populations depends in part upon larval recruitment. Many corals reproduce during the warmest time of year when further increases in temperature can lead to low fertilization rates of eggs and high larval mortality. Microarray experiments were designed to capture and assess variability in the thermal stress responses of Acropora palmata larvae from Puerto Rico. Transcription profiles showed a striking acceleration of normal developmental gene expression patterns with increased temperature. The transcriptional response to heat suggested rapid depletion of larval energy stores via peroxisomal lipid oxidation and included key enzymes that indicated the activation of the glyoxylate cycle. High temperature also resulted in expression differences in key developmental signalling genes including the conserved WNT pathway that is critical for pattern formation and tissue differentiation in developing embryos. Expression of these and other important developmental and thermal stress genes such as ferritin, heat shock proteins, cytoskeletal components, cell adhesion and autophagy proteins also varied among larvae derived from different parent colonies. Disruption of normal developmental and metabolic processes will have negative impacts on larval survival and dispersal as temperatures rise. However, it appears that variation in larval response to high temperature remains despite the dramatic population declines. Further research is needed to determine whether this variation is heritable or attributable to maternal effects.

opencc-zeroDec 2017View details →

Data from: Population density and size influence pollen dispersal pattern and mating system of the predominantly outcrossed Banksia nivea (Proteaceae) in a threatened ecological community

Gene flow is a critical component of plant mating systems and influences population fitness, yet pollen dispersal can be highly variable and influenced by natural and anthropogenic fragmentation. Gene flow through pollen dispersal was investigated in two populations of contrasting size and habitat context in Banksia nivea ssp. uliginosa, a rare species in the Busselton ironstone threatened ecological community with a naturally fragmented distribution. Paternity analysis was conducted with seven microsatellite loci to determine mating system parameters and patterns of pollen dispersal. Outcrossing was high in both populations with a similar level of selfing for both populations despite differences in population size, density and vegetation matrix. Most mating occurred within 10 m of a mother plant in the small, clumped population, while more dispersed mating, up to 50 m from a mother plant, was recorded in the large, less dense population. Our results show that population density and size are important influences on mating system parameters and level of pollen dispersal.

FIGURES 37–43 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 37–43: Zetzellia quasagistemas sp. n. (immatures) 37–38. Larva. 37. dorsum, 38. anogenital region. 39–40. Protonymph. 39. dorsum, 40. anogenital region. 41–42. Deutonymph female. 41. dorsum, 42. anogenital region. 42. Anogenital region of deutonymph male.

FIGURES 23–29 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 23–29: Zetzellia quasagistemas sp. n. (female) 23. dorsum, 24. anogenital region, ventral, 25. palp, 26–29. legs I–IV.

FIGURES 1–7 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 1–7: Zetzellia agistzellia sp. n. (female) 1. dorsum, 2. anogenital region, ventral, 3. palp, 4–7. legs I–IV.

FIGURES 15–22 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 15–22: Zetzellia agistzellia sp. n. dorsum (immatures) 15–16. Larva. 15. dorsum, 16. anogenital region. 17–18. Protonymph. 17. dorsum, 18. anogenital region. 1920. Deutonymph female. 19. dorsum, 20. anogenital region. 21–22. Deutonymph male. 21. dorsum, 22. anogenital region.

FIGURES 30–36 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 30–36: Zetzellia quasagistemas sp. n. (male) 30. dorsum, 31. anogenital region, ventral, 32. palp, 33–36. legs I–IV.

FIGURES 8–14 in Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: disgeneric marriage?

FIGURES 8–14: Zetzellia agistzellia sp. n. (male) 8. dorsum, 9. anogenital region, ventral, 10. palp, 11–14. legs I–IV.

FIGURE 3 in A new and threatened species of Scinax (Anura: Hylidae) from Queimada Grande Island, southeastern Brazil

FIGURE 3. Waveform (upper) and spectrogram (lower) of two advertisement calls of Scinax peixotoi recorded at 21:30h at Queimada Grande Island, municipality of Itanhaém, São Paulo, Brazil. Air temperature = 23 °C.

FIGURE 1. Scinax peixotoi, CFBH 9437 in A new and threatened species of Scinax (Anura: Hylidae) from Queimada Grande Island, southeastern Brazil

FIGURE 1. Scinax peixotoi, CFBH 9437 (holotype), adult male in life from Queimada Grande Island, Itanhaém, São Paulo, southeastern Brazil. SVL = 20.3 mm. Photo by O. A. V. Marques.

FIGURE 2. Scinax peixotoi CFBH 9437 in A new and threatened species of Scinax (Anura: Hylidae) from Queimada Grande Island, southeastern Brazil

FIGURE 2. Scinax peixotoi CFBH 9437 (holotype). (A) Dorsal and (B) lateral views of head; ventral views of (C) left hand and (D) foot.

FIGURE 22 in Two new relict Syncordulia species found during museum and field studies of threatened dragonflies in the Cape Floristic Region (Odonata: Corduliidae)

FIGURE 22. Distribution of 'gomphomacromiine' Afrotropical Corduliidae. Nesocordulia and Syncordulia species are not indicated separately, but the number of species in each region is provided. Idomacromia species are separated (diamond: I. jillianae Dijkstra & Kisakye; inverted triangle: I. lieftincki Legrand; standing triangle: I. proavita Karsch; star: both I. lieftincki and I. proavita).

FIGURES 17–21 in Two new relict Syncordulia species found during museum and field studies of threatened dragonflies in the Cape Floristic Region (Odonata: Corduliidae)

FIGURES 17–21. Geographical distribution of Syncordulia species in South Africa (17) and the Western Cape (18–21). Legend: solid circles: verified records; dotted circles: observations; crossed circles: unverified records. (17–18) S. gracilis; (19) S. legator n. sp.; (20) S. venator; (21) S. serendipator n. sp.

FIGURES 9–12 in Two new relict Syncordulia species found during museum and field studies of threatened dragonflies in the Cape Floristic Region (Odonata: Corduliidae)

FIGURES 9–12. Syncordulia male appendages in dorsal (left), lateral (right) and ventral (S. serendipator n. sp. only) view. (9) S. gracilis; (10) S. legator n. sp.; (11) S. venator; (12) S. serendipator n. sp.

FIGURES 13–16 in Two new relict Syncordulia species found during museum and field studies of threatened dragonflies in the Cape Floristic Region (Odonata: Corduliidae)

FIGURES 13–16. Syncordulia female abdomen tip in lateral (left) and ventral (right) view. (13) S. gracilis; (14) S. legator n. sp.; (15) S. venator; (16) S. serendipator n. sp.