On Madeira, the success of the speckled wood butterfly (Pararge aegeria) has coincided with declining populations of the Madeiran speckled wood (Pararge xiphia): is the colonist to blame?

2020 ◽  
Vol 24 (2) ◽  
pp. 365-374
Author(s):  
Elliot W. Bland ◽  
Lesley A. Lace
2017 ◽  
Vol 27 (10) ◽  
pp. R376-R377 ◽  
Author(s):  
Hui Yu ◽  
Xin Wang ◽  
Lei Cao ◽  
Lu Zhang ◽  
Qiang Jia ◽  
...  

Author(s):  
P. E. Gibbs ◽  
G. W. Bryan

The development of male characters, notably a penis and a vas deferens, on the female (the phenomenon of ‘imposex’) of the dog-whelk, Nucella lapillus, is described. Three stages are recognized: an ‘early’ stage involving the formation of a vas deferens and a small penis, an ‘intermediate’ stage characterized by the enlargement of the female penis to a size approaching that of the male and a ‘late’ stage during which the female opening (vulva) is occluded by overgrowth of vas deferens tissue. This blockage of the pallial oviduct prevents the release of egg capsules and renders the female sterile. The extent and cause of such reproductive failure is evident from the high incidence of females containing aborted capsules in declining populations close to sources of tributyltin (TBT) contamination. These same populations comprise fewer females than expected and it would appear that the accumulation of aborted capsules within the pallial oviduct eventually causes the premature death of the female.


Oryx ◽  
2006 ◽  
Vol 40 (3) ◽  
pp. 266-278 ◽  
Author(s):  
Stuart H.M. Butchart ◽  
Alison J. Stattersfield ◽  
Nigel J. Collar

Considerable resources and efforts have been directed at biodiversity conservation in recent years, but measures of the success of conservation programmes have been limited. Based on information on population sizes, trends, threatening processes and the nature and intensity of conservation actions implemented during 1994–2004, we assessed that 16 bird species would have probably become extinct during this period if conservation programmes for them had not been undertaken. The mean minimum population size of these 16 species increased from 34 to 147 breeding individuals during 1994–2004. In 1994, 63% of them had declining populations but by 2004, 81% were increasing. Most of these species (63%) are found on islands. The principal threats that led to their decline were habitat loss and degradation (88%), invasive species (50%) and exploitation (38%), a pattern similar to that for other threatened species, but with exploitation and invasive species being relatively more important. The principal actions carried out were habitat protection and management (75% of species), control of invasive species (50%), and captive breeding and release (33%). The 16 species represent only 8.9% of those currently classified as Critically Endangered, and 1.3% of those threatened with extinction. Many of these additional species slipped closer to extinction during 1994–2004, including 164 that deteriorated in status sufficiently to be uplisted to higher categories of extinction risk on the IUCN Red List (IUCN, 2006). Efforts need to be considerably scaled up to prevent many more extinctions in the coming decades. The knowledge and tools to achieve this are available, but we need to mobilize the resources and political will to apply them.


2013 ◽  
Vol 73 (2) ◽  
pp. 367-374 ◽  
Author(s):  
A Nemésio

The two largest Atlantic Forest remnants in the state of Espírito Santo, eastern Brazil, namely ‘Reserva Biológica de Sooretama’ (REBIO Sooretama) and ‘Reserva Natural Vale’ (RNV), were surveyed for their orchid-bee faunas. Seventeen scent baits were used to attract orchid-bee males. Three-thousand, two hundred and twenty-five males belonging to 24 species were actively collected with insect nets during 100 hours in March, April and December, 2009. In comparison with a previous study in the same area twelve years before, it is evident that the abundance of all forest-dependent orchid bees analysed declined around 50%, and it was statistically significant (P = 0.022) for Euglossa marianae Nemésio, 2011, the most sensitive to anthropogenic disturbances of all Atlantic Forest orchid bees. On the other hand, the abundance of populations of species tolerant to open or disturbed areas rose. Possible explanations are discussed.


2018 ◽  
Vol 14 (11) ◽  
pp. 20180557 ◽  
Author(s):  
David P. L. Toews ◽  
Henry M. Streby ◽  
Lowell Burket ◽  
Scott A. Taylor

Hybridization between divergent taxa can provide insight into the breakdown of characters used in mate choice, as well as reproductive compatibility across deep evolutionary timescales. Hybridization can also occur more frequently in declining populations, as there is a smaller pool of conspecific mates from which to choose. Here, we report an unusual combination of factors that has resulted in a rare, three-species hybridization event among two genera of warblers, one of which is experiencing significant population declines. We use bioacoustic, morphometric and genetic data, to demonstrate that an early generation female hybrid between a golden-winged warbler ( Vermivora chrysoptera ) and a blue-winged warbler ( V. cyanoptera ) went on to mate and successfully reproduce with a chestnut-sided warbler ( Setophaga pensylvanica ) . We studied the product of this event—a putative chrysoptera × cyanoptera × pensylvanica hybrid—and show that this male offspring sang songs like S. pensylvanica , but had morphometric traits similar to Vermivora warblers. The hybrid's maternal parent had V. chrysoptera mitochondrial DNA and , with six plumage-associated loci, we predicted the maternal parent's phenotype to show that it was likely an early generation Vermivora hybrid . That this hybridization event occurred within a population of Vermivora warblers in significant decline suggests that females may be making the best of a bad situation, and that wood-warblers in general have remained genetically compatible long after they evolved major phenotypic differences.


Ethology ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 645-654 ◽  
Author(s):  
Lesley Vande Velde ◽  
David Damiens ◽  
Hans Van Dyck

Check List ◽  
2015 ◽  
Vol 11 (5) ◽  
pp. 1727
Author(s):  
Ivan N. Bolotov ◽  
Irina A. Bochneva ◽  
Marina V. Podbolotskaya ◽  
Mikhail Yu. Gofarov ◽  
Vitaly M. Spitsyn

The Vinogradovsky District is located at the center of the Arkhangelsk Region, one of the largest federal subjects of Northern European Russia. Boreal spruce forests are the prevalent ecosystem type in this area, but large expanses of agricultural land and herb-grass meadows are also presented there. Based on the studies of 1,699 specimens collected from three meadow sites during period 2011–2013, we provide the first data on the butterfly fauna of the district, which include 56 species, belonging to 35 genera and 5 families. Our data reveal an intense northward expansion of many southern butterfly species to the Arkhangelsk Region, including migrants (Pontia edusa, Issoria lathonia, Vanessa atalanta and Vanessa cardui) and species that have established resident populations there (Pararge aegeria, Nymphalis xanthomelas, Aglais io, Lycaena dispar, Cupido alcetas). Quantitative data on species diversity and phenology of butterflies are reported, including analysis of structure of butterfly assemblages and their seasonal changes.


2021 ◽  
Author(s):  
◽  
Katherine Hailstone

<p>An experience by definition can imply that it leaves an impression. It can be how people experience our small towns that influence its viability and success. Small towns in Aotearoa face aging populations, growing social issues and tend to lack economic viability. Current statistics show population growth in our large cities and declining populations in our regions impacting the urban landscape and the experience of our regional towns. So, how can designing from an experiential approach make a difference to town life?  A traditional approach to changing the experience of towns and cities is through consultation, a production of a master plan and then staging the design over time. Consider what could be gained if we used on-the-ground experience to inform the structure our towns?  If we intensely engage with the ‘on the ground experience’ of the town, looking at how the town structures experience, we should be able to identify opportunities that could re-orientate how people interact with the town. These opportunities or potential design alterations, could reshape the way that the town is structured and therefore inform the development of a master plan or long term plan. Through an experience-based design approach the opportunities that can be identified from this method are often not visible from other techniques such as top down mapping and other common forms of data collection. Through a combination of; an understanding of the experience of the town, its history, influences, though various forms of mapping and the understanding the viability of proposed design alterations we could strategically transform the experience.  Therefore, through an experiential design approach and understanding how our small towns work in Aotearoa; can we focus design actions in the public environment to develop potential future change?</p>


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