scholarly journals From the cage to the wild: Introductions of Psittaciformes to Puerto Rico with emphasis on the invasive ecology of the white-winged parakeet

2018 ◽  
Author(s):  
Wilfredo Falcón L. ◽  
Raymond L. Tremblay
Keyword(s):  
Puerto Rico ◽  
Growth Rates ◽  
Geometric Mean ◽  
Management Strategies ◽  
Invasion Success ◽  
Population Increase ◽  
Current Status ◽  
Steady Increase ◽  
Population Growth Rates ◽  
Myiopsitta Monachus

AbstractIn this study, we assessed invasions of Psittaciformes in Puerto Rico. We reviewed the literature, public databases, citizen science records, and performed in situ population surveys across the island to determine the historical and current status and distribution of psittacine species. We used count data from Ebird to determine population trends. For species whose populations were increasing, we modelled their potential distribution using niche modeling techniques. Focusing on the white-winged parakeet (Brotogeris versicolurus), which was considered the most successful psittacine species by the year 2000, we evaluated the population size, calculated growth rates and estimated the breeding proportion in two populations by performing roost counts for four consecutive years. We found a total of 46 Psittaciformes present in Puerto Rico, of which 26% are only present as pets, at least 29 species have been reported in the wild, and of those, there is evidence that at least 12 species are breeding. Our results indicate that most introduced species which have been detected as established still persist, although mostly in localized areas and small populations. Clear evidence of invasiveness was found for B. versicolurus and Myiopsitta monachus, which have greatly expanded their range. Moreover, Psittacara erythrogenys and Eupsittacula canicularis also showed population increase. The niche models predicted suitable areas for the four species, and also indicate the potential for range expansion. Population estimates of the white-winged parakeet during the study period showed a steady increase, and exhibited exponential growth, with geometric mean population growth rates of 1.25 per year. Currently growth rate of the white-winged parakeet does not appear to be limited by any predator, resources or nest availability, and we expect them to continue increasing and expanding their range. We discuss the factors leading to invasion success, assess the potential impacts, and we discuss possible management strategies and research prospects.

scholarly journals From the cage to the wild: introductions of Psittaciformes to Puerto Rico

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5669 ◽  
Author(s):  
Wilfredo Falcón ◽  
Raymond L. Tremblay
Keyword(s):  
Puerto Rico ◽  
Management Strategies ◽  
Invasion Success ◽  
Current Status ◽  
Small Populations ◽  
Myiopsitta Monachus ◽  
Modeling Techniques ◽  
In The Wild ◽  
Niche Models

Introduced psittacine birds can become highly invasive. In this study, we assessed invasions of Psittaciformes in Puerto Rico. We reviewed the literature, public databases, citizen science records, and performed in situ population surveys across the island to determine the historical and current status and distribution of psittacine species. We used count data from Ebird to determine population trends. For species whose populations were increasing, we modelled their potential distribution using niche modeling techniques. We found 46 Psittaciformes in Puerto Rico, of which 26% are only present as pets, at least 29 species have been reported in the wild, and of those, there is evidence that at least 12 species are breeding. Our results indicate that most introduced species which have been detected as established still persist, although mostly in localized areas and small populations. Clear evidence of invasiveness was found for Brotogeris versicolurus and Myiopsitta monachus, which have greatly expanded their range in recent years. Psittacara erythrogenys and Eupsittacula canicularis also showed population increases, although to a lesser degree. The niche models predicted suitable areas for the four species, and also indicate the potential for range expansion. We discuss the factors leading to invasion success, assess the potential impacts, and we discuss possible management strategies and research prospects.

scholarly journals From the cage to the wild: Introductions of Psittaciformes to Puerto Rico

2018 ◽  
Author(s):  
Wilfredo Falcón ◽  
Raymond L. Tremblay
Keyword(s):  
Puerto Rico ◽  
Management Strategies ◽  
Invasion Success ◽  
Current Status ◽  
Small Populations ◽  
Myiopsitta Monachus ◽  
Modeling Techniques ◽  
In The Wild ◽  
Niche Models

AbstractIntroduced psittacine birds can become highly invasive. In this study, we assessed invasions of Psittaciformes in Puerto Rico. We reviewed the literature, public databases, citizen science records, and performed in situ population surveys across the island to determine the historical and current status and distribution of psittacine species. We used count data from Ebird to determine population trends. For species whose populations were increasing, we modelled their potential distribution using niche modeling techniques. We found 46 Psittaciformes in Puerto Rico, of which 26% are only present as pets, at least 29 species have been reported in the wild, and of those, there is evidence that at least 12 species are breeding. Our results indicate that most introduced species which have been detected as established still persist, although mostly in localized areas and small populations. Clear evidence of invasiveness was found for Brotogeris versicolurus and Myiopsitta monachus, which have greatly expanded their range in recent years. Psittacara erythrogenys and Eupsittacula canicularis also showed population increases, although to a lesser degree. The niche models predicted suitable areas for the four species, and also indicate the potential for range expansion. We discuss the factors leading to invasion success, assess the potential impacts, and we discuss possible management strategies and research prospects.

Using population dynamics modelling to evaluate potential success of restoration: a case study of a Hawaiian vine in a changing climate

2014 ◽  
Vol 42 (1) ◽  
pp. 20-30 ◽  
Author(s):  
TAMARA M. WONG ◽  
TAMARA TICKTIN
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Key Management ◽  
Demographic Data ◽  
Population Decline ◽  
Management Strategies ◽  
Survival Rates ◽  
Population Modelling ◽  
Population Growth Rates

SUMMARYDemographic comparisons between wild and restored populations of at-risk plant species can reveal key management strategies for effective conservation, but few such studies exist. This paper evaluates the potential restoration success ofAlyxia stellata, a Hawaiian vine. Stage-structured matrix projection models that compared long-term and transient dynamics of wild versus restoredA. stellatapopulations, and restored populations under different levels of canopy cover, were built from demographic data collected over a four year period. Stochastic models of wild populations projected stable or slightly declining long-term growth rates depending on frequency of dry years. Projected long-term population growth rates of restored populations were significantly higher in closed than open canopy conditions, but indicated population decline under both conditions. Life table response experiments illustrated that lower survival rates, especially of small adults and juveniles, contributed to diminished population growth rates in restored populations. Transient analyses for restored populations projected short-term decline occurring even faster than predicted by asymptotic dynamics. Restored populations will not be viable over the long term under conditions commonly found in restoration projects and interventions will likely be necessary. This study illustrates how the combination of long-term population modelling and transient analyses can be effective in providing relevant information for plant demographers and restoration practitioners to promote self-sustaining native populations, including under future climates.

scholarly journals Microsatellite characterisation and sex-typing in two invasive parakeet species, the monk parakeet Myiopsitta monachus and ring-necked parakeet Psittacula krameri

2019 ◽  
Vol 47 (2) ◽  
pp. 1543-1550
Author(s):  
Francesca S. E. Dawson Pell ◽  
Ben J. Hatchwell ◽  
Alba Ortega-Segalerva ◽  
Deborah A. Dawson ◽  
Gavin J. Horsburgh ◽  
...  
Keyword(s):  
Invasive Species ◽  
Microsatellite Loci ◽  
Management Strategies ◽  
Invasion Success ◽  
Sex Typing ◽  
Monk Parakeet ◽  
Myiopsitta Monachus ◽  
Psittacula Krameri ◽  
Scale Population ◽  
Negative Impacts

AbstractInvasive species can have wide-ranging negative impacts, and an understanding of the process and success of invasions can be vital to determine management strategies, mitigate impacts and predict range expansions of such species. Monk parakeets (Myiopsitta monachus) and ring-necked parakeets (Psittacula krameri) are both widespread invasive species, but there has been little research into the genetic and social structure of these two species despite the potential links with invasion success. The aim of this study was to isolate novel microsatellite loci from the monk parakeet and characterise them in both monk and ring-necked parakeets in order to facilitate future investigations into their behaviour and population ecology. Sex-typing markers were also tested in both species. Of the 20 microsatellite loci assessed in 24 unrelated monk parakeets, 16 successfully amplified and were polymorphic displaying between 2 and 14 alleles (mean = 8.06). Expected heterozygosity ranged from 0.43 to 0.93 and observed heterozygosity ranged from 0.23 to 0.96. Nine of the 20 loci also successfully amplified and were polymorphic in the ring-necked parakeet, displaying between 2 and 10 alleles. Suitable markers to sex both species and a Z-linked microsatellite locus were identified. A multiplex marker set was validated for monk parakeets. These novel microsatellite loci will facilitate fine and broad-scale population genetic analyses of these two widespread invasive species.

scholarly journals Homosyndrome in planktonic graptolites: implications for reproductive biology, population ecology, and macroevolution

1992 ◽  
Vol 6 ◽  
pp. 215-215
Author(s):  
Charles E. Mitchell
Keyword(s):  
Population Growth ◽  
Sexual Reproduction ◽  
Growth Rates ◽  
Population Increase ◽  
Age Difference ◽  
Upper Ordovician ◽  
Surrounding Water ◽  
Population Growth Rates ◽  
Parent Colony ◽  
Colonial Organisms

Fusion (soft tissue merger and coordinated growth) of conspecific colonies originating from different larvae (i.e., homosyndrome) occurs rarely among a wide variety of benthic colonial organisms, including cnidarians, bryozoans and tunicates. Whether or not individuals fuse upon contact is determined by similarity in their histocompatibility complex. Among higher invertebrates fusion is genetically controlled and largely restricted to close kin (parent-offspring and sib-sib pairs).Two large collections of three-dimensionally preserved graptolites, etched out of Upper Ordovician limestones, contain three homosyndrome colonies. In each a sicula (B) fused with the distal portion of a somewhat more mature but still small rhabdosome (A). In the two Geniculograptus pygmaeus homosyndromes, B passes through the lateral wall of A, and is enveloped by its periderm, including a secondary cortical layer that is continuous across the suture between A and B. The interthecal septa of one A colony (which ordinarily attach to the nema) are instead inserted on B. The B colony of the Orthograptus quadrimucronatus homosyndrome is a mature sicula and immature first theca that incorporated the nema of A in its structure as it developed.Unlike previously reported homosyndromes, these graptolites were planktonic. This, the consistent age difference between A and B colonies, and fusion compatibility studies of other invertebrates together indicate that the B colonies were offspring of the A colony. The most likely scenario for their formation is that a mature larva, brooded within the central lumen of the parent colony, moved out along the colony's nema. There, rather than swimming off into the surrounding water as usual, the larva underwent metamorphosis within or near the open growing end of the parent colony. Subsequent growth of parent and offspring lead to fusion (see figure).In one of the G. pygmaeus homosyndromes the nema of A terminates against B at the level of the fourth thecal pair. The nema in this species ordinarily projects about 0.9 mm beyond the growing edge of the colony. If B in this homosyndrome represents a daughter larva that metamorphosed at the growing tip of the nema, then the parent colony must have begun sexual reproduction when it comprised no more than five zooids. Large colonies of G. pygmaeus commonly contain 30 to 50 zooids. Thus, sexual reproduction in this species may have commenced at a quite early age. Early onset of sexual reproduction, and the resultant high population growth rates, is consistent with sedimentological evidence that suggests both species typically occurred as ephemeral, monospecific swarms within relatively shallow water.Among modern colonial organisms these graptolites appear most similar ecologically to thaliacean tunicates. Both are planktonic, colonial organisms that exhibit low levels of zooid specialization. Both display a combination of depth and water mass specificity in their habitat preferences and frequently occur in swarms. Thus, it is likely that graptolites, like thaliaceans, were primarily opportunist suspension feeders, with high inherent population growth rates as an adaptation to tracking plankton blooms. The multiple macroevolutionary trends toward reduction in colony size and complexity, which pervade graptoloid macroevolution, accordingly become interpretable as a common response to selection for accelerated sexual reproduction and enhanced rate of population increase.

scholarly journals Safe Motherhood in South Asia: Current Status and Strategies for Change

1994 ◽  
Vol 33 (4II) ◽  
pp. 1123-1140
Author(s):  
Zeba A. Sathar ◽  
Bilquees Raza
Keyword(s):  
Population Growth ◽  
South Asia ◽  
Latin American ◽  
South Asian ◽  
Growth Rates ◽  
Contraceptive Use ◽  
Current Status ◽  
Asian Woman ◽  
Female Population ◽  
Population Growth Rates

Women in South Asia comprise close to one third of the world's female population. Not only is South Asia an extremely populous region but population growth rates have been much higher than averages for other developing countries. The implications of high population growth rates are quite direct and severe for women, as they are the result of high levels of fertility which have prevailed for some time in this region. The stable and high levels of fertility along with falling mortality have led to a youthful population structure where about 45 percent of the population is aged under 15. Since childbearing as well as childrearing are almost the sole responsibility of women, these figures reflect the burden of high fertility amongst South Asian women. An average South Asian woman marries at a fairly young age, (even though the region is exhibiting a distinct trend of rising age at marriage for females) and starts bearing children soon after. Though fertility rates have been declining in most of India and Bangladesh while they had already reached quite low levels in Sri Lanka, other countries of the region (mainly Nepal and Pakistan) have still to experience any dramatic declines in fertility. In contrast with trends in the Latin American and South East Asian region, increases in contraceptive use in South Asia have not played as substantive a role in fertility declines as changing marriage patterns, atleast so far. See Table 1 for recent figures on fertility and contraceptive use among females of this region.

Institutional Repositories in Swaziland: An Exploratory Study

Mousaion ◽  
2019 ◽  
Vol 36 (2) ◽  
Author(s):  
Ncamsile Nombulelo Dlamini ◽  
Maritha Snyman
Keyword(s):  
Open Access ◽  
Exploratory Study ◽  
Management Strategies ◽  
Current Status ◽  
Academic Institutions ◽  
African Countries ◽  
Institutional Repositories ◽  
Limited Knowledge ◽  
Advocacy Strategies ◽  
Awareness Level

The purpose of this paper is to assess the current status of institutional repositories (IRs) in Swaziland’s academic institutions. The factors under discussion are the number of IRs in Swaziland, their usage, the level of awareness of these IRs, and the challenges that prevent the implementation of IRs in Swaziland’s academic institutions. A webometric approach, interviews and semi-structured questionnaires completed by IR managers or librarians working for the Swaziland’s academic institutions were used to collect data for this study. Responses were received from 11 respondents. The findings indicated that there is one IR in Swaziland that is accessible to the institution’s community via the intranet. This IR was, at the time when this study took place, not registered in any of the international registries of repositories, such as the Registry of Open Access Repositories (ROAR) and the Directory of Open Access Repositories (OpenDOAR). Currently, this IR faces problems of insufficient content, a low level of IR awareness, limited knowledge of effective and appropriate IR advocacy strategies and limited knowledge of effective IR implementation and management strategies. Based on the findings and information gained from a literature review of IRs, the paper recommends strategies to academic institutions in Swaziland that may enable them to increase their number of IRs, the awareness level of IRs and consequently the use of IRs. The findings and recommendations may also benefit other African countries in similar situations.  

scholarly journals Current Status and Potential of RNA Interference for the Management of Tomato Spotted Wilt Virus and Thrips Vectors

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 320
Author(s):  
Alexander Nilon ◽  
Karl Robinson ◽  
Hanu R. Pappu ◽  
Neena Mitter
Keyword(s):  
Rna Interference ◽  
Tomato Spotted Wilt Virus ◽  
Cultural Practices ◽  
Management Strategies ◽  
Current Status ◽  
Horticultural Crops ◽  
Yield And Quality ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Tomato spotted wilt virus (TSWV) is the type member of the genus Orthotospovirus in the family Tospoviridae and order Bunyavirales. TSWV, transmitted by several species of thrips, causes significant disease losses to agronomic and horticultural crops worldwide, impacting both the yield and quality of the produce. Management strategies include growing virus-resistant cultivars, cultural practices, and managing thrips vectors through pesticide application. However, numerous studies have reported that TSWV isolates can overcome host-plant resistance, while thrips are developing resistance to pesticides that were once effective. RNA interference (RNAi) offers a means of host defence by using double-stranded (ds) RNA to initiate gene silencing against invading viruses. However, adoption of this approach requires production and use of transgenic plants and thus limits the practical application of RNAi against TSWV and other viruses. To fully utilize the potential of RNAi for virus management at the field level, new and novel approaches are needed. In this review, we summarize RNAi and highlight the potential of topical or exogenous application of RNAi triggers for managing TSWV and thrips vectors.

scholarly journals Estimates of regional annual abundance and population growth rates of white sharks off central California

2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Central California ◽  
Population Growth Rates
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