Competition and invasive species impacts on native communities.

2020 ◽  
pp. 341-349
Author(s):  
Andrew M. Rogers ◽  
Salit Kark
Keyword(s):  
Invasive Species ◽  
Functional Traits ◽  
Bird Species ◽  
Interaction Frequency ◽  
Native Communities ◽  
Critical Resources

Abstract This chapter describes the competition for critical resources, the species interacting over the resource and the functional traits that influence interaction frequency and outcome between native and invasive bird species.

scholarly journals How many bird extinctions have we prevented?

Oryx ◽  
2006 ◽  
Vol 40 (3) ◽  
pp. 266-278 ◽  
Author(s):  
Stuart H.M. Butchart ◽  
Alison J. Stattersfield ◽  
Nigel J. Collar
Keyword(s):  
Invasive Species ◽  
Captive Breeding ◽  
Extinction Risk ◽  
Bird Species ◽  
Iucn Red List ◽  
Additional Species ◽  
Conservation Actions ◽  
Declining Populations ◽  
Population Sizes ◽  
Principal Actions

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.

scholarly journals The Occurence of Ecological Traps in Bird Populations: Is our Knowledge Sufficient? A Review

2012 ◽  
Vol 5 (3) ◽  
pp. 36-56 ◽  
Author(s):  
Petr Suvorov ◽  
Jana Svobodová
Keyword(s):  
Exotic Species ◽  
Species Conservation ◽  
Habitat Type ◽  
Bird Species ◽  
Ecological Trap ◽  
Native Communities ◽  
Bird Populations ◽  
Suburban Areas ◽  
Arable Fields ◽  
Insufficient Time

ABSTRACT Anthropogenic changes in a landscape create new cues for birds, which must permanently adapt to these. If landscape changes occur too quickly, individuals have insufficient time to develop adequate reactions. They may, therefore, preferentially nest in low-quality habitats, which can lead to diminished nesting success and to reduction of their population size. This is usually termed the ecological trap hypothesis. We reviewed 38 studies investigating this phenomenon and analysed whether relationships exist between ecological trap occurrence and geographical region, habitat type, and/or life strategies of bird species. Ecological traps were most often associated with the presence of exotic species. Exotic species can modify environmental conditions in ways to which native communities are not adapted. They have been mainly detected in open habitats. Such open habitats as arable fields and meadows are under greater human pressure, and rapid changes probably occur there more frequently. Although more studies from North America were investigated, the hypothesis was supported more frequently in European studies. This is possibly due to higher human population density and, hence, more frequent habitat changes. Our results show that an ecological trap is not likely associated with migration. Ground nests suffered fewer consequences of such traps than did other nest types. Although the implications of the ecological trap hypothesis in species conservation are undisputable, a more detailed approach is still needed. For instance, some habitat types, such as suburban areas, have been neglected in the context of ecological traps, as has been the phenomenon’s appearance in pristine habitats.

scholarly journals Managing alien bird species: Time to move beyond “100 of the worst” lists?

2015 ◽  
Vol 26 (2) ◽  
pp. 154-163 ◽  
Author(s):  
SABRINA KUMSCHICK ◽  
TIM M. BLACKBURN ◽  
DAVID M. RICHARDSON
Keyword(s):  
Invasive Species ◽  
Alien Species ◽  
Expert Opinion ◽  
Bird Species ◽  
Alien Invasive Species ◽  
Common Myna ◽  
Acridotheres Tristis ◽  
Pycnonotus Cafer ◽  
Selection Of Species ◽  
The Impact

SummaryAlien species can cause severe impacts in their introduced ranges and management is challenging due to the large number of such species and the diverse nature and context of their impacts. Lists of the most harmful species, like the “100 of the World’s Worst” list collated by the Invasive Species Specialist Group of the International Union for Conservation of Nature (IUCN) or the “100 of the Worst” invaders in Europe collated by the Delivering Alien Invasive Species Inventories in Europe (DAISIE) project, raise awareness about these impacts among the public, and can guide management decisions. Such lists are mainly based on expert opinion, but in recent years a more objective comparison of impacts has become possible, even between highly diverse taxa. In this study, we use a semi-quantitative generic impact scoring system to assess impacts of the three birds listed among the “100 of the World’s Worst” IUCN list (IUCN100) and the four birds on the list of “100 of the Worst” European invaders by DAISIE (DAISIE100) and to compare their impacts with those of other alien birds not present on the respective lists. We found that generally, both lists include some of the species with the highest impacts in the respective regions (global or Europe), and these species therefore deserve the dubious honour of being listed among the “worst”. However, there are broad overlaps between some species with regards to the impact mechanisms and the related issues of invasions, especially those of the Common Myna Acridotheres tristis and Red-vented Bulbul Pycnonotus cafer on the IUCN100, are very similar which might not warrant listing both species. To make the selection of species on such lists more transparent we suggest moving beyond lists based on expert opinion to a more transparent and defendable system for listing alien species based on published records of their impacts and related mechanisms.

scholarly journals What motivates hunters to target exotic or endemic species on the island of São Tomé, Gulf of Guinea?

Oryx ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 278-286 ◽  
Author(s):  
Mariana Carvalho ◽  
Jorge M. Palmeirim ◽  
Francisco C. Rego ◽  
Nelson Sole ◽  
Aristides Santana ◽  
...  
Keyword(s):  
Invasive Species ◽  
Urban Areas ◽  
Bird Species ◽  
Oceanic Islands ◽  
Structured Interviews ◽  
Local Fauna ◽  
Rural Workers ◽  
Final Destination ◽  
Local Livelihoods ◽  
Endemic Birds

AbstractHunting and invasive species are amongst the main causes of species extinctions on oceanic islands. On the island of São Tomé hunting of introduced mammals (monkeys, civets and pigs) and endemic bird species has contrasting effects in terms of conservation. Hunting of introduced mammals may benefit native fauna and flora but pressure on endemic birds poses a threat to some species. We conducted semi-structured interviews with 119 hunters to assess the relative importance of native and introduced prey species, gathering information on personal profiles, preference and practice, and hunters’ perceptions of trends in prey populations. Eleven species were hunted, including five invasive mammals and five endemic birds of high conservation importance. Based on species hunted, techniques used and final destination of the quarry we distinguished three groups of hunters, using cluster analyses: bird, monkey and feral-pig hunters. Bird hunters were all from urban areas but most pig hunters were rural. Monkey hunters were mostly rural workers but a small proportion were from urban areas. Bird and monkey hunters were primarily motivated by commercial gains but they also hunted for enjoyment and food. In general, hunting of mammals is an opportunistic activity that, if regulated, can be sustainable and contribute to mitigating the effects of invasive species on local fauna as well contributing to local livelihoods. Given the economic drivers involved in hunting of birds, intervention to reduce or eliminate this form of hunting will require enforcement of legislation and raising awareness of the issues involved.

scholarly journals Atlantic forest bird communities provide different but not fewer functions after habitat loss

2015 ◽  
Vol 282 (1811) ◽  
pp. 20142844 ◽  
Author(s):  
Greet De Coster ◽  
Cristina Banks-Leite ◽  
Jean Paul Metzger
Keyword(s):  
Functional Diversity ◽  
Atlantic Forest ◽  
Functional Traits ◽  
Habitat Loss ◽  
Species Turnover ◽  
Bird Species ◽  
Ecological Groups ◽  
Negative Effects ◽  
Functional Integrity ◽  
New Community

Habitat loss often reduces the number of species as well as functional diversity. Dramatic effects to species composition have also been shown, but changes to functional composition have so far been poorly documented, partly owing to a lack of appropriate indices. We here develop three new community indices (i.e. functional integrity, community integrity of ecological groups and community specialization ) to investigate how habitat loss affects the diversity and composition of functional traits and species. We used data from more than 5000 individuals of 137 bird species captured in 57 sites in the Brazilian Atlantic Forest, a highly endangered biodiversity hotspot. Results indicate that habitat loss leads to a decrease in functional integrity while measures of functional diversity remain unchanged or are even positively affected. Changes to functional integrity were caused by (i) a decrease in the provisioning of some functions, and an increase in others; (ii) strong within-guild species turnover; and (iii) a replacement of specialists by generalists. Hence, communities from more deforested sites seem to provide different but not fewer functions. We show the importance of investigating changes to both diversity and composition of functional traits and species, as the effects of habitat loss on ecosystem functioning may be more complex than previously thought. Crucially, when only functional diversity is assessed, important changes to ecological functions may remain undetected and negative effects of habitat loss underestimated, thereby imperiling the application of effective conservation actions.

Alien invasive species at the Romanian Black Sea coast - Present and perspectives

2010 ◽  
Vol 53 (1) ◽  
pp. 443-467 ◽  
Author(s):  
Marius Skolka ◽  
Cristina Preda
Keyword(s):  
Invasive Species ◽  
Alien Species ◽  
Black Sea ◽  
Alien Invasive Species ◽  
Aquatic Animal ◽  
Freshwater Species ◽  
Field Observations ◽  
Native Communities ◽  
Black Sea Coast ◽  
Sea Coast

Alien invasive species at the Romanian Black Sea coast - Present and perspectives Using literature data and personal field observations we present an overview of aquatic animal alien invasive species at the Romanian Black Sea coast, including freshwater species encountered in this area. We discuss records, pathways of introduction, origin and impact on native communities for some of these alien invasive species. In perspective, we draw attention on the potential of other alien species to become invasive in the study area.

scholarly journals Effect of Flood Pulse on the Functional Diversity and Traits Composition of Birds With Different Degrees of Wetland Dependence in the Brazilian Pantanal

2021 ◽  
Author(s):  
Angélica Vilas Boas da Frota ◽  
Breno Dias Vitorino ◽  
Sara Miranda Almeida ◽  
Josué Ribeiro da Silva Nunes ◽  
Carolina Joana Da Silva
Keyword(s):  
Species Richness ◽  
Functional Diversity ◽  
Functional Traits ◽  
Hydrological Cycle ◽  
Bird Species ◽  
Hydrological Regime ◽  
Functional Trait ◽  
Flood Pulse ◽  
Wetland Birds ◽  
Paraguay River

Abstract Hydrological dynamics of the Pantanal wetland drive the availability of resources and niche for aquatic and terrestrial fauna. We consider that changes in the hydrological regime of this floodplain can affect species richness, abundance and functional structure of waterbirds, wetland birds and non-wetland birds. Our study aimed to assess whether the degree of wetland dependence influences the response of bird groups to the flood pulse. We conducted the bird survey in the Paraguay River floodplain system, in five sampling sites, covering the periods of drought, flooding, full flood and ebb of the 2017–2018 hydrological cycle. Species richness and abundance were higher for non-wetland birds than waterbirds and wetland birds. On the other hand, we found that the higher the degree of wetland dependence by birds, the higher the differences in the functional-trait values. Species richness, abundance and all metrics of functional diversity varied significantly when there was an interaction between the degree of wetland dependence and the hydrological period. In all hydrological periods, bird groups occupied distinct niches. Traits such as foraging around or below the water surface were among the dominant functional traits in all hydrological periods. We emphasize the need to consider the functional traits of species in ecological studies of wetlands since measuring only species richness may not reflect the characteristics inherent to this type of ecosystem. In addition, the conservation of wetlands directly implies the maintenance of various niches throughout the hydrological periods, either for dependent or non-dependent bird species in wetlands.

Invasive species differ in key functional traits from native and non‐invasive alien plant species

2019 ◽  
Vol 30 (5) ◽  
pp. 994-1006 ◽  
Author(s):  
Rabia Mathakutha ◽  
Christien Steyn ◽  
Peter C. le Roux ◽  
Izak J. Blom ◽  
Steven L. Chown ◽  
...  
Keyword(s):  
Invasive Species ◽  
Plant Species ◽  
Functional Traits ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
Non Invasive
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