scholarly journals On the island biogeography of aliens: a global analysis of the richness of plant and bird species on oceanic islands

2016 ◽  
Vol 25 (7) ◽  
pp. 859-868 ◽  
Author(s):  
Tim M. Blackburn ◽  
Steven Delean ◽  
Petr Pyšek ◽  
Phillip Cassey ◽  
Richard Field

Author(s):  
Pei-Yu Tsai ◽  
Chie-Jen Ko ◽  
Ya-Jung Lu ◽  
Chia Hsieh ◽  
Mao-Ning Tuanmu

Altitudinal migration, the seasonal and repeateing movement of animal individuals between breeding and non-breeding areas at different elevations, is a common and important but understudied behavior in birds. Difficulty in characterizing avian altitudinal migration has prevented a comprehensive understanding of both patterns and drivers of this behavior. To fill this knowledge gap, we investigated altitudinal migration patterns and underlying mechanisms for a major proportion (~70%) of an entire resident bird community on a subtropical island with an almost 4000-m elevational gradient. We quantified migration tendency of individual bird species based on the seasonal shift in the elevational distribution of their occurrence records in the eBird database. We then built phylogeny-controlled regression models to examine the associations between the birds’ migration tendencies and their functional traits to test major hypotheses on the mechanisms of altitudinal migration. The results showed a common but variable altitudinal migration behavior among the 118 species examined, with 40 and 11 species conducting post-breeding downhill and uphill migration, respectively. The species that have a narrower thermal tolerance range, can tolerate lower temperatures, have a smaller body size, have a more diverse or invertebrate-rich diet, or use an open nest had a higher downhill migration tendency. In contrast, no traits examined showed consistent associations with the uphill migration tendency. This suggests that post-breeding downhill and uphill migrations are driven by different processes and current hypotheses can only explain the former, but not the latter. This relatively comprehensive study demonstrated the power of citizen science data to provide new insights into an old research question from a novel perspective. Using the same approach, we are investigating the behavior in mountain regions around the world. With the global analysis, we will be able to understand the general patterns and mechanisms of avian altitudinal migration and also investigate their variation among mountain regions in different climate zones. In the face of rapid environmental changes in mountain ecosystems, the approach used in this study may also provide essential information for the conservation of mountainous biodiversity.



2012 ◽  
Vol 40 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Robert A. D. Cameron ◽  
Kostas A. Triantis ◽  
Christine E. Parent ◽  
François Guilhaumon ◽  
María R. Alonso ◽  
...  


Oryx ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 278-286 ◽  
Author(s):  
Mariana Carvalho ◽  
Jorge M. Palmeirim ◽  
Francisco C. Rego ◽  
Nelson Sole ◽  
Aristides Santana ◽  
...  

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.



2016 ◽  
Author(s):  
Vanessa M. ZoBell ◽  
Brett J Furnas

Human expansion has negatively impacted biodiversity. Oceanic islands have some of the most diverse, endemic biodiversity. Endemism leads to vulnerability due to the isolated and discrete nature of oceanic islands. Birds are indicator species that adapt to change very quickly. By analyzing birds, we can investigate how changes in behavior and abundance may occur for different species in the future. Nine passerine bird species were studied with automated acoustic recording devices. Recording devices were places in agricultural, forest, and mixed habitats. Three invasive species preferred agriculture areas and low canopy cover, based on call frequency and detection probability. Native bird detectability was significantly lower than invasive bird detectability. Occupancy was above 0.8 for all species, except for the gray-green fruit dove that was >0.6. Native bird populations are at risk, based on their calling number and detection probability.



2015 ◽  
Author(s):  
Heather Zimbler-DeLorenzo ◽  
Bertram Zinner ◽  
Ronald J Scheibel ◽  
F. Stephen Dobson

Extinctions and threats of extinctions in avifaunas on oceanic islands appear to be influenced by several island characteristics and introduced mammalian predators. These predators may have caused a “filter effect”; low numbers of threatened avian species on some islands might be due to high rates of past extinctions. Using path analysis, we examined these factors and the influence of human population size (as an indicator of human activity) on the number of species extinctions and threatened bird species on islands. Human population size had substantial influences on the number of extinctions (standardized partial regression coefficient ρ = 0.315, N = 172, P = 0.0005) but not on the number of threatened species on oceanic islands (ρ = -0.061, P = 0.43), independent of the number of introductions of predator species. The number of extinctions on islands produced a significant filter effect (viz., had a negative impact; ρ = -0.186, P = 0.003) on the number of currently threatened species. The activities of human populations, including mammalian predators they introduced, have likely resulted in a greater number of bird extinctions on these islands, and producing a significant filter effect, wherein islands with larger human populations now have fewer threatened species.



The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Paul C Banko ◽  
Kelly A Jaenecke ◽  
Robert W Peck ◽  
Kevin W Brinck

Abstract In Hawaii and other oceanic islands with few native land mammals, black rats (Rattus rattus) are among the most damaging invasive vertebrate species to native forest bird populations and habitats, due to their arboreal behavior and generalist foraging habits and habitat use. We evaluated the nesting response of Hawaii Elepaio (Chasiempis sandwichensis; Monarchidae), a generalist insectivore, to the removal of black rats using rodenticide in a before-after-control-impact study in high- and low-elevation mesic montane habitat recovering from long-term damage from introduced ungulates and weeds. We monitored nesting success and rat abundance during 2015–2016 before applying rodenticide bait in 2017 to remove rats from two 700 × 700 m treatment plots that were paired with 2 nontreatment plots of the same size. Rat abundance was reduced by 90% during treatment, with combined variables treatment and elevation best explaining the change using GLM methods and AIC model selection. The daily survival rate (DSR) of nests (n = 191) was greater on treated plots after rodenticide application (mean ± SE = 0.980 ± 0.004 treatment; 0.964 ± 0.004 nontreatment), modeled nest success increased from 29% to 50%, and apparent nest success (number of successful nests per total nests) increased from 37% to 52%. The most informative model for predicting DSR included the effect of treatment. Predation by rats was documented at 3 of 16 nests using video surveillance, and we observed additional evidence of rat predation during in-person nest monitoring. Rats targeted adults on the nest and sometimes removed intact eggs, leaving little trace of their activity. Our results demonstrate that reducing rat predation can immediately improve the nesting success of even a common bird species in habitat with a long history of forest restoration. Sustained predator control may be critical to accelerating the recovery of native forest bird communities.



2018 ◽  
Vol 115 (37) ◽  
pp. 9270-9275 ◽  
Author(s):  
Dietmar Moser ◽  
Bernd Lenzner ◽  
Patrick Weigelt ◽  
Wayne Dawson ◽  
Holger Kreft ◽  
...  

One of the best-known general patterns in island biogeography is the species–isolation relationship (SIR), a decrease in the number of native species with increasing island isolation that is linked to lower rates of natural dispersal and colonization on remote oceanic islands. However, during recent centuries, the anthropogenic introduction of alien species has increasingly gained importance and altered the composition and richness of island species pools. We analyzed a large dataset for alien and native plants, ants, reptiles, mammals, and birds on 257 (sub) tropical islands, and showed that, except for birds, the number of naturalized alien species increases with isolation for all taxa, a pattern that is opposite to the negative SIR of native species. We argue that the reversal of the SIR for alien species is driven by an increase in island invasibility due to reduced diversity and increased ecological naiveté of native biota on the more remote islands.



2016 ◽  
Author(s):  
Vanessa M. ZoBell ◽  
Brett J Furnas

Human expansion has negatively impacted biodiversity. Oceanic islands have some of the most diverse, endemic biodiversity. Endemism leads to vulnerability due to the isolated and discrete nature of oceanic islands. Birds are indicator species that adapt to change very quickly. By analyzing birds, we can investigate how changes in behavior and abundance may occur for different species in the future. Nine passerine bird species were studied with automated acoustic recording devices. Recording devices were places in agricultural, forest, and mixed habitats. Three invasive species preferred agriculture areas and low canopy cover, based on call frequency and detection probability. Native bird detectability was significantly lower than invasive bird detectability. Occupancy was above 0.8 for all species, except for the gray-green fruit dove that was >0.6. Native bird populations are at risk, based on their calling number and detection probability.



2008 ◽  
Vol 17 (2) ◽  
pp. 246-251 ◽  
Author(s):  
Tim M. Blackburn ◽  
Phillip Cassey ◽  
Julie. L. Lockwood


2015 ◽  
Author(s):  
Heather Zimbler-DeLorenzo ◽  
Bertram Zinner ◽  
Ronald J Scheibel ◽  
F. Stephen Dobson

Extinctions and threats of extinctions in avifaunas on oceanic islands appear to be influenced by several island characteristics and introduced mammalian predators. These predators may have caused a “filter effect”; low numbers of threatened avian species on some islands might be due to high rates of past extinctions. Using path analysis, we examined these factors and the influence of human population size (as an indicator of human activity) on the number of species extinctions and threatened bird species on islands. Human population size had substantial influences on the number of extinctions (standardized partial regression coefficient ρ = 0.315, N = 172, P = 0.0005) but not on the number of threatened species on oceanic islands (ρ = -0.061, P = 0.43), independent of the number of introductions of predator species. The number of extinctions on islands produced a significant filter effect (viz., had a negative impact; ρ = -0.186, P = 0.003) on the number of currently threatened species. The activities of human populations, including mammalian predators they introduced, have likely resulted in a greater number of bird extinctions on these islands, and producing a significant filter effect, wherein islands with larger human populations now have fewer threatened species.



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