scholarly journals Invasive ants disrupt frugivory by endemic island birds

2009 ◽  
Vol 6 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Naomi E. Davis ◽  
Dennis J. O'Dowd ◽  
Ralph Mac Nally ◽  
Peter T. Green
Keyword(s):  
Habitat Structure ◽  
Bird Species ◽  
High Density ◽  
Scale Insects ◽  
Invasive Ants ◽  
Invasive Ant ◽  
Christmas Island ◽  
Endemic Birds ◽  
Plant Associations ◽  
Avian Frugivore

Biological invasions can alter direct and indirect interactions between species, generating far-reaching changes in ecological networks that affect key ecological functions. We used model and real fruit assays to show that the invasion and formation of high-density supercolonies by the yellow crazy ant (YCA), Anoplolepis gracilipes , disrupt frugivory by endemic birds on Christmas Island, Indian Ocean. The overall handling rates of model fruits by birds were 2.2–2.4-fold lower in ant-invaded than in uninvaded rainforest, and pecking rates by two bird species declined by 2.6- and 4.5-fold, respectively. YCAs directly interfered with frugivory; their experimental exclusion from fruiting displays increased fruit handling threefold to sixfold, compounding indirect effects of ant invasion on resources and habitat structure that influence bird abundances and behaviours. This invasive ant, whose high densities are sustained through mutualism with introduced scale insects, rapidly decreases fruit handling by endemic island birds and may erode a key ecological function, seed dispersal. Because most other invasive ant species form expansive, high-density supercolonies that depend in part on association with hemipteran mutualists, the effects that we report here on avian frugivore–plant associations may emerge across their introduced ranges.

The Effects of Invasive Ants on the Nesting Success of Tristram's Storm-petrel, Oceanodroma tristrami, on Laysan Island, Hawaiian Islands National Wildlife Refuge

2008 ◽  
Vol 14 (1) ◽  
pp. 13 ◽  
Author(s):  
Gregory T. W. McClelland ◽  
Ian L. Jones
Keyword(s):  
Breeding Success ◽  
Hawaiian Islands ◽  
Bird Species ◽  
Invasive Ants ◽  
Breeding Bird ◽  
Nest Sites ◽  
Close Proximity ◽  
Tramp Ant ◽  
Nest Type ◽  
Storm Petrel

The possible impact of invasive ants on the avifauna of the Northwest Hawaiian Islands was investigated by studying the breeding success of Tristram's Storm-petrel Oceanodroma tristrami on Laysan Island. The tramp ant Monomorium pharaonis (L.) was found to be abundant in storm-petrel nesting areas on Laysan Island. There were 380 observations made on incubating adults and 798 observations for chicks, for a total of 1178 observations from 116 storm-petrel nest sites. No ant harassment events involving incubating adult storm-petrels were recorded. Thirteen instances of more than 5 ants on Tristram's Storm-petrel chicks were recorded. One harassment event was recorded, involving approximately 200 ants. The chick left the nest site immediately following the event, did not return, and presumably died. The number of nest failures attributed to M. pharaonis was 1% (n = 116). There was a significant relationship between nest type and ant interactions (G = 24.45, p = <0.0001, n =55), with incidents only recorded from birds nesting under vegetation. It was hypothesized that the ant interactions recorded in this study were a result of Tristram's Storm-petrel chicks being in close proximity to M. pharaonis nests rather than direct predation. Thus no evidence was found of a severe impact of invasive ants on the breeding success of storm-petrels at Laysan Island. Despite no direct ant impact particular attention should be given to the interactions between M. pharaonis and bird species reliant on vegetation for nesting cover, and studies therefore should include additional breeding bird species.

An invasive ant distribution database to support biosecurity risk analysis in the Pacific

2017 ◽  
Vol 23 (3) ◽  
pp. 258 ◽  
Author(s):  
Monica A. M. Gruber ◽  
Meghan Cooling ◽  
Allan R. Burne
Keyword(s):  
Invasive Species ◽  
Risk Analysis ◽  
Native Species ◽  
Small Island ◽  
Accurate Information ◽  
Analysis Tool ◽  
Invasive Ants ◽  
Invasive Ant ◽  
Conflicting Information ◽  
The Pacific

Invasive species are one of the most serious threats to biodiversity. Up-to-date and accurate information on the distribution of invasive species is an important biosecurity risk analysis tool. Several databases are available to determine the distributions of invasive and native species. However, keeping this information current is a real challenge. Ants are among the most widespread invasive species. Five species of ants are listed in the IUCN list of damaging invasive species, and many other species are also invasive in the Pacific. We sought to determine and update the distribution information for the 18 most problematic invasive ant species in the Pacific to assist Small Island Developing States with risk analysis. We compared the information on six public databases, conducted a literature review, and contacted experts on invasive ants in the Pacific region to resolve conflicting information. While most public records were accurate we found some new records had not yet been incorporated in the public databases, and some information was inaccurate. The maintenance of public databases faces an enormous challenge in balancing completeness (~15 000 ant species in this case) with accuracy (the impossibility of constantly surveying) and utility.

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.

Ant-tended scale insects (Hemiptera: Coccidae: Myzolecanium) within lowland rain forest trees in Papua New Guinea

1993 ◽  
Vol 9 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Penny J. Gullan ◽  
Ralf C. Buckley ◽  
Philip S. Ward
Keyword(s):  
Papua New Guinea ◽  
Rain Forest ◽  
Host Plants ◽  
New Guinea ◽  
Scale Insects ◽  
Forest Trees ◽  
Lowland Rain Forest ◽  
Plant Associations ◽  
Host Trees

ABSTRACTEight species of Myzolecanium Beccari (Hemiptera: Homoptera: Coccoidea: Coccidae) are reported from ant nests in stem cavities of living lowland rain forest trees in Papua New Guinea. The coccids are confined to this microhabitat but are associated with a taxonomically broad range of ants and host trees. Attendant ants belonged to six species in three genera and two subfamilies: Anonychomyrma Donisthorpe (Dolichoderinae), Crematogaster Lund (Myrmicinae) and Podomyrma F. Smith (Myrmicinae). Host plants belonged to at least five families and included both apparently specialized (with domatia) and unspecialized species. Saplings containing the nests of Anonychomyrma scrutator (F. Smith), Anonychomyrma sp. 1 and Podomyrma laevifrons F. Smith were dissected and the structure of nest chambers and their contents recorded. Only some chambers had entrance holes, but many were interconnected by transverse passages. The coccids were in low numbers and fairly evenly distributed between ant-occupied chambers. The characteristics of the Myzolecanium-ant association, the role of the coccids as trophobionts, and the nature of the plant associations are discussed. Taxonomically, new combinations are proposed by P. J. Gullan for three species previously placed in Cryptostigma Ferris: Myzolecanium endoeucalyptus (Qin & Gullan), M. magnetinsulae (Qin & Gullan), and M. robertsi (Williams & Watson).

scholarly journals Vulnerability of Elevation-Restricted Endemic Birds of the Cordillera de Talamanca (Costa Rica and Panama) to Climate Change

2020 ◽  
Author(s):  
Zhen Liu ◽  
Luis Sandoval ◽  
Lauren Sherman ◽  
Andrew Wilson
Keyword(s):  
Climate Change ◽  
Costa Rica ◽  
Protected Areas ◽  
Bird Species ◽  
Population Monitoring ◽  
Climate Change Scenarios ◽  
Tropical Mountains ◽  
Endemic Birds ◽  
Community Science ◽  
Cordillera De Talamanca

ABSTRACTAnimals endemic to tropical mountains are known to be especially vulnerable to climate change. The Cordillera de Talamanca (Costa Rica and Panama) is a geographically isolated mountain chain and global biodiversity hotspot, home to more than 50 endemic bird species. We used eBird community science observations to predict the distributions of a suite of 48 of these endemic birds in 2006-2015, and in 2070, under four climate change scenarios. Species distributions were predicted using program Maxent, incorporating elevation, satellite derived habitat data, and WorldClim climate variables. Model fit, as assessed by Area under the Receiver Operator Curve (AUC) was very high for most species, ranging from 0.877 to 0.992 (mean of 0.94). We found that most species are predicted to undergo range contractions by 2070, with a mean of 15% under modest climate change (RCP 2.6) up to a mean of 40% under more severe climate change (RCP 8.5). Most of the current ranges of these species are within existing protected areas (average of 59% in 2006-2015), and with prospective range contractions, the importance of these protected areas is forecast to increase. We suggest that these predicted range declines should elevate conservation concerns for this suite of species, and vigilance, in the form of better population monitoring, is urgently needed.

Density Trends and Range Boundary Constraints of Forest Birds Along a Latitudinal Gradient

The Auk ◽  
1986 ◽  
Vol 103 (4) ◽  
pp. 791-803 ◽  
Author(s):  
John T. Emlen ◽  
Michael J. DeJong ◽  
Michael John Jaeger ◽  
Timothy C. Moermond ◽  
Kurt A. Rusterholz ◽  
...  
Keyword(s):  
Habitat Structure ◽  
Deciduous Forest ◽  
Climatic Factors ◽  
Environmental Gradients ◽  
Species Abundance ◽  
Bird Species ◽  
Population Data ◽  
Day Length ◽  
Latitudinal Gradients ◽  
Habitat Factors

Abstract We plotted the density distributions of 41 land-bird species along a 1,200-km transect spanning 7°28′ (865 km) of latitude through relatively uniform bottomland deciduous forest in middle North America. Standardized counts and observations at 12 survey stations, closely matched in habitat structure and widely distributed along the route, provided population data for all species and indices of total avian foraging pressure (consuming biomass) on each of six major foraging substrates. Density curves for species fluctuated considerably from station to station but tended to be level across range centers and slope peripherally to north and south boundaries at rates of 3-30% per degree of latitude. Substrate foraging pressures declined northward on the aerial and midfoliage substrates and southward on the low-foliage substrate. Summed community densities showed no significant latitudinal trends. We used the distinctive distribution patterns of climate (smooth latitudinal gradients), habitat structure (irregular mosaics of vegetation patches), and competition (reciprocally sloping density gradients) to identify and evaluate the role of these three constraints along the transect. Progressive latitudinal trends in species abundance thus were attributed to climatic factors, irregular station-to-station fluctuations to habitat factors, and inversely sloping density trends in paired profiles to competition. On this basis all species apparently responded to both climatic and habitat factors, and about half of the species showed suggestions of competition. In a correlation analysis across the 12 stations, latitude per se most closely matched density distribution in 12 species, one or another of the habitat parameters in 25 species. We proposed that season length (days available for breeding activity) was the principal constraining attribute of latitude at northern range boundaries, day length (hours available for feeding and provisioning young) at southern boundaries. Boundaries have been essentially stable during the past 50-100 yr in most species, but the northern boundary expanded northward in one species following human-induced habitat enhancement, and temporarily receded southward in another following a winter of severe stress. We attribute this general stability of range boundaries over time to within-population gene flow and the associated peripherally declining mean fitness of phenotypes adapted to central range conditions along radially diverging environmental gradients. We suggest that two boundary lines should be recognized for each species, an inner functional boundary at the line where birth rates drop below death rates, and an outer empirical boundary at the limit of recorded occurrences.

scholarly journals Kelimpahan dan Keanekaragaman Jenis Burung di Enclave Lindu Taman Nasional Lore Lindu

2014 ◽  
Vol 18 (2) ◽  
Author(s):  
Heru Setiawan
Keyword(s):  
National Park ◽  
Diversity Index ◽  
Bird Species ◽  
Bird Diversity ◽  
Point Index ◽  
Endemic Birds ◽  
Bird Watching ◽  
High Level ◽  
Index Of Abundance ◽  
Lore Lindu National Park

AbstractLindu Enclave area is an area that cannot be separated from the Lore Lindu National Park (TNLL) because it is situated in the TNLL area. Lore Lindu National Park is located in the Wallacea area with high level diversity especially for the bird diversity. The existence of TNLL has an important role as habitat for 80% of Sulawesi endemic birds. This study aimed to determine the diversity of birds in the Lindu Enclave. Data was collected using PIA (Point Index of Abundance) method with 14 observation points which were scattered in two villages: Tomado Village and Anca Village. The results of bird watching analysis showed that as many as 51 species of birds from 25 families were found in the Lindu Enclave. Out of 51 birds, there were 14 species categorized in the protected birds and 15 species were endemic birds. Out of 15 species endemic bird, 4 species were categorized in the protected bird species. The most common bird species was intermediate egret (Egretta intermedia), as many as 86 individuals. Bird diversity index in Lindu Enclave area was 3.23 that categorized on the high diversity level.Keywords: Lindu Enclave, biophysical, bird diversity, Lore Lindu National ParkAbstrakKawasan Enclave Lindu merupakan daerah yang tidak dapat dipisahkan dari Taman Nasional Lore Lindu (TNLL) karena letaknya yang berada di dalam kawasan TNLL. Taman Nasional Lore Lindu berada dalam kawasan Wallacea dengan tingkat keanekaragaman hayati yang tinggi khususnya jenis burung. Keberadaan TNLL mempunyai peranan yang penting sebagai habitat burung karena 80% burung endemik Sulawesi terdapat di kawasan  ini. Penelitian ini bertujuan mengetahui keanekaragaman jenis burung di kawasan Enclave Lindu. Pengambilan data menggunakan metode IPA (Indeks Point of Abundance) dengan 14 titik pengamatan yang tersebar di dua desa yaitu Desa Tomado dan Desa Anca. Hasil penelitian menunjukkan sebanyak 51 jenis burung dari 25 famili berhasil ditemukan di kawasan Enclave Lindu. Dari 51 jenis burung tersebut, terdapat 14 jenis yang termasuk dalam jenis burung dilindungi dan 15 jenis burung endemik. Dari 15 jenis burung endemik tersebut terdapat 4 jenis burung yang termasuk dalam jenis burung yang dilindungi. Jenis burung yang paling umum ditemukan adalah Kuntul perak (Egretta intermedia), sebanyak 86 individu. Indeks keanekaragaman jenis burung di kawasan Enclave Lindu adalah 3,23 dengan tingkat keanekaragaman yang tergolong tinggi.Kata kunci: Enclave Lindu, biofisik, keanekaragaman burung, Taman Nasional Lore Lindu

scholarly journals Invasive ants reduce abundance of small rainforest skinks

2022 ◽  
Author(s):  
Lori Lach ◽  
Dylan Case ◽  
Peter Yeeles ◽  
Conrad J. Hoskin
Keyword(s):  
Invasive Species ◽  
Prey Abundance ◽  
Unintended Effects ◽  
Invasive Ants ◽  
Invasive Ant ◽  
Main Method ◽  
Invertebrate Prey ◽  
Lower Abundance ◽  
The Tropics ◽  
Direct Threat

AbstractInvasive ants are among the world’s most damaging invasive species, often directly or indirectly affecting native fauna. Insecticidal baits are the main method for suppressing or eradicating invasive ant populations, but their use must be considered against potential for unintended effects on native organisms. The invasive yellow crazy ant (Anoplolepis gracillipes) is widespread in the tropics, particularly on islands, where they have displaced a range of invertebrates. Effects of this ant on vertebrates, and in continental ecosystems generally, are less studied. We investigated the effects of yellow crazy ants and bait application on rainforest skinks and their invertebrate prey. We compared skink and skink prey abundance across four replicated rainforest site categories: high and low yellow crazy ant sites had both been baited but differed in yellow crazy ant activity; control sites had never had yellow crazy ants or been baited; and buffer sites had never had yellow crazy ants but had been baited. We recorded significantly lower abundance of two small skink species (Lygisaurus laevis and Saproscincus tetradactylus) in high yellow crazy ant sites compared to all other site categories. The differences persisted even after baiting reduced yellow crazy ant activity by 97.8% ± 0.04% (mean ± SD). A larger rainforest skink species (Carlia rubrigularis) was not negatively affected by yellow crazy ant invasion. Skink prey abundance was significantly lower in high yellow crazy ant sites compared to control sites and low yellow crazy ant sites, but not compared to buffer sites. These differences did not persist following baiting. We found no evidence that baiting negatively affects skinks or their invertebrate prey. Our data suggest that yellow crazy ants, but not the bait used to treat them, pose a direct threat to small rainforest skinks.

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