Site selection by parasitic helminths: interspecific interactions, site segregation, and their importance to the development of helminth communities

1973 ◽  
Vol 51 (3) ◽  
pp. 333-347 ◽  
Author(s):  
John C. Holmes
Keyword(s):  
Site Selection ◽  
Interspecific Interactions ◽  
Biotic Interactions ◽  
Site Specificity ◽  
Short Term ◽  
Parasitic Helminths ◽  
Niche Specialization ◽  
Helminth Communities ◽  
Niche Diversification

That parasites actively select specific sites in their hosts is well known. Some parasites respond to changing conditions within the host by making diel or other short-term migrations, which may be modified by the presence of other parasites.Evidence is presented to support the hypothesis that continued interactions between parasites lead to niche diversification, and that site segregation, and consequently narrow site specificity, is an important part of niche specialization. The paucity of cases of interactive site segregation as compared with those of genetically stabilized selective site segregation suggests that parasite faunas are mature communities, the diversity of which has been established to an important extent through biotic interactions.

Ecological succession as an aspect of structure in fossil communities

Paleobiology ◽  
1975 ◽  
Vol 1 (3) ◽  
pp. 238-257 ◽  
Author(s):  
Kenneth R. Walker ◽  
Leonard P. Alberstadt
Keyword(s):  
Environmental Changes ◽  
Food Chains ◽  
Short Term ◽  
Niche Specialization ◽  
Pattern Diversity ◽  
Physical Environments ◽  
Autogenic Succession ◽  
Succession Stage ◽  
Stratigraphic Sequences

Succession involves changes in a community through time, whether internally or externally controlled. As succession progresses, niche specialization, species diversity (variety and equitability), complexity of food chains, and pattern diversity increase; net production and species growth rate decrease. We apply the succession concept to three types of ancient community sequences: 1) fossil reefs (Ordovician—Cretaceous in age), 2) short-term successions occurring through thin stratigraphic intervals, and 3) long-term successions occurring through thicker stratigraphic intervals. Ancient reefs show four vertical zones: (1) a basal stabilization zone (autogenic), 2) the overlying colonization zone (autogenic, pioneer stage), 3) the diversification zone, the bulk of most reefs (diversification culminating in climax), and 4) the uppermost domination zone. The first three zones represent autogenic succession but the final stage may involve allogenic succession. Short-term succession usually occurs where periodic allogenic catastrophes wipe out the community which is rebuilt through autogenic succession. Opportunistic pioneer species are important and in our examples (Ordovician, Silurian, and Cretaceous) are species which pave soft substrata. Paleozoic strophomenid brachiopods filled this role, and inoceramid pelecypods served the function in the Mesozoic. The succession which begins with opportunists progresses to a climax community of equilibrists. Repetition of catastrophe-succession couplets produces a cyclic stratigraphic record. Long-term successions are recorded in thicker stratigraphic sequences, and are of two types: 1) autogenic succession in unchanging physical environments and 2) allogenic succession in changing physical environments. Our examples of these are from the Devonian Haragan-Bois D'Arc formations of Oklahoma and the Lime Creek Formation of Iowa. This type of succession represents a temporal-spatial mosaic. The Haragan data (unchanging environments) indicate characteristic, intergrading, and ubiquitous species in the brachiopod communities. Most ubiquitous species in the pioneer community were eurytopic opportunists. The Lime Creek data allows testing of the prediction that environmental changes cause regression to an earlier succession stage. The brachiopod communities after environmental changes have more ubiquitous and intergrading eurytopic species. These represent an earlier stage in the succession.

scholarly journals Behavioural Stress Propagation in Benthic Invertebrates Caused by Acute pH Drop-Induced Metabolites

2021 ◽  
Vol 8 ◽  
Author(s):  
Lauric Feugere ◽  
Lauren Angell ◽  
James Fagents ◽  
Rebecca Nightingale ◽  
Kirsty Rowland ◽  
...  
Keyword(s):  
Chemical Communication ◽  
Stress Responses ◽  
Benthic Invertebrates ◽  
Interspecific Interactions ◽  
Hermit Crabs ◽  
Sea Bream ◽  
Short Term ◽  
Marine Animals ◽  
Regular Control ◽  
Stress Metabolites

Studies on pH stress in marine animals typically focus on direct or species-specific aspects. We here test the hypothesis that a drop to pH = 7.6 indirectly affects the intra- and interspecific interactions of benthic invertebrates by means of chemical communication. We recorded fitness-relevant behaviours of small hermit crabs Diogenes pugilator, green shore crabs Carcinus maenas, and harbour ragworms Hediste diversicolor in response to short-term pH drop, and to putative stress metabolites released by conspecifics or gilt-head sea bream Sparus aurata during 30 min of acute pH drop. Not only did acute pH drop itself impair time to find a food cue in small hermit crabs and burrowing in harbour ragworms, but similar effects were observed under exposure to pH drop-induced stress metabolites. Stress metabolites from S. aurata, but not its regular control metabolites, also induced avoidance responses in all recipient species. Here, we confirm that a short-term abrupt pH drop, an abiotic stressor, has the capacity to trigger the release of metabolites which induce behavioural responses in conspecific and heterospecific individuals, which can be interpreted as a behavioural cost. Our findings that stress responses can be indirectly propagated through means of chemical communication warrant further research to confirm the effect size of the behavioural impairments caused by stress metabolites and to characterise their chemical nature.

Ecological Interactions and Macroevolution: A New Field with Old Roots

2020 ◽  
Vol 51 (1) ◽  
pp. 215-243 ◽  
Author(s):  
David H. Hembry ◽  
Marjorie G. Weber
Keyword(s):  
Species Interactions ◽  
Interspecific Interactions ◽  
Biotic Interactions ◽  
Evolutionary Change ◽  
Future Research ◽  
Ecological Interactions ◽  
Open Questions ◽  
Work Done ◽  
Lineage Diversification

Linking interspecific interactions (e.g., mutualism, competition, predation, parasitism) to macroevolution (evolutionary change on deep timescales) is a key goal in biology. The role of species interactions in shaping macroevolutionary trajectories has been studied for centuries and remains a cutting-edge topic of current research. However, despite its deep historical roots, classic and current approaches to this topic are highly diverse. Here, we combine historical and contemporary perspectives on the study of ecological interactions in macroevolution, synthesizing ideas across eras to build a zoomed-out picture of the big questions at the nexus of ecology and macroevolution. We discuss the trajectory of this important and challenging field, dividing research into work done before the 1970s, research between 1970 and 2005, and work done since 2005. We argue that in response to long-standing questions in paleobiology, evidence accumulated to date has demonstrated that biotic interactions (including mutualism) can influence lineage diversification and trait evolution over macroevolutionary timescales, and we outline major open questions for future research in the field.

scholarly journals On the temporally flexible structure of plant-pollinator interaction networks

2020 ◽  
Author(s):  
Paul J. CaraDonna ◽  
Nickolas M. Waser
Keyword(s):  
Temporal Variation ◽  
Network Structure ◽  
Species Interactions ◽  
Interspecific Interactions ◽  
Activity Period ◽  
Individual Species ◽  
Ecological Communities ◽  
Short Term ◽  
Temporal Flexibility ◽  
Plant Pollinator

AbstractEcological communities consist of species that are joined in complex networks of interspecific interaction. The interactions that networks depict often form and dissolve rapidly, but this temporal variation is not well integrated into our understanding of the causes and consequences of network structure. If interspecific interactions exhibit temporal flexibility across time periods over which organisms co-occur, then the emergent structure of the corresponding network may also be temporally flexible, something that a temporally-static perspective would miss. Here, we use an empirical system to examine short-term flexibility in network structure (connectance, nestedness, and specialization), and in individual species interactions that contribute to that structure. We investigated weekly plant-pollinator networks in a subalpine ecosystem across three summer growing seasons. To link the interactions of individual species to properties of their networks, we examined weekly temporal variation in species’ contributions to network structure. As a test of the potential robustness of networks to perturbation, we also simulated the random loss of species from weekly networks. We then compared the properties of weekly networks to the properties of cumulative networks that aggregate field observations over each full season. A week-to-week view reveals considerable flexibility in the interactions of individual species and their contributions to network structure. For example, species that would be considered relatively generalized across their entire activity period may be much more specialized at certain times, and at no point as generalized as the cumulative network may suggest. Furthermore, a week-to-week view reveals corresponding temporal flexibility in network structure and potential robustness throughout each summer growing season. We conclude that short-term flexibility in species interactions leads to short-term variation in network properties, and that a season-long, cumulative perspective may miss important aspects of the way in which species interact, with implications for understanding their ecology, evolution, and conservation.

scholarly journals Interspecific attraction between ground-nesting songbirds and ants: the role of nest-site selection

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marta Maziarz ◽  
Richard K. Broughton ◽  
Luca Pietro Casacci ◽  
Grzegorz Hebda ◽  
István Maák ◽  
...  
Keyword(s):  
Site Selection ◽  
Nest Site ◽  
Interspecific Interactions ◽  
Ecological Networks ◽  
Nest Site Selection ◽  
Ant Colonies ◽  
Interspecific Attraction ◽  
Bird Nest ◽  
Nest Site Choice ◽  
Ground Nesting

Abstract Background Interspecific interactions within ecological networks can influence animal fitness and behaviour, including nest-site selection of birds and ants. Previous studies revealed that nesting birds and ants may benefit from cohabitation, with interspecific attraction through their nest-site choice, but mutual interactions have not yet been tested. We explored a previously undescribed ecological link between ground-nesting birds and ants raising their own broods (larvae and pupae) within the birds’ nests in a temperate primeval forest of lowland Europe. We tested whether the occurrence of ant broods within bird nests resulted from a mutual or one-sided interspecific attraction that operated through nest-site choice and was modified by weather conditions. Results We found a non-random occupation of bird nests by ants raising their own broods within them, which indicated interspecific attraction driven solely by the ants. The birds’ preference to nest near tussocks of vegetation showed little overlap with the most frequent placement of ant colonies among fallen deciduous tree-leaves, dead wood and moss. Additionally, birds did not appear to select forest localities with high densities of ant colonies. The occurrence of ant broods within bird nests was also unrelated to bird nest placement near to specific habitat features. The attractiveness of bird nests to ants appeared to increase with the thermal activity of the birds warming their nests, and also during cool and wet weather when the occurrence of ant broods within bird nests was most frequent. Ants often remained in the nests after the birds had vacated them, with only a slight reduction in the probability of ant brood occurrence over time. Conclusions The natural patterns of bird nest colonisation by ants support the hypothesis of ants’ attraction to warm nests of birds to raise their broods under advantageous thermal conditions. Similar relationships may occur between other warm-blooded, nest-building vertebrates and nest-dwelling invertebrates, which depend on ambient temperatures. The findings advance our understanding of these poorly recognised interspecific interactions, and can inform future studies of ecological networks.

scholarly journals The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 683
Author(s):  
Dailos Hernández-Brito ◽  
Martina Carrete ◽  
Guillermo Blanco ◽  
Pedro Romero-Vidal ◽  
Juan Carlos Senar ◽  
...  
Keyword(s):  
Urban Areas ◽  
Native Species ◽  
Nest Site ◽  
Interspecific Interactions ◽  
Biotic Interactions ◽  
Monk Parakeet ◽  
Rural And Urban Areas ◽  
Positive Effects ◽  
Myiopsitta Monachus

While most of the knowledge on invasive species focuses on their impacts, little is known about their potential positive effects on other species. Invasive ecosystem engineers can disrupt recipient environments; however, they may also facilitate access to novel resources for native species. The monk parakeet (Myiopsitta monachus) is a worldwide invader and the only parrot that builds its own communal nests, which can be used by other species. However, the ecological effects of these interspecific interactions are barely known. We compared the role of the monk parakeet as a nest-site facilitator in different rural and urban areas, both invaded and native, across three continents and eight breeding seasons. A total of 2690 nests from 42 tenant species, mostly cavity-nesting birds, were recorded in 26% of 2595 monk parakeet nests. Rural and invaded areas showed the highest abundance and richness of tenant species. Multispecies communal nests triggered interspecific aggression between the monk parakeet host and its tenants, but also a cooperative defense against predators. Despite the positive effects for native species, monk parakeets also facilitate nesting opportunities to other non-native species and may also transmit diseases to tenants, highlighting the complexity of biotic interactions in biological invasions.

scholarly journals Ecology, Taxonomic Status, and Conservation of the South Georgian Diving Petrel (Pelecanoides georgicus) in New Zealand

2021 ◽  
Author(s):  
◽  
Johannes Fischer
Keyword(s):  
Invasive Species ◽  
New Zealand ◽  
Site Selection ◽  
Nest Site ◽  
Interspecific Interactions ◽  
Meta Analysis ◽  
Nest Site Selection ◽  
Phenotypic Differences ◽  
Conservation Actions ◽  
Diving Petrel

<p>Procellariiformes is a diverse order of seabirds under considerable pressure from onshore and offshore threats. New Zealand hosts a large and diverse community of Procellariiformes, but many species are at risk of extinction. In this thesis, I aim to provide an overview of threats and conservation actions of New Zealand’s Procellariiformes in general, and an assessment of the remaining terrestrial threats to the South Georgian Diving Petrel (Pelecanoides georgicus; SGDP), a Nationally Critical Procellariiform species restricted to Codfish Island (Whenua Hou), post invasive species eradication efforts in particular. I reviewed 145 references and assessed 14 current threats and 13 conservation actions of New Zealand’s Procellariiformes (n = 48) in a meta-analysis. I then assessed the terrestrial threats to the SGDP by analysing the influence of five physical, three competition, and three plant variables on nest-site selection using an information theoretic approach. Furthermore, I assessed the impacts of interspecific interactions at 20 SGDP burrows using remote cameras. Finally, to address species limits within the SGDP complex, I measured phenotypic differences (10 biometric and eight plumage characters) in 80 live birds and 53 study skins, as conservation prioritisation relies on accurate taxonomic classification. The results from the meta-analysis revealed that New Zealand’s Procellariiformes are at risk from various threats (x̅= 5.50 ± 0.34), but species also receive aid from several conservation actions (x̅= 7.19 ± 0.33). Results from a logistic regression showed that smaller species are more threatened onshore than offshore. The majority of the conservation actions appear in place where needed. However, habitat management, native predator control and the mitigation of risks associated with environmental stochasticity may need improvement. Analysis of SGDP nest-site selection showed dependency on mobile, steep, seaward-facing foredunes. Invasive plant species, the presence of conspecifics, or the presence of other seabird species did not influence SGDP nest-site selection. Assessment of interspecific interactions at SGDP burrows showed seven species occurring at burrows, but only Common Diving Petrels (P. urinatrix; CDP) interfered with SGDP breeding success. Assessment of phenotypic differences within the SGDP revealed that the New Zealand SGDP population differs in five biometric and three plumage characters from all other populations and warrants species status based on a species delimitation test with quantitative criteria. I propose to name this Critically Endangered species Pelecanoides taylorii sp. nov. These findings indicate that P. taylorii is of considerable conservation concern and additional measures, even after successful eradication of invasive species, may be required to safeguard this species. Based on the habitat preference, stochastic events, such as storms and storm surges, appear a major threat to P. taylorii. The assessed interspecific interactions at nest-sites, indicate competition with CDPs to be a minor threat. I propose a translocation as a potential strategy to relieve the pressure on P. taylorii, but further monitoring and research is needed to enable the implementation of such a conservation strategy.</p>

scholarly journals “We’re looking out through a window to a field of weeds and sand and stones”: The Stadium Broadcast, a Radio Memorial

2018 ◽  
Vol 22 (4) ◽  
pp. 357-368
Author(s):  
Zita Joyce
Keyword(s):  
New Zealand ◽  
Local People ◽  
Small Scale ◽  
Site Specificity ◽  
Short Term ◽  
Current State

This article explores the scope of small-scale radio to create an auditory geography of place. It focuses on the short-term art radio project The Stadium Broadcast, which was staged in November 2014 in an earthquake-damaged sports stadium in Christchurch, New Zealand. Thousands of buildings and homes in Christchurch have been demolished since the February 22, 2011, earthquake, and by the time of the broadcast the stadium at Lancaster Park had been unused for three years and nine months, and its future was uncertain. The Stadium Broadcast constructed a radio memorial to the Park’s 130-year history through archival recordings, the memories of local people, observation of its current state, and a performed site-specificity. The Stadium Broadcast reflected on the spatiality of radio sounds and transmissions, memory, postdisaster transitionality, and the impermanence of place.

scholarly journals Adaptation and latitudinal gradients in species interactions: nest predation in birds

2019 ◽  
Author(s):  
Benjamin G. Freeman ◽  
Micah N. Scholer ◽  
Mannfred M. A. Boehm ◽  
Julian Heavyside ◽  
Dolph Schluter
Keyword(s):  
Nest Predation ◽  
Species Interactions ◽  
Interspecific Interactions ◽  
Interaction Strength ◽  
Biotic Interactions ◽  
Western Hemisphere ◽  
Evolutionary Rates ◽  
Latitudinal Gradients ◽  
Biotic Interaction ◽  
The Tropics

AbstractThe “biotic interactions” hypothesis—that stronger interspecific interactions in the tropics drive faster evolution and speciation, giving rise to the latitudinal diversity gradient—has inspired many tests of whether certain biotic interactions are indeed stronger in the tropics. However, the possibility that populations have adapted to latitudinal differences in species interactions, blunting effects on evolutionary rates, has been largely ignored. Here we show that mean rates of nest predation experienced by land birds vary minimally with latitude in the Western Hemisphere. This result is surprising because nest predation in birds is a canonical example of a strong tropical biotic interaction. We explain our finding by demonstrating that (1) rates of nest predation are in fact higher in the tropics, but only when controlling for the length of the nesting period, (2) long nesting periods are associated with reduced predation rates, and (3) tropical birds have evolved particularly long nesting periods. We suggest this is a case example of how adaptation to a biotic interaction can alter observed latitudinal gradients in interaction strength, potentially equalizing evolutionary rates among latitudes. More broadly, we advocate for tests of the biotic interactions hypothesis to consider both latitudinal patterns in interaction strength and evolutionary responses to these interactions.

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