scholarly journals Habitat simplification affects nuclear-follower foraging association among stream fishes

2011 ◽  
Vol 9 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Fabrício Barreto Teresa ◽  
Renato de Mei Romero ◽  
Lilian Casatti ◽  
José Sabino
Keyword(s):  
Habitat Structure ◽  
Species Abundance ◽  
Stream Fishes ◽  
Prochilodus Lineatus ◽  
Assemblage Composition ◽  
Food Items ◽  
Nuclear Species ◽  
Habitat Simplification ◽  
Plateau Central ◽  
Foraging Associations

Nuclear-follower interaction is a particular kind of interspecific foraging association that includes a nuclear species, which dig in or inspect the bottom, and follower species, which access the food items made available by the nuclear. In this study we examined the effect of habitat structure on nuclear-follower relationship in a stream of Bodoquena Plateau, Central-West Brazil. Foraging associations were registered while snorkeling in 24 observation sessions, totaling six hours in unaltered and altered sites. Overall, 272 nuclear-follower associations were registered, having four species acting as nuclear and seven as followers. The dominant nuclear species were different in each site. Prochilodus lineatus was the main nuclear species in the altered site and Leporinus macrocephalus in the unaltered site. The richness of follower species was similar between sites, however, follower species abundance per interaction were significantly higher in the unaltered site than in the altered site. These differences seem to be a consequence of the alterations in assemblage composition and feeding behavior of the nuclear species that presumably are affected by different substrate composition and food availability between the structurally distinct areas.

scholarly journals Feeding association between benthic and nektonic Neotropical stream fishes

2008 ◽  
Vol 6 (1) ◽  
pp. 109-111 ◽  
Author(s):  
Fabrício Barreto Teresa ◽  
Fernando Rogério Carvalho
Keyword(s):  
Poecilia Reticulata ◽  
General Idea ◽  
Behavioural Plasticity ◽  
Sediment Suspension ◽  
Stream Fishes ◽  
Small Stream ◽  
Food Items ◽  
Nuclear Species ◽  
Neotropical Stream ◽  
Alternative Feeding

Following behaviour among Neotropical stream fishes have been scarcely reported. This type of feeding association was observed in a small stream in the upper rio Paraná system between the catfish, Aspidoras fuscoguttatus, acting as a nuclear species, and Knodus moenkhausii, Poecilia reticulata, and Astyanax altiparanae as follower species. Aspidoras fuscoguttatus individuals dug in the bottom during feeding, causing sediment suspension. Their followers picked food items in the "cloud" of suspended particles. Food items of sediment are no longer consumed by the catfish when in suspension, but are still available for K. moenkhausii, P. reticulata and A. altiparanae. Following behaviour is an alternative feeding tactic for these species, which reinforces the general idea of behavioural plasticity among follower species.

scholarly journals The contribution of environmental factors to fish assemblages in the Río Acahuapa, a small drainage in Central America

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Francisco S. Álvarez ◽  
Wilfredo A. Matamoros ◽  
Francisco A. Chicas
Keyword(s):  
Fish Species ◽  
Habitat Structure ◽  
Fish Assemblages ◽  
Species Abundance ◽  
Main Channel ◽  
Estuarine Fish ◽  
Species Origin ◽  
High Temperature Water ◽  
Distribution Of Fish ◽  
Temperature Water

ABSTRACT The ichthyofauna of the Río Acahuapa was analyzed sampling 17 sites that included the basin main channel and its tributaries. Fish were collected using dip-nets, seine-nets and electrofishing. Fish standard length and species abundance were recorded. Species origin and salinity tolerance criteria were used to classify fish species. Water physicochemical variables, habitat structure and sampling sites elevation were recorded. A total of 33 fish species were registered, 12.1% are primary, 45.5% are secondary and 42.4% are of marine derivation. Fish species richness declined with increase of elevation (R2=0.55, p=0.0006). Two assemblages of fishes were identified: the first one associated to sites of low elevations (19-184 masl), composed mainly of secondary and marine-estuarine fish species related with high temperature, water velocity, river width, dissolved oxygen and low sand and silt substrate cover; the second one associated to sites of middle and higher elevations (185-519 masl), composed by primary and secondary freshwater fishes related with high pH, logs and rocks substrate cover. In summary, elevation and environmental variables contributed to the composition and distribution of fish in the Río Acahuapa.

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 Bird mixed-flocks and nuclear species in a tecoma savanna in the Pantanal

2008 ◽  
Vol 68 (3) ◽  
pp. 511-518 ◽  
Author(s):  
PP. Amaral ◽  
J. Ragusa-Netto
Keyword(s):  
Species Abundance ◽  
Bird Species ◽  
Abundant Species ◽  
Direct Observations ◽  
Risk Of Predation ◽  
Nuclear Species ◽  
Contact Calls ◽  
Satellite Species ◽  
Mixed Flock ◽  
Respective Rate

In bird mixed flocks, a prominent species, the so-called nuclear species, improves the cohesion and maintenance of the flocks, while other less conspicuous species are assumed as satellite. In this study we described the composition, as well as examined the existence of both nuclear and satellite species in mixed flocks of a savanna in the Pantanal. The observations were developed using three transects during the dry season of 2002. Bird species abundance and respective rate of participation in mixed flocks were surveyed by transects, while intraspecific sociality, communication, foraging maneuvers of species, and responses to predators were sampled by direct observations. These parameters were evaluated to distinguish nuclear from satellite species. We observed 41 bird mixed flocks, which included from 2 to 17 species of which Suiriri suiriri (Vieillot), one of the most abundant species, was present in most flocks, often represented by 2-4 individuals, whereas most other species occurred lone or in pairs. While foraging by acrobatic maneuvers S. suiriri often gave contact calls, as well as earlier giving alarm calls if faced with a risk of predation. In addition, S. suiriri always started mixed flocks movements. Conversely, most other species were silent and closely inspected the vegetation while foraging. Such species always followed S. suiriri and seldom gave contact calls. Hence, the conspicuous traits exhibited by S. suiriri, potentially, are exploited by the other bird species as cues, which are important references for bird mixed flock cohesion in a savanna in the southern Pantanal.

Reef fish functional composition and metrics reveal spatial differences in three protected islands in the Eastern Pacific

2020 ◽  
Vol 635 ◽  
pp. 139-150
Author(s):  
D Morales-de-Anda ◽  
AL Cupul-Magaña ◽  
FA Rodríguez-Zaragoza ◽  
C Aguilar-Betancourt ◽  
G González-Sansón ◽  
...  
Keyword(s):  
Reef Fish ◽  
Habitat Structure ◽  
Fish Assemblages ◽  
Management Strategies ◽  
Species Abundance ◽  
Eastern Pacific ◽  
Ecosystem Functions ◽  
Spatial Differences ◽  
Coral Communities ◽  
Interesting System

Reef fish assemblages in the Eastern Pacific (EP) represent an interesting system to understand how areas with lower diversity respond to multiple factors and their effect on ecosystem functions and services. Among the multiple approaches that have emerged, the evaluation of functional metrics provides an initial comprehension of these relationships. In this context, to better understand reef fish variability in the EP, we evaluated spatial differences in ecological metrics, the composition of fish assemblages, and their relationship with habitat structure in coral communities at 3 islands in Mexico (Marietas, Isabel, and Cleofas). To include a functional approach, we created a functional entity (FE) matrix using species abundance and 6 categorical functional traits; specifically, we calculated ecological metrics that reflect the representation or under-representation of species in the functions or FEs (redundancy and vulnerability) and the rarity in FEs and species and their relationship with habitat structure. Overall, most of the fish FEs in the EP were represented by 1 species (i.e. high vulnerability and low functional redundancy). Despite the low redundancy recorded in the islands, reef fish performed multiple key functions; however, many functions remained rare. Furthermore, both metrics and fish composition showed high variability among sites and islands, but this variability was only partially explained by a few variables of habitat structure (i.e. rugosity). These results, in combination with the unique characteristics of coral communities in the EP, highlight the need to identify the drivers of fish assemblages and their effect on the ecosystem processes and services in order to implement unique management strategies for each island.

scholarly journals How selection structures species abundance distributions

2012 ◽  
Vol 279 (1743) ◽  
pp. 3722-3726 ◽  
Author(s):  
Anne E. Magurran ◽  
Peter A. Henderson
Keyword(s):  
Habitat Structure ◽  
Fish Community ◽  
Rank Order ◽  
Species Abundance ◽  
Estuarine Fish ◽  
Ecological Communities ◽  
Abundance Distribution ◽  
Species Abundance Distributions ◽  
Characteristic Species ◽  
Safety In Numbers

How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in large bodied species in guilds where habitat structure provides protection from predators, but not in those guilds associated with open habitats and where safety in numbers is a mechanism for reducing predation risk. We further demonstrate that while there is temporal turnover in the abundances and identities of species that comprise these guilds, guild rank order is conserved across our 30-year time series. These results demonstrate that ecological communities are not randomly assembled but can be decomposed into guilds where capacity is predictably allocated among species.

scholarly journals Development of habitat suitability criteria for Neotropical stream fishes and an assessment of their transferability to streams with different conservation status

2013 ◽  
Vol 11 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Fabrício Barreto Teresa ◽  
Lilian Casatti
Keyword(s):  
Fish Species ◽  
Habitat Suitability ◽  
Good Predictor ◽  
Conservation Status ◽  
Species Abundance ◽  
Southeastern Brazil ◽  
Stream Fishes ◽  
Opposite Pattern ◽  
Pattern Preference ◽  
Neotropical Stream

We assessed the preference of 10 fish species for depth and velocity conditions in forested streams from southeastern Brazil using habitat suitability criteria (HSC curves). We also tested whether preference patterns observed in forested streams can be transferred to deforested streams. We used data from fish sampled in 62 five-meter sites in three forested streams to construct preference curves. Astyanax altiparanae, A. fasciatus, Knodus moenkhausii, and Piabina argentea showed a preference for deep slow habitats, whereas Aspidoras fuscoguttatus, Characidium zebra, Cetopsorhamdia iheringi, Pseudopimelodus pulcher, and Hypostomus nigromaculatus showed an opposite pattern: preference for shallow fast habitats. Hypostomus ancistroides showed a multimodal pattern of preference for depth and velocity. To evaluate whether patterns observed in forested streams may be transferred to deforested streams, we sampled 64 five-meters sites in three deforested streams using the same methodology. The preference for velocity was more consistent than for depth, as success in the transferability criterion was 86% and 29% of species, respectively. This indicates that velocity is a good predictor of species abundance in streams, regardless of their condition

scholarly journals Landscape-related variation in the diet composition of the common buzzard (Buteo buteo) in Belarus

2016 ◽  
Vol 10 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Anna A. Sidorovich ◽  
Vladimir V. Ivanovskij ◽  
Vadim E. Sidorovich ◽  
Irina A. Solovej
Keyword(s):  
Habitat Structure ◽  
Diet Composition ◽  
Small Rodents ◽  
Forest Habitat ◽  
Predator Prey ◽  
Food Items ◽  
Common Buzzard ◽  
Buteo Buteo ◽  
The Common ◽  
Food Niche

Abstract We examined common buzzard (Buteo buteo) feeding patterns in landscapes with different habitat structure in Belarus. A total of 561 pellets and prey remains were sampled in 1998-2012 from which 1065 prey and other food items were identified. Effects of habitat structure on buzzard diet composition were investigated using correlation analysis. The most abundant group in buzzards’ diets were small rodents (49-80% of the biomass consumed), followed by other mammals and birds. Reptiles, anurans, fish and invertebrates constituted the rest. Proportions of all food items varied greatly between landscapes. The mean-weighted body mass of vertebrate prey hunted by common buzzards in different landscapes ranged from 107 to 244 g, constituting on average 180 g. Among small rodents, voles of the genus Microtus were hunted selectively. The food niche breadth was directly proportional to the amount of forest habitat. With increasing amount of forest habitat, the proportion of Microtus voles in buzzards’ diets decreased and the proportions of other food items grew. These findings confirm the majority of previous results indicating feeding opportunism of the common buzzard. Our investigation enables better understanding of predator-prey interactions and the prey choice of the common buzzard in Belarus.

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