Limits...
Niche partitioning and the role of intraspecific niche variation in structuring a guild of generalist anurans

View Article: PubMed Central - PubMed

ABSTRACT

Intra-population niche differences in generalist foragers have captured the interest of ecologists, because such individuality can have important ecological and evolutionary implications. Few researchers have investigated how these differences affect the relationships among ecologically similar, sympatric species. Using stable isotopes, stomach contents, morphology and habitat preference, we examined niche partitioning within a group of five anurans and determined whether variation within species could facilitate resource partitioning. Species partitioned their niches by trophic level and by foraging habitat. However, there was considerable intraspecific variation in trophic level, with larger individuals generally feeding at higher trophic levels. For species at intermediate trophic levels, smaller individuals overlapped in trophic level with individuals of smaller species and larger individuals overlapped with the smallest individuals from larger species. Species varied in carbon isotopes; species with enriched carbon isotope ratios foraged farther from ponds, whereas species with depleted carbon isotope values foraged closer to ponds. Our study shows that these species partition their niches by feeding at different trophic levels and foraging at different distances from ponds. The intraspecific variation in trophic level decreased the number of individuals from each species that overlapped in trophic level with individuals from other species, which can facilitate species coexistence.

No MeSH data available.


Related in: MedlinePlus

(a) SVL (mm) by species. Anaxyrus americanus and A. fowleri were the smallest species, followed by Lithobates sphenocephalus and L. clamitans. Lithobates catesbeianus was the largest species but also had the largest variance, with individuals falling within the body size range of all other species. (b) Distance to pond (m) by species. Both toad species are infrequently found near ponds and A. fowleri generally are found farther from ponds than A. americanus. Lithobates clamitans and L. catesbeianus have about an equal distance to pond, with both species frequently found within ponds (negative numbers). Lithobates sphenocephalus is found farther from ponds than the other two frog species but nearer ponds than both toad species.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5383860&req=5

RSOS170060F1: (a) SVL (mm) by species. Anaxyrus americanus and A. fowleri were the smallest species, followed by Lithobates sphenocephalus and L. clamitans. Lithobates catesbeianus was the largest species but also had the largest variance, with individuals falling within the body size range of all other species. (b) Distance to pond (m) by species. Both toad species are infrequently found near ponds and A. fowleri generally are found farther from ponds than A. americanus. Lithobates clamitans and L. catesbeianus have about an equal distance to pond, with both species frequently found within ponds (negative numbers). Lithobates sphenocephalus is found farther from ponds than the other two frog species but nearer ponds than both toad species.

Mentions: Species differed in SVL (ANOVA: figure 1a; F = 119.3, d.f. = 4,237, p < 0.001). Tukey's honest significant differences test showed that L. catesbeianus was longer than the other four species (p < 0.001 for all comparisons). In addition, L. clamitans was longer than L. sphenocephalus (p = 0.003), A. anaxyrus (p < 0.001) and A. fowleri (p < 0.001), and L. sphenocephalus was longer than the two toads (A. americanus: p = 0.053; and A. fowleri: p = 0.013).Figure 1.


Niche partitioning and the role of intraspecific niche variation in structuring a guild of generalist anurans
(a) SVL (mm) by species. Anaxyrus americanus and A. fowleri were the smallest species, followed by Lithobates sphenocephalus and L. clamitans. Lithobates catesbeianus was the largest species but also had the largest variance, with individuals falling within the body size range of all other species. (b) Distance to pond (m) by species. Both toad species are infrequently found near ponds and A. fowleri generally are found farther from ponds than A. americanus. Lithobates clamitans and L. catesbeianus have about an equal distance to pond, with both species frequently found within ponds (negative numbers). Lithobates sphenocephalus is found farther from ponds than the other two frog species but nearer ponds than both toad species.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383860&req=5

RSOS170060F1: (a) SVL (mm) by species. Anaxyrus americanus and A. fowleri were the smallest species, followed by Lithobates sphenocephalus and L. clamitans. Lithobates catesbeianus was the largest species but also had the largest variance, with individuals falling within the body size range of all other species. (b) Distance to pond (m) by species. Both toad species are infrequently found near ponds and A. fowleri generally are found farther from ponds than A. americanus. Lithobates clamitans and L. catesbeianus have about an equal distance to pond, with both species frequently found within ponds (negative numbers). Lithobates sphenocephalus is found farther from ponds than the other two frog species but nearer ponds than both toad species.
Mentions: Species differed in SVL (ANOVA: figure 1a; F = 119.3, d.f. = 4,237, p < 0.001). Tukey's honest significant differences test showed that L. catesbeianus was longer than the other four species (p < 0.001 for all comparisons). In addition, L. clamitans was longer than L. sphenocephalus (p = 0.003), A. anaxyrus (p < 0.001) and A. fowleri (p < 0.001), and L. sphenocephalus was longer than the two toads (A. americanus: p = 0.053; and A. fowleri: p = 0.013).Figure 1.

View Article: PubMed Central - PubMed

ABSTRACT

Intra-population niche differences in generalist foragers have captured the interest of ecologists, because such individuality can have important ecological and evolutionary implications. Few researchers have investigated how these differences affect the relationships among ecologically similar, sympatric species. Using stable isotopes, stomach contents, morphology and habitat preference, we examined niche partitioning within a group of five anurans and determined whether variation within species could facilitate resource partitioning. Species partitioned their niches by trophic level and by foraging habitat. However, there was considerable intraspecific variation in trophic level, with larger individuals generally feeding at higher trophic levels. For species at intermediate trophic levels, smaller individuals overlapped in trophic level with individuals of smaller species and larger individuals overlapped with the smallest individuals from larger species. Species varied in carbon isotopes; species with enriched carbon isotope ratios foraged farther from ponds, whereas species with depleted carbon isotope values foraged closer to ponds. Our study shows that these species partition their niches by feeding at different trophic levels and foraging at different distances from ponds. The intraspecific variation in trophic level decreased the number of individuals from each species that overlapped in trophic level with individuals from other species, which can facilitate species coexistence.

No MeSH data available.


Related in: MedlinePlus