Ontogenetic diet shift in Commerson’s dolphin (Cephalorhynchus commersonii commersonii) off Tierra del Fuego

RiccialdelliSeth, Luciana; Newsome, D.; Goodall, Natalie

doi:10.1007/s00300-013-1289-5

Cited by 58 publications

(42 citation statements)

References 53 publications

(79 reference statements)

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“…This result parallels previous demographic comparisons showing that juvenile dolphins (less than 6 years old) feed at a lower trophic level than adult females (Rossman et al 2014). Previous studies of sperm whales, killer whales and Commerson's dolphins which documented a similar increase in δ 15 N values with age, attributed the trend to many factors including changes in trophic fractionation due to growth rate, a change in diet resulting from leaving the natal band or offshore migration, or an increase in the size of prey consumed (Mendes et al 2006;Newsome et al 2009a, b;Riccialdelli et al 2013). We cannot exclude isotope effects resulting from changes in growth rate or other changes in metabolism.…”

Section: Discussionmentioning

confidence: 92%

“…The low δ 15 N value of age classes 2-4 and 4-8 years may result from reliance on pinfish, the lowest trophic level diet item consumed by Sarsota Bay dolphins (Rossman et al 2014). The increase in female bottlenose dolphin δ 15 N values in the >15 years age class likely reflects the ability to consume larger, higher trophic level fish as the result of larger gape size or development of foraging skills (Mendes et al 2006;Riccialdelli et al 2013;Rossman et al 2014).…”

Section: Discussionmentioning

confidence: 94%

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Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary

et al. 2015

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We examine individual specialization in foraging habits (foraging habitat and trophic level) of female bottlenose dolphins (Tursiops truncatus) resident in Sarasota Bay, Florida, USA, by analyzing time series of stable isotope (δ(15)N and δ(13)C) values in sequential growth layer groups within teeth. The isotope data provide a chronology of foraging habits over the lifetime of the individual and allowed us to show that female bottlenose dolphins exhibit a high degree of individual specialization in both foraging habitat and trophic level. The foraging habits used by adult females are similar to those they used as calves and may be passed down from mother to calf through social learning. We also characterized the foraging habits and home range of each individual by constructing standard ellipses from isotope values and dolphin sightings data (latitude and longitude), respectively. These data show that Sarasota Bay bottlenose dolphins forage within a subset of the habitats in which they are observed. Moreover, females with similar observational standard ellipses often possessed different foraging specializations. Female bottlenose dolphins may demonstrate individual specialization in foraging habits because it reduces some of the cost of living in groups, such as competition for prey.

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Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 94%

Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary

et al. 2015

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“…Deposit Riccialdelli et al (2013) and support field observations that this species feeds on microphytobenthos (Guzmán and Ríos 1986).…”

mentioning

confidence: 99%

“…Our data for Patagonotothen cornucola are close to values reported for the closely related Patagonotothen spp. (Riccialdelli et al 2013).…”

mentioning

confidence: 99%

Trophic structure of shallow-water benthic communities in the sub-Antarctic Strait of Magellan

et al. 2016

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Trophic structure is among the most fundamental characteristics of an ecosystem since it is a useful way to determine the main energy flow at the ecosystem level. In the Magellan Strait, the local spatial heterogeneity at the shallow-waters ecosystems may have a great variety of potential food sources; however, knowledge about their biological communities and their structure is still unclear. We examined the trophic structure of shallow-water-mixed bottom communities at two sites in the sub-Antarctic Magellan Strait based on carbon (d 13 C) and nitrogen (d 15 N) stable isotope ratios. The benthic communities were composed of 46 species from 20 major taxa at Bahía Laredo (BL) and 55 species from 18 major taxa at Punta Santa Ana (PSA). Benthic macroalgae and organic matter associated with sediment are the major primary food sources at both sites. Although both sites are quite similar in their food sources and in their vertical trophic structure (Cthree trophic levels), the food web structure varied distinctly. Functionally, predators and grazers dominated both communities, but top predators were shorebirds, carnivore anemones and predatory nemerteans at BL, and sea stars, shorebirds, crabs and fishes at PSA. The distinct differences in the trophic structure at BL and PSA highlight the important variability of d 15 N at the base of the benthic food web, the role of local environmental conditions and community dynamics in structuring shallow-water communities.

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“…Given the large number of strandings following the DWH oil spill (Litz et al 2014, Venn-Watson et al 2015b), a subset of available skin samples from stranded animals was selected for stable isotope analysis using several criteria: (1) the strandings oc curred after the beginning of the DWH oil spill (on or after 20 April 2010), (2) the stranding occurred within the geographic range most affected by the DWH oil spill (Louisiana to the western Panhandle of Florida; Michel et al 2013, DWH NRDAT 2016, (3) the total length of a stranded animal was >170 cm to exclude perinatal and young of the year (Fernandez & Hohn 1998) to avoid ontogenetic effects (Knoff et al 2008, Riccialdelli et al 2013, and (4) …”

Section: Sample Collectionmentioning

confidence: 99%

Assigning stranded bottlenose dolphins to source stocks using stable isotope ratios following the Deepwater Horizon oil spill

Hohn¹,

Thomas²,

Carmichael³

et al. 2017

Endang. Species. Res.

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The potential for stranded dolphins to serve as a tool for monitoring free-ranging populations would be enhanced if their stocks of origin were known. We used stable isotopes of carbon, nitrogen, and sulfur from skin to assign stranded bottlenose dolphins Tursiops truncatus to different habitats, as a proxy for stocks (demographically independent populations), following the Deepwater Horizon oil spill. Model results from biopsy samples collected from dolphins from known habitats (n = 205) resulted in an 80.5% probability of correct assignment. These results were applied to data from stranded dolphins (n = 217), resulting in predicted assignment probabilities of 0.473, 0.172, and 0.355 to Estuarine, Barrier Island (BI), and Coastal stocks, respectively. Differences were found west and east of the Mississippi River, with more Coastal dolphins stranding in western Louisiana and more Estuarine dolphins stranding in Mississippi. Within the Estuarine East Stock, 2 groups were identified, one predominantly associated with Mississippi and Alabama estuaries and another with western Florida. δ 15 N values were higher in stranded samples for both Estuarine and BI stocks, potentially indicating nutritional stress. High probabilities of correct assignment of the biopsy samples indicate predictable variation in stable isotopes and fidelity to habitat. The power of δ 34 S to discriminate habitats relative to salinity was essential. Stable isotopes may provide guidance regarding where additional testing is warranted to confirm demographic independence and aid in determining the source habitat of stranded dolphins, thus increasing the value of biological data collected from stranded individuals.

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Ontogenetic diet shift in Commerson’s dolphin (Cephalorhynchus commersonii commersonii) off Tierra del Fuego

Cited by 58 publications

References 53 publications

Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary

Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary

Trophic structure of shallow-water benthic communities in the sub-Antarctic Strait of Magellan

Assigning stranded bottlenose dolphins to source stocks using stable isotope ratios following the Deepwater Horizon oil spill

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