Patrones de residencia y movimientos a largo plazo de las toninas Tursiops truncatus, en la región sureste del Golfo de México

Delgado-Estrella, Alberto

doi:10.12933/therya-15-265

Cited by 4 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the high number of transient individuals in the sample (Figure 2), the asymptotic trend in the discovery curves (Figure 4) indicated that most of the marked individuals in the population had been photographed by the end of the study period. For the full sample, the existence of two plateaus and decrease in the discovery rate of new individuals after the rainy season of 2009 suggest that the addition of new members is low, with sporadic immigration pulses as occurs in this, and other areas within the southern Gulf of Mexico (e.g., Martínez-Serrano et al, 2011;Valdés-Arellanes et al, 2011;Morteo et al, 2014Morteo et al, , 2017Morteo et al, , 2019Delgado-Estrella, 2015). On the other side, the similarity between the discovery curves of the whole sample, occasional visitors, and transients showed that the dynamics of this population is mainly regulated by the influx of non-resident individuals.…”

Section: Discussionmentioning

confidence: 92%

“…It is noteworthy that, unlike other study areas, this core community -living in an open habitatlargely behaves as a closed population. This situation may be more common than previously thought for the species across the Gulf of Mexico, where many individuals remain in relatively small but well provisioned areas, whereas short-term residents and visitors come from the adjacent coastal populations, or have nomadic habits in their constant pursuit of food and mates (Shane, 1980;Irvine et al, 1981;Wells et al, 1987;Ruíz-Hernández, 2014;Delgado-Estrella, 2015;Morteo et al, 2019, among others). The existence of such core communities in the northern Gulf of Mexico has been generally established based on qualitative criteria, mainly the overlap in the presence of transients with year-round and seasonal residents (i.e., Shane, 1980Shane, , 1990Wells et al, 1987;Balmer et al, 2008;Tyson et al, 2011, among others) and, in most cases, refer to dolphin populations living in inshore, estuarine habitats.…”

Section: Discussionmentioning

confidence: 93%

See 1 more Smart Citation

Population Dynamics Reveal a Core Community of the Common Bottlenose Dolphin (Tursiops truncatus) in Open Waters of the South-Western Gulf of Mexico

et al. 2021

View full text Add to dashboard Cite

The presence of transient and temporary individuals in capture-mark-recapture studies may violate the assumption on equal catchability, and thus yield biased estimates. We investigated the effects of residency patterns on population parameters of bottlenose dolphins inhabiting the coastal waters off the Alvarado Lagoon System (ALS), Veracruz, Mexico. We hypothesized that this population is open but there exists a “core community” that behaves as a closed population. Between 2006 and 2010, we conducted 75 photo-identification surveys and recorded 263 dolphin group encounters, in which 231 dolphins were identified. Individuals present during only one season, classified as transients (n = 85), were excluded from the study, and a standardized residency index (IH4) was computed for each dolphin that remained in the sample (n = 146). We used the K-means clustering method to split the sample into groups based on individual (seasonal, annual) IH4 values. These clusters were named as regular residents (RR, n = 55), occasional residents (OR, n = 45), and occasional visitors (OV, n = 46). The cumulative frequency of newly identified individuals displayed an asymptotic trend for the whole sample and all clusters, indicating that most of the individuals present in the study area during the study period were identified. The assumption of demographic closure was tested to define the core community, and was rejected for the whole sample and the OV cluster (p < 0.001 in both cases), indicating that the population is open. The closure assumption was not rejected for RR and OR clusters (χ2 = 6.88, DF = 13, p = 0.91, and χ2 = 17.8, DF = 16, p = 0.33, respectively), indicating that these clusters were demographically closed over the 5-year period. Thus, we defined this aggregation of individuals as the “core community”. The closed population model Mth indicated that the total abundance of this core community was 123 individuals (95% CI: 114–133). Our results provide quantitative evidence of the existence of a core community in open waters of the Gulf of Mexico, and points toward residency pattern as a main driver of population dynamics. These results highlight the importance of considering residency patterns when dealing with heterogeneity in the sample of a highly mobile species.

show abstract

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 93%

Population Dynamics Reveal a Core Community of the Common Bottlenose Dolphin (Tursiops truncatus) in Open Waters of the South-Western Gulf of Mexico

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Despite the high number of transient individuals in the sample (Figure 2), the logarithmic trend in the discovery curve (Figure 3) for all groups indicated that, in general, new or not previously photo-identified individuals were uncommon by the end of the study (see Morteo et al, 2017). The evident decrease in the discovery rate over the first year shows that the dolphin population is open (Colwell et al, 2004), but strongly suggests that the addition of new members is low, with sporadic immigration pulses as occurs in this and other areas within the southern Gulf of Mexico (i.e., Delgado-Estrella, 2015;Martínez-Serrano et al, 2011;Morteo et al, 2014Morteo et al, , 2017Morteo et al, , 2019Valdés-Arellanes et al, 2011).…”

Section: Discovery Rate and Catchabilitymentioning

confidence: 79%

Seasonal population parameters reveal sex‐related dynamics of common bottlenose dolphins in open waters of the southwestern Gulf of Mexico

Bolaños‐Jiménez

Morteo

Fruet

et al. 2021

Marine Mammal Science

View full text Add to dashboard Cite

In coastal populations of the common bottlenose dolphin, resident females are usually more abundant and have more restricted home ranges than males. Here, we studied sex‐specific population dynamics of bottlenose dolphins off the Alvarado Lagoon System, southwestern Gulf of Mexico. We used standard photo‐identification and capture‐mark‐recapture methods to determine population parameters under the superpopulation approach. Seasonal survival fluctuated around 0.96 (range: 0.80–1.00) and was equal for the sexes; recruitment of putative females (PF) and males (PM) was low, asynchronous, and reached 0.14 (range: 0.04–0.10) and 0.09 (range: 0.09–0.09), respectively, indicating high residency. PF abundance ranged from 60, 95% CI [48, 74] in the northern winds' season of 2008 to a low of 38, 95% CI [31, 47] in the dry season of 2010. PM abundance ranged from a high of 14, 95% CI [12, 16] in the northern winds' season of 2008 to a low of 9, 95% CI [7, 11] in the dry season of 2010. A regression analysis showed significant autocorrelation, and a pattern in the residuals of abundance, indicating no trends as well as temporal fluctuations that suggest a possible carrying capacity effect. Accordingly, high site fidelity, restricted ranging patterns, and low sporadic recruitment from the superpopulation are likely driving population parameters for this population.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The most common odontocete in the Southern Gulf of Mexico marine ecoregion is the bottlenose dolphin ( Tursiops truncatus ). This species is the only one that inhabits river mouths, coastal lagoons and littoral, neritic and oceanic zones, and its presence is therefore associated with areas of high variability in temperature, salinity and productivity (Waring et al, 2010; Martínez‐Serrano et al, 2011; Delgado‐Estrella, 2015; Serrano et al, 2017; Greller et al, 2020). Moreover, the species is used as a bioindicator in monitoring the health status of marine ecosystems (Fossi et al, 2018), since it is an apex predator (Reif et al, 2017) and coexists with activities of great economic importance for Mexico such as fishing and petroleum extraction (Valdes‐Arellanes et al, 2011; Hernández‐Candelario et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Abundance of the bottlenose dolphin (Tursiops truncatus) and proposal for a priority area of conservation in the Southern Gulf of Mexico marine ecoregion

Muñoz

2023

Aquatic Conservation

View full text Add to dashboard Cite

Demographic studies are crucial for assessment of the status of dolphin populations and their relationship with anthropogenic activities as a way to make effective management and conservation decisions. In the Gulf of Mexico, the interaction between bottlenose dolphins (Tursiops truncatus) and anthropogenic activities merits special attention. The objective of this study was therefore to determine the annual abundance and area of preference of the coastal population of T. truncatus (period 2005–2020), and to delimit a priority area for its conservation in the Southern Gulf of Mexico marine ecoregion. Abundance was calculated using the Jolly–Seber model and habitat preference was determined per climatic season (dry, rainy and cold northerly fronts) as a function of environmental variables. The association between anthropogenic activities and dolphin distribution was studied and the priority area delimited using potential distribution models. Off the coasts of Tuxpan and Tamiahua, the results show that the dolphin population numbered 306 individuals (95% CI: 162.97; 607.33) and has remained relatively constant over time. The pattern of dolphin distribution varied between seasons, possibly owing to changes in food availability. However, river mouths and lagoons are of importance to T. truncatus throughout the year. On the other hand, fishing and maritime traffic can potentially affect this species. Finally, this study shows that the delimitation of sites of importance for T. truncatus is a strategic tool with which to help conserve the species and associated coastal ecosystems.

show abstract

Patrones de residencia y movimientos a largo plazo de las toninas Tursiops truncatus, en la región sureste del Golfo de México

Cited by 4 publications

References 7 publications

Population Dynamics Reveal a Core Community of the Common Bottlenose Dolphin (Tursiops truncatus) in Open Waters of the South-Western Gulf of Mexico

Population Dynamics Reveal a Core Community of the Common Bottlenose Dolphin (Tursiops truncatus) in Open Waters of the South-Western Gulf of Mexico

Seasonal population parameters reveal sex‐related dynamics of common bottlenose dolphins in open waters of the southwestern Gulf of Mexico

Abundance of the bottlenose dolphin (Tursiops truncatus) and proposal for a priority area of conservation in the Southern Gulf of Mexico marine ecoregion

Contact Info

Product

Resources

About