scholarly journals Interannual fine‐scale site fidelity of male ballan wrasse Labrus bergylta revealed by photo‐identification and tagging

2019 ◽  
Vol 95 (4) ◽  
pp. 1151-1155 ◽  
Author(s):  
Gonzalo Mucientes ◽  
José Irisarri ◽  
David Villegas‐Ríos
Keyword(s):  
Site Fidelity ◽  
Fine Scale ◽  
Photo Identification ◽  
Labrus Bergylta

scholarly journals Capitoline Dolphins: Residency Patterns and Abundance Estimate of Tursiops truncatus at the Tiber River Estuary (Mediterranean Sea)

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 275
Author(s):  
Daniela Silvia Pace ◽  
Chiara Di Marco ◽  
Giancarlo Giacomini ◽  
Sara Ferri ◽  
Margherita Silvestri ◽  
...  
Keyword(s):  
Population Size ◽  
Tursiops Truncatus ◽  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
River Estuary ◽  
Suitable Habitat ◽  
Tyrrhenian Sea ◽  
Abundance Estimate ◽  
Photo Identification ◽  
Tiber River

Periodic assessments of population status and trends to detect natural influences and human effects on coastal dolphin are often limited by lack of baseline information. Here, we investigated for the first time the site-fidelity patterns and estimated the population size of bottlenose dolphins (Tursiops truncatus) at the Tiber River estuary (central Mediterranean, Tyrrhenian Sea, Rome, Italy) between 2017 and 2020. We used photo-identification data and site-fidelity metrics to study the tendency of dolphins to remain in, or return to, the study area, and capture–recapture models to estimate the population abundance. In all, 347 unique individuals were identified. The hierarchical cluster analysis highlighted 3 clusters, labeled resident (individuals encountered at least five times, in three different months, over three distinct years; n = 42), part-time (individuals encountered at least on two occasions in a month, in at least two different years; n = 73), and transient (individuals encountered on more than one occasion, in more than 1 month, none of them in more than 1 year; n = 232), each characterized by site-fidelity metrics. Open POPAN modeling estimated a population size of 529 individuals (95% CI: 456–614), showing that the Capitoline (Roman) coastal area and nearby regions surrounding the Tiber River estuary represent an important, suitable habitat for bottlenose dolphins, despite their proximity to one of the major urban centers in the world (the city of Rome). Given the high number of individuals in the area and the presence of resident individuals with strong site fidelity, we suggest that conservation plans should not be focused only close to the Tiber River mouths but extended to cover a broader scale of area.

Ecology and comparison of coastal and offshore bottlenose dolphins (Tursiops truncatus) in California

2009 ◽  
Vol 60 (6) ◽  
pp. 584 ◽  
Author(s):  
Maddalena Bearzi ◽  
Charles A. Saylan ◽  
Alice Hwang
Keyword(s):  
Tursiops Truncatus ◽  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
Photo Identification ◽  
Santa Monica Bay ◽  
Santa Monica ◽  
Inshore Waters

Populations of coastal and offshore bottlenose dolphins (Tursiops truncatus) are considered to differ ecologically, with implications for their protection and management. We assessed occurrence, distribution and behaviour of coastal and offshore populations of dolphins during a photo-identification study in Santa Monica Bay and nearby areas (1997–2007). Bottlenose dolphins occurred year-round and were encountered on 44.2% of all surveys (n = 425). We photo-identified 647 individuals; of these, 375 (58.0%) were coastal (<1 km from shore), 241 (37.2%) offshore (1–65 km from shore) and 31 were both (4.8%). Dolphins mostly travel (69.0%) and travel-dive (61.5%), with offshore dolphins socialising more (22.6%) than coastal. There were low re-sighting rates for both coastal and offshore dolphins. Low re-sighting rates of coastal individuals provide little evidence of year-round site fidelity, suggesting their range is greater than the study area. Several individuals were re-sighted between and over 1-year periods, often foraging. This suggests that coastal dolphins: (1) are highly mobile within inshore waters, but spend time foraging in the study area, and (2) range >1 km from shore, contrary to what has been previously reported.

scholarly journals Abundance estimate and seasonal patterns of grey seal (Halichoerus grypus) occurrence in Brittany, France, as assessed by photo-identification and capture–mark–recapture

2007 ◽  
Vol 87 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Maureen Gerondeau ◽  
Christophe Barbraud ◽  
Vincent Ridoux ◽  
Cécile Vincent
Keyword(s):  
Breeding Season ◽  
Site Fidelity ◽  
Seasonal Abundance ◽  
Breeding Period ◽  
Home Ranges ◽  
Grey Seal ◽  
British Isles ◽  
Mark Recapture ◽  
Abundance Estimate ◽  
Photo Identification

It has been suggested that the large grey seal colonies around the British Isles form local populations within a metapopulation, and that seal movements outside the breeding season lead to considerable overlap between individual home ranges. Individual behaviour and population dynamics of small peripheral colonies may also play a role in the metapopulation. We studied the French grey seal colony of the Molène archipelago, at the southern-most limit of the species' range. We analysed photo-identification data with capture–mark–recapture techniques in order to estimate the total seasonal abundance of grey seals in the archipelago and to quantify the seasonal rates of occurrence or movements of male and female seals. We found that between 58 (95% confidence interval: 48–71) and 98 (95% CI: 75–175) individuals hauled out in the archipelago during the summers of 1999 and 2000. The use of multistate models allowed the assessment of seasonal site fidelity and indicated that it varied between key periods of the annual cycle, particularly for females. Males showed a constant fidelity rate of 56% from one season to another. Hence, even though they showed high inter-annual site fidelity, they did not seem to have a preferred season for using the archipelago. On the contrary, female grey seals showed the highest site fidelity between moult and summer (around 80%), and the lowest fidelity between summer and the breeding period (34–43%). Thus, females seem to use the Molène archipelago preferentially in summer and leave the site before the breeding season, which explains the very low local pup production. Philopatry may explain this pre-breeding emigration, and we suggest that most grey seals observed in the Molène archipelago were born and breed in other local breeding populations, probably the south-western British Isles.

scholarly journals Site Fidelity and Residency of Tursiops truncatus off the Aragua Coast, Venezuela-First Records of Long Residency

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
S. Cobarrubia-Russo ◽  
Sawyer I. ◽  
M. Gómez-Alceste ◽  
A. Molero-Lizarraga
Keyword(s):  
Bottlenose Dolphin ◽  
Marine Mammals ◽  
Site Fidelity ◽  
Marine Protected Area ◽  
Extended Period ◽  
Comprehensive Analysis ◽  
Agglomerative Hierarchical Clustering ◽  
Photo Identification ◽  
Whale Sharks ◽  
First Time

This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua, Venezuela, over a multi-year period. Using photo-identification, the most recent study (2019-2020) identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting. Site Fidelity (SF) and Residence (RES) indices were calculated and Agglomerative Hierarchical Clustering (AHC) modeling was performed, with three patterns of residence obtained: resident (25%), semiresident (17.86%) and transient (57.14%). These results were contrasted with remodeled data from a previous study (2006-2007), showing similar patterns: resident (24.44%), semi-resident (28.89%) and transient (46.67%). Importantly, two individuals were found to have been resident over the extended period. A breeding female sighted for the first time in 2004 and again in 2020 (16 years) and the other from 2005 to 2020 (15 years). This region is an important area for marine mammals, known to support a resident reproductive population over many years, as well seabirds, sea turtles, whale sharks and fishermen. We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.

Insights on site fidelity and calving intervals of the marine tucuxi dolphin (Sotalia fluviatilis) in south-eastern Brazil

2001 ◽  
Vol 81 (6) ◽  
pp. 1049-1052 ◽  
Author(s):  
Marcos César de Oliveira Santos ◽  
Luciana Barão Acuña ◽  
Sergio Rosso
Keyword(s):  
Small Area ◽  
Site Fidelity ◽  
Photo Identification ◽  
South Eastern ◽  
Eastern Brazil ◽  
Ecological Aspects ◽  
Sotalia Fluviatilis ◽  
Calving Intervals ◽  
Long Term Studies

Ecological aspects of the marine tucuxi dolphin, Sotalia fluviatilis (Cetacea: Delphinidae), remain poorly known. Important information can be gathered in long-term studies using photo-identification. Using this methodology, the authors present the first evidence of site fidelity for marine tucuxis in the Cananéia Estuary (25°03′S 48°01′ W), south-eastern Brazil. A total of 86 easily recognizable individuals was catalogued from June 1996 to August 2001, but most of them have been sighted from May 2000. From June 1997 to August 2001, three female tucuxis were sighted on nine (KN #19), 22 (KN #30) and 28 (KN #10) different days in a relatively small area (∼16 km2). Each of them was observed with a calf in 1997–1998 and again with a new offspring in 2000–2001. Thirteen other individuals were reported on eight to 19 different days in the same area between May 2000 and August 2001. Our observations lead to conclusions on the evidence of site fidelity and indicate that calving intervals may range between two and three years for this species in the surveyed area.

scholarly journals Strong site-fidelity increases vulnerability of common bottlenose dolphins Tursiops truncatus in a mass tourism destination in the western Mediterranean Sea

2013 ◽  
Vol 94 (6) ◽  
pp. 1227-1235 ◽  
Author(s):  
Joan Gonzalvo ◽  
Jaume Forcada ◽  
Esteve Grau ◽  
Alex Aguilar
Keyword(s):  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
Local Population ◽  
Western Mediterranean ◽  
Marine Biodiversity ◽  
Tourism Destination ◽  
Photo Identification ◽  
Mass Tourism ◽  
Management Actions ◽  
Common Bottlenose Dolphin

The local population of common bottlenose dolphin in the Balearic Islands coastal waters, a mass tourism destination in the western Mediterranean subject to increasing anthropogenic pressures, was monitored over a three-year period. Photo-identification surveys provided a relatively small population estimate, even though the islands are considered to be a hotspot for the species in the Mediterranean. Dolphins showed strong site-fidelity and relatively limited mobility across the archipelago, which makes them highly dependent on waters which are severely affected by overfishing, habitat degradation and boat disturbance resulting from a continuously-growing tourism and shipping industry. Ecosystem-based management actions are urgently needed to ensure the conservation of this fragile population of bottlenose dolphins. Conservation measures should be developed within the already-existing political and legal marine biodiversity conservation framework and in collaboration with local authorities and stakeholders.

Fine-scale movement patterns, site fidelity, and habitat selection of ocean whitefish (Caulolatilus princeps)

2008 ◽  
Vol 91 (2-3) ◽  
pp. 325-335 ◽  
Author(s):  
Lyall F. Bellquist ◽  
Christopher G. Lowe ◽  
Jennifer E. Caselle
Keyword(s):  
Habitat Selection ◽  
Site Fidelity ◽  
Movement Patterns ◽  
Fine Scale ◽  
Selection Of

scholarly journals Long-term site fidelity and residency patterns of bottlenose dolphins (Tursiops truncatus) in the Tramandaí Estuary, southern Brazil

10.5597/00224 ◽  
2017 ◽  
Vol 11 (1-2) ◽  
pp. 155-161 ◽  
Author(s):  
Amanda Baron Di Giacomo ◽  
Paulo Henrique Ott
Keyword(s):  
Tursiops Truncatus ◽  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
Southern Brazil ◽  
Local Conservation ◽  
Entire Study ◽  
Photo Identification ◽  
Average Observation ◽  
Number Of Individuals

The occurrence of common bottlenose dolphins (Tursiops truncatus) in Tramandaí Estuary, southern Brazil, is described based on a photo-identification study conducted between January 2009 and February 2010. A total of 128 survey days were conducted with an average observation effort of 2.6 hours per day (SD = 0.6). Approximately 2050 photographs were taken from a shore land location at the mouth of the estuary. A total of nine dolphins were identified, including three calves. The dolphins were observed during all seasons, with a greater frequency during fall (79.3% of the days) and winter (60.7% of the days). The summer presented the lowest occurrence (2.4% of the days) of dolphins. During the entire study period, the maximum number of individuals sighted in any given day ranged from one to seven (average = 2.8 dolphins; SD = 1.35; n = 51). The residence indices, based on the resighting frequency of dolphins during the study period, ranged from 0.02 to 0.24 (average = 0.13; SD = 0.08; n = 9). However, most of the animals (67%) were resighted in over five months during a year and could be classified as residents. Longterm site fidelity was detected by resightings of four dolphins for over 18 years. These data combined reinforce the importance of the Tramandaí Estuary for the common bottlenose dolphins in the region and highlight the need for local conservation efforts to guarantee the long-term persistence of these coastal populations.

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