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Anguilla marmorata collected in the Odana River lower reaches were passive integrated transponder-tagged displaced and released into the upper river reaches (54 up-transported eels), and eels collected in the upper reaches were tagged and released downstream (52 down-transported eels). Their movements were detected once per day for 10 days using a portable radio-frequency identification (RFID) system. The homing rate of the down-transported eels was 38.9%, compared to 3.7% for the up-transported eels, suggesting that eels inhabiting upstream areas have relatively high fidelity to their habitats and downstream eels have less fidelity.

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Effective conservation and management necessitate an understanding of the ecological mechanisms that shape species life histories in order to predict how variability in natural and anthropogenic impacts will alter growth rates, recruitment, and survival. Among these mechanisms, the interaction between parturition timing and prey availability frequently influences offspring success, particularly when postnatal care is absent. Here, we assess how parturition timing and nursery conditions, including prey abundance and environmental conditions, influence the growth and potential survival of blacktip sharks (Carcharhinus limbatus) in western Gulf of Mexico (GOM) estuaries over their first year. Catch data from long-term gillnet monitoring allowed for clear delineation of cohorts based on size frequency distribution plots, and showed that late parturition cohorts born in estuaries with fewer prey resources exhibited more rapid growth than early parturition cohorts that experienced more abundant prey. Compensatory behaviors that promoted accelerated growth led to reduced second year residency, likely due to reduced survival resultant from greater risk taking and potentially due to reduced site fidelity attributed to larger body size. Water temperatures influenced blacktip growth rates through physiological increases in metabolism and potential premigratory foraging cues associated with cooling temperatures. Gradual warming of the GOM (0.03°C year-1) was also correlated with earlier parturition across the study period (1982-2017), similar to other migratory species. Considering current trends in climate and associated phenological shifts in many animals, testing hypotheses assessing compensatory growth-risk trade-offs is important moving forward to predict changes in life histories and associated recruitment in concert with current and future conservation actions, like wildlife management.

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Patterns of ranging behavior and space use are key for evaluating current ideas about the evolution and maintenance of pair-living and sexual monogamy as they provide insights into the dispersion of females, the potential for territoriality, and whether males are limited to defending an area that can support only one female and her offspring. We examined ranging behavior and space use to evaluate the potential for territoriality in five groups of red titi monkeys (Plecturocebus discolor) during a 10-year study in Ecuadorian Amazonia. Mean home range size, calculated using a time-sensitive local convex hull estimation procedure, was 4.0 ± 1.4 ha. Annual home ranges of neighboring groups overlapped, on average, 0%-7%. Mean daily path length was 670 ± 194 m, resulting in defendability indices of 2.2-3.6 across groups. Groups visited, on average, 4 of 12 sections of their home range border area per day, but that was not more often than would be expected by chance, and intergroup encounters were infrequent. We did not find evidence of active monitoring for intruders in border areas, in that groups did not travel either faster or slower when at the border than when in central areas of their range. The absence of overt monitoring might be compensated for by engaging in loud calls, which the study groups did throughout their home ranges; these calls may serve as an advertisement of occupancy and a deterrent to intruding conspecifics. Our finding that red titis have a high potential for territoriality is consistent with several of the main hypotheses proposed to explain pair-living in mammals.

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This study is the first description of the residency and diel movements of Sphyrna lewini at the Revillagigedo National Park, Mexico. Eleven adult scalloped hammerheads of total length 200-300 cm were monitored using acoustic telemetry during 2013-2015 at four sites at San Benedicto Island. Diel and residency patterns were described based on 58,055 detections by four autonomous receivers. The sharks displayed high daytime residency in two of the four sites, with movements away into the pelagic environment at night. This study generates a baseline for effective monitoring to improve the conservation and management of an iconic but endangered species at this marine reserve.

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Natural history of the marsupial frog Gastrotheca albolineata (Anura: Hemiphractidae) in lowland Brazilian Atlantic Forest. Gastrotheca albolineata is a marsupial frog endemic to the Atlantic Forest in southeastern Brazil. It remains poorly studied in nature and is uncommon in herpetological collections. We studied the natural history of G. albolineata during a four-year period (2015 to 2019), in Ubatuba, São Paulo state, Brazil, at its southernmost distribution. Our results show that G. albolineata is arboreal, perches from low to medium heights, and breeds during the dry season without chorus aggregation. Calling activity occurs during the day but is more intense during the first half of the night. We used dorsal body markings to identify individuals. Six individuals were recaptured during the study, indicating site fidelity during the active season. The defensive repertory of G. albolineata contains seven different behaviors, including a high-pitched distress call. Egg development in the female’s dorsal pouch took at least 87 days, and fully formed froglets were born with a snout–vent length of 16 mm. Our data substantially add to the knowledge of the natural history of Brazilian marsupial frogs and can be helpful to delineate conservation strategies for elusive species such as G. albolineata.

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BACKGROUND: Site fidelity is considered as an animal's tendency to return to a previously occupied place; this is a component of animal behaviour that allows us to understand movement patterns and aspects related to the animal's life history. Although there are many site fidelity metrics, the lack of standardisation presents a considerable challenge in terms of comparability among studies. METHODS: This investigation focused on the theoretical development of a standardised composite site fidelity index and its statistical distribution in order to obtain reliable population-level site fidelity comparisons. The arithmetic and harmonic means were used as mathematical structures in order to create different indexes by combining the most commonly used indicators for site fidelity such as Occurrence, Permanence and Periodicity. The index performance was then evaluated in simulated populations and one real population of Commerson's dolphins (Cephalorhynchus commersonii (Lacépède 1804)). In the first case, the indexes were evaluated based on how they were affected by different probability values such as the occurrence of the individual within the study area (φ) and capture probability (p). As a precision measure for the comparison of the indexes, the Wald confidence interval (CI) and the mean square error were applied. Given that there was no previous data concerning the distribution parameters of this population, bootstrap CIs were applied for the study case. RESULTS: Eight alternative indexes were developed. The indexes with an arithmetic mean structure, in general, had a consistently inferior performance than those with a harmonic mean structure. The index IH4, in particular, achieved the best results in all of the scenarios and in the study case. Additionally, this index presented a normal distribution. As such, it was proposed as a standardised measure for site fidelity (Standardised Site Fidelity Index-SSFI). DISCUSSION: The SSFI is the first standardised metric that quantifies site fidelity at a populational level. It is an estimator that varies between zero and one and works in situations where detection is not perfect and effort can be constant or not. Moreover, it has an associated CI that allows users to make comparisons.

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There were 479 reported whale shark Rhincodon typus encounters between 1999 and 2011 at the island of Utila, which forms part of the Meso-American Barrier Reef System (MBRS) in the western Caribbean Sea. The majority of R. typus were found to feed on small bait fish associated with various tuna species. Ninety-five individual R. typus, ranging from 2 to 11 m total length (LT ), were identified through their unique spot patterns. A significant male bias (65%) was present. There was no significant difference between the mean ± s.d. LT of female (6·66 ± 1·65 m) and male (6·25 ± 1·60 m) R. typus. Most R. typus were transient to Utila, with 78% sighted only within a single calendar year, although some individuals were sighted in up to 5 years. Mean residency time was modelled to be 11·76 days using maximum likelihood methods.

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For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998-2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their "final" foraging sites. We identified new foraging "hotspots" where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species.

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White-tip reef sharks are common inhabitants of the shallow waters surrounding the Galapagos Islands, where several known aggregation sites have become touristic attractions. With the aim to describe site fidelity and residency patterns of the white-tip reef sharks in a saltwater creek, we used the ultrasonic telemetry method. The study was undertaken in a saltwater channel South of Academy Bay, Santa Cruz Island, from May 2008-September 2009. A total of nine transmitters were attached to sharks and ultrasonic receivers were deployed at the inner and outside areas of the creek. From the total of fitted sharks, four lost their transmitters. The results obtained with the remaining sharks showed an elevated use of the inner area of the channel during the day, with more use of the external area during the night. However, none of the sharks were detected at the site every day, suggesting that they may have a number of preferred sites within their home range. More studies are needed to detail the home range and habitat use of this species, and to guide its protection level in the AcademyBay area. Rev. Biol. Trop. 60 (2): 735-743. Epub 2012 June 01.

Los tiburones punta blanca de arrecife son habitantes comunes de las aguas que rodean las Islas Galápagos, por lo que muchos de sus sitios de agregación se han convertido en atractivos turísticos. Con el objetivo de describir la fidelidad del sitio y los patrones de residencia de nueve tiburones desde mayo 2008-septiembre 2009, se utilizó telemetría ultrasónica en un canal de agua salada en el sur de Bahía Academia, Isla Santa Cruz. A pesar de que cuatro tiburones perdieron sus transmisores, los restantes tiburones monitoreados mostraron un uso elevado del interior del canal durante el día y del exterior durante la noche. Sin embargo, ninguno de los tiburones fue detectado en el sitio diariamente, lo cual sugiere que deben tener un número mayor de sitios preferidos dentro de su área de vida.

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A diversidade de anfíbios no Cerrado é ameaçada principalmente pelo aumento das atividades antrópicas. A legislação vigente exige de empreendimentos potencialmente impactantes a implantação de programas ambientais que incluem a recuperação de áreas degradadas e o estudo dos mecanismos ecológicos associados à recolonização de áreas alteradas. Os objetivos deste estudo foram: avaliar possíveis diferenças na composição de espécies em assembléias de anuros entre áreas de topografia modificada (ATM) e áreas de topografia não modificada (ATNM); e comparar a riqueza de anuros entre ATM e ATNM. Apesar do maior número de espécies registradas na ATM (28 espécies) em relação à ATNM (22 espécies), não houve diferença na riqueza quando comparamos as curvas de rarefação ou a riqueza estimada (jackknife1). Entretanto, as duas assembléias diferiram quanto às curvas de abundância relativa, especialmente quanto ao padrão das espécies mais abundantes. Localmente, a análise de co-ocorrência demonstrou que as espécies na ATM co-ocorrem menos do que o esperado ao acaso, o que indica a partilha dos ambientes para reprodução mediada por interações competitivas. A presença de corpos d'água artificiais com alta heterogeneidade estrutural, associados a fragmentos florestais em bom estado de conservação são fatores que contribuem para a manutenção de uma alta diversidade de anfíbios na área.

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The aim of the present study was to provide a preliminary description of habitat use by Guiana dolphins, Sotalia guianensis (Van Bénéden, 1864) in the Paranaguá Estuarine Complex (PEC), state of Paraná, Brazil. Approximately 124 km² were surveyed by small boat from April 2006 to July 2008 in the following subsets of the PEC: Canal do Superagui (~28 km²); Pinheiros Bay (~34 km²); part of Laranjeiras Bay, which included the Guaraqueçaba sub-estuary (~38 km²); and part of the Mixture Section of the PEC (~24 km²). Our efforts were unevenly distributed in the study area. During 55 survey days covering seven distinct seasons, we spent 165 hours observing 323 groups of S. guianensis. Group size varied from two individuals to aggregations as large as approximately 100 dolphins. A total of 49,921 photographs were analyzed; 15,038 (30%) were considered useful for identification purposes. A total of 182 individuals were catalogued, from which 122 (67%) were cataloged in the last three seasons, when the surveyed area was expanded. The number of individual sightings in distinct days varied from one to 16. A total of 94 individuals (51.6%) were re-sighted at least once. From the 37 individuals cataloged in the first season, 18 (48.6%) were re-sighted in the last season. Eleven individuals with 5+ sightings were always observed in the same subset of the estuary, including an individual with 13 sightings. Sixteen individuals with three to 16 sightings were observed in three of the four estuary subsets surveyed. An individual cataloged in May 2002 in a pilot study was re-sighted up to August 2006. Our preliminary results correspond to the first evidence of site fidelity for several monitored individuals; it also revealed, for the first time, the flexibility of movements throughout the entire estuarine complex by several other individuals

RESUMO

The aim of the present study was to provide a preliminary description of habitat use by Guiana dolphins, Sotalia guianensis (Van Bénéden, 1864) in the Paranaguá Estuarine Complex (PEC), state of Paraná, Brazil. Approximately 124 km² were surveyed by small boat from April 2006 to July 2008 in the following subsets of the PEC: Canal do Superagui (~28 km²); Pinheiros Bay (~34 km²); part of Laranjeiras Bay, which included the Guaraqueçaba sub-estuary (~38 km²); and part of the Mixture Section of the PEC (~24 km²). Our efforts were unevenly distributed in the study area. During 55 survey days covering seven distinct seasons, we spent 165 hours observing 323 groups of S. guianensis. Group size varied from two individuals to aggregations as large as approximately 100 dolphins. A total of 49,921 photographs were analyzed; 15,038 (30%) were considered useful for identification purposes. A total of 182 individuals were catalogued, from which 122 (67%) were cataloged in the last three seasons, when the surveyed area was expanded. The number of individual sightings in distinct days varied from one to 16. A total of 94 individuals (51.6%) were re-sighted at least once. From the 37 individuals cataloged in the first season, 18 (48.6%) were re-sighted in the last season. Eleven individuals with 5+ sightings were always observed in the same subset of the estuary, including an individual with 13 sightings. Sixteen individuals with three to 16 sightings were observed in three of the four estuary subsets surveyed. An individual cataloged in May 2002 in a pilot study was re-sighted up to August 2006. Our preliminary results correspond to the first evidence of site fidelity for several monitored individuals; it also revealed, for the first time, the flexibility of movements throughout the entire estuarine complex by several other individuals

RESUMO

The aim of the present study was to provide a preliminary description of habitat use by Guiana dolphins, Sotalia guianensis (Van Bénéden, 1864) in the Paranaguá Estuarine Complex (PEC), state of Paraná, Brazil. Approximately 124 km² were surveyed by small boat from April 2006 to July 2008 in the following subsets of the PEC: Canal do Superagui (~28 km²); Pinheiros Bay (~34 km²); part of Laranjeiras Bay, which included the Guaraqueçaba sub-estuary (~38 km²); and part of the Mixture Section of the PEC (~24 km²). Our efforts were unevenly distributed in the study area. During 55 survey days covering seven distinct seasons, we spent 165 hours observing 323 groups of S. guianensis. Group size varied from two individuals to aggregations as large as approximately 100 dolphins. A total of 49,921 photographs were analyzed; 15,038 (30%) were considered useful for identification purposes. A total of 182 individuals were catalogued, from which 122 (67%) were cataloged in the last three seasons, when the surveyed area was expanded. The number of individual sightings in distinct days varied from one to 16. A total of 94 individuals (51.6%) were re-sighted at least once. From the 37 individuals cataloged in the first season, 18 (48.6%) were re-sighted in the last season. Eleven individuals with 5+ sightings were always observed in the same subset of the estuary, including an individual with 13 sightings. Sixteen individuals with three to 16 sightings were observed in three of the four estuary subsets surveyed. An individual cataloged in May 2002 in a pilot study was re-sighted up to August 2006. Our preliminary results correspond to the first evidence of site fidelity for several monitored individuals; it also revealed, for the first time, the flexibility of movements throughout the entire estuarine complex by several other individuals

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Reproductive period and geographic distribution of the toad Incilius aucoinae in Golfito, Costa Rica. The biology of neotropical amphibians is not well known. Some toad species of the Bufonidae family are common, thus allowing the study of their populations. We studied a population in río Cañaza, Golfito, Costa Rica, in a sector 360 m upstream of Barrio Ureña, divided in 36 sectors of 10 m. The study was carried out for five years, but taking samples of adults in January 1995, 1997, 1998 (except March), and 1999. We also studied tadpoles during four days in 1997. In total, 443 males and 7 females were marked, with 315 males recaptured and no females. Females are bigger (91.1 mm) than males (61.3 mm). Most recaptured individuals occurred in the same or adjacent sectors, with a maximum movement of 28 sectors. One individual was recaptured repeatedly in all the samples. This indicates that they survived at least five reproductive cycles. The reproductive cycle takes place during the dry season, between December and April. We found more individuals during the reproductive cycle of 1997 and less during 1995. Sector 6 had the most number of males and sector number 4 had the least. Sectors with semi-open vegetation had more males compared to sectors with more forest cover. February is the month with the highest abundance of males. There are intermediate values in December and January, and fewer individuals in March and April. In every month, except February, the abundance of individuals was greater where there were beaches. Tadpoles were found both during the day and night in the 31 river sectors, but it was less likely to find tadpoles in the river section during the night. During the day all tadpoles were found scattered around the river, at night they congregated near river margins. The reproductive cycle of this toad occurs during the dry season and females are present only in the reproductive season, resulting in an almost only male sex ratio (only seven females were found). Males can reproduce at least in 5 reproductive cycles, and -unexpectedly- day and night distribution of tadpoles varies. Rev. Biol. Trop. 57 (Suppl. 1): 301-311. Epub 2009 November 30.

Se estudian algunos aspectos de la biología reproductiva del sapo Incilius aucoinae en una población en el río Cañaza, Golfito, Costa Rica; en una sección de 360 m aguas arriba dividida en 36 sectores de 10 m. La duración del estudio con adultos fue de cuatro años, con muestreos en enero de 1995, 1997, 1998 (excepto marzo) y enero de 1999; los renacuajos se estudiaron en cuatro días de 1997. Se marcaron 443 machos (con 315 reobservaciones) y 7 hembras (no fueron recapturadas). Un individuo fue recapturado en todos los periodos de estudio, lo que indica que por los menos sobreviven a 5 épocas reproductivas. La época reproductiva corresponde a los meses secos, de diciembre a abril. En la época reproductiva de 1997 se encontró más individuos y menos en 1995; el sector 6 es el que tiene más machos y el 4 menos; la mayor cantidad de machos se encontró en sectores con vegetación semiabierta, los sectores con mayor cobertura vegetal tienen menos; febrero es el mes con mayor abundancia de machos, con valores intermedios en diciembre y enero, y con muy pocos individuos en marzo y abril. En todos los meses, excepto febrero, la abundancia fue mayor donde había playones. Este sapo se reproduce en la época seca, y en el sitio reproductivo las hembras apenas entran a reproducirse. Se da una relación de sexos de casi solo machos, pues solo hubo 7 hembras observadas, y sorprende los cambios de distribución entre el día y la noche en los renacuajos.

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Nest and or nest site reuse within and between breeding seasons was reported by the Euler's Flycatcher (Lathrotriccus euleri), the Sepia-capped Flycatcher (Leptopogon amaurocephalus) and the Gray-hooded Flycatcher (Mionectes -rufiventris) in forest fragments from southeastern Brazil. Nest and or nest site reuse between some years was frequent within a single breeding season by the Sepia-capped Flycatcher. Nest reuse, however, was not related to nesting success in the previous breeding attempt. Nest turnover rates (movement to a new site between years) were low for L. amaurocephalus, intermediate for L. euleri and high for M. rufiventris.

Foram registrados vários eventos de reutilização de ninho ou do sítio de nidificação dentro e entre estações reprodutivas por Lathrotriccus euleri, Leptopogon amaurocephalus e Mionectes rufiventris em fragmentos de floresta do sudeste do Brasil. A reutilização do ninho ou do sítio de nidificação ocorreu entre estes tiranídeos e foi freqüente dentro de uma única estação reprodutiva para L. amaurocephalus. A reutilização do ninho, contudo, não foi relacionada ao sucesso das tentativas anteriores. As taxas de retorno ao ninho foram baixas para L. amaurocephalus, intermediárias para L. euleri e altas para M. rufiventris.

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Nest and or nest site reuse within and between breeding seasons was reported by the Euler's Flycatcher (Lathrotriccus euleri), the Sepia-capped Flycatcher (Leptopogon amaurocephalus) and the Gray-hooded Flycatcher (Mionectes -rufiventris) in forest fragments from southeastern Brazil. Nest and or nest site reuse between some years was frequent within a single breeding season by the Sepia-capped Flycatcher. Nest reuse, however, was not related to nesting success in the previous breeding attempt. Nest turnover rates (movement to a new site between years) were low for L. amaurocephalus, intermediate for L. euleri and high for M. rufiventris.

Foram registrados vários eventos de reutilização de ninho ou do sítio de nidificação dentro e entre estações reprodutivas por Lathrotriccus euleri, Leptopogon amaurocephalus e Mionectes rufiventris em fragmentos de floresta do sudeste do Brasil. A reutilização do ninho ou do sítio de nidificação ocorreu entre estes tiranídeos e foi freqüente dentro de uma única estação reprodutiva para L. amaurocephalus. A reutilização do ninho, contudo, não foi relacionada ao sucesso das tentativas anteriores. As taxas de retorno ao ninho foram baixas para L. amaurocephalus, intermediárias para L. euleri e altas para M. rufiventris.