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The loggerhead nesting season runs from September through March. Nighttime monitoring of nesting females that has been conducted since the bases were established, in order to gather information about their reproductive biology that support conservation actions. When nesting females were encountered on the beach, Monel (used until 2003) or Inconel (used exclusively since 2003) metal tags (National Brand and Tag Company, Kentucky, USA) were attached to the trailing edge of the turtle’s front flippers. Each tag included a unique number and contact information for the TAMAR/ICMBio Project. The tagged females were also measured (curved carapace length) and information about date, place, and time were also collected and stored in a standardized database (Marcovaldi & Marcovaldi 1999). Nests were monitored until hatchling emergence, and were subsequently inventoried to calculate hatching success. The nightly monitoring effort was irregular for the first two decades of the project, reflecting changes in logistical conditions over the years. Since the 2005/2006 season, nighttime monitoring effort, including tagging of nesting females, was standardized, occurring daily between October and January.

Between 1982-2014, 2119 different females were encountered and tagged on the beaches monitored by the bases of Comboios and Povoação, and multiple turtles have been recaptured over this time. Thomé et al. (2006) documented two nesting loggerhead turtles (with tags BR 0276 and BR 0279) observed in 2004 that were first encountered and tagged in 1982, giving them at least a 22-year reproductive span. These two animals have been subsequently observed nesting on ES beaches: in 2006, 2008 and 2010 (BR 0276), and in 2014 (BR 0279), which corresponds to reproductive longevity of 28 and 32 years, respectively. In Povoação Beach, a female tagged in December 1988 was recaptured in December 2013, totaling up 25 years of recorded breeding activity (Table 1).

These records are the longest intervals of reproductive longevity registered for this species that we are aware of. The small number of long-term nighttime tagging programs is a limiting factor in documenting females with long reproductive histories; few such programs have persisted longer than 15 years (Pfaller et al. 2013; TEWG 2009). Ehrhart et al. (2014) reported one female loggerhead that had been observed nesting over a 23-year interval in central Florida, USA, which was recorded during 31 years of monitoring.

The maximum range between observed nesting locations for the three recaptured turtles in ES was 7-12 km (Table 1). In northern Bahia, Brazil, loggerhead females monitored by satellite telemetry (Marcovaldi et al. 2010) showed an average movement between nests of 8.8 km, but some individuals moved as much as 41 km between nest locations, in the same breeding season. Although our dataset is small, these long-term nesting females do display strong nest site fidelity that is reportedly characteristic of the species (Miller 1997).

Fig. 1. Tag BR 9603 found on a loggerhead turtle on 09 December 2014.

Table 1. Recaptures data of three loggerhead turtle females with long reproductive longevity on the north coast of Espírito Santo between 1982-2014. The strikethrough represent tags intentionally removed and replaced. CB - Comboios; PV - Povoação; KM – km sector on beach where turtles was found; CCL - Curved carapace length (m); Bold - Monel tags; n/a – information not recorded.

A potentially important limiting factor for evaluating long-term monitoring programs is tag loss, and it may bias the estimates of survival rates (Phillips et al. 2014). Between 1982 and 1991, only one tag was applied to each female; since 1992, two tags, one per front flipper, have been applied to all females. Nevertheless, even with known tag loss, such as with BR 9605, BR 276 (Table 1), or the need for tag substitution, such as with BR 279, BR 3087, BR 31657 (Table 1), we were able to document long-term reproductive activity by individual loggerhead females.

Until 2003 the flipper tags used by TAMAR were made exclusively from Monel alloy, which has been reported to be more susceptible to corrosion and loss than other types of tags, including Inconel (Bellini et al. 2001; Limpus 1992; Troeng et al. 2007). Interestingly, two Monel tags were recovered in good condition after 22 (see cover) and 25 years (Table 1). However, we were unable to adequately address tag loss in our study area because there was inconsistent collection of information on tag loss exhibited by nesting females in the form of scars and traces of tagging on their flippers.

The carapace length of two of females increased 0.06 and 0.28 cm/year; the third female presented deformities in the shell since its first tagging (Table 1). The growth rates of these two individuals are variable, and more comprehensive analysis of a larger dataset would facilitate a better understanding of growth rates of nesting loggerhead sea turtles from Brazil. It would be important to take into account measurement error, which may explain the apparent negative growth rates in some years for these turtles (Table 1).

Overall, these three cases of nesting loggerheads with long reproductive histories highlight the value of long-term tag-recapture studies that use two tags per turtle, and a thorough evaluation of each individual regarding the need for readjustment or replacement of tags.

Acknowledgements. We are grateful to all the people who have been part of the Projeto TAMAR - ICMBio, Fundação Pró-Tamar and REBio Comboios - ICMBio.

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