Habitat details as listed in assessment
Within the UAE the species uses sandy beaches for nesting. Whilst several of the nesting sites are within protected areas, they are often in near proximity to developed areas.No new nesting sites are likely due to extensive development.A four-year research project monitoring post-nesting Hawksbill turtles in the Gulf identified foraging habitats that were spread over vast areas but at the individual turtle level they typically ranged over only 40-60 km<sup>2</sup> with core areas of only 3-5 km<sup>2</sup> in size (Pilcher et al. 2014a). Based on the project ground-truthing surveys, the feeding areas were found to be limited to small reef mounds only a few 100s of metres across. In addition, the project revealed short-term migrations that were related to temporal climatic shifts during the summer months. The results indicate that Gulf Hawksbills employ thermoregulatory responses moving to northern and cooler areas during the summer. This type of behaviour is presumably taking them out of high temperature and potentially physiology-threatening conditions. Growth and reproduction are integrally linked to foraging ecology (Bjorndal 1997) and limitations to foraging or food availability can impact the productivity of individuals and populations. Similarly, exposure to temperatures which exceed normal tolerances can lead to a decrease in nutritional uptake and growth. Gulf turtles are amongst the smallest adult turtles worldwide, in comparison to Omani turtles which are an average of 10 cm larger in carapace length as nesting adults, suggesting that growth in Gulf turtles is nutrient-limited.Hawksbills mainly feed on corals, sponges and crustaceans. In the water, the species is reef-associated, and reefs are undergoing a continuing decline in extent and quality. In the western Arabian Gulf, the species was found using more fragmented feeding sites (and females were <10 cm shorter than females from Oman).Hawksbills in the UAE may nest up to six times in a season with an average of three nests per turtle (Pilcher et al. 2014a), with 2-3 nests per female noted locally, however, recent genetic analysis found lower numbers of nests per female, at least in Dubai and Sir Bu Nair (A. Natoli pers. comm. 2018). The distribution of foraging habitat in the Gulf region has been described by Pilcher et al. (2014a) based on satellite tracking of 90 post-nesting female Hawksbills from nesting sites in Iran, Oman, Qatar and the UAE. In this study most of the turtles tagged in Qatar, Iran and the UAE migrated to southern and southwestern waters in the Gulf shared by the UAE and Qatar. A smaller number of turtles migrated northward towards Bahrain, Saudi Arabia, and Kuwait. Turtles spent 68% of the time in foraging grounds with home ranges of 40-60 km<sup>2</sup> and small core areas of 6 km<sup>2</sup> were found to be larger than those used by Omani turtles (core areas ~3 km<sup>2</sup>). In addition, adult female turtles from the Arabian Gulf were significantly smaller than Omani turtles (by ~11 cm CCL). Arabian Gulf turtles spend an average of 20% of time undertaking summer migration loops, a thermoregulatory response to avoid elevated sea surface temperatures, as the Arabian Gulf regularly experiences sustained sea surface temperatures of over 30 '°C (Pilcher et al. 2014b).Genetic analyses revealed differences in mating behaviour between Sir Bu Na'air, Dubai and Abu Dhabi nesting sites, with a high level of single paternity in Dubai and Abu Dhabi nests and high multiple paternity in Sir Bu Na'air nests. Across the time of the study (2008 -2010) no females were detected to nest in more than one nesting site and males rarely sired at different nesting sites, further supporting the presence of different breeding grounds in UAE (Natoli et al. 2017).In the Arabian region, Hawksbill turtles deposit multiple clutches and nest during the short summer seasons, typically between April/May and July (Pilcher et al. 2014a).Hawksbills nest on insular and mainland sandy beaches throughout the tropics and subtropics. Newly emerged hatchlings enter the sea and are carried by offshore currents into major gyre systems where they remain until reaching a carapace length of some 20 to 30 cm (Mortimer and Donnelly 2008). However, recent studies (Vargas et al. 2015, Natoli et al. 2017) have found the species to have more distinct sub-populations, including a clade restricted to the Gulf. One in the sea, they move into foraging habitat that may comprise coral reefs or other hard bottom habitats, seagrass, algal beds, or mangrove bays and creeks (Musick and Limpus 1997) or mud flats. As they increase in size, immature turtles typically inhabit a series of habitats, with some tendency for larger turtles to inhabit deeper sites (van Dam and Diez 1997, Bowen et al. 2007). Once sexually mature, they undertake breeding migrations between foraging grounds and breeding areas at intervals of several years (Witzell 1983, Dobbs et al. 1999). Global population genetic studies have demonstrated the tendency of female sea turtles to return to breed at their natal rookery (Bowen and Karl 1997), even though as juveniles they may have foraged at developmental habitats located hundreds or thousands of kilometres from the natal beach. While Hawksbills undertake long migrations, some portion of immature animals may settle into foraging habitats near their beaches of origin (Bowen et al. 2007). Generation Length (from Mortimer and Donnelly 2008)Generation length is defined here as the age to maturity plus one half the reproductive longevity (Pianka 1974). Hawksbills mature very slowly, taking 20 to 40 years, and so are long-lived (Chaloupka and Musick 1997). Age to maturity in the Indo-Pacific requires a minimum of 30-35 years (Limpus 1992, Limpus and Miller 2000, Mortimer et al. 2002, 2003).Data on reproductive longevity in Hawksbills are limited, but becoming available with increasing numbers of intensively monitored, long-term projects on protected beaches. During the last decade, numerous individual Caribbean Hawksbills have been recorded actively nesting over a period of 14-22 years (Parrish and Goodman 2006). In the Indo-Pacific Mortimer and Bresson (1999) and Limpus (1992) have reported nesting over 17-20 years, comparable to other Chelonid turtles which range from 20 to 30 years (Carr et al. 1978, FitzSimmons et al. 1995).Given estimated ages to maturity of 25 years in the Caribbean and 35 years in the Indo-Pacific, with half of reproductive longevity estimated at ten years, a conservative generation length of 35 years (25 + 10 years) is calculated for the Caribbean and Western Atlantic, and 45 years (35 + 10 years) in the Indo-Pacific. In analyzing the data, declines over three generations are therefore measured for up to 135 years in the Indo-Pacific. In fact, generation length may well have been longer in the days when population density was higher (Bjorndal et al. 2000).