2012). We thus undertook a branding study of northern elephant seals at Año Nuevo in 1985 aimed at studying survival rates of seals throughout their lifespan. All branding was done during 1985–1987 at the elephant seal colony in Año Nuevo State Park (37.113°N, LY2157299 nmr 122.329°W), 31 km north of Santa Cruz, California. The colony was established as a breeding site in 1961 (Radford 1965) but expanded rapidly and had 1,500–1,700 pups born during the branding years and as many as 2,500 after 1995 (Le Boeuf and Panken 1977, Le Boeuf et al. 2011). Weanlings, 8–14 wk of age, were captured on the Año Nuevo mainland in March– May during their postweaning fast. They were restrained in cone-shaped canvas bags

opened at both ends (Ortiz et al. 1978, Reiter et al. 1978, Crocker et al. 2006, Hassrick et al. 2007). Brands fashioned out of welded steel rods, each a single digit 15 cm high, slightly concave, and ringed by a guard to hold the brand evenly against the animal, were heated until dark red (600–650°C)

with a propane torch, or in a propane oven. The brands were applied to the flank for 3–4 s. Each animal was given a 1–3 digit number, always on the left side in 1985 and 1987 and the right side in 1986. The entire procedure took 5–8 min. Subjects were released immediately after branding, and within 5 min engaged in normal behavior, including sleeping, Trametinib manufacturer swimming, and socializing. The brand site blistered and opened within a few days, then dried and began healing

within two weeks; none became infected. Similar methods have been used for hot-branding in southern elephant seals, and long-term studies showed no deleterious effects and few brands lost (van den Hoff et al. 2004). After branding 78 animals in 1985, we redesigned Tacrolimus (FK506) the brands, adding the guard ring to ensure uniform application, resulting in digits that were easier to read. The new brands were applied to 294 animals in 1986 and 1987 (Table 1). As a check for failure or illegibility, two plastic Rototags (Dalton USA Inc., Fort Atkinson, WI) were attached to the hind flippers of 239 of the branded animals (Le Boeuf et al. 1972). Searches for marked seals were done at the Año Nuevo colony from 1986 to 2012 on 95% of all days during the January–February breeding season, and >100 individual seals with brands or tags (including those without brands) were identified every year (median 261 animals, minimum of 108 in 1999, maximum of 505 in 1986). In 1986–1989, additional searches were done during March–June, a juvenile haul-out period, covering 85% of all days. Hair dye was applied to the fur of identified individuals when possible to facilitate subsequent observations within the year (Le Boeuf and Peterson 1969). Observations were also made at the two colonies nearest Año Nuevo (Fig. 1): Southeast Farallon Island (37.698°N, 123.005°W; Huber et al. 1991) was searched every day in winter and spring haul-outs, and Point Reyes (37.995°N, 123.009°W; Allen et al.