Poly(ethylene glycol) (PEG) having a polymerizable methacryloyl group at one end and an aldehyde group at the other end was quantitatively synthesized. Potassium 3,3-diethoxy-1-propanoxide initiated the anionic polymerization of ethylene oxide to form an acetal-ended PEG having potassium alkolate at the ω chain end. By adding methacrylic anhydride to the reaction mixture, the ω end was quantitatively converted to the methacryloxy group. When the PEG with an acetal group at one end and a methacryloyl group at the other end was treated with 90% acetic acid solution, the hydrolysis of the acetal end group proceeded to form a PEG macromonomer possessing an aldehyde end group. The end groups were characterized by 1H NMR and MALDI-TOF-MS spectroscopies. Copolymerization of the aldehyde-PEG macromonomer with methacrylate monomers quantitatively gave the PEG graft polymer with an aldehyde group at the free end of the graft chain.

The study of seabird behaviour has largely relied on animal-borne tags to gather information, requiring interpretation to estimate at-sea behaviours. Details of shallow-diving birds’ foraging are less known than deep-diving species due to difficulty in identifying shallow dives from biologging devices. Development of smaller video loggers allow a direct view of these birds’ behaviours, at the cost of short battery capacity. However, recordings from video loggers combined with relatively low power usage accelerometers give a means to develop a reliable foraging detection method. Combined video and acceleration loggers were attached to streaked shearwaters in Funakoshi-Ohshima Island (39°24’N,141°59’E) during the breeding season in 2018. Video recordings were classified into behavioural categories (rest, transit, and foraging) and a detection method was generated from the acceleration signals. Two foraging behaviours, surface seizing and foraging dives, are reported with video recordings. Surface seizing was comprised of successive take-offs and landings (mean duration 0.6 and 1.5s, respectively), while foraging dives were shallow subsurface dives (3.2s mean duration) from the air and water surface. Birds were observed foraging close to marine predators, including dolphins and large fish. Results of the behaviour detection method were validated against video recordings, with mean true and false positive rates of 90% and 0%, 79% and 5%, and 66% and <1%, for flight, surface seizing, and foraging dives, respectively. The detection method was applied to longer duration acceleration and GPS datasets collected during the 2018 and 2019 breeding seasons. Foraging trips lasted between 1 − 8 days, with birds performing on average 16 surface seizing events and 43 foraging dives per day, comprising <1% of daily activity, while transit and rest took up 55 and 40%, respectively. This foraging detection method can address the difficulties of recording shallow-diving foraging behaviour and provides a means to measure activity budgets across shallow diving seabird species.

No abstract

No abstract