Katarzyna Wojczulanis-Jakubas

Countries have committed to expanding the marine protected area (MPA) network to 30% of the world's ocean by 2030, more than tripling current coverage, and focusing on areas important for biodiversity. For such expansion to translate into effective conservation of marine biodiversity, it must rely on the best available knowledge. Here, we analyze tracking data on > 13,000 individuals (44 species, eight families) to map the distribution of highly mobile seabirds in the Atlantic Ocean and adjacent seas throughout the year. We identify regions important year‐round or seasonally. The High Seas are as important as national waters for highly mobile seabirds but are even less protected. Current Atlantic MPAs hold < 14% of tracked species density, but their expansion to 30% of the ocean could protect up to two thirds. We share this new knowledge layer to support national and international efforts and policies to strategically expand the Atlantic MPA network.

Seabirds adjust their foraging behaviour to cope with changing environmental conditions by changing prey choice, foraging locations and trip characteristics. We studied the foraging ecology of zooplanktivorous little auks (Alle alle) during chick-rearing in SW Spitsbergen across seven years (2011–2024), using GPS tracking, oceanographic data and diet analyses. Across years, little auks consistently foraged within the same core and home ranges over the continental shelf and its break, within a 150-km buffer around the colony. However, within this range, they demonstrated plasticity by adjusting their foraging strategies in response to environmental conditions. Birds adopted a consistent foraging strategy under optimal conditions and shifted to a flexible strategy when conditions became suboptimal, primarily by changing local foraging sites. These shifts resulted in interannual variation in habitat niche size: under favourable conditions (low sea surface temperature and intermediate chlorophyll-a), birds utilized a narrow niche, whereas in warmer, high-productivity years, they broadened it. Despite environmental variability, diet remained dominated by cold-water copepods (Calanus glacialis, 74.6%–89.7%). In suboptimal years, as in warm 2023, they supplemented chick diets with 16% furcilia larvae of Euphausiacea sp. Our results suggest that, in seabirds, habitat niche breadth is a valuable indicator of ocean-related conditions.

Across their entire Atlantic breeding range, Atlantic puffins Fratercula arctica have experienced decreases in food availability, often leading to population declines. The species is one of the most numerous seabirds in Føroyar (the Faroe Islands, in English) but has faced apparent, unquantified population declines. To better understand the underlying processes of this decline in Føroyar, we studied the change in the average, estimated age of puffins (i.e. the population age structure) harvested over a 20‐year period (1989–2008). We assessed how the population age structure changed over time and in relation to food availability indices (i.e. phytoplankton primary production, juvenile fish) . We showed that the average age of the birds in the population increased over time during the studied period, as the contribution of younger age classes declined, and cohort sizes decreased. Further, we showed that population age structure was significantly affected by food availability in the hatch year and the years preceding the hatch year, but only one of the relationships with food availability in the harvest year was significant. Our study thus suggests that reduced reproductive success driven by variability in foraging conditions is an important factor in the Atlantic puffin population decline in Føroyar.

In the search for universals shaping acoustic communication across species, we increasingly look for patterns known from human languages and music in non-human animals. These parallels are often explored separately and with limited ecological context. Here, we take a deep dive into the temporal structure of a complex call used by the little auk ( Alle alle ), a pelagic seabird with elaborate vocal behaviour and socially complex colonial life. Based on syllable durations, intervals and silences, we examine its conformance to linguistic laws, rhythmic structure and information content. This reveals intricate problems of temporal organisation: while the calls conform not only to linguistic laws of brevity but also to the initial and final lengthening known from human prosody, these effects interact with the internal structure of the call and information carried within it. To our knowledge, this is the first time that conformance to multiple linguistic laws, exceeding simple vocal efficiency, has been described for a non-human, non-vocal learning animal. The calls’ rhythmic structure shows a progressive rallentando — a systematic slowing driven by changes in syllable and silence durations and the intervals between syllable onsets. The exact patterns of this rallentando are indicative of the caller’s sex and individually specific. These results reveal how seabird communication is shaped not only by efficiency universals, but also the specific pressures of colonial life. Our work highlights the temporal structure as an important axis of communication evolution, but also serves as a reminder to consider the species’ ecological reality and the function, not only presence, of temporal organisation. Abstract Figure:

Cognitive abilities play a critical role for migratory birds encountering unfamiliar habitats at stop-over sites. We investigated factors (age, sex, fuel reserves, vertical/horizontal activity, and mercury level) affecting cognitive abilities behavior (problem-solving task—escaping from an experimental cage) in a long-distance migratory passerine, the sedge warbler (Acrocephalus schoenobaenus) at an autumn stop-over site. During the experiment, after two minutes of acclimatization, we remotely opened the door of the cage and recorded whether each bird escaped or remained in the cage. A mixed-effects Cox model revealed that the probability of escaping from the cage was significantly affected by variance in horizontal movements along the horizontal axis of the cage during the acclimatization phase (in models for all individuals and immatures) and sex (in immatures). Individuals moving more were more likely to escape from the cage. Immature males, at any given time, were 2.3 times more likely to escape from the cage than females. We interpreted this in the context of risk-partitioning with males adopting a high-risk, high-reward strategy and females using a low-risk, low-reward strategy, which may be associated with a predisposition for sex-specific roles in breeding. The repeatability of escape response was low (7.3%) for the same recaptured individuals.

How well does the information contained in vocal signals travel through the environment? To assess the efficiency of information transfer in little auk (Alle alle, an Arctic seabird) calls over distance, we selected two of the social call types with the highest potential for individuality coding. Using available recordings of known individuals, we calculated the apparent source levels, with apparent maximum peak sound pressure level (ASPL) of 63 dB re 20 μPa at 1 m for both call types. Further, we created a sound attenuation model using meteorological data collected in the vicinity of the little auk colony in Hornsund, Spitsbergen. Using this model, we modelled the calls to reflect higher frequency filtering and sound level loss occurring during spherical spreading in perfect local conditions, down to the putative hearing threshold of the species, calculated to equal ASPL of signals “propagated” to roughly one kilometre. Those modelled calls were then used in a permuted discriminant function analysis, support vector machine models, and linear models of Beecher’s information statistic, to investigate whether transmission loss will affect the retention of individual information of the signal. Calls could be correctly classified to individuals above chance level independently of the distance, down to and over the putative physiological hearing threshold. Interestingly, the information capacity of the signal did not decrease with its filtering and attenuation. While this study touches on signal properties purely and cannot provide evidence of the actual use by the animals, it shows that little auk signals can theoretically travel long distances with negligible information loss, and supports the hypothesis that vocalisations could facilitate long-distance communication in the species.