Influence of natal habitat preference on habitat selection during extra-home range movements in a large ungulate

On the interface between cultural transmission, phenotypic diversity, demography and the conservation of migratory ungulates

Recent evidence indicates that green-wave surfing behaviour in ungulates and the migrations that stem from this behaviour are socially learned, culturally transmitted across generations and become more efficient via cumulative cultural evolution. But given a lack of corroborative evidence, whether ungulate migration is a cultural phenomenon remains a hypothesis deserving of further testing. In this opinion piece, we summarize the role memory and social learning play in the green-wave surfing that underlies ungulate migration, and when combined with the natural history of ungulates, we argue that the most likely mechanism for maintenance of ungulate migration is animal culture. We further our argument by providing a synopsis of processes that promote diversification of migratory behaviour and link these processes to their emergent ecological patterns, which are common in nature but have not historically been considered as potential cultural phenomena. The notion that diverse portfolios of migratory behaviour may buffer populations from environmental change emerges from this synthesis but requires empirical testing. Finally, we contend that, because the migratory behaviour of ungulates stems largely from cultural transmission as opposed to a genetic programme, the diversity of observed migratory strategies represents 'culturally significant units' deserving of the same conservation effort afforded to evolutionarily significant units.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Imprinted habitat selection varies across dispersal phases in a raptor species

Natal Habitat Preference Induction (NHPI) plays a significant role in shaping settlement decisions in dispersive animals. Despite its importance, limited research has explored how NHPI varies during natal dispersal phases and across different types of natal habitats. In this study, we examined NHPI in 77 GPS-tagged juvenile red kites (Milvus milvus) originating from different natal habitats along an elevational gradient in Switzerland. We applied individual-based step selection analysis to investigate habitat selection from independence to settlement. We found that during the prospecting phase, individuals predominantly selected habitats similar to their natal environments. However, this pattern changed in the settlement phase: individuals fledged from habitats at higher elevations or closer to urban areas mostly avoided similar habitats (negative NHPI), while those from areas with more farmlands or pastures (combined with forests) showed a preference for similar habitats (positive NHPI). Moreover, the magnitude and individual variation in NHPI differed depending on the natal habitat types from which individuals originated. These findings highlight that strength, direction, and individual variation in NHPI differ between natal habitat types and dispersal phases. Natal habitats therefore can have pervasive legacy effects on subsequent habitat selection, likely affecting population and range dynamics.

Integrating learning into animal range dynamics under rapid human-induced environmental change

Human-induced rapid environmental change (HIREC) is creating environments deviating considerably from natural habitats in which species evolved. Concurrently, climate warming is pushing species' climatic envelopes to geographic regions that offer novel ecological conditions. The persistence of species is likely affected by the interplay between the degree of ecological novelty and phenotypic plasticity, which in turn may shape an organism's range-shifting ability. Current modelling approaches that forecast animal ranges are characterized by a static representation of the relationship between habitat use and fitness, which may bias predictions under conditions imposed by HIREC. We argue that accounting for dynamic species-resource relationships can increase the ecological realism of range shift predictions. Our rationale builds on the concepts of ecological fitting, the process whereby individuals form successful novel biotic associations based on the suite of traits they carry at the time of encountering the novel condition, and behavioural plasticity, in particular learning. These concepts have revolutionized our view on fitness in novel ecological settings, and the way these processes may influence species ranges under HIREC. We have integrated them into a model of range expansion as a conceptual proof of principle highlighting the potentially substantial role of learning ability in range shifts under HIREC.