Europe
Bryde’s Whales have a seasonal presence in southern European waters (Madeira, the Canary Islands and to a lesser extent the Azores) from late spring to early autumn, when water temperature is warmer. In the Azores, they were recorded at 21.6–23.5 ºC (Steiner et al. 2008). Bryde’s Whales seem to take advantage of the seasonally higher productivity of insular habitats and surrounding sea mounts (Freitas and Penry 2021). They were reported at depths between 500 and 1,000 m in the Azores (Steiner et al. 2008), while in Madeira and the Canary Islands animals have been sighted in offshore waters over 2000 m in depth and in waters less than 100 m deep, very close to shore (L. Freitas and J. Marrero-Pérez pers. comm. 2022). Females with calves are regularly observed in Madeira and the Canary Islands and have been reported occasionally in the Azores (Steiner et al. 2008, Alves et al. 2018, J. Marrero-Pérez pers. comm. 2022).

In European waters, Bryde’s Whales seem to feed on schooling fish in all three Macaronesia archipelagos (Steiner et al. 2008, Alves et al. 2010, Brederlau et al. 2011, J. Marrero-Pérez pers. comm. 2022). In the Canary Islands, animals were observed surface feeding on Longspine Snipefish, Sardines, Mackerel, Horse mackerel and Anchovy (Brederlau et al. 2011, J. Marrero-Pérez pers. comm. 2022), while in Madeira and the Azores they feed on Horse Mackerel, and possibly Sardines, Blue Jack Mackerel or Chub Mackerel (Steiner et al. 2008, L. Freitas pers. comm. 2022). Off Madeira, time-depth recorders revealed a differential day-night activity likely correlated with zooplankton diel vertical migrations: shallow dives of less than 40 m occurred both day and night, but deeper dives with lunge activity started at dusk (up to at least 292 m) (Alves et al. 2010).

Madeira and the Canary Islands, and to a lesser extent the Azores, seem to be important feeding and calving areas for the species. Preferred habitat in offshore waters is not well identified but Bryde’s Whales seem to be attracted to productivity areas around seamounts while wintering and breeding areas are not known but believed to be closer to the Equator or even in the southern hemisphere (Freitas and Penry 2021). Their preference for warm water temperatures could increase their presence in temperate European waters in the future due to climate change. In the last years, possible mating behaviours have been occasionally observed in the SW of Tenerife (J. Marrero-Pérez pers. comm. 2022), which could indicate that some whales do not need to migrate to lower latitudes in winter.

Global
The ecology of Bryde’s Whales differs among populations and it is hard to make generalizations. The resident South African small inshore form showed no marked seasonality in reproduction and fed mainly on Anchovy, Pilchard, and Jack Mackerel, while the offshore (ordinary) form bred primarily in autumn and fed primarily on euphausiids and myctophids (Best 1977). Kawamura (1977) found that Bryde’s Whales from the South Pacific and Indian Oceans fed solely on euphausiids, but Ohsumi (1977) and Watanabe et al. (2012) found that in the northwestern Pacific they consumed Anchovy in addition to euphausiids. Bryde’s Whales caught in the Arabian Sea fed mainly on myctophids, Mackerel, and Sardines (Mikhalev 2000).

Europe
In the North Atlantic Ocean, the distribution of Bryde’s Whales is not well known. Their presence in European waters has recently been reviewed by Freitas and Penry (2021) who confirmed a regular presence of the species in subtropical and tropical waters of Macaronesia. Bryde’s Whales are observed regularly in the Canary Islands where there are the most common baleen whales between spring and autumn (Pérez-Vallazza et al. 2008, Carrillo et al. 2010, SECAC 2014). In the past decade, they have been observed regularly every month of the year, especially in the SW of Tenerife Island (J. Marrero-Pérez pers. comm. 2022). They are also the most commonly observed mysticete species in the Madeira archipelago, mostly present between June and November (Freitas et al. 2012, Alves et al. 2018) but observed sporadically all year long in the last years (L. Freitas, pers. comm. 2023). Few whales have been photographed in both archipelagos (Ferreira et al. 2021). Despite their usual tropical distribution, they have been first identified in the Azores in 2004 and observed occasionally in the summer months since then (Steiner et al. 2008, Silva et al. 2014).

Although the main target species was the Fin Whale (Balaenoptera physalus), whaling statistics for the Strait of Gibraltar include 10 caught Bryde’s Whales in 1948 and 102 caught Sei Whales in the six following years (Sanpera and Aguilar 1992). The authors attribute this difference either to confusion in the species identification or to a possible area of overlap for these species. The fact that 1948 catches happened in winter, opposite to the seasonal presence of Bryde’s Whales at the northern limit of their range, seems to give more support to the hypothesis of species misidentification. Sporadic observations of Bryde’s Whales have been reported in 2020 and 2021 in southern waters of mainland Portugal (Castro et al. 2021). One stranded animal was reported in 1997 in the Spanish Gulf of Cadiz (Gutiérrez- Expósito et al. 2013) and two in 2010 and 2013 in the western Mediterranean Sea near the Strait of Gibraltar (Junta de Andalusia stranding network). A whale stranded in Egypt in 2018 was assigned to Bryde’s Whales based on mitochondrial DNA (Abo-Taleb et al. 2020) but identified as Fin Whale (B. physalus) based on morphological features (Farrag et al. 2019, 2022) so it is not considered as confirmed here. The two northernmost records are the sighting followed by stranding of a young 7 m male in the inner Danish waters in September 2000 (Kinze 2006) and a recent live stranding of a 10 m animal in October 2020 on the French coast of the English Channel (Dabin 2022), which are considered extralimital records and are not shown on the map.

There are currently no morphological studies of Bryde’s Whales in European waters and subtropical neighbouring waters to confirm if the observed animals belong to the smaller inshore or larger offshore form. However, two genetic studies associate one animal from Madeira and another from the Canary Islands to the offshore South African Bryde’s Whales B. e. brydei clade (Alves et al. 2010, Rosel and Wilcox 2014, Luksenburg et al. 2015). Similarly, the specimens stranded near the Strait of Gibraltar were assigned to B. e. brydei (P. Gauffier pers. comm. 2022). From a morphologic point of view, Bryde’s Whales observed in Madeira, the Azores and the Canary show oval-shaped pits (Steiner et al. 2008, Freitas and Penry 2021, Montañés et al. 2022), which was described as a possible diagnostic feature for the offshore South African population of B. e. brydei (Best 2001).

Historical presence of Bryde’s Whales in European waters is not well understood. Considering the current regular sighting of the species in local inshore waters, it seems unlikely that Bryde’s Whales (or misidentified Sei Whales) would have gone unnoticed in the Canary Islands, and even more in Madeira archipelago where artisanal coastal whaling took place during forty years (1941–1981) and no records of Sei or Bryde’s Whales exist (unpublished data from the “EBAM - Empresa Baleeira do Arquipélago da Madeira”, Madeira Whale Museum). Best (1992) is the only reference reporting the catch of 62 Bryde’s Whales between the Canary Islands and Madeira in 1976. Previous whaling records do not mention the presence of Bryde’s or Sei Whales near these archipelagos, only further south towards Cape Verde or Senegal. The species was not recorded in the Azores whaling grounds either (Brito 2008).

They seem to show a latitudinal gradient of presence, from year-round presence in the Canary Islands to a higher seasonal presence in summer and autumn in Madeira and mostly summer appearances in the Azores. The species distribution seems to be related to warm sea temperatures, and these could have recently become more frequently suitable in southern Macaronesia, explaining the current regular sightings in the Canary Islands and Madeira. The future increase of temperature due to climate change might extend their range towards temperate waters of the northeast Atlantic, as could be suggested by the recent occasional sightings in the southern Iberian Peninsula and Azores archipelago.

Global
Strandings from the Moroccan Atlantic coast were all attributed to a dozen Fin and a dozen Sei Whales (Masski and de Stephanis 2018), which could indicate that they do not use Moroccan waters regularly. However, some whales were in an advanced state of decomposition, which could have prevented correct species identification. Bryde’s Whales were recently recorded off Mauritania (Baines and Reichelt 2014, Russell et al. 2018) and off Cape Verde (Hazevoet et al. 2010) during winter, confirming the presence of the species in lower latitudes in the North Atlantic in that season. A newborn calf was found near Dakhla in Western Sahara (Notarbartolo-Di-Sciara et al. 1998).

On the western Atlantic, Bryde’s Whales are rarely found as far north as Cape Hatteras in the northwestern Atlantic (Rice 1998) and records from Gulf of Mexico are from a recently recognized species Rice’s Whale B. ricei (Rosel and Wilcox 2014; Rosel et al. 2016, 2021). Bryde’s Whales occur throughout the wider Caribbean Sea (Ward et al. 2001). Four Bryde’s Whales stranded in Aruba, southern Caribbean, clustered with offshore B. e. brydei from South Africa and one from Madeira (Luksenburg et al. 2015). Bryde’s Whales occur year-round throughout the coastal waters of Brazil (Zerbini et al. 1997) and strand regularly in southeastern Brazil (De Moura and Siciliano 2012). Samples of whales from Brazil have been assigned phylogenetically to B. e. brydei (Pastene et al. 2015).

Because the number of species, subspecies, or subpopulations of Bryde's Whales is still unresolved, and because the different forms are not readily distinguishable at sea, considerable uncertainty remains with regard to the geographic range of each form. Moreover, they can be easily confused with other Balenopteridae species from a distance, especially with Sei Whales (Balaenoptera borealis). In fact, it was not until 1972 that Bryde’s Whales were differentiated from Sei Whales in international whaling statistics (Cooke and Brownell Jr. 2018), which makes some early whaling reports difficult to take into account (Sanpera and Aguilar 1992).

Large-type Bryde’s Whales occur in the Pacific, Indian, and Atlantic oceans between about 40°N and 40°S (Kato and Perrin 2009). At least one form also occurs in the Red Sea. Migration to tropical waters in winter is documented for the southeastern Atlantic subpopulation (Best 2001) and for the northwestern Pacific subpopulation (Kanda et al. 2007). The migration patterns of other subpopulations are poorly known. Their occurrence in the North Pacific is generally confined to waters warmer than 20°C (Omura 1959, Sasaki et al. 2013), but they are also found in colder waters off the west coast of southern Africa and northward to at least 3°N (off Cameroon) in the Benguela Current (Best 2001).

There is a resident inshore population of small Bryde’s Whales off South Africa which shows some morphological and genetic differences from ordinary offshore Bryde’s Whales (Best 1977, 2001). Its main distribution is on Agulhas Bank between East London and Saldanha Bay (Best 2001). This population is closer phylogenetically to B. e. brydei and B. borealis than to B. e. edeni (Penry 2010). A subpopulation of Bryde's Whales summers off the west coast of southern Africa and migrates to West African equatorial waters (Cameroon-Gabon) in winter (Best 2001). This population has not yet been sampled genetically.

Globally, the Bryde’s Whale is listed as Least Concern by the IUCN Red List (Cooke and Brownell Jr. 2018). The Bryde’s Whale is included in Appendix I of the Convention on International Trade in Endangered Species although Japan has held a reservation against this listing since 1983. The species (as B. edeni) is listed in Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals, and vagrants are protected by the ACCOBAMS agreement in the Mediterranean, Black Sea and adjacent Atlantic area (https://accobams.org).

Although not created for the specific purpose of protecting Bryde’s Whales, two Sites of Community Importance (SCI) declared under the EU Habitat Directive include important feeding and calving habitat in Madeira and the Canary Islands. These are SCI “Cetáceos da Madeira” (PTMMD0001), encompassing all the coastal waters of the main Madeira Archipelago islands up to 2,500 m (6,815 km²) and the SCI “Espacio marino del oriente y sur de Lanzarote- Fuerteventura” (ESZZ15002), encompassing the coastal waters of the east and south of Lanzarote and Fuerteventura islands up to 2,000 m (14,328 km²).

Bryde’s Whales have been proposed to be monitored in Madeira and the Canary Islands for Descriptor 1 of the Good Environmental Status in application of the EU Marine Strategy Framework Directive in the Macaronesia subregion (Mistic Seas II 2019).

Further research is needed to assess population structure within European waters and the level of exchanges with the rest of the Atlantic Ocean.