Japan's Wildlife Year
Month by month the flora and fauna of Japan are in constant change. From spring blossoms to autumn colours, from migrant birds to resident mammals; there is always something interesting to look for.
I think of Japan as having six seasons, though only four are typically referred to. In addition to the standard, Spring, Summer, Autumn and Winter, Japan also has an early summer "Rainy Season", and a late summer/early autumn "Typhoon Season".
Because of the long spread of the archipelago from north to south, the seasons overlap. Despite spring having arrived in the south in February in Okinawa for example, it is still winter in the north, in Hokkaido, so the season depends very much on the region. In addition seasonality varies with the altitude; hike a mountain and you can literally peel back the season by a month.
Spring: February to May
Rainy Season: June/July
Summer: May to August
Typhoon Season: August to October
Autumn: September to November
Winter: December to March
January. This mid-winter month sees low temperatures throughout the country. Snow may extend as far south as Kyushu. Many mammals are hibernating. In the north most small passerine birds have moved south leaving behind only the larger wintering species. In central and western Honshu and Kyushu many wintering species have joined the resident species making for good birding in many areas. Species such as cranes, swans, geese, owls and so on have settled into their fixed winter patterns with regular feeding and roosting sites.
Only in the far south, the Nansei Shoto islands between Kyushu and Taiwan, can one expect mild temperatures.
February. An exciting month when Hooded and White-naped Cranes are present in Kagoshima Prefecture, Kyushu, at peak numbers - reaching 13,000 birds in some years - and when Red-crowned Cranes can be seen gathering and dancing at their winter feeding grounds in east Hokkaido. At one of these sites, live fish are put out for the cranes and this scenario regularly attracts up to a dozen White-tailed Sea Eagles.
During February, sea-ice extends down the Sea of Okhotsk reaching the northeast coast of Hokkaido and in particular the Shiretoko Peninsula. This is the time of year to take a boat trip out of Rausu to see the gathering of Steller's Sea Eagles in the Nemuro Channel, between Shiretoko and Kunashiri. Ural Owls are occupying their winter roost sites and Blakiston's Fish Owls are courting. Red Fox and Sika Deer are particularly conspicuous at this time of year, and the nocturnal Sable can be seen at certain locations. Meanwhile in southern Japan the first cherry blossoms are blooming in Okinawa and the first plum blossoms appear in Kyushu.
Birdwatching in the Arasaki area of Kyushu and in the Karuizawa area of central Honshu are especially rewarding at this time of year.
March sees the wave of Cherry Blossom move northwards through Kyushu, and by the end of the month trees are in blossom from northern Kyushu to Nara and Kyoto, yet in the far north of Japan sea-ice may still linger on the Sea of Okhotsk shore of Hokkaido and in the Nemuro Channel.
Considerable migration is taking place throughout the month, with hordes of Whooper Swans and bevies of Bewick's Swans winging north through Honshu and into Hokkaido. Tens of thousands of Greater White-fronted Goose, and smaller numbers of Taiga and Tundra Bean Goose are also on the move.
Wintering birds are beginning to leave the country. The last Steller's Sea Eagles are also moving north, most of the adults have headed into Russia leaving behind a higher proportion of young and subadults; it is usually possible to find the last lingering birds in east Hokkaido until the end of the month. Some White-tailed Sea Eagles linger to breed in Hokkaido, and by this month Red-crowned Cranes are beginning to move out to their breeding territories from their winter feeding grounds.
Japanese Squirrels in Honshu and Eurasian Red Squirrels in Hokkaido are gathering nesting material for their birthing dens, and Japanese and Siberian Flying Squirrels are emerging more conspicuously each night as dusk falls.
April. Spring brings changeable and rapidly warming weather with warm winds from the south. The Cherry blossom front is moving quickly north and east across Honshu and soon azaleas and irises will be in bloom.
As the southern cranes (White-naped and Hooded) are leaving Kyushu, the Red-crowned Cranes of Hokkaido are occupying their territories. Many migrant birds are on the move with shorebirds concentrating at coastal bays and river mouths, while waterfowl are flooding northwards towards their breeding grounds in Russia. The last of the geese and swans are bound for Hokkaido and Sakhalin.
By May, southern Japan is already experiencing summer heat, rising towards 30°C, however in the north much snow still remains in the mountains and it is very much a spring month.
Summer birds are already breeding and woodlands now are alive with the songs of our best songsters, such as Japanese Thrushes and Narcissus Flycatchers.
August. Despite it being late summer, temperatures can remain high at this time of year. Temperatures exceeding mid 30°C in central Honshu and high 20°C in Hokkaido are not unusual.
Late flowering summer flowers are still in evidence at low altitudes, but at high altitudes early autumn colours begin in the higher mountains of central Hokkaido.
Autumn bird migration has begun, with early returning shorebirds appearing at coastal wetland sites, and forest birds steadily draining away from the higher and more northerly parts of their breeding range.
The first typhoons have usually occurred in southern Japan by now, meaning that this summer month overlaps with the Typhoon Season - be prepared for torrential rain in the south.