Dmitry Kaygorodov

Forester, ornithologist, forest‑technology specialist, educator and popularizer of natural science-often called the "father of Russian phenology". Writer Lev Razgon described him as a "soul open to nature".

Born in Polotsk to Major‑General N. I. Kaygorodov, a mathematics teacher at the Polotsk Cadet Corps, Dmitry’s childhood among gardens and nearby woods sparked a lifelong love of nature.

After graduating from the Polotsk Cadet Corps (1863), the Konstantinovsky School (1864) and the Mikhailovsky Artillery School (1865), he served briefly in artillery before being posted in 1867 to the Okhta Powder Works near Saint Petersburg. Working amid vast woodlands, he spent his free time observing birds, collecting insects and studying plants.

In 1869 he entered the Agronomic (later Forestry) Institute and graduated with the title Candidate of Agriculture and Forestry. The institute retained him to teach and sent him on internships to Germany, Sweden and Switzerland.

Returning to Russia, Kaygorodov established a new school of forest engineering by teaching Forest Technology. After defending his doctoral dissertation in 1882 he headed the Department of Forest Technology and later the Department of Forest Engineering for thirty years.

He studied the technical properties of wood and invented an instrument for measuring wood’s physical properties that remained in use. About half of his more than 300 publications address wood science and forest technology; his 1883 Forest Commodity Dictionary became an essential reference.

Kaygorodov was also a gifted popularizer and lyrical writer. He authored many well‑known works, including Conversations About the Russian Forest, Petals, About Our Migratory Birds, From the Realm of the Feathered, Our Spring Flowers, From the Green Kingdom and Our Summer Flowers.

He helped pioneer school field excursions and designed nature‑based curricula organized by habitat (forest, garden, meadow, river, etc.).

As a founder of the Russian Society of Amateur Naturalists and head of its phenology section, in 1885 he began building a phenological network for bioclimatic zoning of European Russia. By 1912 the network included 617 observers; by 1918 he had received over 23,000 local observations and about 3,000 observation points contributed data that produced bird arrival charts and phenological maps for European Russia.

In his later years Kaygorodov worked in the Forest Department of the State Institute of Experimental Agronomy, processing decades of phenological data.

Dmitry Kaygorodov died on 11 February 1924 at age 77 and is buried in the park at the Forest Technical Academy in Saint Petersburg.