When the museum opened in 1904 its collections were primarily based on natural history specimens. These included many zoological specimens from the Cleveland Lit & Phil Naturalist’s Field Club, the hunting collections of A.E. Pease and a collection of birds purchased by H.W.F. Bolckow in 1874. In 1918 the T.H. Nelson collection of birds and eggs were bequeathed and put on permanent display. During the late 1960s to early 1970s when the museum was part of Teesside Museums Service a large number of zoological specimens were transferred to the newly established School’s Museum Service. It was during this time that the main galleries were redisplayed changing the emphasis from natural history to local history although the Nelson Bird Room was kept. Due to the fragility of the materials most of the extant zoological collections are now held in store and only displayed for short periods in special exhibitions. A few large mounts can be seen in the shop area, including the museum’s adopted emblem – the A.E. Pease lion.
The museum’s zoological collections still represent the major part of its holdings, numbering in excess of 150,000 specimens. The bulk of the collections are made up of invertebrates, especially molluscs and insects.
The majority of the invertebrate collection is made up of insects c.50,000 and molluscs c.65,000.
- Butterflies: approximately 3,000 specimens including a large packeted collection of Indian species. A number of cased exotics transferred from Darlington.
- Moths: a large collection of UK moths, especially micro moths.
- Spiders: large spirit collection from local surveys carried out in the former County region of Cleveland during the 1970’s. Report available.
- Beetles: a large 19th. century collection of world wide specimens acquired around 1934, possibly part of the collections of Alexander Fry (1821-1905).
- Other groups represented by just a small number of specimens in mixed collections, some relating to the 1970’s surveying.
- Tropical molluscs: around 65,000 specimens including part of the J.H. Fryer collection (also in Hancock Museum); G.L. Dorman collection and others. Mostly 19th century and requiring further documentation work.
- UK molluscs: large collection of fresh water and land molluscs collected by Baker Hudson and Rev. John Hawell, mostly local, late 19th century and early 20th. century. Mostly very local.
- Corals & sponges: about 200 tropical specimens.
- Others: small collections of crustacea, echinoderms etc. Also some early 20th century large scale plaster models.
The majority of the vertebrate collection is made up of bird specimens, including eggs and nests.
- Birds: About 1,000 specimens mostly mounted or de-mounted, few study skins. Principal collection is that of Thomas Hudson Nelson, author of the Birds of Yorkshire donated in 1918 and mostly on display in a dedicated gallery (see the Nelson Room under the Galleries pages for more information).
- Bird Nests: about 150 specimens including an unusual early 20th century wooden boxed collection with whole clutches transferred from Darlington Museum, collector unknown (to be researched), otherwise mostly single 20th. century acquisitions.
- Bird Eggs: about 3,500 specimens. Principal collection is T.H. Nelson, other smaller cabinet collections. Notable collection of guillemot eggs showing immense colour, markings and shape variations. About 2,500 specimens 19th to 20th century. Many on display in the Nelson Room gallery.
- Mammals: a mixed collection mostly A.E. Pease 19th century material from NE and S Africa comprising skulls, large mounts and trophy heads. Some Australian marsupials acquired for display in the Capt. Cook Birthplace Museum. A few small cased mammals illustrating British wildlife.
- Fish: a small number of fish cast mounts now in poor condition.
- Amphibians: a small number of cased examples mostly British
- Reptiles: a few full mounts including crocodiles, alligator, tortoise etc. Some skins, skulls and turtle carapaces.