Chevin Forest Park GeoTrail #18: Nocturnal Sentinel
The 18th and last cache of the series, a small camo-taped plastic pot, is located in a shady grove just beyond the lower end of the flagged trail leading NE off the main trail along the ridge from Surprise View and heading back down into the woods.
For background info on the Chevin Forest Park including a map showing parking options, trails and cache locations, see GCB7RA1.
To Find the Cache:
Go to the large interpretation panel The Story of a Landscape at the published coordinates. By studying this you will note that:
1. (bottom left) Rivers flowing out of mountainous lands north of Britain deposited sand and mud over a wide delta region during a period of A0 million years
2. The image of the globe shows the continent of Gondwana 31B million years ago
3. The panoramic photo shows the view with places highlighted. The last place on the right has C letters in its name.
4. A total of D prehistoric animals is shown on the board
5. (middle) The last glacier ice in the valley below ‘finally melted E0,000 years ago’
Note 1/10/25: some brain-dead individual has badly damaged the info board, obscuring the required figure in the process, so use E=1
6. Now look at the leftmost of the three coloured columns on the right of the board showing geological and historical timescales. The yellow block shows a well-known period which started 1FF years ago.
The cache is hidden just over 300m away at:
N 53 53.(A+B)C(F-E) W 1 41.(B-C)(A+D)(F-C)
One of the iconic but less-commonly seen birds on The Chevin is the Tawny Owl (Strix aluco) - one of the most familiar and widespread owls in the UK. With its rounded head, large dark eyes, and unmistakable hoot, this secretive nocturnal bird is deeply embedded in British culture and folklore. Found throughout England, Wales, and parts of Scotland, the tawny owl is the only member of its genus commonly resident in the UK. It is thought it dislikes crossing large bodies of water, which is why they are only found on mainland UK.
It is a medium-sized, stocky bird about 37-39cm long (about the size of a woodpigeon) and a wingspan of around 94-104 cm. It has a rounded face and large, forward-facing dark eyes, which are well-adapted for low-light vision. Unlike a barn owl, it does not have a heart-shaped facial disc. Its mottled brown, rufous, or grey plumage allows to blend seamlessly into the bark of trees. There are 2 main colour morphs in the UK: brown and grey. These colour differences are not due to age or sex but are genetic variations probably evolved for different environments.
This colouration makes them tricky to spot up in the canopies, but their vocalisations often betray their localisation. They are especially vocal during late autumn and winter months, looking for mates before their breeding season kicks off early in the year.
Its haunting ‘twit-twoo’ call, often heard at night, is actually a duet between a male and female. The male produces the hooting ‘twoo’ and the female responds with a sharp ‘ke-wick’. Hearing this on a moonlit night is one of the most evocative experiences of the natural world (listen here and here).
It is a highly territorial and sedentary bird, usually sticking to one area throughout its life. It prefers deciduous and mixed woodlands but is also found in urban parks, large gardens, and even cemeteries, as long as there is sufficient tree cover.
Field and Type of Vision
A true nocturnal predator, it is most active during the hours of darkness. It uses its exceptional hearing and vision to locate prey in complete darkness. Its flight is silent, thanks to the structure of its feathers, allowing it to swoop undetected on small mammals such as voles, mice, and shrews. Birds, frogs, beetles, and even earthworms also make up part of its varied diet.
It is fiercely territorial, especially during the breeding season, which typically starts in late winter. Males call to establish territories and attract females. Once paired, the female lays 2-4 eggs in a tree cavity, old crow’s nest, or even a nest box. She incubates the eggs while the male provides food. The chicks hatch after about a month and fledge within 5 weeks, though they often remain dependent on their parents for some time afterward.
In the UK, it is a species of Least Concern, being relatively common in suitable habitats. However, long-term monitoring by organisations such as the British Trust for Ornithology (BTO) has shown a decline in some populations, particularly in areas where habitat loss and changes in land use have impacted woodland ecosystems.
Another concern is the fragmentation of habitats, which isolates populations and reduces breeding success. Collisions with vehicles are a frequent cause of mortality, especially where roads cut through wooded areas. Despite these challenges, it is a resilient species, partly due to its adaptability to semi-urban environments.
It has long been associated with mystery and the supernatural in British folklore. Its eerie calls have often been linked with omens and death, although modern appreciation has shifted toward admiration for its ecological role and nocturnal beauty. It frequently appears in literature, such as the works of Shakespeare, and is a staple in children’s books and media, often portrayed as wise and watchful.
See here for more info on this iconic species. See here and here for an excellent short videos and here for a wonderful longer video with great footage including of wild owls adopting 6 orphans.
See gallery for more!