Buff-tailed Bumblebee (Bombus terrestris), 12 December 2019. Photo Ken Dobson.

December 2019 at RBGE gave the impression of being somewhat dull and wet although the graphs do not bear this out. Total rainfall was 52.4 mm, most of it being spread over the first ten days. Sunshine amounted to 58.3 hours, spread pretty evenly through the month. The highest maximum temperature was 13.3°C and the lowest air minimum -4.5°C, while the means were 8.3°C (maximum) and 2.4°C (minimum).  Air frost was recorded on seven dates but ground frosts were much more frequent, with the grass minimum being at or below freezing on more than half the nights. The coldest nights were right at the beginning of the month (-9.4°C on 1st) and again at the very end when it did not dip quite as low.

For the second month in a row, no new Garden wildlife records were made and the total count at the end of December, and of calendar year 2019, remained at 1,131, an increase of 54 since the end of December 2018.

Female Blackcap (Sylvia atricapilla), 9 December 2019. Photo Ken Dobson.

Birds: Thirty-eight bird species were recorded at RBGE during December 2019. The most notable was unfortunately an unconfirmed record: an owl seen flying over the Garden by day on 3rd may possibly have been a Short-eared Owl. The last definite record of Short-eared Owl at the Botanics was 57 years ago, by J.H. Swan on 23 May 1963. It is unfortunate that on this occasion the two observers did not get a good enough view of the bird to make a positive identification. The month’s confirmed records included 14 of Kingfisher, 10 of Sparrowhawk, 9 of Grey Heron, 7 of Redwing, 6 of wintering Blackcaps and 5 of Nuthatch. Grey Wagtail was recorded twice (16th and 19th), Buzzard twice (17th and 21st) and Pink-footed Geese flew northwards on 22nd. However, the Collared Doves that have been resident in the Garden since springtime seemed to desert it in December, being recorded only once, on 16th.  Waxwings did not appear to visit the Garden during December despite there being quite a lot of sightings elsewhere in the city, including Princes Street Gardens and a supermarket car park. The complete list of 37 definite and one unconfirmed species recorded during December 2019 was: Blackbird, Blackcap, Black-headed Gull, Blue Tit, Bullfinch, Buzzard, Carrion Crow, Chaffinch, Coal Tit, Collared Dove, Dunnock, Feral Pigeon, Goldcrest, Goldfinch, Great Spotted Woodpecker, Great Tit, Greenfinch, Grey Heron, Grey Wagtail, Herring Gull, Kingfisher, Long-tailed Tit, Magpie, Mallard, Mistle Thrush, Moorhen,  Nuthatch, Pink-footed Goose, Redwing, Robin, Siskin, Song Thrush, Sparrowhawk, Tawny Owl, Tree Creeper, Wood Pigeon, Wren and the unconfirmed Short-eared Owl.

Mammals and amphibians: A Brown Rat was seen on five different dates, while a similar but smaller animal, possibly a juvenile, was also seen and photographed. A Fox was seen on 16th, and there was the usual visible evidence of Badgers’ nocturnal grubbing activities on the lawns. Amphibians were apparently hibernating, with none being recorded.

Insects and other invertebrates: Even fewer invertebrates were recorded during December than in the previous month. No butterflies or moths were reported.  Buff-tailed Bumblebee was seen out and about twice, on 12th and 31st, indicating the presence of an active winter nest. Marmalade Hoverflies were seen on 29th and an orange-bodied fly photographed on the same date (see below) was most likely Phaonia subventa.  

Probable Phaonia subventa, 29 December 2019. Photo Ken Dobson.