Blue-grey Tanager. Colombia 2025

Every day fresh, ripe bananas are put on a feeder along the fence line of the garden by the owner of Kumanday Lodge which is situated on the edge of the village of La Florida in Colombia.  The village is at 1,670 metres (5,480 ft) on the western side of the Cordillera Central of the northern Andes.

Birders visiting the Otún Quimbaya reserve stay at the hotel and are soon entertained by fruit-eating birds at the feeder, including a group of Blue-grey Tanagers, Tangarus (previously Thraupis) episcopus. The bird is common in its range (northern South America and north to Mexico).

The Blue-grey is a true tanager (family Thraupidae). Many of what were called tanagers because they were brightly coloured and mainly ate fruit have been shown not to be tanagers at all. Some have turned out to be cardinals (Cardinalidae), others true  finches (Fringillidae).

The Smooth Snake. New Research: Now Venomous but still Harmless

The ‘third’ British snake, the Smooth Snake (Coronella austriaca), is one I have never seen. Of limited distribution, heathland in parts of the south of England, it also occurs widely in continental Europe. Until a few weeks ago the way in which it feeds was thought to be simple. In terms of prey though the preference or availability appears to vary. In Britain small mammals are taken more frequently than lizards; in Italy lizards are the main prey. Young smooth snakes seem to rely heavily on small lizards although they have even been known to eat bluebottles and spiders.

All observers have agreed that once caught in the jaws, the prey is manipulated in to a position where it can be more easily swallowed. During this process coils of the body may help to subdue but not constrict the animal that has been caught. The unfortunate mouse, shrew or lizard is then swallowed alive. Thus the smooth snake was considered to neither venomous nor a constrictor. That is the standard story but in their New Naturalist series book Trevor Beebee and Richard Griffiths raised the point, ‘…so how the snake escapes severe bites from these mammals is not at all clear’. The recent research suggests how that how is achieved.

The authors of the new study, Alessandro Paterna and Grégoire Meier, rely, first, on their own evidence from an anatomical study of the teeth and jaws and, second, on experiments on the closely related species, Coronella girondica, the Southern Smooth Snake, the results of which were published in 1922 in France. In both species they found fangs on the posterior maxilla, the bases of which are enclosed by a sheath. The sheath enables secretion Duvernoy’s gland to be delivered into a wound caused by the fangs. In other words there is every reason to suspect that whole arrangement acts for the conveyance of a noxious secretion into the wound, especially in circumstances where the bite is prolonged and there is time for such a low-pressure system aided by chewing motion of the jaws to work.

There has been endless discussion of whether secretions from Duvernoy’s gland should be called venom and I will not prolong that agony. However, using the term venom for any combination of chemicals used by a predator to the detriment of its prey the question is: does Duvernoy’s gland in this species produce venom? Here one the authors provided useful anecdotal evidence:

…in a field study in the Laga Mountains in the province of Teramo (Abruzzo), one of us (AP) was bitten by an adult male Coronella austriaca while handling the specimen. The bite was prolonged, allowing time to take a photograph while the “mastication” action was still in progress…Following the bite, itching and redness quickly appeared in the affected area. A second photograph, taken 11 minutes after the photo showing the bite, shows redness corresponding to the maxillary arch’s shape, where the holes caused by some anterior maxillary teeth and the pair of posterior fangs

are visible. Over time, in addition to the redness, swelling developed at the site of the small lacerations caused by the teeth, which was also accompanied by itching. The most evident symptoms lasted a few minutes, then gradually subsided in less than an hour. As researchers in both field and controlled environments, we both frequently receive snake bites in different contexts. Nevertheless, this case, although extremely mild, represents the only one to date in which we have personally observed a reaction other than bleeding following a bite of a colubrine snake.

If the bite resulted in irritation to human skin, what about potential prey? Here Marie Félicie Phisalix (née Picot)(1861-1946), who worked in Paris and was one of the leading experts on snake venoms in the first half of the 20th century, provided experimental evidence which I am surprised nobody gathering information on smooth snakes seems to have taken on board earlier.

Marie Physalix
in 1929
Autochrome by
George Chevalier

Marie Phisalix prepared material for injection from whole, dried Duvernoy’s glands. The gland is tiny. She noted in the largest snakes it only weighed 1 mg when dried (equivalent to around 4 mg wet weight). Since it is not known how much secretion would reach a bitten animal, the results show the sort of maximum effect that could be achieved. The findings though were pretty spectacular. An extract from two glands given intravenously to a rabbit put it into a state of torpor for 10 minutes. It then died after 15-20 minutes of respiratory arrest. Six glands-worth killed an adult guinea pig. A green lizard showed transient narcosis after a two-gland dose.

These experiments do suggest the presence of powerful agents in Duvernoy’s gland of smooth snakes. However, I can hear my former and late colleague sitting on my shoulder warning that some of the effects could be due to the presence of extraneous substances like bacterial toxins from the mouth and I do hope that the recent work is being followed up to see what biologically active substances are present in the Dubernoy’s gland of smooth snakes. Secretions from the gland of other rear-fanged species have been studied, for example by Robert Hill and Stephen Mackessy in 2000, and a comparison with such findings is now essential.

Smooth Snake
The colour plate from Malcolm Smith's The British Amphibians and Reptiles published in 1951
in the Collins New Naturalist Series
Photograph by Walter Sydney Pitt (1900-1983)

It would seem though that the evidence is highly suggestive of a rear-fanged, low pressure venom delivery system. Observations on C. austriaca collected by Malcolm Smith for his New Naturalist series book published in 1951 indicate that some items of prey, small lizards for example are caught and swallowed quickly. However, larger prey like small mammals with the capacity to bite back may be held onto for longer, allowing noxious agents from Duvernoy’s gland to seep into the wound, enter the bloodstream and render the mouse, vole or shrew quiescent.

Thus it seems we should now consider the Smooth Snake to be Britain’s second venomous snake with the proviso that the venom is so weak that even if a human being were to be bitten the only effect would be slight and temporary inflammation in the area surrounding the puncture marks. Perhaps we should just say Britain still has two snakes that are entirely harmless to the human population.

Paterna A, Meier G. 2026. Reclassification of the smooth snake. Analysis of the rear fangs, venom system, and the cephalic anatomy of Coronella austriaca (Serpentes: Colubridae). Zootaxa 5873 (1): 145–160. https://doi.org/10.11646/zootaxa.5873.1.8

Phisalix M. 1922 .Animaux Venimeux et Venins. Vol. 2. Paris: Masson et Cie,

Beebee TJC, Griffiths RA. 2000. Amphibians and Reptiles. A Natural History of the British Herpetofauna. London: HarperCollins.

Smith M. 1951. The British Amphibians and Reptiles. London: Collins.

Hill RE, Mackessy SP, 2000. Characterization of venom (Duvernoy’s secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins. Toxicon 38,1663-1687 https://doi.org/10.1016/S0041-0101(00)00091-X

Purple-throated Woodstar. Colombia - November 2025

This female Purple-throated Woodstar (Philodice mitchellii) was gathering nectar from the flowers in the garden of the Hotel Kumanday on the edge of the village of La Florida, a popular place for those visiting the Otún Quimbaya reserve on the western side of the Cordillera Central of Colombia. The village is at 1,670 metres (5,480 ft).

The bird occurs from 700-2,200 metres along the chain of the Andrews from Colombia into Ecuador. There is what appears to be an isolated population in southern Panama. 

Barely 3 inches long with their flight resembling a bee, this one spent a great deal of time keeping its energy supply up - for all that flying and hovering. Their demand for sugar and they way their body bodies handle that sugar to keep up with demand can really be appreciated by seeing and watching hummingbirds in the wild.

Western Bluebird: a colour plate from 1937

In the days when colour printing was extremely expensive, the Avicultural Society had special appeals for funds to support the appearance in Avicultural Magazine of the occasional colour plate. A well-known bird artist was then commissioned. Although the whole run of the Society’s magazines can be found online, the plates rarely see the light of day. Therefore I decided to show one, now and again, on this site. This is the 24th in the series.

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The plate is by Roland Green (1890-1972) a well-known bird and mammal artist who lived in Norfolk. He was the son of a taxidermist. He illustrated a number of books, including one of his own.

The author of the accompanying text was the well-known aviculturist and very wealthy, Alfred Ezra (1872-1955). He understood that the bird had never been imported into Britain before those brought by Jean Delacour. A pair bred in one of Ezra’s aviaries.

The Western Bluebird (Sialia mexicana) is from western North America and Mexico.

Avicultural Magazine September 1937

A Comma in the garden

Alloway, Ayrshire, Scotland. 1 August 2026

It is difficult to imagine the look on a 1950s lepidopterist’s face had she or he been told a Comma butterfly had been spotted in Ayrshire. Even in England the butterfly then had a limited distribution in the south, although it was spreading back to earlier haunts as the 1951 edition of that classic The Observer’s Book of British Butterflies explained:

Up to about 1924 this butterfly had been gradually disappearing from all its old localities, and was more or less confined to Herefordshire, Worcestershire, and Monmouthshire. Since then there has been a remarkable increase in its numbers, and it has been reported from the southern, western, and midland counties and even the London district*.

The Butterfly Conservation website takes up the story:

…the most remarkable feature of the Comma has been its severe decline in the twentieth century and subsequent comeback. It has spread northwards through England and is now widespread in south-east and central Scotland and its range is expanding.

Over the past years there have been a number of reports of Commas in Ayrshire and this one is the second we have seen in the garden.

The Comma, Polygonia c-album, has an unusual specific name in that it it hyphenated. However, that was the one given to it by Linnaeus himself and the Comma was a species with which he would have been familiar since it occurs throughout Europe and into western Asia.

Informative studies have been made on the genetics of the food preferences of the Comma caterpillar. At present in Britain the preferred food plant is common nettle with hops, elms, currants and willows following on behind. The great decline in the 19th and early 20th centuries was thought to have been caused by a major reduction in the cultivation of hops. If that decline was responsible then the shift to nettles and subsequent recovery could have been an event as significant as industrial melanism and its reversal in the Peppered Moth.

The underside shows how well the butterfly is camouflaged when its wings are closed
The white marking is in the shape of a comma; hence the name

*The Oxford comma (no pun intended) was alive and well in this Observer’s Book. Described as the compiler of the book William John Stokoe had drawn the information from The Butterflies of the British Isles by Richard South (also published by Frederick Warne). The first edition of The Observer's Book of British Butterflies book appeared in 1938 when Stokoe was 74; it ran for many editions, some long after the compiler’s death. William John Stokoe was born on 30 July 1864, the son of a railway signalman. In the 1921 Census and the 1939 Register he was living in Finchley with his wife. In 1921 he was art manager for Frederck Warne and in 1939 ‘Book Publisher’s Editor’. Stokoe died on 16 March 1947. His name continued to be associated the the various Observer’s Books he had compiled.