Older Logs: LabLog14 (January to June 2014) / LabLog14B (July to December) / WaterLog Water Quality issues only (Oct 2012 - Dec 2013 ) / Log 2013 / Log 2012
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LABLog 2015(Field Trips and Observations — Water Quality and Biodiversity reports: January to December 2015)

2015: May

This is the 10th year of Lough Allen biological surveys. This year’s surveys are collected together in Monthly Pages (starting with March)

<--- Main Locations and Names are shown Left and Right --->

Recording Water Quality issues:

The Yellow / Orange / Red warning scheme initiated last year is retained as a banner that will appear at the top of any day’s Log entry where there have been Environment Quality concerns.


Environment Issue

YELLOW Alert: Unsightly

ORANGE: Potential Risk to Habitat

RED Alert: Real risk to Animals and People

A Red warning would relate to such issues as CyanoBlooms (‘blue-green algal blooms’) which may necessitate a Swimming Ban and special care for Dogs and other animals. Hopefully these will not recur this year but we need to be prepared in light of problems in November 2013 and 2014.
Orange Warnings relate to contamination where there appears little possibility of harm or health risk but where a condition may be damaging to wildlife in the area or limit the amenity value of the Lake. Yellow warnings will solely describe situations which may be unsightly and which should be eliminated. We anticipate there may be several Yellow Bars in the Logs below during 2015!

IMPORTANT NOTE: Water/Weather conditions for each report are located in a Table at the bottom of this page.:

May, 2015

[1st. May... 7th May... 13th May... 23rd May... 26thMay...]

[ 2015 Log monthly index ]

A) 1st May, 2015

‘MAYDAY’: a walking trip around parts of the north end of Lough Allen.


Mayday is a strange time of year... between Spring and Summer. Even today both seasons could be experienced with Summery conditions in the morning around the east and north east shores of Lough Allen. However, the forecast had promised increasing easterly winds by midday or early afternoon. So this trip was done by foot and conditions were quite balmy at first with a slight easterly breeze on our backs as we explored the north east corner of the lake.

The main significant species encountered was a very healthy, and excited, party of Mergansers emerging from a cove on the north shore of Kilgarriff and heading out into the bay. 9 males and 3 females were counted in this group and they were actively using exaggerated fishing behaviour as a form of courtship — bowing and bobbing their heads, rushing after one another, and the males posing to one another. This was a very sexually unbalanced group of ducks! There were three times as many males as females. Mergansers do not bond for life and migrate separately but do spend time together at sea. So how the numbers that turn up in Lough Allen can be explained is difficult? Most of the minding of young is undertaken by the females with the males disappearing back to sea in late Summer while the mothers are still minding ducklings on Lough Allen. Consequently there was much competition within the membership of this group.

The largest flock of Merganser we have ever seen at this time of year in Lough Allen

This is the largest Spring group of Mergansers we have seen on Lough Allen, and only a small part of the lake was covered. We expect there will be a similar (or smaller) group to be found at the south end of the lake when it is next studied. This might amount to the largest breeding stock ever recorded from the lake but weather conditions will then be very important in determining the number of eggs laid and young reared.

Other Spring activity in Plants and Animals.

Meadow Pipit (LEFT)

This is a little hole in the side of a clay mound in a muddy field full of sheep... with a nest full of hungry Meadow Pipit chicks.

Poplar (RIGHT)

The early deliciously burnished bronze leaves of the Poplar. But this is not any Poplar. This is the native Black Poplar, a significant but under sung part of the Lough Allen shoreline. Everywhere there is a bouldery shore on Lough Allen these trees are found. They are as characteristic of Lough Allen as the adjoining Alder carr. They stand out from the Alders by growing as significant tall individual trees on prominent points all around the lake. They can be quite tall and where they grow the ground will be littered with baby Black Poplar seedlings or runners from the parent tree.




Common Sandpiper

A Summer visitor from Africa. Today was the first day we saw them, more or less back on time. They breed all around the lake with single pairs occupying a stretch of beach, or a rocky shore, or vying with another pair for ownership of one of the offshore islands.

They breed widely and it is hard to estimate their numbers or see their young. However from now on their shrill persistent piping calls can be heard all around the water’s edge. It is one of the sounds of Lough Allen particularly on a Summer’s day.


Spring & Summer plants


Here are four common but interesting plants:

A White Violet!

On the way down to Kilgarriff we encountered a south facing roadside bank where these were found. Hardly any dark blue (normal) coloured Violets were seen, and several almost pure white specimens, such as this, were seen. A dear colleague of ours has studied the white forms of many plants and they do seem to be genetically modified, i.e. they breed true to their new colour when their seeds are propagated. It is curious the way they occur randomly in among ‘normal’ violets?

Vetch (RIGHT)

Another very common plant with a slightly unusual colour. This is the Bush Vetch which can be much bluer in the Summer but these specimens had striking dull purple, almost brownish, colour to the flowers. Makes a change from the normal raucous blue of mid-Summer Vetches and provided a subdued tone to the flower lined roadside.




Early Purple Orchid.

The earliest of Irish Orchids, these plants have been out in places since March but are only now starting to appear sporadically along the roadside leading down to Kilgarriff. They are neither an abundant or widespread species around Lough Allen. But they are common nationally and they can become straggly and overblown quite quickly. However, they do have lovely complex flowers with a mixture of white and deep purple when they are freshly flowering. These plants were short and stocky and growing right alongside the tar surface of the road. They too can occur as white flowering variants!

Bog Myrtle (RIGHT)

Most often encountered after it flowers and releases dense clouds of brown pollen into the air, this plant forms shining brown clumps of bushes in wet bogs and and moorland. It looks attractive from the distance because of its warm colour but, also, close up when the intricate details of the flowers can be seen, only as buds here. It flowers as catkins with male and females on separate plants. It is basically a small tree! Widespread in the west of Ireland, these specimens were found near the Royal Fern plantation on the eastern side of the Shannon near where it enters Lough Allen.


Today was mainly a day of attractive and beautiful life coming back to Lough Allen. The large size of the Merganser flock was important. Otherwise, only a pair of Lapwing were to be seen over The Spit. Observing from Cormongan, we could have missed more and this trip did not bring us near their other important site at Yellow River. No Curlew or other Waders were seen. Among smaller birds the main visiting Warblers well all present and singing, Willow Warbler, Chiffchaff, Blackcap and Grashopper Warbler. Cuckoos were calling. No other ducks (apart from Mallard) were noted and only 2 Cormorants were seen — but this was a shore based walking trip!

Herons are noticeably absent and we sought a location for a new Heronry. Herons seem to be being driven off their old haunt (by Ravens) to a new one in coniferous forestry on the mainland adjacent to their former colony on Church Island. None were seen either on the shore or flying over head in 4 hours spent around the north of Lough Allen! 2 Great Crested Grebes were found in Kilgarriff; formerly scarce in Lough Allen they now seem to be increasing

Water Quality:

With a steady to strong easterly breeze the water in all areas visited during the first part of the day was beautiful clear and foam free — like lakes of our childhood days! It was only when we reached Spencer Harbour at midday that the full force of the strong easterly winds could be felt and seen. Sizeable waves were coming through both sides of Corry Island and causing the mooring pontoons to bend and rock quite strongly. Foam was coming ashore here and building up in stable bands on the beaches and foliage facing east into the oncoming waves. But it was not too severe.

B) 7th. May, 2015

Interesting and Varied waterbirds.

Corry Strand to Rossmore and back via Tarmon Abbey

Lough Allen has a good range of interesting birds that breed near water. Numbers may not be great but the diversity is good. Today we encountered Goldeneye (which breed much further north) and Mergansers (now settling in to breed here). It is strange to see all these species together in one place. Low breeding numbers may reflect the natural variation in the lake in terms of water level and nutrition levels, but also the probably growing degree of water contamination may have a deleterious affect. In this regard, we are quite concerned about the Heron. This is a widespread breeding bird around Ireland and has always been quite visible in Lough Allen. In recent months it has been seen often as single birds and quite infrequently. Unlike the rest of the species mentioned the Heron is in Lough Allen all year round and is also a strictly shoreline breeder. This is the area where foam based pollution may lie (depending on wind) and we have seen many instances of this foam leading to Cyanoblooms (blooms of ‘Blue Green algae’). These produce toxins which we have known to kill Mussels. Another species tied to the shoreline throughout the year might also fall victim to these toxins?


A charming newly arrived little lady from the Wintering quarters off West Africa. The Common Terns are back and seemed very excitable when encountered on their old breeding post on Lough Allen today.



Common Tern, Sterna vulgaris, first sighting this year.


The big flock of Mergansers seen last month is breaking up or, at least, pairs are coming together and starting to establish breeding bonds. Pairs, or 2 pairs together, have been seen in most of the likely breeding sites around the north end of the lake. These birds are behaving in a slightly distracted manner and this allows close quiet approach for study purposes. Normally Mergansers are the most flighty of ducks and will take rise and fly away at great speed well beyond the range of our cameras.

Also, the attachment between birds can be readily seen. They may mingle with other males and females but if disturbed will often return to the company of one particular male. Males will contest between themselves but it is very much ritualised and they will use the same warning stance to other objects they want to scare off, like our boat!


Two pairs of Red-breasted Mergansers seen together in Rossbeg Bay. Birds had been seen coming and going from Rossmore but it seems the total in this area may have been 4 pairs. Also one lone female was later seen off Corry Island and a further pair at Drummans Bay, though these could easily have flown over from Rossmore?

The pair on the left show common fishing behaviour but it is an enactment. Margansers do not normally feed in close proximity. For a large part of the Summer the female may be sitting on eggs and will take quick trips out to feed while covering her eggs in loads of very soft Merganser duck down!

Food and feeding is often associated with courtship and this is what we think is going on here. Mind you, we have never seen Mergansers actually providing food as a gift to a female being courted, as many other species do.





The same pair now swimming fast to avoid the boat. They have separated somewhat from the other pair who went the other direction but are strongly attached  together with the female appearing very subservient to the male.

Much courtship and display may takes place at sea. The plumage of the male shown here is good but already he is starting to lose the strong green gloss to his head and the red breast is also fading. Sea populations often show much more brilliant colours which, in the male, quickly start to disappear as the breeding season commences.

Wintering Mergansers are common off the Sligo and all Irish coasts but it is not known if these are Irish breeding birds. They may just migrate locally from lake to sea or they may undertake longer international migrations. In temperate regions it often stays close to breeding areas and it is quite likely that Lough Allen birds simply follow the local geography and end up in Sligo Bay for the Winter.





This is the male making his escape — soon followed by the female.

These birds are very water based and are designed both for swimming and hunting. They are adapted to hunting by being super fast fliers and very strong swimmers. They can get around Lough Allen very quickly. We sometimes view the populations north and south of the lake as somewhat separate, simply because we rarely see many Mergansers in the middle band of the lake. However they are capable of flying from one end of the lake to the other in c.20 mins.

However, normally, they will fly from one preferred habitat to an other and have selected preferred areas where they are happy to swim, fish, and establish their nests.

The legs are very powerful and they stride across the water when taking to the air (whereas the Teal sort of jumps out of the water). The legs are placed fairly far back and the feet are proportionally larger than other similarly sized ducks. This adaptation makes them strong and deep divers and they may stay underwater for up to 1 minute in their pursuit of fish.


The pair escape together. Note.. the male has three white bars on the wing, the female has two.


A northern species of duck, the Goldeneye, winters in Ireland. Every year there are a few present in Lough Allen. They seem to be specialist feeders and come to particular areas of the lake where food is available. They are often found in shallow areas where good supplies of Mussels are found. They have a wide breeding range from Scandinavia across northern Russia to the Pacific, but they do not breed regularly in western Europe. It would be lovely to see this species breeding in Lough Allen but that is hardly possible as this is essentially a bird of the far north.

Three birds were seen in the northern half of Lough Allen during much of the past Winter (and we have some photos of them in earlier pages of this Log). The group consisted of 2 males and 1 female, always seen together. Today it was only the two males flying together. Where was the female... we don’t even like to speculate. But it is unusual for Goldeneye to be seen in this region so late in the year when they should be breeding further north? Today they were very wild and, while we saw them on a number of occasions, they always flew away before we could get near enough to them to take a photo.

Towards the end of this trip two very fast high-flying, black and white ducks passed us flying north over Corry Strand. These were difficult to identify with certainty but could well have been the two Goldeneye. We watched them for quite a while struggling to confirm identity. However, though flying fast, they were circling and over ten minutes or so rapidly gained altitude until they were just one speck in the sky. However they remained very much over the same spot making rapid sharp turns to keep on station. We then noticed that several Lesser Black-backed Gulls were also circling high up in the sky and also becoming smaller and smaller. Apparently there was a strong upward airlift in the air and the birds had become aware of it and were using it. However, even though the weather was fair it was not exactly ‘thermal soaring’ weather and there were no evident cumulus clouds readily noticeable. Were the Goldeneye using this lift to gain altitude to help them on their way on a much delayed migration? We will keep an eye out for them... but we may not see them again this Summer!

Common Terns:

Three Common Terns were seen near Corry Island. It is the first sighting this year and the two birds that remained were clearly excited to be back, exchanging fish as part of the celebrations. They allowed us to drift down very close to them and hence the following nice close shots of what are normally active and difficult subjects. A pair successfully bred at this location in the past 2 years and it is good to see them back. Anyone with land or property near the shore might benefit from anchoring a small raft just off the shore. Rafts are the preferred breeding site for this species in many inland sites in Ireland and Britain. They are an attractive species to have around the lake and are another fish eating species which add to the array of biological monitors we can deploy to ensure that water quality still remains healthy enough for these species.


LEFT: Male and female pair.

Sexes are similar and both vary a bit but we identify these as a male and a female from their behaviour. The male, on the left of the pair, is showing off to the female and had recently presented her with a small fish... typical courtship behaviour.


MIDDLE: Closer view of male.

This shows the typical posture of a posing male. He emphasises his size by raising his neck and beak while simultaneously lowering his body and dropping his wings towards the ground. If the female is interested (as she was) she will reciprocate and her  behaviour is then seen as an invitation to mate.







The ‘male’ of the pair. Common Terns are a species that do not have different forms for each sex. However this bird was stronger, haughtier, with a thicker and longer beak, and was playing the male role in courtship to his companion. So, we assume it was a pair.

These two birds (female is shown at top of Log) were easily recognised. Firstly this birds beak was clearly longer and thicker and the black shading at the tip ran further into the red bas which was never as red as the other birds beak. Normally in a colony it would not be possible to compare the two partners; it was handy here as there were the only two Common Terns around. The other bird, present at the beginning had moved on.







Side by side comparison of the two birds.

The male is in the foreground to the left of the picture.

This pair may well breed here and further breeding could be facilitated by the provision of more securely anchored large rafts offshore.


An idyllic scene — a Heron stalking through the shallow shoreline at Rossmore. Graceful, almost primitive, birds, part of the Irish landscape and still widely known as Cranes. At home on lake shores and seashore, also on wider streams and rivers wherever they can land comfortably with their big wingspan.

This year they are often alone., and very infrequent. This was one of two Herons encountered on a 4 hour study of the north end of the Lake. In previous years numbers were much greater and, depending on the time of the year, many birds could be seen together. It is hard to quantify this decline and there are other issues to be considered. Sometimes we take these birds for granted, always meaning to study them and photograph them... some other day.

Herons have bred on Lough Allen. They may have moved their treetop colonies somewhere else. Traditionally they have nested on Church Island (Inishmcgrath) in a small colony that has been there for a long time. They share this small hilly island with a small field of sheep, many trees around the edges and also on the hill top where a burial site exists... and also with a pair of Ravens. Ravens can be very aggressive birds but have in the past happily coexisted with the Herons, both species successfully rearing young. This Spring, for the first time, we have seen severe competition between the Ravens and the Herons. Herons had 4 to 5 nests in the high trees in the centre of the island, Ravens were lower down. For some reason the Ravens seem to be trying to keep the Herons away, with Herons resting on trees on the mainland and frequently attempting to go to the island, only to be rebuffed and driven away. We thought we had located (by sound) a new colony in the deep coniferous plantation on the west side of Kilgarriff Bay but this too is quiet this year. It is, of course, possible, that they have moved away from Lough Allen and are breeding and feeding near another lake. We hope so as, otherwise, their decline in Lough Allen would be worrying!

Anyone, with information regarding the location of Heron colonies in this area... do please CONTACT us.

This ends the list of significant wildlife observations for this trip. Sandpipers were more widely present, as indicated by their calling but not yet present in large numbers. Mallard are breeding in good numbers and, thankfully, no breeding Canada Geese were seen on this trip. Teal and Wigeon should be recorded as completely absent which is normal for this time of year. Teal tend to linger a bit but none seen today. This makes the presence of 2 Goldeneye even more interesting.


Water quality was poor overall. This is always a great disappointment and this time is the first time we have sought to question could the widely present contamination be affecting resident birds that are largely resident shoreline feeders. Initially water looked good as we left a sheltered bay with the wind blowing offshore. No foam and no scum. However large stretches of water, where the surface tension had been radically altered, were encountered in many open areas across the north west of the lake. Routine observations showed size and persistence level of bubbles generated by the hull of the boat travelling at 5 knots that we would classify as severe — if we only had the time to do the tests! Lough Allen water often looks good if you are standing where the wind is blowing away from you. But on a lee shore persistent foam is often present. In open calm water in the path of the Shannon persistent unnatural chains of bubbles will regularly be left behind the path of your boat.

That is why we have rated water contamination as severe in one category of our water quality data for today. Hopefully, Irish Water and Local Authorities may yet grasp this nettle and make Lough Allen safe to swim in again. A wise man recently suggested that.. ‘it may take 10 years to slowly destroy a place but it can also be fixed in a year!’

C) 13th. May, 2015

Quiet wildlife but good water!

Cormongan to Mountallen Bay and back via Inishfail and the Islands.

Mountallen Bay looking north...

Water quality: Excellent.

We like, whenever we can, to report days on Lough Allen when all seemed right. Today wildlife was scarce in the areas visited, but the water quality seemed good — probably due to weather conditions. Large waves can break up foam and scum. As can be seen in the above photograph the southern end of the lake was consistently exposed to a gentle southeast wind which produced a uniform pattern of gentle rippling. Unusually, almost no calm areas were left and the calming effect of river flow was obliterated. No patches of foam or scum, even small ones were visible as we crossed the lake and returned. On shore signs of pollution around Lough Allen peak under conditions of gentle onshore breezes. Today the open water was perfect and no foam was present on those western shores where we landed (Mountallen Bay).


A particularly quiet day for birds. This can mean two things, either the birds are breeding or absent! High water levels and persistent cold wet weather may have deterred Mergansers from actively breeding but 1 pair was eventually seen near The Spit. Sandpiper pairs were present on all the islands and the Cormongan shore. These seem to be here in good numbers but we would hope to see more Mergansers breeding at the southern end of the lake!

Missing birds which we particularly sought today were Lapwings, Curlew and even Herons... none recorded. Some interest from Lapwings was recorded last month, both in this area and further north. Their main site here is The Spit and this is largely flooded at this stage. The presence of Curlew on Lough Allen has rapidly become unusual. A few years ago good numbers were present in the Derrintobber area of the lake both in Autumn and Spring. None have been seen here since April 6th when 2 were recorded from Spiranthes Islands. Many people are concerned by this rapid decline and any record of Curlews in the area are now valuable.

an interesting image of Harestail Cotton Grass
recorded from Mountallen


D) 23rd. May, 2015

Slightly farther afield...

Drumharlow Lake, Carrick-on-Shannon

Orchid time of year again!

A little bit farther away from Lough Allen, but still in the upper Shannon region, other Orchids species occur in Drumharlow Wood, a broad-leaved wood on the Shannon north of Carrick-on-Shannon. Today we recorded the amazing Birdsnest Orchid, some Broad-leaved Helleborines, and large numbers of Early Purple Orchids. This latter species occurs on roadsides and wet fields around Lough Allen but not as prolific or as large as the specimens seen in this wooded area.

The Birdsnest Orchid is a non-photosynthesising plant. Hence its scaly appearance and absence of green — the only such Orchid in Ireland. It is a Saprophyte. It is a medium sized orchid and emerges from the ground in dark woodlands where it grows in association with fungi and only produces this striking flowering stem at maturity. They are often associated with the similar looking remnants of last years flowers and these specimens were found close to the trunks of large oak trees. Strongly scented, these orchids rely on flies to fertilise the flowers; this was the subject of research by a meticulous early pioneer whose work is still fascinating and detailed.

Charles Darwin: Insect Fertilisation of Orchids

Birdsnest Orchid Neottia nidusavis

Many leaves are present all along the stem, similar in many ways to other Orchids. But they are colourless and scalelike and have no photosynthetic function. Why do they remain; are they perhaps important in respiration? ie. Absorbing air for growth? The nutrition for that growth comes from associated decomposing fungi underground. In this closer view of Birdsnest Orchid (BELOW) the very early stage flowers can be seen starting to burst open. Long thin bracts are entwined among the lower flowers.

Early Purple Orchid Orchis mascula

A common species but it can be surprisingly local as well as very variable in size and colour. Here, in Drumharlow there were many stunning specimens up to 40 cm high and varying in colour from white to soft pink to deep purple. Note how similar these leaves are to Neottia, apart from their green coloration!

Broad-leaved Helleborine Epipactis helleborine

Also present here today in good numbers but, as this species does not flower until much later, we leave photographs for a subsequent report.

D) 26th. May, 2015

Violets explored!

Dowra, Kilgarriff and Drumshanbo

Today’s report is a collection of observations of a variant of the common Dog Violet (Viola riviniana). This species will vary in colour from a washed out sky blue to an almost deep purple. Commonly they are a strikingly deep cobalt blue. BUT there are white variants and these have been collected by a good friend in Kildare and reproduced both vegetatively and from seed. They always reproduce as pure white flowers — as shown below! A really charming plant!

Is this Viola riviniana alba?

A Subspecies or a Variant?

It is interesting that this plant breeds ‘true’. ie. it produces white flowering youngsters instead of reverting back to the blue format. It is clear that this is the Dog Violet; the spur (the backward pointing part of the flower) is notched and the leaves are broader than long. All the pictures shown below are of this species apart from the lovely mauve Marsh Violet (bottom left). So why the colour change and... why is it persistent through the generations?

These images are quite unusual. If you conduct a Google search for ‘white’ ‘violets’ and then go to the collection of images shown you will see that most white violets have either a coloured spur (purple or dark blue) or totally white lower petals or lower petals with dark blue black veins. This search will turn up various species of violets and the coloured spur is typical of the Sweet or Wood Dog Violets. No images were found to replicate these images of white Common Dog Violets, yet specimens from widely different parts of the Ireland are identical. The only colour in these specimens is the chlorophyll (presumably) in the veins feeding the lower petal in particular.

The fact that this variation is consistent and similar in two distant parts of the country would seem to indicate that it is a self-fertilising variant that can sustain a constant appearance. This sounds like a subspecies?


White Dog Violets...



Specimen derived from wild plants, Co. Kildare. Note the typical extended spur (with notch) and the broad leaves.



Another white specimen recorded from the roadside near Annagh Lake, Co. Leitrim. This specimen was in among many pale blue Violets. These may have been suffering from harsh Spring weather conditions. However, this individual was the only pure white specimen on that stretch of roadway, and it is more or less identical to the Kildare specimen shown Above and Left





A different species... the Marsh Violet (Viola palustris). This is widespread, but not abundant, around Lough Allen in suitable wet lumpy ground.



A ‘standard’ Common Dog Violet. Though the photographs are taken from different angles, the format of this flower and the white one above are similar. This would tend to imply that it is the same species but the fact that the white one breeds white suggests that it is a self sustaining subspecies present in small numbers.




MONTH’s Data Sheet: May 2015













Air Temp. °C

Wind (Dir/F.)


Temp. °C

Level m.

Quality (Bubbles)



1st, 0815-1245 *

Sunny then cloudy



rippled to stormy

n/a *



minor on W shore


7th 0800-1215




calm to rippled






13th, 1215-1545




gently rippled






23th, 1100-1400




 Drumharlow: not a L. Allen boat trip




26th, 1430-1700




Dowra: not a L. Allen boat trip.




* Field work not boat based.

This is one month’s record of our work on Lough Allen in 2015. Other months are Linked through the Monthly Blog Index.