Wednesday, 2 September 2020

Hull Dragons 2020: August summary

We've had some excellent dragonfly weather this August, with plenty of warm, sunny days. Although the last week had plenty of wind and rain, it was often warm enough even when overcast to entice some dragonflies out, until the very end of the month, dominated by cold northerly winds.

Odonata highlights

We've got a whooping 200 records from 12 species in the month of August. These are from at 35 1 km squares for August from 13 recorders, thank you all who have contributed records!

The season is over for many species (Hairy Dragonfly, Large Red Damselfly, Broad-bodied Chaser, Banded Demoiselle), and is coming to an end for others: Azure Damselfly, Four-spotted Chaser or Black-tailed Skimmer.

Migrant Hawkers (top shot) have been the top species, with a third of all, followed by Common Darter,and Blue-tailed Damselfly. Although there has been no new species added for the year in August, there is a chance we may still record Willow Emerald as the first records las year were in September.

Brown Hawkers

Brown Hawkers bumper year has continued, they are the 5th species in number of records for the month. In July many observations involved patrolling males on territory, but in August, ovipositing has been observed, twice at Foredyke Green (on the muddy shore, on floating wood and on floating polystyrene) and also likely ovipositing behaviour at East Park.
Female Brown Hawker rests between ovipositing bouts.
Oviposition on polystyrene.

Migrant Hawker

Most records involving hawkers away from water, hunting at 4-5 m high, sometimes in twos and threes are highly likely to be Migrant Hawkers in our area. Two or three individuals have been present regularly in my garden, and I was lucky enough to spot one of them basking quite low on a potted olive tree. It allowed for very close approximation.
A male Migrant Hawker Photo taken by my son with his mobile phone. 22nd August.
And a female, from the 31st of August.
There were several exciting Migrant Hawker highlights. One of them was to find a total of 6 exuviae at East Park. Exuviae is the formal name for a moulted larval skin, which can be found on marginal or emergent plants, after the adult has emerged. The presence of exuviae in a site provides evidence that a species has successfully bred in a site. As far as I know this is the first confirmation of successful breeding in the city of Hull after last years observed ovipositing in several sites.
Migrant hawker exuviae in situ.
Another interesting observation involved an individual flying underneath an ivy overhang and settling on it, moments before a rain shower. I found another individual near it. I wonder what makes the hawkers seek refuge, maybe the sudden darkening of the sky?

I was at Pearson Park Wildlife garden during muggy, but cloudy weather. During a sunny spell followed by a strong breeze, at least 20 migrant hawkers took to the wing and started hunting over the garden. This is the largest number of individuals I have seen of this species.
Finally, I have been able to observe Migrant Hawkers active during cloudy weather and temperatures as low as 13-14 oC. They might be able to achieve temperatures high enough for flight by basking during brief sunny spells. When windy, they forage around trees at the lee side of the wind in sheltered, sun-facing spots.

Blue-tailed damselfly mating behaviour
The following photo show a mating pair of Blue-tailed damselflies. In this species, copulation is very long, up to 8 hours and in dense populations a form similar in colour to males increases in frequency, as these females avoid the costs of prolonged copulations.
Females oviposit alone. I was at Foredyke Green site about to take a photo of an ovipositing female, when a male came out of nowhere, knocked the female over, and immobilised her by holding her with jaws, legs and mating appendages. The following is a series of photos documenting how the male gains hold of the female, in the last photo he has already adopted the tandem position. I wonder had I only seen the last part of the behaviour, with the female already on the water, if I would have concluded that this was an example of a 'damsel in distress' being rescued by the male. I'm glad I got the whole sequence!

Small Red-eyed Damselfly

The Pickering Park and East Park populations are thriving: hundreds of individuals were present at East Park model boating lake and some as well in the main lake. A record in a new location was at St Andrews Quay Pond. The records show a establishment of the species in both large parks at Hull. Copulation and ovipositing was observed at East Park and Pickering park.

Small Red-eyed Damselfly at Pickering Park.
Small Red-eyed at East Park.
Small Red-eyed at East Park.
Copulating Small Red-eyed damselflies at East Park.

Best sites this year so far:

  • East Park: 13 sp.
  • Noddle Hill LNR: 12 sp.
  • Foredyke Green Pond 11 sp.
  • Oak Road Lake 9 sp.
  • Pickering Park 8 sp.
  • St Andrews Quay Pond 8 sp.
  • Beverley & Barmston Drain 7 sp
  • Paull Holme Strays 7 sp.
  • Humber Bridge Country Park 7 sp.
  • Pearson Park Wildlife Garden (closed due to COVID, but surveyed with permission) 6 sp.
  • Willerby Carr Dyke, 6 sp.
  • Beverley & Barmston drain, 6 sp.

Other species Gallery

Teneral Common Darter.
Common Darter in obelisk position
Emerald Damselfly at Noddle Hill LNR.
Ruddy Darter at Noddle Hill NR.
Southern Hawker at Noddle Hill LNR
Ovipositing Emperor at Foredyke Green pond.
Common Blue Damselfly.
A late Azure damselfly. Numbers have been steadily falling during the month of August.

Wednesday, 12 August 2020

Common garden damselflies and dragonflies in the Hull area

Although a total of 23 species of dragonflies and damselflies have been recorded in Hull, only a subset of them can be considered regular in gardens, and a few species will even turn up in gardens without a pond. Here, I will present seven of the species most common in gardens, with identification tips. These species provide a useful benchmark to help you to identify rarer dragonflies and damselflies when in other habitats.

Two species of damselfly are common in gardens, where they regularly breed. They are even tolerant of fish, provided there are areas of thicker vegetation where their larvae can seek refuge, and will be even present in ornamental ponds with hard edges. Both are blue and black. 
1. Azure Damselfly
The Azure Damselfly gives an all vivid blue impression, it has a distinctive black hook or spur pointing forward on the side of its thorax, which distinguishes it in our area from the Common Blue Damselfly. I should have said males are all blue, as females are often green and black, as in the photo above. They can be found even in tiny garden ponds, provided they have plenty of vegetation near or in the pond. It flies from early May to early August.
2. Blue-tailed Damselfly
The Blue-tailed damselfly is the most common species recorded in Hull. It tolerates of all sorts of conditions: brackish ponds, polluted ponds, fish, and even poor weather! It  It has been described as a 'flying magic wand', as its black abdomen contrasts with the blue band near the tip. It has a distinctive two-colour wing spot, which is useful to identify females, which come in 5 different colour forms. It has a long flying season, from late April to late September.

3. Broad-bodied Chaser
This is a stunning dragonfly, the immatures are yellow and brown, with dark wing bases and a characteristic wide abdomen. In flight it is very reminiscent of a hornet. Mature males develop a powdery blue colour in their abdomen. This is a species likely to use newly built ponds, or ponds with plenty of bare or muddy margins. They fly early in the season, from mid May to mid August.

4. Migrant Hawker
This is the most common hawker in Hull, and is regularly found in gardens away from water. The individual pictured is a mature male, but it is immatures that are commonly found in gardens, and these have subdued colours and milky eyes. They tend to fly in the open at 3-5 m high, often going round and round in a relatively small area. It tolerates other individuals, which will congregate in gardens with plenty of food. It flies from late July to late October or early November. Although plentiful in gardens during their immature stage, they tend to breed in lakes and ditches. 
The usual view of a flying migrant hawker over a garden.

5. Southern hawker
A large colourful hawker, one of the most strikingly marked. The combination of apple green and blue markings in mature individuals is characteristic, as their habit of being curious towards humans, flying close as if checking you out. It tends to hawk close to the ground alongside paths and close to tree canopies, often in shaded, sheltered places. Females will lay eggs on floating wood or marginal vegetation in relatively shaded ponds. It has a long flight season, from mid-June until October.

6. Common Darter
A small dragonfly that hunts from the ground, or a perch, to which it returns. Immature individuals are yellow, but males become orangey-red, with two yellow panels on the side of the thorax. All individuals have a thin yellow stripe alongside their legs. One of the most common dragonflies. It can breed in garden ponds of medium or large size and including ornamental ponds. It has a long flight season, from June until November.

7. Ruddy Darter
The Ruddy Darter is less common than the Common Darter. It prefers to hunt from a perch, or from the ground, to which it returns after catching prey. Males have a more intense red than the common darter and a more waisted abdomen. Immature individuals and females are orange/yellow. The legs in both sexes are black. Flies from mid June to mid October. It breeds in ponds with plenty of marginal vegetation, although it can roam, and can be found in gardens away from ponds.

More information
  • If you are interested in identifying dragonflies and damselflies, Yorkshire Dragonfly Group has plenty of information on all the species and interesting sites to visit and runs an active Facebook group.
  • If you have any dragonfly records from your garden in the Hull area you can either submit the record to iRecord, or message me in the blog comments or on Twitter.
  • For more information on Hull Dragonflies and damselflies you can read the City of Dragons 2019 report here.

Saturday, 1 August 2020

Hull Dragons 2020: July summary

The first three weeks of July had very changeable weather, with plenty of overcast, muggy weather and some showers. Sunny spells were few, short and far between until the last week, where we enjoyed a few days of warmer, consistent sunny weather. 

Odonata highlights
Records were initially slow coming in July, but overall the month had a total of 113 records from 13 species have been submitted by 7 recorders from 20 km2, a few more than in June. As expected, the Blue-tailed Damselfly tops the list in terms of numbers of records, followed by the Emperor Dragonfly, and the Common Darter, with the same number of records. The surprise is that the Brown Hawker is tied 4th with the Azure Damselfly, with 11 records, more than were recorded during the whole of last year. The year total so far stands at 18 species.

First records of the year
  • Ruddy Darter, 11th July
  • Common Darter 11th July
  • Emerald 19th July
  • Brown Hawker 19th July.
  • Migrant Hawker, 24th July
  • Small Red Eyed Damselfly, 25th July
Emperor behaviour
Emperors seem to be having a good year at the recording area. I've had a great time watching the behavioural differences between males and females. Males are a very showy dragonfly, 'presiding' over their territory, a pond, lake or a stretch of ditch, flying powerfully, over the open water, occasionally hovering on a spot, rising to catch an insect or flying over the banks, even checking birds flying past (I watched a brief Swallow-Emperor face off, both flying away!). They are always pulled back to the water, unlike other hawkers. At some point, they stop their hunting and patrolling to bask or finish a meal, usually on marginal vegetation facing the sun, but also rarely on the ground.
An emperor resting on the ground is an unusual sight. It is likely that it was sheltering from the wind.
Female's behaviour is completely different. They approach the water stealthily, flying low and near the shore, searching for oviposition locations (sticks or floating vegetation). They can be as colourful as males, as the following photo shows. If a male discovers a female, she will try and fly higher than him, curling her abdomen down in a signal of rejection. I've never witnessed a copulation in this species.
Ovipositing Emperor at Foredyke Green Pond. 
Male Emperor at Pickering Park. 
Pickering Park lake is large enough for several Emperors, but the northern side of the pond seems to be the most attractive and it is a place that year after year allows me to see males chasing and clashing for territory. In this case, one of the males landed in the vegetation to rest, while the other one carried on the patrolling. Ovipositing was also observed in the same area of the park. Ovipositing in July was also observed at Noddle Hill Lake, and Foredyke Green Pond.

Watching Brown Hawkers
Brown Hawkers are also having a good year . Four were seen hunting along rides and paths at Noddle Hill nature reserve. At the Beverley and Barmston drain near Beresford Avenue, I watched one for 20 minutes as it hunted repeatedly flying up and down the drain. It took advantage of the light breeze to glide back, then flew powerfully upwind, checking every passing insect, releasing some that were not of his taste. I was slightly amused as the hawker checked every passing creeping thistle seed (just like me!), and there were plenty floating in the breeze. I was hoping the Brown Hawker will have a rest at some point, but it didn't. Its territory-  and it was a male - was 20-30 meters along drain, with plenty of emergent and floating vegetation and a hedgerow on one side by the allotments. It flew high over the water, maybe over 1 m high, and then occasionally charged against the marginal vegetation, possibly to dislodge resting insects. Although I've got no photo opportunities so far, I enjoyed watching the species behaviour from a great vantage point.

Species gallery
Four-spotted chaser at Foredyke Green Pond.
Teneral Southern Hawker at Setting Dyke.
An Azure Damselfly rejects another's advance.
Blue-tailed Damselfly.
Teneral Common Darter at Pickering Park.
Common Darter at Midmeredale Pond.
Mating Blue-tailed damselflies at Pickering Park (note that the female is the same colour as the male, they are known as androchrome females).
Emerald, one of two males at Noddle Hill NR.
Small Red-eyed Damselfly at Paull Holme Strays. A mating pair was observed at Pickering Park.
A record shot of my first Migrant Hawker this year.

Tuesday, 30 June 2020

Hull Dragons 2020: June summary

June has been a much more variable month than the dry and sunny May, with some rain, storms, more windy and more cloud. There were some good days for dragonfly watching, including a heat wave on the 3rd week, when temperatures reached 29°C in Hull. A total of 106 records of 11 species have been submitted during the month by 9 contributors. Foredyke Green Pond and East Park, with 7 species each, were the best sites in number of species. The only species recorded in May with no June records is the Large Red Damselfly. The Red-eyed Damselfly, Black-tailed Skimmer and Southern Hawker were added to the year list. An unidentified darter was recorded on the 25th June. 

My June odonate highlights
  • Watching a female Hairy Dragonfly coming to the shore by my feet at Noddle Hill fishing lake and start ovipositing on a dead branch was my highlight of the month. She moved on pretty fast before I could set the camera on her. As far as I know, this is the first time the species has been recorded ovipositing in the Hull area. 
  • Spotting a Red-eyed Damselfly at Foredyke Green, a new location for the species. 
  • At Ennerdale South Pond there was a strong damselfly emergence on the 2nd June. House Sparrows were feeding on them, sometime as I disturbed them and they flew up. As I watched and followed a female Banded Demoiselle by the river Hull, a house sparrow chased her and captured her!
  • Watching an ovipositing Broad-bodied chaser at Foredyke Green Pond.
  • Watching an Emperor and Hairy Dragonfly males patrolling and hunting on a stretch of the Beverley and Barmston drain, occasionally clashing.
  • As I was examining an emperor exuviae, I was surprised to see it moving, and a lodger emerged: a Larinioides cornutus spider! I had never seen spiders using dragonfly exuviae as retreats.

June species and breeding evidence

Southern Hawker. First and only record so far on the 26th June.
An emperor dragonfly resting briefly on plants near Foredyke Green pond.
Emperor Dragonfly. 8 records. Exuviae found at Foredyke Green Pond and Ennerdale South Pond.
Hairy Dragonfly. 2 records, with ovipositing female at Noddle Hill Lake.

Banded Demoiselle. Interestingly, all 4 records from the 2nd June from River Hull, Ennerdale S Pond and Cottingham.

Azure Damselfly. 22 records. Teneral at Beverley and Barmston Drain and Setting Dike. Oviposition noted at Pearson Park and Beverley and Barmston Drain.
Common Blue Damselfly. 16 records. Tenerals at Ennerdale S Pond. Mating pairs at Foredyke Green Pond and Ennerdale Pond.
Red-eyed Damselfly. Four records from four sites, the first on the 1st of June. They include a new site for the species, Foredyke Green Pond.
Female Blue-tailed Damselfly with Arrenurus mites (17th June).
Male Blue-tailed Damselfly with mites. Both at Foredyke Green pond (14th June). These are parasitic mites that feed on the host blood and drop to water once the host comes to mate to water. 
Blue-tailed Damselflies mating.
Blue-tailed Damselfly.
Blue-tailed Damselfly. 27 records, the most commonly recorded species. Tenerals were found at Oak Road, Ennerdale S Pond and Setting Dyke, oviposition was recorded at Beverley and Barmston Drain and Noddle Hill Lake.
Broad-bodied Chaser. 5 records. Oviposition at Foredyke Green Pond, where the photo above was taken.
Four-spotted Chaser. 6 records from 5 sites, including individuals emerging in a private garden.
Black-tailed Skimmer. 5 records, the first of the year on the 2nd June. A female was seen ovipositing at Snuff Mill Lane.