Monday, 27 May 2019

Dragonflies to watch for in June

This is the second instalment of the dragonflies that are likely to be observed in Hull, with four species to look for in June.
5. Broad-bodied Chaser, Libellula depressa
Flight period from Mid May to mid August, peaking in June. Both sexes have dark markings in the base or each wing and a distinctive, flattered abdomen. Mature males have a pale blue abdomen with side yellow spots. They are very territorial and patrol their territory, chasing intruders and regularly perching in favourite spots, hanging from their perch (above). Females are brown and yellow, and when in flight they can be confused with a large wasp or hornet. Immatures look similar to females. The broad-bodied chaser prefers small, shallow, sunny ponds with bare edges. This species is still increasing in range in the area and there are few Hull records, but has been found at a private garden pond, Snuff Mill Lane and this year at Pearson Park wildlife garden.
6. Common Blue damselfly, Enallagma cyathigerum
Late April to late September, peaking in June and July. Prefers larger ponds and lakes with floating vegetation, where it often perches. It is found in several parks in Hull (East Park, Pickering Park), Noddle Hill Lake and Oak Road Lake amongst others.
7. Blue-tailed damselfly, Ishnura elegans
Late April to late September, peaking in June and July. A very common and widespread species present in a range of habitats, including polluted and brackish ponds and ditches, even rapidly colonising small garden ponds. Often very abundant when present, settled in marginal vegetation, and active even in dull weather.
8. Red-eyed Damselfly, Erythromma najas
Early May to end of August, peaking in June. A species favouring large canals and lakes with floating vegetation, where it settles, often far from the shore. In the area is found in Oak Road Lake and Noddle Hill Fishing lake, but given its habits, might be under-recorded.

Wednesday, 22 May 2019

Broad-bodied Chasers

I popped at the YWT local wildlife garden after work. The staff alerted me to the presence of a Broad-bodied chaser on a patch of Red Campion. I popped out to find it there straight away. It sat on the flowers and repeatedly darted to catch an insect, only to return to the same perch, flycatcher style. It didn't have to fly far as it was warm and sunny and there were plenty of small insects about. This, one of the most spectacular of our dragonflies, is my first species for the Hull Dragons challenge! A quick walk around the pond revealed there were at least 5 individuals about, each sallying from their favoured perch hunting almost in succession. All of them had yellow abdomens, including two males, indicating that they had emerged recently, most likely from the pond in the garden. They mostly ignored one another, despite being in quite close proximity, another sign that their male territorial behaviour hadn't kicked in. Despite their amazing colour, they are quite cryptic and merge into the foliage as soon as they stop.
Immature male.
This species is still uncommon in the Hull area, with only a handful of records. As I covered in a previous post, it was unknown in south east Yorkshire before 1995, although it is becoming more widespread. It is a good colonist and one of the earliest dragonflies to breed in new ponds. The pond in the garden was re-dug in February 2016, and given that the larvae only emerge after 2 or three years it is likely that the species bred in the pond the first summer after it was refilled.
The pond being re-lined in February 2016. I will post some photos of the pond as it is now in a future post. 
A walk around the pond revealed one, possibly two Azure damselflies. It is not a very large pond, but always interesting and I have records of a good range of damselflies and dragonflies: Common Emerald, Azure Damselfly, Blue-tailed, Common Darter, Ruddy Darter, Southern Hawker and Migrant Hawker. Broad-bodied Chaser is a great addition to the list!
Another immature male. Note the white reflections on the wing indicating that this individual has emerged very recently (teneral)
An immature female, note the wider abdomen in comparison with the males.
Immature female.

Friday, 3 May 2019

Early dragonflies and damselflies

The dragonfly season is already under way in the south of the country, although here I still haven't seen any dragonflies and damselflies. It's time to prepare though, as during May, several species emerge from their larval stages and are most likely to be encountered around ponds and wetlands. These are four species worth keeping your eyes open for as you visit suitable sites in and around Hull.
1. Large Red Damselfly, Pyrrhrosoma nymphula
The earliest flying damselfly is usually the distinctive Large Red Damselfly. It emerges from the end of April to early May, flying until late July, and peaking on the 3rd week of May. It has very uncommonly been recorded in the Hull area, even though it has been recorded in the Tickton area east of Beverley and in the eastern fringes of the Wolds near Brantingham.
2. Hairy Dragonfly, Brachytron pratense
Its early flight period (end of April to Early July) helps separate this species from related hawkers. Peaks on the 3rd week of May. This is a recent colonist to East Yorkshire and there is only one record (2018) in the Hull area, but we expect their numbers to steadily increase so it's worth keeping an eye for them. It holds breeding populations in the middle river Hull area (Tophill Low and Leven Canal).
3. Azure Damselfly, Coenagrion puella
Peaks on the 3rd week of May. It can be abundant in suitable habitats, which include small garden ponds, especially if they have abundant marginal vegetation. It's main distinguishing feature from other local blue damselflies is the spur on the side of the thorax. Several locations known in Hull. Males hang onto females while they oviposit and often many pairs oviposit together.
4. Four-spotted Chaser, Libellula quadrimaculata
Long flight period, from end of April to end of August, peaking on early June. It can be dull in flight, without distinctive features, but males are territorial and like to sit in prominent perches overlooking water, where their lovely markings can be appreciated. The dark spots in the middle of each wing are diagnostic. Females oviposit by flicking eggs into the water, while makes guard them at a distance. They are good colonists and there are records from a few Hull locations including Oak Road Lake, Pickering Park and Noddle Hill.