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.

Chasing the climate: Broad-bodied chaser and the dragonflies of East Yorkshire

There are 45 dragonfly and damselfly species in the UK, of which 23 breed in East Yorkshire. I was amazed to find that 15 of these have established themselves in the county only after WWII. The recent colonists include now common and widespread species like the Common Darter, the Blue-tailed Damselfly and the Emperor Dragonfly.

Cumulative number of East Yorkshire dragonfly and damselfly species and the first record of each colonist species (data compiled from Paul Ashton's Dragonflies of South East Yorkshire, 2013).

 Recent studies taking advantage of the wealth of records held by the British Dragonfly Society indicate that warming climate largely explains northward range shifts, range expansions and earlier emergence observed in most British dragonflies and damselflies. In contrast, the few northerly species have also shifted their range north, and their ranges remained stable or slightly contracted in size. Some extreme examples of range expansions are the Common Darter, with a northern distribution range that moved north 346 km in 40 years, the Keeled Skimmer shifted 190 km.

  One of the recent East Yorkshire colonists is the Broad-bodied Chaser, with a first record in 1995. It is now quite widespread but still establishing and expanding its range.

Today I visited a pond in a site in the outskirts of the city, which has maintained water until now this year probably due to the higher than usual rainfall this winter and spring. I took advantage of a short sunny spell this afternoon in an altogether warm muggy day to try and see the Broad-bodied Chaser I had seen there before in mid May. This is a large, striking dragonfly, which readily colonises new ponds, including garden ponds. They have a flattened abdomen and dark spots on the base of the wings. Males have a powdery blue abdomen and yellow spots on the sides (top shot), the females a yellow/brown abdomen (below). Males maintain territories in ponds, where females may only approach the pond to mate and oviposit. As an adaptation to the shallow, small ponds where they develop, their larvae are able to move over damp, but otherwise dry terrain if the pools where they are developing are dry.

A female Broad-bodied Chaser (22nd May 2017, Leven Canal)

  Not long after I arrived, a male passed flying by hunting and patrolling over the pond, about half a meter above the water. I briefly saw a female too, which didn't settle. This species flies in a zigzagging way which makes it hard to follow, but it is a large animal, and has a habit of perching in favourite spots regularly, which more than compensates for it. The male settled on the most inaccessible part of the pond a few times, but finally it alighted on a large clump of Yellow Flag irises near me, where I could watch and photograph it easily.

More information

Ashton, P. (2013) Dragonflies of South-east Yorkshire. 105 pp.

Hassall, C., Thompson, D. J., French, G. C. & Harvey, I. F. Historical changes in the phenology of British Odonata are related to climate. Glob. Chang. Biol. 13, 933–941 (2007).

Hickling, R., Roy, D. B., Hill, J. K. & Thomas, C. D. A northward shift of range margins in British Odonata. Glob. Chang. Biol. 11, 502–506 (2005).

Piersanti, S., Rebora, M., Salerno, G. & Gaino, E. Behaviour of the larval dragonfly Libellula depressa (Odonata Libellulidae) in drying pools. Ethol. Ecol. Evol. 19, 127–136 (2007).