Optimise your own observations for the UK Hoverfly Recording Scheme

Did you know that the UK Hoverfly Recording Scheme (HRS - Part of the National Biodiversity Network – NBN, via the Dipterist’s Forum) automatically receives Research Grade observations from iNaturalist? These may then be verified by the HRS. This is a very large amount of data, and improving the overall quality and formatting of that data will make a big difference to the person receiving it! The following information should help you to create observations that are received by the HRS with as much value as possible. (Similar advice will apply to other UK recording schemes).

We can break this down into two parts:
 1) Creating the most useful records on iNat
 2) Getting the most useful observations in the wild!

1) Creating the most useful records on iNat
A good record needs at least three things: an accurate time/date, an accurate location and adequate evidence. These are the same things needed for a ‘Research Grade’ record! But…

   Are your observations licensed for use?

   Are your photos separately licensed for use?

You have separate licence settings for the data and the photographs in your observations. In order for your observation data and your photos to be received by the HRS the licences must be CC0, CC-BY or CC-BY-NC. There is more information about this here and also on the NBN atlas. You can access your licence settings by substituting your username into uk.inaturalist.org/people/YOUR-USERNAME/edit#content (or www.inat... etc if you only use the international site).

   Do you use obscured/private coordinates?

At the moment if you use these privacy settings, recording schemes cannot receive the true coordinates. (‘Obscured’ records will be sent with a 25km radius uncertainty that includes, but is not centred on, the true location). Unfortunately this makes those records completely unusable for the HRS.

At the moment the best alternative is to create a ‘pinned location’ for each of the locations you normally obscure. This location should be a pin in the map somewhere away from the true location, with an uncertainty circle that includes the location. Exactly how large you make the circle’s radius is up to you - 200m, 300m, 1km... but smaller is obviously more useful. This pinned location can be saved so that you don’t have to create it anew whenever you add an observation in that place. It is also possible to retrospectively change your existing obscured records in bulk - but you have to draw the location afresh (you cannot look up your pinned location). More information about how to do these things can be found here. Be aware that the name you give to a pinned location is visible to other users, so don’t call it “My house, 1 Naturalist Way”.

If you do however feel the need to use obscured/private location settings, but you still want your observation to be useful to the HRS, consider submitting it with the true location on the HRS Facebook group – but remember to mention that the observation is on iNat too (give the URL) to avoid duplication.

   …and what is your name?

It is good practice for biological records to be attached to the name of the observer, and it creates a lot of work for recorders if the name is generic or inconsistent. The HRS receives the ‘display name’ from your profile (not your username). Ideally, if you are happy, this 'display name' should be your true ‘full’ (i.e. first + last) name, not a pseudonym, nickname or just ‘Jim’ or ‘Ann’. If you also submit records on other platforms such as iRecord it is particularly helpful if you can use the same name so that all your records can be matched.

2) Getting the most useful observations in the wild!

Ultimately, you will create the most useful data set if you look for hoverflies deliberately, and if you learn about them. Then you will also know what to photograph. You may like to become familiar with a particular site, or a short route that you can walk regularly. You will get to know the best places to find hoverflies and become more familiar with their habits. You will see the way species ebb and flow across the seasons. Over time you will become able to find a greater diversity of hoverflies in the same area.

Check out the post ‘Is it a hoverfly?'

Resources for learning about hoverflies can be found here

Hoverflies prefer to fly in warm sunny weather, but not so much when it is extremely hot. Only a couple of species fly in the winter. Mid-morning is often regarded as the best time of day. They are keen pollinators, so check flowers - plants with collections of shallow flowers, such as umbellifers, hemp agrimony, dandelions, thistles and burnets are particularly popular as well as willows and Prunus species (especially blackthorn) in the spring.

Not all hoverflies are best found this way - some like to bask on sun-drenched foliage, others are attracted to sugary sap runs. One way to attract hoverflies on cool or dull days is to spray foliage with a solution of sugar in water. Another strategy is to seek out the places female hoverflies like to lay eggs: Hoverflies in the subfamily Syrphinae feed on aphids in the larval stage - you may find females laying eggs near aphid colonies; Many hoverflies in the subfamily Eristalinae have aquatic larvae - so look for them around ponds, stagnant pools, or rot holes in trees (look away from fast flowing currents though).

Many hoverflies are identifiable from quite poor photos, but a fair number are difficult or even impossible to identify the exact species, even from excellent photos. To give yourself the best chance when photographing hoverflies (and indeed any flies) try to get (in order of importance):

 1) a top-down angle: get the wing venation in focus if you can. This will normally get you the genus and often the species. It is usually best if the wings are open, showing the abdomen.

 2) The next best angle to get is from the side showing the legs - sometimes the colour of the feet or the hairs on the legs are valuable

 3) If you can, get the face from the front (i.e. showing both above and below the antennae).

 4) Obviously the more angles, and the more detail the better. It is worth trying to get a distant photo first - just so that you’ve definitely got something, then go in for the closer, more detailed shots which run a greater risk of frightening it away.

Happy hoverating!

Posted on 28 June, 2023 13:52 by matthewvosper matthewvosper

Comments

Thank you very much for the information. That looks really useful.

Posted by jarvo 8 months ago

I don't want to add my real name to my observations, in part because I have thousands of observations already on GBIF with my internet name (and no biological research under any other name), partly because I don't want people to realise when the only household with this surname in this town is away from home.

Posted by kitbeard 8 months ago

@kitbeard indeed, ultimately how you use your settings is up to you and your circumstances, and that consistency across different platforms is probably the most valuable thing.

Posted by matthewvosper 8 months ago

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