Nature 101

Nature 101 – Base Knowledge – Citizen Science

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Introduction

Due to workloads I’ve had to shift some things around and delay a couple of posts. I’ve decided to post this one now, as it links into some issues I’ve mentioned in recent posts.

First let me briefly cover what citizen science is and then below I will mention some methodologies and organisations. It comes down to where non-scientists help the scientific community to gain data on the environment around us. This can be through monitoring insect populations, having a weather station on a property, being part of a bioblitz (an intensive field study over a period of time, maybe only a day or a week), and many more methods. Why is this done? Because scientists end up spending a lot of time doing paperwork, processing data, attending conferences and meetings etc. and the actual time that they are out in the field can be fairly limited (although I’m sure most wish they could be out there every day, for hours on end).

We cannot expect scientists to be out there gathering information, and at the same time formulating theories and opinions on what is happening in our natural environment, influencing regulatory bodies etc. etc. etc. There are many changes happening very fast (urbanisation, climate change etc.).
At the same time, there have been massive leaps in technological advancements (DNA genome sequencing), which provide the opportunity to obtain a deeper and broader understanding of the natural world. But DNA sequencing takes time and a lot of effort. How can scientists keep pace with all these developments and advancements?

Meanwhile, there are sections of the scientific community that are very conservative and do not fully appreciate citizen science. I’ve witnessed this first-hand in Facebook groups. This can be incredibly disheartening, as the expert is basically telling you your observations are worthless because you do not have a scientific background. For someone who loves learning and is not afraid to speak their mind (like me) this is infuriating. However, we cannot let this minority in the scientific community hold back positive advancements.

Methodologies

There are two general ways to approach citizen science:

  • Scientific-community driven.
  • Individual driven.

And then there are of course hybrid forms of the above.

Scientific-community driven

Scientists, organisations, universities, and such can set up activities, in which regular citizens take part, to create large data dumps, which can then be used for trend analysis and more. Examples might include:

  • An annual bioblitz to build up a species database for a local nature zone.
  • A national, annual day where interested parties record which birds or butterflies are seen in their garden.
  • An elaborate monitoring scheme where citizens walk the same transect over a period of time every week or two.

In many cases, scientists will be present to help with identification (a bioblitz) and in others there will be a public information campaign, where due to the massive load of data coming from the activity any mistakes in identification (anomalies) will fade away into the full data set (yay, statistics!).

Individual driven

This is where individuals are keen to record what they see in the natural environment, be it their garden, on vacations, and on daily walks. Where 40 years ago those observations might have been recorded in a diary, they can now be uploaded into online databases.

I’m an example in this space … I started recording things that interest me using an app that was recommended to me by a friend. Since then, I’ve recorded 1000s of observations in many locations. I’ve taken pictures to be able to back my observations and uploaded those to a public database. Many of these have subsequently been verified by experts.

Data Storage & Organisations

There are countless non-governmental organisations (NGO) that you can become a member of and who support and stimulate citizen science in many ways. While they are critical, what it comes down to for the general scientific community is how all that data is stored … e.g., those bioblitz datasets can be stored in online data repositories or they can keept in an Excel sheet on a PC.

There are some brilliant data repositories:

  • eBird – Set up by Cornell University (was looking at studying there back in the day, wish I’d made more of an effort to go there) in the USA, an absolutely stunning site and app. If you are only interested in birds, this is quite something. But that is its limitation … only birds. https://ebird.org/home
  • iNaturalist – Set up by someone at UC Berkley this has grown into a massive database covering everything. There is a focus on North America so a recommendation if your live there. Used by millions of people. https://www.inaturalist.org
  • Observation.org – Initially set up in The Netherlands and Belgium it has become a massive global database that covers everything. Also used by millions of people and organisations. I use this site and app and I highly recommend it; your photos are verified by volunteer experts/scientists. https://observation.org

The above all share their verified data with GBIF, which is important for scientific studies and data analysis. A new developmen has been that those apps are incorporating AI to identify species based on the photos you upload. Are there limitations? Yes, but it is amazing … and will only get better as AI is trained to identify more and more species and so help process data.

I would personally advise against using other data repositories than the three mentioned above. For example, a while back I had a little rant about Biodiversidad Virtual, a well-intentioned Spanish citizen science site, but extremely limited in scope (Spain) and with an interface that is far from user-friendly. Last month they communicated the intention of migrating all the data to Observation.org and joining forces. Amazing stuff! (Since then this has happened, all data has been migrated, and annotated, into the Observation.org database).

If enough people upload their observations, slowly those empty gaps in distribution maps (see Tuesday’s post) will be filled up. However, we need to realise that most observations will be in nature hotspots (national parks etc.) and in cities/urban areas, and most observations will be biased towards species that are easy to identify, come across, and species groups that most people have an interest in (e.g. birds). Furthermore, observation numbers will grow with user numbers. This does not mean that even though numbers are increasing, certain species are becoming more common. Finally, if a special species is seen and recorded, it often means that others will go to that same location to see the same animal or flower. So, one individual might be counted 100s of times (as is the case for vagrant birds), which is reflected in the numbers in the data base but does not mean it is a very common species to see.

However, even considering all the negatives, what we cannot lose sight of is the massive data set that we are slowly building up.

Conclusion

Of course there are issues with citizen science, and those need to be addressed if they can. Most of the issues concern verification. If there are many users, the number of photos that come in daily can be overwhelming for volunteers to deal with. Imagine a warm summer day across Europe and the 100s of butterfly pictures coming in on that day. Then there’s the issue with being able to properly identify species based on photographic evidence.
However, the data is there, and a scientist can use verified data or take non-verified data as a starting point for an investigation. It is better to have a data set that will include some faulty data than to have no data set at all.

I am also aware of the Dunning-Kruger effect, which comes down to people with limited expertise overestimating their knowledge in an area. The way to educate those with overconfidence in their abilities, is to do just that, educate them, show them that there is more to know than what they know. I am very self-critical and “I know that I know very little”. I need to be conservative with my observations, where if I don’t know something, I put it as uncertain or do not record it if I do not have evidence. I came to realise this because I actively went out to learn more and more, others might need a gentle push.

Therefore, we must push forward, knowing the limitations of the system, and develop, and adapt emerging technologies and solutions to help process the data. Proactive scientists are already using citizen science data to achieve amazing results and I’m super excited to know that I am playing an infinitesimally tiny part in the application of all this data and knowledge.

Sorry, it has been a long one, but I’m a bit passionate about this topic. As always, I’ve left out a lot, but feel free to go out and educate yourself further … it is not difficult, it can start by posting a question here.

Nature 101 – Base Knowledge – Citizen Science

Nature 101 – Base Knowledge – Odonata

bartvanhoof, , , , , 3 Comments

Introduction

As with the previous Nature 101 on Lepidoptera, today we will cover a specific order within insects. Just to remind you, the taxonomic term “order” deals with a group of insects (in this case) that have similar characteristics.

As was the case with Lepidoptera (butterflies and moths), Odonata can be split into two groups … actually, in this case it already gets a bit more complicated than Lepidoptera because there have been several taxonomical developments in the last few years …:

  • Zygoptera – this is the suborder that contains all damselflies.
  • Epiprocta – this suborder contains both Anisozigoptera and Anisoptera as infraorders. The first of which (in the past a separate suborder of Odonata) does not have any representatives in Europe (only Asia), and the second of which used to be a separate suborder too and contains all true dragonflies.

Phew, okay that was the first step. So, basically, we know that here in Europe (or the Americas) we’re trying to identify the differences between damselflies and dragonflies.

Again, I’ll refer you to the Nature 101 Naming post that gives a better/basic overview view of how the taxonomy system fits together.

1.0 Common Aspects

There are no strong characteristics that set Odonata apart from other insects (like scaly wings), but it is usually pretty clear that the insect you are looking at (in the imago stage) is a dragonfly or damselfly. They have long, slender abdomens with 4 large wings (compared to body size), very short antenna, and big eyes. In both larval and imago life stages they devour other insects (and even small fish and tadpoles) like there’s no tomorrow.
When they are still in the larval stage most people wouldn’t have a clue that they are looking at a dragonfly. How can those strange, drab (they are usually brown and covered in mud) alien creatures turn into vibrant metallic-coloured dragonflies?

With regards to life stages there are:

Egg – larva (naiad/nymph) – imago (dragonfly or damselfly)

So, there’s no pupa stage. Larvae crawl out of the water up onto rocks or vegetation, break open the back of the larval shell and emerge as an imago, slowly pumping insect blood (haemolymph) around their bodies and wings (Fig. 1). It is quite stunning to see. They leave behind the shell of the larval body, called an exuvia, and that is absolutely critical (see below) when considering that Odonata can live up to 5 years in the larval stage! We notice them as imagoes, and most will only fly for a few weeks.

Metamorphoses of a Large pincertail.
Fig. 1 – Large pincertail (Onychogomphus uncatus), male, emerging from larval form. Cabezón de la Sal (Río Saja), Cantabria, 30TVN09. 12.vii.18. Notice that the eyes do not touch at the top of the head (see exceptions below).

Odonata life is strongly associated with water, but each species usually has quite some restrictions to the preferred habitat … running water or stagnant (e.g., a pond), no fish presence (or doesn’t matter), sandy or rocky bottom of the body of water, lots of vegetation or very little, and so forth. Most lay their eggs in the water, stuck to clumps of vegetation, and all larvae develop in water (or mud). Anisoptera imagoes are great fliers and can be found far from bodies of water, where Zygoptera are generally “weaker” fliers.

There are insects that could be mistaken for Odonata, which include owlflies and antlions. Owlflies strange-looking insects that are not directly associated with water and have long antenna with a bulb ending (similar to butterflies). Antlions are also not associated with water, have longish antenna and hunt ants (what’s in a name, eh?). Both owlflies and antlions are more common in drier, warm climates and fly towards the end of the day into the night. Both are part of the order Neuroptera, which is just filled with wonderful weirdness … but that is for a future post (with pictures).

Exuvie of two different Odonata.
Fig. 2 – Evuvie. Common bluet (Enallagma cyathigerum), Miengo, Cantabria, 30TVP10. 20.vii.20. The proct has the dark “vein” running through it at towards the bottom of the exuvie.; Western spectre (Boyeria irene), Mazcuerras, Cantabria, 30TVN09. 10.ix.16. The bottom ends in three sharp points.

2.0 Differentiating Aspects

There are three fairly clear ways to tell damselflies and dragonflies apart, although one is during the larval stage only:

  1. Larval stage only – damselfly larvae have 3 “feather-like” appendages (called procts), which are actually their breathing apparatus, sticking out of the tip of their abdomen (see Fig. 2).
  2. Eye placement – during the imago stage, the eyes are placed differently on the head, with dragonflies having eyes that are placed close together on the head, often touching, and damselflies having each eye quite distant and separate from the other (Fig. 3).
  3. Wings at rest – when at rest, dragonflies hold their wings spread out from their body, whereas most damselflies fold their wings in along their abdomen. This can make damselflies very difficult to spot when at rest (Fig. 4).
Eye position of Odonata.
Fig. 3 – Eye placement. Vagrant emporer (Anax ephippiger) (left), Miengo, Cantabria, 30TVP10. 30.iii.23. A dragondly with large eyes clearly connected at the top of the head.; Migrant spreadwing (Lestes barbarus) (top right), Miengo, Cantabria, 30TVP10. 06.v.22. A damselfly with the eyes at opposite ends of an elongated head.; Green-eyed hawker (Aeshna isoceles) (bottom right), Miengo, Cantabria, 30TVP10. 20.vii.20. Another dragonfly with eyes joined along the middle of the head.

There are of course exceptions, as was also the case in the Lepidotera post, to the statements above.

  • Dragonflies in the Gomphidae family (clubtails, pincertails and hooktails) do have a noticeable space between their eyes, see Fig. 1. But their wings are always held open at rest.
  • Damselflies in the Lestidae family (spreadwings) hold their wings … spread out … at rest. The nameplate states it. Though their eyes are clearly far apart. One interesting characteristic about Lestidae is that some place their eggs in plant tissue (e.g., under tree bark), well out of the water.
Different wing positions of Odonata.
Fig. 4 – Wing position at rest. Red-veined darter (Sympetrum fonscolombii) (left), Cabezón de la Sal, Cantabria, 30TVN09. 00.ix.15. Dragonfly with wings spread wide.; Keeled skimmer (Orthetrum coerulescens) (top right), Cabezón de la Sal, Cantabria, 30TVN09. 25.viii.21. Another dragonfly with wings spread wide.; Small redeye (Erythromma viridulum) (bottom right), Miengo, Cantabria, 30TVP10. 25.ix.21. Damselfly with wings held close to the abdomen.

Conclusion

Damselflies and dragonflies are not that difficult to differentiate, but maybe reading the above has shown you that there are many subtle variations that you can take into account when observing nature.

Finally, it is often stated that dragonflies are good bioindicators of the health of an ecosystem. I was going to write a paragraph on just what makes them so useful, but as I was writing it I felt I was adding too much extra to an already information-loaded post. I will copy/paste that piece into a future Nature 101 post on Citizen Science or Ecosystem Monitoring … stay tuned.

Again, feel free to ask any questions. Up next in the series will be something on Biogeography or Phenology (cycles in nature), not sure which yet.

Nature 101 – Base Knowledge – Odonata

Nature 101 – Base Knowledge – Lepidoptera

bartvanhoof, , , , , 2 Comments

Introduction

Today we’ll cover the order of Lepidoptera … In the Nature 101 Naming post we discussed a little bit about where order fits into the taxonomy picture. Basically, order covers a whole group of animals/insects/plants/etc. that have fairly similar characteristics.

Within the order of Lepidoptera we have both butterflies (Rhopalocera – a clade, or natural group) and moths (Heterocera) … what are common characteristics and what makes them different? Is it the time of day at which they fly or is that more an over-generalisation?

1.0 Common Aspects

There are two key common elements within Lepidoptera:

  1. Scaly wings – Lepidoptera is a term that is derived from Greek … “lepis” meaning scale and “ptera” meaning wing.
  2. The life cycle – this can be split into:

Egg – larva (caterpillar) – pupa (cocoon/chrysalis) – imago (butterfly or moth)

1.1 Scales

The closest insects to butterflies and moths are caddisflies, which are part of the order Trichoptera. The main difference is that their wings are covered in hairs (“trich”) and not scales! It can be really tricky to spot the difference. One of the ways to tell is that if you catch a moth in your hand and close it into a fist (don’t crush it!), when you release it you can notice that the palm of your hand is covered in a light dust, those are the scales that have fallen off (been knocked off) the wings while it was fluttering and trying to escape. A caddisfly won’t leave anything behind. But I’d suggest you take good macro photos and then you can sort of see the scales (or not).

1.2 Lifecycle

When it comes to life cycle, most of us only really notice the last stage, that of imago. It is during that stage when we see them fluttering (or zipping, some are amazing fliers) around, looking for a mate or food (nectar from flowers or minerals from mud, or rotting fruit or dog poo). They can have brilliant colours, but even the drab ones can catch our eye as they spring up to defend their sunny patch of woodland.

Eggs are tiny and you must know what you are looking for or spot them in big bunches for some species. So, they generally go unnoticed.

Larvae are either easy to spot or super difficult. Some are bunched by the hundreds is silky nests that look like giant spider webs. Other are brightly coloured. Then there are caterpillars that look like twigs or are within parts of a plant.

Then there are pupae … again something that is less common to see … most tend to be well camouflaged and hidden; some are even underground. But I guess that should be self-evident … the two life stages at which they are most vulnerable (egg and pupa – cannot do much against attackers) they are hidden and least noticeable.

There’s one area I want to touch upon but not really go into too deep because buy can it get detailed … but basically each moth or butterfly is associated with a plant or group of plants. This is because the imago will lay an egg on a specific plant so that when it hatches the larva has plenty of food that it can eat straight away. No use laying an egg on a blade of grass if the caterpillar is only interested in eating cabbage leaves. This plant is called a larval host plant (LHP), and this is super critical in the life of a moth or butterfly … either it can be labelled a pest if the LHP happens to be a plant us humans rely on for food (or really like). Or the moth/butterfly can get itself into a really tricky situation (nature conservation-wise) if that LHP happens to become scarce (think climate change or humans changing the landscape (e.g., drying out marshy areas)).

What this means is that the average moth or butterfly you see is probably a generalist regarding LHP (so can lay eggs on lots of different types of plants) or feeds on plants we do not value much (e.g., nettles). Therefore, if you really want to see different types of Lepidoptera it often means going to very specific ecosystems … which can be used as the basis for an adventure …

2.0 Differentiating Aspect

Before I go into the one key differentiating factor, first the following:

  • Not all Lepidoptera can fly in the imago stage. There are several moth species (in Europe) where the female is basically wingless (she has little stubs). Males find her (from quite far away) through a pheromone she emits. She just nestles tightly against the tree’s bark waiting for the males to figure out how to find her.
  • Butterflies fly by day but not all moths fly at night. Or in other words … there are day-flying moths. Quite a few actually, so no, the time of day is not always accurate. That said, a moth trap (a light trap emitting UV light) set out during the night is still the best way to see large numbers of moths.

So, what is that key differentiating factor? … if you know Greek you might have guessed by the name of their clades …

Butterflies have little clubs at the end of their antenna, whereas moths have straight or feathery antenna (see Fig. 1).

Three types of antenna for Lepidoptera.
Fig. 1 – Euphydryas aurinia (left), Rionansa, 17.vi.18 (butterfly with a club antenna); Aglia tau (top right), Valdáliga, 05.iv.19 (moth with a feathery antenna – males fly around during the day); Hypena proboscidalis (bottom right), Cabezón de la Sal, 15.x.21 (moth with a straight antenna – it came to my light trap at night).

Now, as you might expect, it is not all as crystal clear as that (when is it ever?) … there are moths whose antenna look “clubby” in shape … examples are clearwing moths (Sesiidae) and burnet moths (Zygaenidae), both of which fly by day. There are also butterflies that have antenna that look less “clubby” in shape, such as skippers (Hesperiidae). (Fig. 2)

Fig. 2 – Pyrgus armoricanus (left), Valdeprado del Río, 08.v.21 (a butterfly with fairly flat antenna); Pyropteron chrysidiformis (top right), Camargo, 07.vi.17 (a beautiful dayflying moth from the Sesiidae family); Zygaena rhadamanthus (bottom right), Valdeprado del Río, 06.vi.18 (another stunning dayflying moth with chunky antenna).

Conclusion

Well, I hope this has been informative. Butterflies have been the insect that help draw me into nature observation. There is so much more I could cover, like flight generations etc. but that would make this post too long. I wanted to keep the post relatively short and not overwhelm the reader with too much (new) information in one go.

The next Nature 101 will probably cover Odonata, another favourite of mine.

If you have any questions, please feel free to ask I can either answer them below or decide to dedicate another Nature 101 to it if the topic is extensive (e.g., migration, lifecycles etc.).

Nature 101 – Base Knowledge – Lepidoptera