Dragonflies & the Dry Citizen Science Project Final Report 2017 Image of common gliders at East Point, May 2017 Photo credit: Marleen van Maastricht Professor Jenny Davis School of Environment & RIEL Charles Darwin University Summary • Charles Darwin University, Territory NRM and Identifly collaBorated to run ‘Dragonflies and the Dry’, a citizen science project, from April to July 2017. • The Top End community suBmitted photographs of dragonflies and damselflies to the project using a weB-Based portal: https://identiflyapp.com/competition.html. • A monthly prize was awarded for the Best photo ($500) and a random draw ($250). Participants could suBmit as many photos as they wished. Additional information included the date and location of the image. • A free app, Identifly - a guide to the dragonflies and damselflies of the Top End, was availaBle to help participants identify the specimens photographed (although identification was not a condition of entry). • A total of 222 people participated in the project, with the suBmission of 2,265 images over the four months. • A total of 1,202 dragonflies representing 33 species and 268 damselflies representing 12 species (TaBle 3) were recorded across the Top End during the competition. • The largest number of participants and the largest number of images were recorded in April. Lower numbers were recorded in the following months, with the number of participants and images Being highly correlated (R2 = 0.94). • Analysis of relative aBundances revealed that high numbers of the common glider, Tramea loewii, the slender skimmer, Orthetrum sabina, the graphic flutterer, Rhyothemis graphiphtera, the coastal glider, Macrodiplax cora, and the common Bluetail, Ischnura heterostica, did herald the end of the Wet season. In contrast, the painted grasshawk, Neurothemis stigmatizans, and the redtail, Ceriagrion aeruginosum, steadily increased in relative aBundance from April to July. • The reason for the large number of gliders present at the end of the Dry season is not known. One possiBle explanation is the prevailing Top End winds, that switch from the northwest to the southeast in April, Bring large numbers of emerging dragonflies from the extensive wetlands of the Adelaide, Mary and Alligator Rivers floodplains. These large dragonflies are highly visiBle whilst gliding on the thermal updrafts of the Darwin coastline. • The photographic quality of many of the images suBmitted to the project was exceptionally high. Images will Be added (with permission) to the Identifly app. The images not only provide species records, they demonstrate the variaBility in colour that can exist Between males and females of the same species and a range of Behaviours and haBitat use. • Conclusion: Do large numbers of dragonflies herald the arrival of the Dry season in the Top End? YES….... But only certain species, mainly the large- winged gliders, flutterers and emperors. Some species are always present, regardless of the season. 2 Acknowledgements This project could not have Been undertaken without the following support. Territory NRM providing essential funding, with logistical support from Tida Nou. The Identifly app team, James Friend and Dora Kojevnikov, administered the project and provided ongoing voluntary support. Caroline Camilleri (Darwin Photographic Professionals) donated valuaBle expertise to the photographic competition and judging panel. Danielle Choveaux, Charles Darwin University, mapped the location data. The citizen scientists of the Top End of the Northern Territory (and Beyond) who provided the outstanding images, across a wide variety of times, dates and locations, and who made this project possiBle. The project received some great feedBack: I have only just realised the beautiful variety of dragonflies and damselflies we have in the Top End - quite amazing and the Identify App certainly helps us amateurs on the path to identifying the species we manage to capture through the lens. ….and some truly spectacular images! Photo credits L-R: Gerald EnhrenBrandtner, David WeBB, DeB Jovanovich 3 Introduction Dragonflies, with their variety of colours, Behaviours and incrediBle flying skills are eminently watchaBle. They are also a distinctive part of the tropical Biodiversity that distinguishes Darwin from all other Australian capital cities. Top Enders will tell you that the appearance of large numbers of dragonflies heralds the end of the Wet season. However, we have little scientific data to support this theory. The aim of this citizen project was to collect information on dragonflies and damselflies with the help of Top End residents and tourists through a photo competition that anyone with a camera or smart device could participate in. This information would help us understand how dragonfly and damselfly numbers change from the Wet to the Dry. It would also provide information on the location of dragonfly and damselfly ‘hotspots’. Methods The Top End community was asked to photograph dragonflies and damselflies through the months of April, May, June and July and suBmit the images to the competition using a form availaBle on the Identifly – Dragonflies and Damselflies of the Top End weBsite https://identiflyapp.com/competition.html. In addition to the image, which provided a visual record of the dragonfly or damselfly, participants were asked to provide the location where the photo was taken and the date. Participants were advised that they could use the recently released Identifly app to name their dragonfly or damselfly, but it was not essential. The request for information was kept to a minimum to ensure that the suBmission process did not Become a Barrier to participation. A monthly prize for the Best photo ($500) and one for an entry drawn at random from the suBmitted photos ($250) was provided to act as an incentive to participation. Participants could provide as many photos as they wished. A free app, 'Identifly - a guide to the dragonflies and damselflies of the Top End', was availaBle to help participants identify the specimens photographed (although identification was not a condition of entry). The app was produced By James Friend and Dora Kojevnikov and Based on an unpuBlished guide produced By Jenny Davis, John Hawking and others. The competition and project was launched with a community event at the George Brown Botanic Gardens on Saturday, March 25, from 9-11am. The flyer advertising the event is provided in the Appendix. The competition was advertised through local media. Channel 9 provided video coverage of the event on the nightly news on March 25. ABC radio Broadcast an interview with Jenny Davis on the morning of the event. The project and competition was advertised on FaceBook on the Territory NRM page, https://www.faceBook.com/TerritoryNRM and the Identifly app page, faceBook.com/IdentiflyApp/. Regular updates and winners were announced on the FB pages. Jenny Davis used her Twitter account (@waterpenny10) to advertise the project and provide updates. 4 A panel was assembled, comprising Tida Nou (Territory NRM), Caroline Camilleri (Darwin Photographic Professionals) and Jenny Davis (CDU) to judge the winning image for each month. Dora Kojevnikov, from Identifly, selected the random draw each month (using a random number generator) and administered the prize notifications and payments. Results Citizen Science Participation A total of 222 people participated in the project, with the suBmission of 2,265 images over the four months. The number of participants and number of images suBmitted in each month are given in TaBle 1. Table 1 The number of people who submitted images in each month of the competition, the number of images submitted in each month and the number of unique images used in the analyses Month Participants Images Unique Images April 131 700 615 May 74 549 449 June 43 412 245 July 35 604 152 Often multiple images of the same specimen were suBmitted to the photo competition. These were useful Because, in addition to providing occurrence records they provided information on the Behaviour and haBitat use of selected species. However, for the purpose of analysing the change in numbers over time only unique images were used. Removal of multiple images resulted in a working set of 1,461 images. The largest numbers of dragonflies and damselflies were recorded in April But the number of citizen scientists suBmitting images in this month was also the highest. The number of participants and the number of dragonflies declined each month from April to July (Fig. 1). The number of images was highly correlated with the number of citizen scientists (R² = 0.94). 5 700 April y = 4.6197x + 38.407 R² = 0.93877 600 May 500 400 June 300 July 200 No. of images submitted 100 0 140 120 100 80 60 40 20 0 No. of participants in each month Fig. 1 Change in the number of participants and images submitted from April to July, 2017 Change in Dragonfly and Damselfly Numbers over Time A total of 33 dragonflies (TaBle 2) and12 damselflies (TaBle 3) were recorded across the Top End during the competition. At the start of the competition the aptly named common glider, Tramea loewii, dominated the dragonfly images. The equally aptly named common Bluetail, Ischnura heterosticta, dominated the damselfly images. Given that we could not ascertain whether more citizen scientists recorded images in April than July Because more dragonflies were present, or Because there had Been greater puBlicity for the project in this month, we analysed the change in numbers over time By considering relative aBundances (Figs 2 & 3). The common glider, Tramea loewii occurred in the highest relative aBundance (30%) in April But had declined to only 5% of the records By July (Fig. 2). The slender skimmer, Orthetrum sabina, was relatively highly aBundant in the first three months But was not recorded at all in July. The graphic flutterer, Rhyothemis graphiphtera, was more aBundant in April and May than June and July. The coastal glider, Macrodiplax cora, also declined over the four months. In contrast to these species, the painted grasshawk, Neurothemis stigmatizans, steadily increased in relative aBundance from April to July.