Citizen scientists count nearly 2 million birds and reveal a possible kookaburra decline


Kerryn Herman, Deakin University

The fourth Aussie Backyard Bird Count has just ended, with nearly 2 million birds from 635 species submitted to the BirdLife Australia app. The count, which is in its fourth year, has created a national database of birds found in our backyards.

We don’t know yet exactly how many people participated this year, but more than 60,000 people submitted checklists in 2016. Participants span the whole country, though participation is highest in our urban areas. By surveying our backyards (rather than “good” bird spots), these citizen scientists provide ecologists – like me – with information from urban areas we would not otherwise sample.

This includes data on a range of common bird species that are not frequently analysed because these species are believed to be secure. One of the most surprising results is a decline in the frequency of occurrence of the laughing kookaburra across southeast Australia.

Counting birds

Everyone has a bird story – and fortunately for ecologists, everyone is willing to share them. With 85% of Australia’s population living in cities and towns, birds are an important connection to our natural environment.


BirdLife Australia

But birds are also good environmental indices. They’re generally easy to measure, they respond quickly to environmental change and we know a reasonable amount about the ecology of most species.

Between 1998 and 2014, BirdLife Australia volunteers collected a significant amount of data. This was used to develop a terrestrial bird index in 2015 – a bird “Dow Jones” to track our biodiversity. It was here that the decline in kookaburras was first identified.

The data were drawn from BirdLife Australia’s ongoing atlas project, now called Birdata. However, there are biases in this data set, as people obviously like to go birdwatching where they will see more birds. This may inflate the frequency of encountering some species and decrease the chances of encountering others – particularly rare and cryptic species.

For the last four years, we’ve asked volunteers to add to this data by counting birds around their home for a week in October, when many birds are highly active and visible. These counts complement the data already available in Birdata by allowing access to backyards across Australia, which are generally poorly represented in the larger data set.

While there are still limitations in the Backyard Bird Count data, such as the risk of mis-identification, for common species like the laughing kookaburra we can generally be confident that the identification is correct. Even if the same bird is counted multiple times, our models report only a species’ presence or absence, so inflated numbers don’t affect the trend.

Are kookaburras really declining?

The below figures show modelled trends for the kookaburra across metropolitan Melbourne and Sydney. These figures are derived from the volunteer-collected Birdata, much of which comes from green spaces and remnant vegetation in these landscapes.

I wondered whether these declines are true changes in the populations, or reflect a change in the way kookaburras are using the landscape, possibly moving into the matrix of urban backyards that just don’t get surveyed. Looking solely at the backyard count data, I found similar trends in the reporting rates of kookaburras as those in the models, supporting that this decline is at the population level. What started out in 2014 as a way of engaging the broader community with their birds is now collecting useful ecological data.

Further exploration of the ABBC data across other capital cities found some interesting things. In both Perth and Hobart, where the kookaburra is considered an introduced species, the birds are recorded more frequently than in Melbourne and across the ACT. In Perth, increases in 2016 compared to previous years suggest an increase in the species there.

Modelled trends for Kookaburras from 1998-2014. The figure on the left is for Melbourne, and on the right is for Sydney. The reporting rate shows the percentage of surveys where kookaburras were recorded as present. The thick black line is the modelled trend (with confidence intervals in dashed line), the pink line shows the statistically significant linear trend, the thin black line shows the monthly calculated reporting rate, and the green spots show acceleration (or a favourable change) in the trend. Note that due to modelling method, the ends of figures tend to blow out as there is no data from which to predict trend.
Unpublished models/K. Herman/BirdLife Australia, Author provided

While three years does not make a trend, Aussie Backyard Bird Count data from heavily urbanised areas suggest we are seeing a decline in this iconic species in the eastern capitals. Likely reasons for this are the loss of nesting hollows and possibly reductions in the availability of prey as we increasingly modify our urban landscapes. We don’t really know as this is not an area that has been researched.

We need citizen scientists

Collecting enough data (especially from the backyards of towns and cities) to detect these kinds of changes can be an overwhelming task. This is where citizen science programs like the Aussie Backyard Bird Count can help.

As well as helping ecologists track large-scale biodiversity trends, it also gives people the chance to connect with their natural environment and gain a greater appreciation of our unique fauna.

As with all citizen science projects, there are limitations in the data being collected. However, the Backyard Bird app has been designed to make counting as simple and standardised as possible, providing confidence in the tally of common and “iconic” species, and filling in the gaps found in other data sets.

The good old kookaburra is neither rare or cryptic. If anything, if people are seeking out “good” bird habitat to survey we would expect that kookaburras would be one of those species subject to inflated reporting. But this is not what we encountered.

The ConversationIf we are starting to see declines in species that we have traditionally considered secure, what does this mean for those that are already at risk? Once all the data from the Aussie Backyard Bird Count have been collated and vetted we will continue to explore the developing trends in Australia’s urban birds. Increasing engagement and awareness in our communities can help ensure our backyard birds are still around to count next year.

Kerryn Herman, Research Ecologist, Deakin University

This article was originally published on The Conversation. Read the original article.

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Citizen scientist scuba divers shed light on the impact of warming oceans on marine life



File 20171019 1045 3eh0e1.jpg?ixlib=rb 1.1
A volunteer diver surveys marine life at Lord Howe Island.
Rick Stuart-Smith/Reef Life Survey, Author provided

Madeleine De Gabriele, The Conversation

Rising ocean temperatures may result in worldwide change for shallow reef ecosystems, according to research published yesterday in Science Advances.

The study, based on thousands of surveys carried out by volunteer scuba divers, gives new insights into the relationship of fish numbers to water temperatures – suggesting that warmer oceans may drive fish to significantly expand their habitat, displacing other sea creatures.

Citizen science

The study draws from Reef Life Survey, a 10-year citizen science project that trains volunteer scuba divers to survey marine plants and animals. Over the past ten years, more than 200 divers have surveyed 2,406 ocean sites in 44 countries, creating a uniquely comprehensive data set on ocean life.

Reef Life Survey takes volunteers on surveying expeditions at hard-to-reach coral reefs around the world.
Rick Stuart-Smith/Reef Life Survey, Author provided

Lead author Professor Graham Edgar, who founded Reef Life Survey, said the unprecedented scope of their survey allowed them to investigate global patterns in marine life. The abundance of life in warm regions (such as tropical rainforests and coral reefs) has long intrigued naturalists. At least 30 theories have been put forward, but most studies have been based on relatively limited surveys restricted to a single continent or group of species.

By tapping into the recreational scuba diving community, Reef Life Survey has vastly increased the amount of information researchers have to work with. Professor Edgar and his colleagues provide one-on-one training to volunteers, teaching them how to carry out comprehensive scans of plants and animals in specific areas.

Dr Adriana Vergés, a researcher at the University of New South Wales specialising in the impact of climate change on ocean ecosystems, said that the Reef Life Survey has already substantially improved our understanding of the marine environment.

“For example, Reef Life Survey data has greatly contributed to our understanding of the factors that determine the effectiveness of effectiveness of marine-protected areas worldwide. The team have made all their data publicly available and more and more research is increasingly making use of it to answer research questions,” she said.

Some of the divers have been working with Reef Life Survey for a decade, although others participate when they can. One volunteer, according to Professor Edgar, was so inspired by the project that he began a doctorate in marine biology (he graduated this year).

There’s a strong link between fish numbers and water warmth, which means warming oceans are likely to change global fish distribution.
Rick Stuart-Smith/Reef Life Survey, Author provided

Warming oceans means fish on the move

One of the important insights delivered by the Reef Life Survey datatbase is the relationship between water temperature and the ratio of fish to invertebrates in an ecosystem. Essentially, the warmer the water, the more fish. Conversely, colder waters contain more invertebrates like lobster, crabs and shrimp.

Professor Stewart Frusher, director of the Centre for Marine Socioecology at the University of Tasmania (and a former colleague of Professor Edgar) told The Conversation that he believes we will see wide-scale changes in fish distribution as climate change warms the oceans.

“Species are moving into either deeper water or towards the poles. We also know that not all species are moving at the same rate, and thus new mixtures of ecosystems will occur, with the fast-moving species of one ecosystem mixing with the slower moving of another,” he said.

As species migrate or expand into newly warmed waters, according to Professor Frusher, they will compete with and prey on the species already living in that area. And while it’s uncertain exactly how disruptive this will be, we do know that small ecosystem changes can rapidly lead to larger-scale impacts.

In order to predict and manage these global changes, scientists need reliable and detailed world-wide data. Professor Frusher said that, with research funding declining, scientists do not have the resources to monitor at the scales required.

The Conversation“Well-developed citizen science programs fill an important niche for improving our understanding of how the earth is responding to change,” he said.

Madeleine De Gabriele, Deputy Editor: Energy + Environment, The Conversation

This article was originally published on The Conversation. Read the original article.