Survey estimates much higher Alberta bird populations than thought

BOB WEBER

EDMONTON, ALBERTA

THE CANADIAN PRESS

PUBLISHED JUNE 21, 2020  UPDATED JUNE 21, 2020

There may be many, many more songbirds in Alberta forests than previously thought, say University of Alberta scientists who have come up with a new way of counting them.

But researchers say that while the new counts may be good news – some estimates are more than 10 times higher – they don’t change the overall declining trend of the province’s boreal songbirds.

“Our estimates just highlight that our understanding is incomplete,” said Peter Solymos, whose paper was recently published in The Condor, the journal of the American Ornithological Society. “We need to understand the limitations.”

Bird populations across the continent have been in decline for years. A paper last fall estimated populations have dropped by three billion overall since the 1970s.

Numbers have been estimated for years using data from the Breeding Bird Survey, which uses a standard, consistent method across North America.

Solymos said that survey uses assumptions and techniques that may distort Alberta results. It sends counters out along prescribed roads, stopping at regular distances and counting birds heard and seen within a certain time. Those raw numbers are adjusted to account for factors such as birds singing more at some times of day than others.

Solymos said that may work in southern Alberta and the United States, where roads go almost everywhere. But northern Alberta is full of roadless bush. Roadside counts bias results in favour of roadside habitat.

“Roads are usually built in upland environments and go through upland vegetation. (As well), you get the disturbed habitat along the road.

“You get a nonrandom sample. You have to go into the bush.”

Solymos took the bird survey data and combined it with dozens of off-road bird surveys done over the years for forestry companies and agencies such as the Alberta Biodiversity Monitoring Institute.

Out of 81 bird species, Solymos came up with significantly higher estimates for 45 of them. Four species – crows, goldfinches and two types of sparrow – came in lower, and the rest were comparable.

Solymos came up with populations estimates that are, on average, 3.7 times higher.

Some differences are huge. The Breeding Bird Survey puts 70,000 blackpoll warblers in Alberta; Solymos reckons 1.3 million.

Jeff Wells, head of boreal conservation for the Audubon Society, calls Solymos’s work significant.

“It may show that there are more birds in the intact boreal than we thought, which is good news. It means we still have lots of chances to keep them that way.”

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Underestimating combined threats of deforestation and wildlife trade will push Southeast Asian birds

Date:  October 7, 2018

Source:  University of Sheffield

The combined impact of deforestation and wildlife exploitation on bird numbers is severely underestimated and could lead to some species becoming extinct, a joint study by the University of Sheffield and National University of Singapore has found.

Scientists focused on Sundaland -- a hotspot of biodiversity in Southeast Asia, spanning Borneo, Sumatra, Java and Peninsular Malaysia -- where habitat loss, and hunting and wildlife trades are particularly intense.

Looking at 308 forest-dependent bird species, they found that when the loss of forest habitat and bird trapping in the area was examined together it resulted in a much higher average population loss than when accounted for separately.

The study calls for the threats to biodiversity to be considered in totality in order for effective measures to be implemented.

The research, which was conducted between October 2016 and July 2017, also suggests that about 50 to 90 of forest-dependent species in the region, such as the ruby-throated bulbul and white-crowned hornbill will be extinct by 2100.

Tropical forests are the most biodiverse ecosystem globally, however, extensive loss of tropical forests driven primarily by the expansion of agricultural land threatens the survival of forest species. Coupled with other anthropogenic disturbance such as logging, hunting and fires, the threat to biodiversity in these forests is amplified.

While the International Union for Conservation of Nature (IUCN) has been tracking the different forms of threats to wildlife, the assessments tend to look at each form of threat separately. These threats, are however, interconnected and the combined impact could be more severe than currently estimated.

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UK: Special farm wildlife scheme beats organic at boosting birds

Threatened farmland birds are likely to survive the winter better on conventional farms with specially designed wildlife habitats than on organic farms without according to a new study from the University of Southampton.

Winter farmland bird populations compared across three different wildlife schemes showed the ‘Conservation Grade’ approach, that aims to grow crops efficiently while requiring farmers to establish and manage specific habitats for wildlife, produced higher survival rates than the organic sites.

The researcher, Dominic Harrison, said the greatest numbers of chaffinches, skylarks, yellowhammers and lapwings were recorded on Conservation Grade farms.

“A strong link was found between the number of specially-designed habitats created and the richness of bird species found,” he said.

Continued