Using Tracking Data to Identify Gaps in Knowledge and Conservation of the Critically Endangered Siberian Crane (Leucogeranus leucogeranus)

The critically endangered Siberian crane (Leucogeranus leucogeranus) is the world’s third most endangered species of crane. Despite the enhanced conservation actions in recent years, there are pieces of evidence that suggest that its population is continuously decreasing. To gain insights into the possible causes of the population decline, we tracked nine Siberian cranes in Russia and Mongolia using GPS transmitters. We obtained migration episodes based on over 0.31 million subsequent locations from 3283 bird days between June 1995 and December 2021. Siberian cranes migrated an average of 5604 ± 362 km in spring from wintering to breeding areas and a mean of 5265 ± 454 km from breeding to wintering areas. We identified 35 staging sites along the migration corridor, including 17 critical staging sites at which birds staged for >14 days and 18 stopover sites that supported individuals for more than two days within a ca. 200 km-wide migratory corridor. Of the areas used by the tagged cranes, 77% of the breeding areas in Russia, 55% of the staging areas, 99% of the non-breeding summering area in Mongolia, and 50% of the wintering areas in Poyang Lake in China lay outside the current protected area network. Although we should be prudent about interpreting the conservation gaps of the entire population from only a few tracked birds, these results strongly suggest that the current protection network for this numerically rare species is inadequate, requiring urgent review

Using Tracking Data to Identify Gaps in Knowledge and Conservation of the Critically Endangered Siberian Crane (<i>Leucogeranus leucogeranus</i>)

The critically endangered Siberian crane (Leucogeranus leucogeranus) is the world’s third most endangered species of crane. Despite the enhanced conservation actions in recent years, there are pieces of evidence that suggest that its population is continuously decreasing. To gain insights into the possible causes of the population decline, we tracked nine Siberian cranes in Russia and Mongolia using GPS transmitters. We obtained migration episodes based on over 0.31 million subsequent locations from 3283 bird days between June 1995 and December 2021. Siberian cranes migrated an average of 5604 ± 362 km in spring from wintering to breeding areas and a mean of 5265 ± 454 km from breeding to wintering areas. We identified 35 staging sites along the migration corridor, including 17 critical staging sites at which birds staged for >14 days and 18 stopover sites that supported individuals for more than two days within a ca. 200 km-wide migratory corridor. Of the areas used by the tagged cranes, 77% of the breeding areas in Russia, 55% of the staging areas, 99% of the non-breeding summering area in Mongolia, and 50% of the wintering areas in Poyang Lake in China lay outside the current protected area network. Although we should be prudent about interpreting the conservation gaps of the entire population from only a few tracked birds, these results strongly suggest that the current protection network for this numerically rare species is inadequate, requiring urgent review

Migration of whooper swans and outbreaks of highly pathogenic avian influenza H5N1 virus in eastern Asia.

Evaluating the potential involvement of wild avifauna in the emergence of highly pathogenic avian influenza H5N1 (hereafter H5N1) requires detailed analyses of temporal and spatial relationships between wild bird movements and disease emergence. The death of wild swans (Cygnus spp.) has been the first indicator of the presence of H5N1 in various Asian and European countries; however their role in the geographic spread of the disease remains poorly understood. We marked 10 whooper swans (Cygnus cygnus) with GPS transmitters in northeastern Mongolia during autumn 2006 and tracked their migratory movements in relation to H5N1 outbreaks. The prevalence of H5N1 outbreaks among poultry in eastern Asia during 2003-2007 peaked during winter, concurrent with whooper swan movements into regions of high poultry density. However outbreaks involving poultry were detected year round, indicating disease perpetuation independent of migratory waterbird presence. In contrast, H5N1 outbreaks involving whooper swans, as well as other migratory waterbirds that succumbed to the disease in eastern Asia, tended to occur during seasons (late spring and summer) and in habitats (areas of natural vegetation) where their potential for contact with poultry is very low to nonexistent. Given what is known about the susceptibility of swans to H5N1, and on the basis of the chronology and rates of whooper swan migration movements, we conclude that although there is broad spatial overlap between whooper swan distributions and H5N1 outbreak locations in eastern Asia, the likelihood of direct transmission between these groups is extremely low. Thus, our data support the hypothesis that swans are best viewed as sentinel species, and moreover, that in eastern Asia, it is most likely that their infections occurred through contact with asymptomatic migratory hosts (e.g., wild ducks) at or near their breeding grounds

Migration chronology and transmission history summary.

<p>Table does not include s584, for which messages were not received >7 d after release.</p

Long distance migration movements recorded for whooper swans during fall 2006 and spring 2007.

<p>Long distance migration movements recorded for whooper swans during fall 2006 and spring 2007.</p

Mean weekly exposure of whooper swans to poultry by annual cycle stage.

<p>Mean weekly exposure of whooper swans to poultry by annual cycle stage.</p

Poultry density and H5N1 outbreak locations [circles (poultry), diamonds (migratory waterbirds), and triangles (wild non-waterbirds)] in eastern Asia (2003–2007).

<p>Poultry density and H5N1 outbreak locations [circles (poultry), diamonds (migratory waterbirds), and triangles (wild non-waterbirds)] in eastern Asia (2003–2007).</p

Relationships among migratory whooper swan movements, the timing of H5N1 outbreaks, and the density of poultry in eastern Asia.

<p>Solid line represents mean poultry density at whooper swan locations through the annual cycle. Circles (poultry), diamonds (migratory waterbirds), and triangles (wild non-waterbirds) indicate the timing and underlying poultry density at each H5N1 outbreak event.</p

Frequency of poultry and wild bird H5N1 outbreak events in relation to season as determined by whooper swan annual cycle stage.

<p>Circles, squares, diamonds, and triangles represent the expected number of outbreaks in each of bird sector, bars represent the actual number of outbreaks, and arrows up/down indicate if there were greater than or less than expected numbers of outbreaks, respectively.</p

Whooper swan movements (2006–2007) and proximity to HPAI outbreak locations (2003–2007) affecting poultry (circles) and wild non-waterbirds (triangles) in (a) northeastern China and (b) the Korea Peninsula.

<p>Whooper swan movements (2006–2007) and proximity to HPAI outbreak locations (2003–2007) affecting poultry (circles) and wild non-waterbirds (triangles) in (a) northeastern China and (b) the Korea Peninsula.</p