Thread by @JenGill3

1 #ISTC20 #Sesh2 Hi everyone! Migratory ranges emerge from individual journeys between breeding and winter sites each year. Tracking these individual journeys in space and time can help us understand how migratory ranges form and change wadertales.wordpress.com/2019/07/29/gen… #ornithology

2 #ISTC20 #Sesh2 Since the 1990s, and with an amazing network of observers (‘godwiteers’), we have marked thousands of Icelandic black-tailed godwits and tracked them on their annual journeys between Iceland and W Europe wadertales.wordpress.com/2015/10/06/the… #ornithology

3 #ISTC20 #Sesh2 The breeding and winter ranges of Icelandic godwits have expanded northwards, but have these changes involved (a) individuals shifting sites or (b) generational change, with new generations occupying different sites? besjournals.onlinelibrary.wiley.com/doi/full/10.11… #ornithology

4 #ISTC20 #Sesh2 Tracking of individual godwits since the 1990s has revealed that they consistently use only a few sites, so range change is not explained by individuals shifting sites royalsocietypublishing.org/doi/full/10.10… #ornithology

5 #ISTC20 #Sesh2 But tracking has also revealed generational changes in settlement, with recently-ringed birds settling in recently-colonised (mostly northern) sites more than previous generations royalsocietypublishing.org/doi/full/10.10… #ornithology @RSocPublishing

6 #ISTC20 #Sesh2 Individual winter site settlement could be influenced by conditions experienced after hatching, on passage and/or at the destination. Changes in any of these conditions could therefore drive range changes royalsocietypublishing.org/doi/full/10.10… #ornithology

7 #ISTC20 #Sesh2 In godwits, the breeding range expansion into north-east Iceland, where breeding is later, is likely to have increased numbers of late-fledging chicks in the population onlinelibrary.wiley.com/doi/full/10.10… #phenology #ornithology

8 #ISTC20 #Sesh2 Late-departing juveniles may lack the time and access to adults needed to locate more southerly sites. Increased numbers of late-departers could therefore drive northwards range expansion #phenology #ornithology

9 #ISTC20 #Sesh2 Tracking data show that colour-ringed individuals from new breeding sites are indeed more likely to winter in new sites royalsocietypublishing.org/doi/abs/10.109… #ornithology

10 #ISTC20 #Sesh2 Timing of fledging could therefore be an important driver of where individuals settle within migratory ranges, and current changes in breeding phenology could be contributing to current range changes #phenology #ornithology

11 #ISTC20 #Sesh2 If settlement, survival & site-fidelity are key processes, why do we focus on resource competition to explain distributions? Are we projecting human perspectives about competition onto other species? More here: waderstudygroup.org/article/13238/ #OpenAccess #ornithology

12 #ISTC20 #Sesh2 Migratory systems emerge from interactions between space and time; one of the many features that make them endlessly fascinating. Thanks @WaderStudy & @IBIS_journal and thanks for watching! More godwiteer info: wadertales.wordpress.com/2016/02/01/god… #ornithology