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Excited to share a new paper w/ @KluaneSquirrels out today in @CurrentBiology!
We explore how relationships w/ territory neighbors affect fitness in red squirrels.
Coauthored w/ @McAdam_lab, @boutinlab, @ben_dantzer, Jeff Lane & Dave Wilson
https://bit.ly/37xzsQV
(1/22)
We explore how relationships w/ territory neighbors affect fitness in red squirrels.
Coauthored w/ @McAdam_lab, @boutinlab, @ben_dantzer, Jeff Lane & Dave Wilson
https://bit.ly/37xzsQV
(1/22)
Social relationships, we know, play a key role in the lives of group-living organisms and have important health and fitness benefits across a wide range of taxa.
https://science.sciencemag.org/content/368/6493/eaax9553
(2/22)
https://science.sciencemag.org/content/368/6493/eaax9553
(2/22)
But what about for a solitary, territorial species like the red squirrel?
Both male & female
defend exclusive territories around a cache of food resources & rarely come into physical contact.
Could social relationships still matter for a species like this?
(3/22)
Both male & female
defend exclusive territories around a cache of food resources & rarely come into physical contact. Could social relationships still matter for a species like this?
(3/22)
We thought YES.
Despite living alone, interact socially w/ their neighbors through unique territorial vocalizations called ‘rattles’.
These reoccurring interactions allow for the formation of 'relationships' b/w neighbors that might have important benefits.
(4/22)
Despite living alone,
interact socially w/ their neighbors through unique territorial vocalizations called ‘rattles’. These reoccurring interactions allow for the formation of 'relationships' b/w neighbors that might have important benefits.
(4/22)
Using 22 years of data from over 1000 red squirrels collected as part of the @KluaneSquirrels Project in the Yukon, Canada, we set out to answer this question about the importance of relationships with territory neighbors. #LongTermResearch
We had two hypotheses:
(5/22)
We had two hypotheses:
(5/22)
1) We expected that living near relatives might provide fitness benefits through kin selection.
@KluaneSquirrels research has shown that act altruistically toward kin by nest sharing ( https://link.springer.com/article/10.1007/s00265-013-1499-4) & adopting orphaned relatives ( https://www.nature.com/articles/ncomms1022).
(6/22)
@KluaneSquirrels research has shown that
act altruistically toward kin by nest sharing ( https://link.springer.com/article/10.1007/s00265-013-1499-4) & adopting orphaned relatives ( https://www.nature.com/articles/ncomms1022). (6/22)
2) We expected that living near familiar neighbors might provide fitness benefits.
@KluaneSquirrels research has shown that w/ familiar neighbors face reduced risk of territory intrusion ( https://www.sciencedirect.com/science/article/abs/pii/S0003347217302828) & spend less time on defense ( https://www.sciencedirect.com/science/article/abs/pii/S0003347219300673)
(7/22)
@KluaneSquirrels research has shown that
w/ familiar neighbors face reduced risk of territory intrusion ( https://www.sciencedirect.com/science/article/abs/pii/S0003347217302828) & spend less time on defense ( https://www.sciencedirect.com/science/article/abs/pii/S0003347219300673) (7/22)
We were particularly interested in exploring the relative benefits of BOTH kinship & familiarity to offer insight into the evolutionary importance of kin selection vs. mutually-beneficial interactions for mitigating conflict & facilitating the evolution of cooperation.
(8/22)
(8/22)
Surprisingly, we found that living near kin did not have any effects on fitness.
However, living near familiar neighbors increased both annual survival and reproductive success for male & female red squirrels.
(9/22)
However, living near familiar neighbors increased both annual survival and reproductive success for male & female red squirrels.
(9/22)
These fitness benefits were strongest in later life.
For squirrels 4 years & older the benefits of being familiar with neighbors were strong enough to offset age-related declines in survival and reproductive success.
(10/22)
For squirrels 4 years & older the benefits of being familiar with neighbors were strong enough to offset age-related declines in survival and reproductive success.
(10/22)
Given how substantial these fitness benefits of having familiar neighbors are, we suggest that our findings open up the interesting possibility that otherwise adversarial red squirrels might actually cooperate with each other to help keep their neighbors alive!
(11/22)
(11/22)
What this 'cooperation' might look like - whether it's sharing food resources, predator alarm calling, or forming defensive coalitions - is an interesting question for future research!
(12/22)
(12/22)
Importantly, we were able to demonstrate that spatial autocorrelation in survival & repro success was rare & inconsistent.
This helped ensure that our results weren't driven by localized areas of 'high quality' leading to high survival & therefore high familiarity.
(13/22)
This helped ensure that our results weren't driven by localized areas of 'high quality' leading to high survival & therefore high familiarity.
(13/22)
To provide a mechanistic understanding of how familiarity might lead to increased fitness we also showed that in familiar neighborhoods male :
1) Traveled farther to mate.
2) Sired more offspring outside their 'social neighborhood'.
(14/22)
:1) Traveled farther to mate.
2) Sired more offspring outside their 'social neighborhood'.
(14/22)
This is likely because males with familiar neighbors have more energetic resources due to either...
1) reduced pilferage of food stores or
2) reduced time spent on territory defense...
in familiar neighborhoods.
(15/22)
1) reduced pilferage of food stores or
2) reduced time spent on territory defense...
in familiar neighborhoods.
(15/22)
So why is this study important?
1) Being solitary does not equate to being asocial.
We've shown that solitary species, like their social counterparts, can have important social relationships that directly affect survival and reproductive success.
(16/22)
1) Being solitary does not equate to being asocial.
We've shown that solitary species, like their social counterparts, can have important social relationships that directly affect survival and reproductive success.
(16/22)
2) It's not all about kin!
Mutually beneficial interactions, in the form of social familiarity, can can play an important role in mitigating conflict and therefore potentially facilitating the evolution of cooperation.
(17/22)
Mutually beneficial interactions, in the form of social familiarity, can can play an important role in mitigating conflict and therefore potentially facilitating the evolution of cooperation.
(17/22)
3) The key to anti-aging?
Our results indicate that maintaining social relationships into later life might help buffer squirrels from age-related declines in fitness and therefore have the potential to affect the evolution of senescence.
(18/22)
Our results indicate that maintaining social relationships into later life might help buffer squirrels from age-related declines in fitness and therefore have the potential to affect the evolution of senescence.
(18/22)
This question of how social relationships affect the aging process is a question of key interest (including in humans!) and is one I'm continuing to explore in rhesus macaques as a postdoc with @ljnbrent at @CrabExeter.
(19/22)
(19/22)
We are very grateful to the Champagne and Aishihik First Nations ( @ShadhalaAsheyi) on whose land this work was conducted. Without their continued support & willingness to share their land with us, none of this long-term research would have been possible.
(20/22)
(20/22)
The Kluane Red Squirrel Project ( @KluaneSquirrels) is a hugely collaborative effort & this research would not have come to be without the hard work of hundreds of field technicians who have contributed to the long-term KRSP database over the past 30 years!
(21/22)
(21/22)
Finally, a big thank you to our funding sources including @NSERC_CRSNG, @NSF, @Mammalogists, @ArcticSynthesis and @UMich.
(22/22)
(22/22)
