2025-08-04 カリフォルニア大学サンタバーバラ校 (UCSB)
<関連情報>
- https://news.ucsb.edu/2025/021980/both-flexibility-and-persistence-make-some-birds-successful-human-made-environments
- https://peercommunityjournal.org/articles/10.24072/pcjournal.573/
- https://peercommunityjournal.org/articles/10.24072/pcjournal.582/
行動の柔軟性は採食行動と関連するが、社会行動や生息地利用行動とは関連しない、急速に分布範囲を拡大している種における研究 Behavioral flexibility is related to foraging, but not social or habitat use behaviors, in a species that is rapidly expanding its range
Logan, Corina; Lukas, Dieter; Geng, Xuewen ; Hardy, Kristin; LeGrande, Christa; Marfori, Zara; MacPherson, Maggie; Rowney, Carolyn; Smith, Caroline; McCune, Kelsey
Peer Community Journal published:2025-07-22
DOI:https://doi.org/10.24072/pcjournal.573
Abstract
The ability of other species to adapt to human modified environments is increasingly crucial because of the rapid expansion of this landscape type. Behavioral flexibility, the ability to change behavior in the face of a changing environment by packaging information and making it available to other cognitive processes, is hypothesized to be a key factor in a species’ ability to successfully adapt to new environments, including human modified environments, and expand its geographic range. However, most tests of this hypothesis confound behavioral flexibility with the specific proxy aspect of foraging, social, or habitat use behavior that was feasible to measure. This severely limits the power of predictions about whether and how a species uses flexibility to adapt behavior to new environments. To begin to resolve this issue, we directly tested flexibility using two measures (reversal learning and puzzlebox solution switching) and investigated its relationship with foraging, social, and habitat use behaviors in a flexible species that is rapidly expanding its geographic range: the great-tailed grackle. We found relationships between flexibility and foraging breadth and foraging techniques, with the less flexible individuals using a higher proportion of human foods and having more human food sources within their home range, suggesting that they specialize on human foods. These relationships were only detectable after a flexibility manipulation where some individuals were trained to be more flexible via serial reversal learning and compared with control individuals who were not, but not when using data from outside of the flexibility manipulation. There were no strong relationships between flexibility and social or habitat use behaviors. Given that this species is rapidly expanding its geographic range and recently shifting more toward urban and arid environments, our findings could suggest that foraging breadth and foraging technique breadth are factors in facilitating such an expansion. Overall, this evidence indicates that cross-species correlations between flexibility and foraging, social, and habitat use behaviors based on proxies have a high degree of uncertainty, resulting in an insufficient ability to draw conclusions.
行動の柔軟性は、地理的分布範囲を急速に拡大している種とそうでない種の間で類似している、2つの近縁種における研究 Behavioral flexibility is similar in two closely related species where only one is rapidly expanding its geographic range
Logan, Corina J. ; McCune, Kelsey B.; Rowney, Carolyn; Lukas, Dieter
Peer Community Journal Published:2025-07-22
DOI:https://doi.org/10.24072/pcjournal.582
Abstract
Human-modified environments are rapidly increasing, which puts other species in the precarious position of either adapting to the new challenges or, if they are not able to adapt, shifting their range to a more suitable environment. It is generally thought that behavioral flexibility, the ability to change behavior when circumstances change, plays an important role in the ability of a species to rapidly expand their geographic range. To determine whether species differences in range expansion propensity are linked to differences in behavioral flexibility, we compared two closely related species, great-tailed grackles (Quiscalus mexicanus; GTGR) and boat-tailed grackles (Quiscalus major; BTGR). GTGR are rapidly expanding their geographic range by settling in new areas, whereas BTGR are not. We previously found that GTGR are behaviorally flexible, however not much is known about BTGR behavior. Using the comparative method thus provides an ideal way to test the hypothesis that behavioral flexibility plays a key role in the GTGR rapid range expansion. We compared the behavioral flexibility of two GTGR populations (an older population where they have been breeding since 1951 in the middle of the northern expansion front: Tempe, Arizona, and a more recent population where they have been breeding since 2004 on the northern edge of the expansion front: Woodland, California) with one BTGR population from Venus, Florida (the age of the population is unknown, but likely thousands of years old), to investigate whether the rapidly expanding GTGR, particularly the more recent population, are more flexible. We found that both species, and both GTGR populations, have similar levels of flexibility (measured as food type switching rates during focal follows). Our results elucidate that, while GTGR are highly flexible, flexibility in foraging behavior may not be the primary factor involved in their successful range expansion. If this were the case, we would expect to see a rapid range expansion in BTGR as well. This comparative perspective adds further support to our previous intraspecific findings that persistence and the variance in flexibility (rather than population average flexibility) play a larger role in the edge GTGR population than in the GTGR population away from the edge. Our research indicates that the hypothesis that higher average levels of flexibility are the primary facilitators of rapid geographic range expansions into new areas needs to be revisited.
