Social network connections are positively related to temperature in winter flocks of black-capped chickadees
Data files
Mar 12, 2024 version files 21.75 MB
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Birds_Yr1.csv
1.96 KB
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Birds_Yr2.csv
1.31 KB
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README.md
2.95 KB
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RFID_data_Yr1.csv
15.35 MB
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RFID_data_Yr2.csv
6.39 MB
Abstract
Social species often share with conspecifics the responsibilities of finding food, defending against predators or caring for young. Within a social group, individuals’ roles can be influenced by age, sex, and personality. Black-capped chickadees, Poecile atricapillus, are nonmigratory passerine birds that spend their winters living in social flocks. Due to the intense metabolic stress placed on chickadees by low winter temperatures, the role of flocking in resource localization and allocation among flockmates is an important aspect of individual fitness, especially during winter. Understanding changes in flock structure in response to the environment may provide insight into the consequences of social behaviour variability on overwinter survival. Here, we used social network analysis to quantify the effects of ambient temperature on social foraging behaviour in winter flocks of black-capped chickadees over two winters in Massachusetts, USA. Contrary to our expectations, we found that two measures of social connection were higher on warm days than on cold days. We found no evidence that sex or dominance rank influenced birds’ behavioural responses to temperature. Furthermore, contrary to previous research, we found male-biased sex ratios in most of our flocks. Our findings that birds had more and stronger social connections on warm days and that an individual’s response to temperature was not related to their status in a flock beg further investigation as to the specific costs and benefits of flocking in chickadees and other birds.
README: Social network connections are positively related to temperature in winter flocks of black-capped chickadees
Samantha E. Rothberg, Sarah E. Wolf, and Ethan D. Clotfelter
These data tabulate instances of bird feeder use for radiofrequency identification (RFID) banded black-capped chickadees. They also provide information about individuals' attributes. Data was collected in Amherst, Massachussetts from November to the end of February in both 2020-2021 and 2021-2022. The study conducted with this data observational and attempted to correlate flocking patterns with outside temperature.
The two files (RFID_data_Yr1.csv and RFID_data_Yr1.csv) contain each field season's RFID feeder data (2020-2021 and 2021-2022 respectively). A total of ten different RFID-enabled feeders were filled regularly throughout the 2020-2021 season. In 2021-2022, eight of the ten feeders were deployed at any one time over a slightly smaller area, and the other two were used as backups in case of damage. The feeders are named as follows:
- blackcapped
- boreal
- carolina
- chestnutbacked
- fin
- greyheaded
- humpback
- minke
- mountain
- sei
Both files are formatted in the same way. The first column is named "Event" to indicate each time a bird was recorded at a feeder. The second column is named "ID" and contains the alphanumeric sequence associated with each bird's RFID band. The third column is named "Date," and is the date of the associated feeder event (MM/DDYY). The next column is called "Time," and contains the time (HH:MM:SS) since midnight of that calendar date. Finally, the last column is called "Feeder," and contains the string name of the bird feeder at which that data point was collected.
The second pair of files (Birds_Yr1.csv and Birds_Yr2.csv) contains information about individual birds. The first column "Bird" is simply an ordinal list of birds caught that year. The second column, "ID," contains the alphanumeric sequence associated with each bird's RFID band, just as in the files above. The third column, "Flock," contains numbers corresponding to the flock that individuals were assigned by the fastgreedy flocking algorithm. Individuals with the same integer (within a year/file) were assigned by the algorithm to the same flock. The fourth column, "Sex," has an M for individuals who were determined to be male (homogametic) in a PCR, an F for individuals who were determined to be females (heterogametic), and empty for individuals who did not have a blood sample available for PCR analysis. Finally, the last column, "Wing," contains the measured wing chord length of individuals as measured during the banding process. All wingspans are in millimeters. Missing values for "Sex" and "Wing" are indicated by the word "null."