Data from: Call rate and types of calls produced vary with flock movements in wild Pine Siskins (Spinus pinus)
Data files
Nov 20, 2025 version files 305.87 KB
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Call_Rates_and_Types.csv
285.42 KB
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Group_Movements.csv
15.36 KB
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README.md
5.09 KB
Abstract
For social animals, communication and social information can help synchronize activities, maintain group cohesion, alert others to predators, and improve individual assessments of food availability. We tested the hypotheses that the call rate and types of calls produced by Pine Siskins (Spinus pinus) may be used to coordinate flock activities. Pine Siskins produce a variety of calls, but call function and use in the wild are unknown. We studied post-breeding flocks of Pine Siskins feeding in discrete patches of native sunflower (Helianthus annuus) between 8 August and 3 October 2020. We observed and recorded flock vocalizations of Pine Siskins engaged in four different behaviors--arrival, baseline (foraging in patch), circling, and departure. We took 30-minute audio recordings of Pine Siskin foraging flocks (56 recordings total), noting the exact time and estimated number of individuals participating in arrival, departure, and circling behaviors, and noting the time during each observation when we saw a raptor hunting or flying above the foraging area. For each recording, we categorized each analyzed minute as baseline (N = 980 min), arrival (N = 107 min), circling (N = 18 min), or departure (N = 81 min). We noted whether or not an observational minute included the presence of a raptor ("Raptor" = yes/no) or occurred within 3 min of the observation of a raptor ("Raptor_3min" = yes/no). Pine Siskin calls were categorized as one of four call types ("TBP", "C", "R", or "Z"), though "Z" calls were very rare and excluded from analyses. We find that call rate was significantly greater during flock movements than during periods of baseline feeding. Notably, different behaviors were associated with differences in production of specific types of calls. Additionally, Pine Siskins were more likely to engage in circling behavior and produced more "TBP" and "R" calls in the presence of raptor predators. Overall, these results support the hypotheses that Pine Siskins use different types of calls and variation in call rate to help coordinate group movements and predator responses.
Dataset DOI: 10.5061/dryad.b2rbnzstj
Description of the data and file structure
We recorded 56 audio recordings of Pine Siskin flocks foraging in one of two foraging areas at our field site. During observations, we noted the time of siskin movements (arrivals to the foraging area, circling above the foraging area, or departures from the area) and the number of individuals participating in these behaviors. We also noted the time we observed a raptor flying above the foraging area. We identified siskin calls as one of four types of calls ("TBP," "C," "R," or "Z").
Our unit of analysis was a minute. We categorized each analyzed minute as one of four flock behaviors: baseline, arrival, circling, or departure. Minute intervals that included multiple different movement behaviors (i.e. arrival and circling, and arrival and departure) were excluded from analysis because we could not attribute call rate to a specific behavior. Minute intervals that included circling and departures were categorized as departures. We also noted whether each observational minute included the presence of a raptor within that same minute ("Raptor" = yes/no) or within 3 minutes of the observational minute ("Raptor_3min" = yes/no).
In order to reduce overall audio analysis time and ensure adequate sampling of flock activity, we used two approaches to analyze our recordings, with half of the recordings randomly assigned to each approach. For 29 recordings, we fully analyzed the entire recordings. For 27 recordings, we used a subsampling procedure as described in the text of the associated manuscript.
Files and variables
File: Group_Movements.csv
Description: This file includes data about the number of individual siskins participating in movements (arrival, circling, or departure).
Variables
- Area: refers to the foraging area. The levels of this factor are "Indian Ridge" and "Woodchuck," which refer to Areas 1 and 2 in Supplementary Figure 1 (in associated manuscript), respectively.
- Behavior: refers to the siskin movement behavior. The levels of this variable are "arrival," "circling," and "departure."
- Number_of_siskins: refers to the number of siskins observed participating in the movement.
- Date: refers to the date of the observation in mm/dd/yy format
- Time of Day: indicates whether the recording was made before or after noon. (Levels = "Morning," "Afternoon")
- Recording: is a unique ID for each recording session. The first character ("W" or "I") refers to the area ("Woodchuck" or "Indian Ridge"), the next four characters indicate the date (mmdd), and the last two characters refer to the time of day ("AM" or "PM").
File: Call_Rates_and_Types.csv
Description: This file includes data about the call rate and types of calls produced by siskins during each minute of recording, which flock behavior was observed during that minute, and whether raptors were observed during that same observational minute or within 3 minutes of the observational minute.
Variables
- Recording: is a unique ID for each recording session. The first character ("W" or "I") refers to the area ("Woodchuck" or "Indian Ridge"), the next four characters indicate the date (mmdd), and the last two characters refer to the time of day ("AM" or "PM").
- Minute: indicates the number of minutes from the start of the recording. (E.g. Calls produced when Minute = 0 are calls produced any time between the start of the recording and 59 seconds after the start of the recording.)
- Call_Type: refers to one of four types of calls. Levels = TBP, C, R, or Z. Z calls were very rare and excluded from analyses that refer to specific types of calls.
- calls_per_minute: indicates the number of calls produced during an observational minute
- Area: refers to the foraging area. The levels of this factor are "Indian Ridge" and "Woodchuck," which refer to Areas 1 and 2 in Supplementary Figure 1 (in associated manuscript), respectively.
- date: refers to the date of the observation in mm/dd/yy format
- Julian_Day: is the number of days since the start of the year
- Behavior: refers to the siskin behavior during the observational minute. The levels of this variable are "baseline," "arrival," "circling," and "departure."
- TimeOfDay: indicates whether the recording was made before or after noon. (Levels = "Morning," "Afternoon")
- Raptors: indicates whether a raptor was observed during the same observational minute. Levels of this variable are "y" (yes, a raptor was observed) and "n" (no, a raptor was not observed).
- Raptors_3min: indicates whether a raptor was observed within 3 min of the observational minute. Levels of this variable are "y" (yes, a raptor was observed) and "n" (no, a raptor was not observed).
- Full_or_Sub: indicates whether the analyzed minutes come from a recording that was analyzed in its entirety ("Full") or from a recording that was subsampled ("Sub").