C57BL/6J vs wild-derived mice in field enclosures

The experiment

Two enclosures (A and B), each 15.2 × 38.1 m of open field, held eight weather-proof resource zones, each with food, water and a single entrance tube (Fig 1, Fig S1). Every mouse carried a PIT tag, and an RFID antenna underneath each resource zone recorded activity in the zone. Each trial released 10 males and 10 females (one wild-derived trial had 9 males) into one enclosure for ten days; days run noon to noon.

Watch the mice move

All seven trials play together, lined up by time since release. Each dot is one mouse, at the zone where it was last detected: a filled dot's visit to that zone is still going on, a ring's last visit there has ended. Lines trace the last eight hours of moves between zones. Click a trial to hide or show it.

Speed Trails

Space use

Where each mouse went

Each small map is one mouse on one day, its eight squares laid out like the enclosure (zones 1–2 at the bottom); colour is the number of RFID reads in that zone, on a log scale. Pick any C57 and any wild-derived trial.

C57 trial Wild-derived trial

Comparing the four groups

Means ± SEM across mice, all trials pooled. Pick a measure for each chart; click a legend entry to hide or show a group.

Show each mouse

Male territories

Males of both kinds carved the enclosure into territories rather than forming one dominance hierarchy, but C57 males took longer to settle it (Fig 2).

Who held each zone

Every trial at once: each small map is one day, each square one zone, coloured by the male with the most reads there that day (one colour per male within a trial). Stronger colour means he made a larger share of the zone's male reads. Hover for names.

How completely the top male held his zone

Share of each zone's male RFID reads made by its top male that day (Fig 2B).

Winning at home

Territory holders' win rate in displacements at their own zones and away from them. Each line is one male (Fig 2E).

Priority access

Each day a mouse scores its share of same-sex time at every zone it visited, minus one if it held a majority at none of them; the priority access score is the running total. A male that held one zone all trial ends near +10. By day 10, males had split into territory holders and the rest; females had not.

{Occupancy}_{M, D, z} = \frac{{time}_{M, D, z}}{\sum_{m \in S_{M}} {time}_{m, D, z}}

{Capture Score}_{M, D} = {\begin{matrix} \sum_{z = 1}^{8} {Occupancy}_{M, D, z} & if \exists z \in {1, \dots, 8} : {Occupancy}_{M, D, z} > 0.5 \\ \sum_{z = 1}^{8} {Occupancy}_{M, D, z} - 1 & otherwise \end{matrix}

{PAS}_{M, D} = \sum_{d = 1}^{D} {Capture Score}_{M, d}

After the paper's Methods, which give the first two equations and describe the third in words. M: a mouse; D, d: a day; z: a resource zone; time: the mouse's time in the zone that day, from its RFID-defined visits; S_M: the mice of M's sex in the trial (usually 10). Occupancy is 0 for a zone the mouse did not visit, so a day without visits scores −1. Example from the paper: if male A spends 4 h a day in a zone that only male B also visits, for 1 h a day, A scores 0.8 each day and B 0.2 − 1 = −0.8.

Territory holders and the rest

Males split by whether their priority access score ended day 10 above zero. Holders spent far more time with females; the rest kept moving between zones.

Cumulative time with females

Zones visited each day

Encounters between pairs of mice

Every time two mice shared a zone, by when it happened in the trial and how long it lasted. C57 males spent long stretches together in the first days before their encounters became brief and rare; wild-derived males got there within a day.

Pairs

Social structure

Mice that were in the same zone at the same time are counted as together (Fig S1F).

Who was together

Hours per trial spent in each group make-up, by the number of males and females present (Fig 4A).

C57BL/6J

Wild-derived

Time alone and with others

Show each mouse

Cagemates

Each female shared her trial with sisters from her lab cage (cagemates). Preference is the share of a female's time with other females that she spent with cagemates, minus the share expected by chance from how many cagemates and other females were present that day (Fig 3D).

Networks in motion

Each network is built from a window that slides through the trial an hour at a time: links join mice that shared zones within the window, thicker for a higher association index (simple ratio index). Each frame starts from the previous frame's layout and relaxes it (Fruchterman–Reingold), so mice drift together and apart as their associations change. Circles grow with the number of partners; faint rings have no partners in the window. Outlines mark groups found by Louvain community detection.

Window Speed Groups

Network structure, day by day

Daily networks (noon to noon), as analysed in the paper. Means ± SEM across trials.

Show each trial

Each mouse's place in the network

Show each mouse

About the data

All numbers come from the tables deposited with the paper, cut at noon on day 10. In two trials (T006 and T007) the mice stayed in the field beyond ten days; those later data are not part of the paper and are not shown.
Charts follow the paper's own analysis scripts, including which mice were excluded on which days, and reproduce the published panels except where noted below. Daily network measures are the published values; the sliding-window networks are rebuilt from the deposited group-by-individual tables with the same association index (rebuilt daily networks reproduce the published degree and strength of every mouse on every day).
Durations. In the deposited movement-bout table, 185 bouts on 27 mouse-days record their duration in minutes rather than seconds, a quirk of how R chooses time units. Here they are converted back to seconds, which raises the tracked total from the paper's h to h (+1.1%). It nudges the priority access scores (Figs 2D, S3B–C; two females' day-10 scores cross zero) and time in the most used zone (Figs S2B, S3E; group means by at most 0.1 points). No result changes.
New mice met (Fig S4C). The original script dated each pair's first meeting by the first matching row of a table sorted by zone rather than time, so the published curves for days 1–9 run low (C57 females on day 2: 4.5 published, 8.8 corrected). The corrected values are shown; day 10, which the paper's statistics used, is unchanged.
Male–male encounters per day (Fig S2C). The published means skipped trial-days with no encounters (wild-derived days 4, 6 and 8); those zeros are included here.
Time with females (Fig 2F). Reproduces the published panel, in which a male counts from his first day with females and carries his total over a day without data. The deposited script differs slightly (wild-derived territory holders on day 10: 603 instead of 574 min).
Times are local (EDT). A dot's position within a zone is only for display; the data say which zone, not where in it.