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Mutual Aid · Chapter

I: Swarms of Butterflies, Dragonflies, etc. explained

This chapter examines mass flights and swarming behaviors in butterflies, dragonflies, and grasshoppers, suggesting that these aggregations may be driven by environmental factors like monsoons and involve multiple species, with possible pur

What happens

This chapter examines mass flights and swarming behaviors in butterflies, dragonflies, and grasshoppers, suggesting that these aggregations may be driven by environmental factors like monsoons and involve multiple species, with possible purposes including copulation and migration.

Themes in this chapter

  • Sociability in Nature

    The chapter highlights gregarious and swarming behaviors in insects, illustrating natural sociability.

Characters to notice

  • Henry Walter Bates

    Observed mass assemblies of Callidryas butterflies on the Amazon.

  • W. H. Hudson

    Documented swarms of dragonflies and gregarious grasshoppers on the Pampas.

Key passages

  • Bates saw, on the Amazon, the yellow and the orange Callidryas 'assembling in densely packed masses, sometimes two or three yards in circumference, their wings all held in an upright position, so that the beach looked as though variegated with beds of crocuses.'

    Bates observed dense clusters of yellow and orange Callidryas butterflies on the Amazon, their upright wings making the beach resemble beds of crocuses.

    Illustrates mass aggregation in butterflies.

  • Dragonflies, in their long migrations across the Pampas, come together in countless numbers, and their immense swarms contain individuals belonging to different species (Hudson, Naturalist on the La Plata , pp. 130 seq .).

    Hudson reported that dragonflies migrating across the Pampas form enormous swarms composed of multiple species.

    Shows cross-species swarming in dragonflies.