Bumble bee nest density is lower in drought years

Climate change is driving more frequent and intense droughts in many parts of the world. While we hold a broad understanding of how drought impacts plant populations, predicting drought’s demographic effects on animal populations remains a challenge, particularly for invertebrates. Here, we use seven years of bumble bee nest surveys spanning a period with two historic droughts to estimate the impacts of drought on bumble bee nest abundance and apparent survival. Nest abundance significantly declined with drought (average of 19.3 vs. 11.3 nests in non-drought vs. drought years). Relative nest abundances of Bombus impatiens and Bombus griseocollis, two common species in this system, did not change with drought despite differences in life history strategies and apparent survival. Bombus impatiens abundance in forests increased during droughts (~60% of nests in forests, 20%-40% in drought versus non-drought years). Surprisingly, nests of rarer species were absent from our survey area after ..., , # Bumble bee nest density is lower in drought years

Dataset DOI: [10.5061/dryad.6t1g1jxbn](10.5061/dryad.6t1g1jxbn)

## Description of the data and file structure

These data come from the current manuscript, which was a study of bumblebee nest density in relation to drought.

### Files and variables

#### File: drought.figures.R

**Description:** This file contains code for Figure 1 and Figure 2 (in the main manuscript) using two datasets of Palmer Drought Indices.

#### File: nestRmarkPalmerDrought.R

**Description:** This file performs mark-recapture analyses of bumble bee nest detection and creates Figures 3A and 3B (in the main manuscript) from the output of the mark-recapture analysis. It also includes post-hoc analyses using linear regression and creates Figures 4A, 4B, and 4C (in the main manuscript) from the output of these post-hoc analyses. The supplementary tables S1, S2, and S3 were produced from the mark-recapture analysis model selection output.

#### File: palmer_index_...,