% R constructed Latex table
\documentclass[10pt,english]{article}
\usepackage{pdflscape}
\usepackage{longtable}
\usepackage{fullpage}
\usepackage{lipsum}
\begin{document}

% R constructed Latex table
\documentclass[10pt,english]{article}

\hline
year & \multicolumn{2}{c|}{females (CI)} & pups born & \multicolumn{2}{c|}{pups weaned (CI)} & \multicolumn{2}{c|}{\%pup mortality (CI)}\