The Red Crossbill is a medium-sized red finch with dark-brown wings and a distinctive crossed-bill. The Red Crossbill uses its specially adapted bill for opening its main food source: conifer seeds; however, Red Crossbills have also been observed eating insects and caterpillars. North American in its distribution, the Red Crossbill can be found in the mountains of central Mexico and as far south as northern Nicaragua. Even in temperate regions of North America, the Red Crossbill has the unusual ability to breed at any time of year, as long as there are sufficient conifer seed crops to feed their young. Up to nine "types" of Red Crossbill have been described, each having a distinct flight call and bill size; additional genetic analysis is needed to determine if any or all of these subspecies are reproductively isolated. Very little work has been conducted on crossbills in Mexico, Guatemala or Nicaragua but initial field work suggests several undescribed types occur.