Calidris

{{Short description|Genus of birds}}

{{Automatic taxobox

| image = Semipalmated sandpiper at JBWR (30545).jpg

| image_caption = Semipalmated sandpiper (Calidris pusilla), Jamaica Bay Wildlife Refuge

| taxon = Calidris

| authority = Merrem, 1804

| type_species = Tringa calidris{{cite web |url= https://www.aviansystematics.org/4th-edition-checklist?viewfamilies=59 |title= Scolopacidae |author= |date= |website= aviansystematics.org |publisher= The Trust for Avian Systematics |access-date= 2023-07-26}} = Tringa canutus

| type_species_authority = Gmelin, 1789

| synonyms =

• Philomachus Merrem, 1804
• Limicola Koch, 1816
• Canutus Brehm, 1831
• Micropalama Baird, 1858

}}

Calidris is a genus of Arctic-breeding, strongly migratory wading birds in the family Scolopacidae. These birds form huge mixed flocks on coasts and estuaries in winter. Migratory shorebirds are shown to have decline in reproductive traits because of temporal changes of their breeding seasons.{{Cite journal |last1=Weiser |first1=Emily L. |last2=Brown |first2=Stephen C. |last3=Lanctot |first3=Richard B. |last4=Gates |first4=H. River |last5=Abraham |first5=Kenneth F. |last6=Bentzen |first6=Rebecca L. |last7=Bêty |first7=Joël |last8=Boldenow |first8=Megan L. |last9=Brook |first9=Rodney W. |last10=Donnelly |first10=Tyrone F. |last11=English |first11=Willow B. |last12=Flemming |first12=Scott A. |last13=Franks |first13=Samantha E. |last14=Gilchrist |first14=H. Grant |last15=Giroux |first15=Marie-Andrée |date=February 2018 |title=Life-history tradeoffs revealed by seasonal declines in reproductive traits of Arctic-breeding shorebirds |url=https://onlinelibrary.wiley.com/doi/10.1111/jav.01531 |journal=Journal of Avian Biology |language=en |volume=49 |issue=2 |page=1 |doi=10.1111/jav.01531 |bibcode=2018JAvBi..49....1W |issn=0908-8857|url-access=subscription }} They are the typical "sandpipers", small to medium-sized, long-winged and relatively short-billed.

Their bills have sensitive tips which contain numerous corpuscles of Herbst. This enables the birds to locate buried prey items, which they typically seek with restless running and probing.{{cite journal|author1=Nebel, S.|author2=Jackson, D.L.|author3=Elner, R.W.|title=Functional association of bill morphology and foraging behaviour in calidrid sandpipers|doi=10.1163/1570756054472818|url=http://publish.uwo.ca/~snebel2/nebel05AnimBiol.pdf|year=2005|journal=Animal Biology|volume=55|issue=3|pages=235–243|access-date=2016-06-03|archive-url=https://web.archive.org/web/20110610081512/http://publish.uwo.ca/~snebel2/nebel05AnimBiol.pdf|archive-date=2011-06-10|url-status=dead}}