I am sure this will be a multiple-part post about shorebirds and their incredibly hard-to-decipher field marks. I don’t know if the difficulty of identifying certain species in the field makes birding fun or extremely frustrating, but it keeps some excitement in the process. I can get behind the very minute details that separate sparrows from one another. Still, there is something about shorebirds, in particular the genus Calidris (your sandpipers that you will encounter at the beach, mudflats, or near most bodies of water) that causes such confusion. I am far from an expert at shorebird identification but I wanted to log some of my attempts at understanding the differences in the common sandpipers in my area.
Learning to separate or group the different types of shorebirds into a larger subgroup based on their looks, behaviors, or habitat (geographic location) can be one of the first steps in shorebird identification. For example, understanding what attributes make a plover a plover compared to your small to medium-sized typical sandpipers can help dramatically in the process of properly identifying a Killdeer at your local park. An upright bird with a stubby bill will point you in the direction of plovers instead of sandpipers because the more upright nature and the stubby bills are their telling characteristics. You can then place the bird even further noticing the habitat. Most likely the Killdeer would be in parks, gravel roads, or often far from water. This inland or upland trait would point you toward two birds: the mountain plover and the Killdeer. Based on your geographic location (mountain plovers summer in the Rocky Mountain area and winter in SW US and Mexico – Killdeers are found all around North America year-round) you can either confirm the ID or look towards the most obvious of attributes: the plumage. Killdeer have quite different field markings than a Mountain Plover and would be easily identified.
Of course, this process of identification is standard for most birds but with shorebirds in particular it is helpful since within these subgroups there are added idenitcation troubles. Having the bird separated out in your head by understanding their GISS (overall impression or appearance) can help you rule out dozens of other birds and help narrow down the search to a particular genus or two. The above example of the Killdeer was easier to identify than one of a Semipalmated Sandpiper, but the logic still stands and the process would be similar (with a few extra steps).
For myself and my path to getting a better understanding of shorebirds, I have broken up the term “shorebird” into 6 categories. While the sorting is somewhat based on taxonomic similarities, it is not a hard and fast rule but rather one that is convenient when it leads to a better and easier understanding of shorebird identification.
These categories are:
- Plovers
- Typical Sandpipers
- Distinctive Sandpipers (based on habitat or behaviors)
- Large Long-billed Shorebirds
- Large Curve-billed Shorebirds
- Others
Plovers: Plovers are the 9 (across 2 genera) commonly found shorebirds in the continental US with stubby bills, are more upright in nature, and tend to seem to be thicker in nature than sandpipers. You can see this difference more in the neck area. Look for differences in the ‘scaling’ plumage on Plovers compared to Sandpipers – plovers seem to be more uniform in plumage color on their back. The stubby bills are normally the most reliable of field IDs.
Typical Sandpipers: This category does follow a taxonomic line as all members are in the genus Calidris. The taxa are not incredibly important in the ID of Sandpipers, but it does help to know that there is a closer relation between all these birds and why they tend to be very difficult to ID. Sandpipers are longer billed than Plovers and tend to wade into shallow water more often than Plovers.
Distinctive Sandpipers: This category separates out those Sandpipers who may not fall into the typical Sandpiper category above due to habitat and behavior. These birds include Spotted Sandpiper, Upland Sandpiper, and Buff-breasted Sandpiper. Upland and Buff-breasted are found more in grassland habitats. Spotted Sandpiper is normally found individually near banks of creeks and lakes across North America.
Large Long-billed Shorebirds: Yellowlegs & the genus Tringa, Willets, Dowitchers, and Snipe fall into this category based on their large appearance and very distinctive large bill. These shorebirds can be difficult to identify based on their plumage or the quality of your line of sight since very often all you see of these birds is their back since they are probing for food.
Large Curve-billed Shorebirds: Curlews and Godwits make up this category based on their habitat and their most defining trait: their very large curved bills. These large rarer shorebirds can be identified from other types of shorebirds fairly easily with a good look at their bill but quite often they feed in mudflats or grassland that are away from a shore or good viewing area which leads to less than ideal views at times.
Others: This is the catch-all category for other members of the shorebird family that are either rarer or do not fit as neatly into the categories above. Some examples are Turnstones, Phalaropes, Woodcock, and Ruff.
In subsequent posts, I will cover each of these 6 categories in more detail and work through how I would go about identifying these species, particularly the more difficult-to-distinguish species. I will be sure to add details from the resources I have used to help make this process easier. A large amount of these shorebirds (peeps in particular) give me trouble on a daily basis so it is all a learning process.
