From the sieving whio to the sipping korimako: what do beaks tell us about a bird’s diet?

While feet also provide clues, the most obvious indicator of a bird’s feeding habits is in the size and shape of their beaks.

The diet of birds varies widely from species to species. Some exist on flower nectar and small insects while others can be spotted tearing into meaty flesh. Knowing about different kinds of beaks and how they work can help us provide the right feed for our backyard birds. It is also good info for those who like to identify birds while out and about.

Birds with conical beaks are seed eaters

Small, stout cone-shaped beaks – think sparrows and finches – are designed for cracking open seeds. These smaller birds appreciate backyard seed feeders and will also fossick in grasses and shrubs for wild seed. You can also feed them by leaving a few plants to go to seed over winter.

On a much larger scale, the takahē also has a conical bill, which it uses to snip grasses and tug the side blades away from tussocks. When grasses are in seed, takahe run their beaks along the stem to strip away the seeds. This method does not destroy the grass, so their food source is maintained long term.

Birds with curved beaks are nectar sippers

The kākā could learn from the sustainable feeding practices of the takahē. This native bird is one of only a few sap-feeders in the world, using its strong curved beak to rip away bark to reveal the sap. Along with their habit of digging into the wood of trees for huhu bugs, kākā can do a lot of damage. However, they are also an important pollinator, using their brushed tipped tongues to (somewhat awkwardly!) sip nectar from native plants like the kōwhai and rātā.

Korimako (New Zealand bellbird) and tūī also have curved bills, albeit at a much smaller scale to the kākā, and use their long, brushed tipped tongues to drink nectar. Both birds also sip honeydew from scale insects on the trunks of beech trees and use their beaks to nip up the odd invertebrate. The beak of the tūī is longer than the korimako’s beak, making them especially adept at digging into flax flowers. 

Hooked beaks can mean meat…

Our most prominent native bird of prey is the kārearea (New Zealand falcon),  which spies its prey from on high with  large yellow eyes, before using strong-taloned feet and a hooked beak to catch and feed. Kārearea mainly eat small birds, lizards, and mammals such as rabbits. They are sometimes mistaken for the swamp harrier, which feeds on roadside carrion with its hooked beak, but the kārearea won’t lower itself to this kind of behaviour unless desperate. 

There are also several native sea birds with hooked beaks. The grey faced petrel is a key example with its sharp hooked beak used to slice through its preferred meal of squid. Shags also have hooked beaks, used to snap up and tear into fish and crustaceans.

…unless the bird is a parrot

Our mountain parrot, the kea, and the kākāriki (red crowned parakeet) both have hooked beaks, too, however these two stick to mostly seeds and fruit. Kākāriki will also nibble on invertebrates, especially scale insects eaten in the spring before breeding. Kea go for slightly juicier morsels, digging in the soil for insect larvae and excavating rotten logs for huhu grubs, and will also eat plant tubers when available.

Clever beaks: These are the niche eater

Aside from these three main categories, there are some interesting beaks to be seen around the country. Here are some of our more unique outliers.

●    Our namesake, the kiwi, technically has the shortest beak of any bird. This is because beaks are measured from the nostril to the tip, and kiwi have their nostrils (and whiskers!) at the end of their beaks. This helps them sniff out invertebrates and worms underground, and also helps them navigate in the dark.

●    The whio (blue duck) uses rubbery flaps at the end of their bills to scrape food off rocks, while a sieve-like structure inside the bill is used to filter larvae and insects from the water.

●    The spoonbill may look slightly comic with its over-sized, curve-tipped bill, but this shape is perfect for dragging back and forward while wading in tidal waters, hunting out fish and shrimp. When they detect an animal has entered the spoon-like end of its bill, they will snap the bill shut then tip it up so the prey slides down its throat.

●    The extinct huia had different shaped beaks for males and females. While it can’t be known for sure, scientists hypothesise they fed on different prey to avoid competition for food within a pair. 
If this beak info has inspired you to polish your binos for some bird watching, we have feeders and feed to bring them closer to home. Happy spotting!

Banner image taken by Darlene_Nicholls, Kārearea image taken by Michael Geros, Kākā image taken by Martin Barwood, Kākāriki image taken by Diego Carena-Santiago.