Spring is in the air and for many birds that means it’s time to start breeding. Here are some facts about tomtit breeding – the how, what, when, and where.
In New Zealand spring starts on 1 September. Since that time I’ve been seeing a pair of tomtits hanging out often around the Dawson Falls visitor centre on Mt. Taranaki. This couple is doing what many animals and other tomtits do at this time of year – breeding. You can read some general facts about tomtits in this other post, but in this one I want to talk about tomtit breeding, specifically for North Island tomtits.
Tomtit Breeding Facts
Similar to most birds, but not all, tomtits are monogamous (have one partner) that they tend to keep year after year.
Males and females look different (they are sexually dimorphic) and behave a bit differently. Males are the familiar black and white while females have a similar body profile, but are more greyish and white. The males are bright and showy and the females are drabber.
For most of the year the male is quite curious and can often be seen by people as it flys around looking for food. In contrast, the female is usually more secretive and avoids people. During the breeding season the female can more likely be seen as she comes out to get food from her partner or makes quite a racket before reentering her nest. The nest is most often located in a shallow cavity, such as inside of a hollow tree.
They usually lay eggs between September to January. During this breeding time, a pair may raise up to 3 broods. That may be what the birds are capable of, but unfortunately that rarely happens as predators often will eat the clutch of eggs or brood of nestlings. This is the same story that many native New Zealand birds face. The introduced mammalian predators, such as rats and stoats have created serious risks for the survival of many native species.
The female tomtit lays 4 – 6 cream coloured eggs with yellowish/purplish spots on them. Eggs are laid daily, usually after sunrise. The female then incubates (sits on the eggs) for 15 – 17 days. During this time the male’s job is to find food for himself and also for the female, whom he will feed a couple of times an hour near the nest. After the chicks are born, the male will feed the female near the nest while she is caring for the brood of nestlings. Both the male and female will feed the nestlings and later the fledglings.
Then after about 17 – 20 days the birds fledge, leaving the nest. Fledglings are fed by both the male and female, but once the female starts to lay more eggs the male assumes all parental care.
Juveniles begin foraging for food around 28 days, but continue to be fed until about 35 days old. After that, they are fully independent and the juveniles soon fly off to find their own territory. Those young birds and other birds that don’t have a mate will fly around looking for a good territory and for a mate. They may fly tens of kms during this time. This is similar to young adults who leave the house to make their way in the world.