User:Katelmahan/sandbox

Species essays

Student name, Kate Mahan

Student ID, 1143599

Wikipedia assessment

Introduction

The Bar-tailed godwit is a declining species of bird, in the family Scolpacidae and the ‘Limosa’ genus. The science name is ‘Limosa lapponica’ (Linnaeus, 1758). For most of their time in New Zealand they are nondescript birds, they do the longest nonstop flight for any non-seabird. There is a cultural significance for the people of New Zealand. They can be found in many harbours and estuaries around New Zealand. When breeding season begins, the birds start to arrive around September after a 8-9 day flight non-stop, around 11,000 kilometres. They only start breeding in their third or fourth year. The Bar-tailed godwit mainly eats polychaetes 70% of their diet, but that also includes small bivalves and while breeding cranefly larvae and other invertebrates. (NZ birds online, 2021)

Description

The Bar-tailed godwit has long legs, brown upper body and pale lower body, the bill is dark at the tip and pale at the base. Males have shorter bills than the females. (NZ birds online, 2021). On average the males are smaller than the females with some overlap, and also regional difference on sizes. The Limosa Lapponica can tell apart from the black-tailed godwit by its black and white horizontally barred tail and lack of white wing bars. From what research has been done there is likely to be five generally subspecies of Bar-tailed godwits.

Distribution

Eastern bar-tailed godwits breed in Western Alaska and then migrate to New Zealand and Eastern Australia. The birds are widely distributed around the different harbours and estuary’s, the larger sites do include Tasman, and Golden Bay, Avon Heathcote River, Farewell Spit and many others, godwits like to forage on soft intertidal land, but may also be found on wet pasture. (NZ birds online, 2021). The different subspecies of ‘Limosa lappnica’ have different flight paths when migration happens, and some end up in different countries. (Figure 1). Fewer of the birds have been using the East African estuaries since 1979.

Figure 1, showing the Northern hemisphere summer where the Bar-tailed godwits breed in red, the non-breeding in blue in the Southern hemisphere and it shows the migration routes of each subspecies.

Life cycle

The females lay around four eggs in a slight hole in the ground which is lined with moss and grass for protection. The male and the female take turns to incubate the eggs, the eggs hatch in 20-22 days and do not need parents to help, they leave shortly after hatching. The lifespan is around 34 years.

When it’s time to start migration, they travel south and wait for a storm with a strong tail winds of 40-60 kilometres per hour before they start. Before traveling back northwards they have to stock up on food, in which they double their body mass. In the southern hemisphere they arrive in September, in the spring when the weather is just starting to get warmer. The live and feed in large flocks. (Te ara, 2021). Its likely that Bar-tailed godwit relies mostly on the sun as a compass to navigate migrating from New Zealand to Alaska. (Pathwayz, 2021)

Interaction

The Bar-tailed godwit eats a lot of invertebrates such as molluscs, worms, and some aquatic insects. The bird stands in the shallow water or mud and stick their long bills quicky into the bottom to pick up any food they find. The birds forage over the intertidal zone at low tide, either in loose formation or individually dispersed over the beach.

Further information

The Bar-tailed godwit is projected in New Zealand, annual the population decline of nearly 2%, the main impact is loss of habitat at the staging areas in the yellow sea region. The godwits seem to get scared and spooked easily. The threats include loss of habit, and climate change can effect their annule cycle like the time of breeding.

The population of subspecies baueri (eatern bar-tailed godwit) is less than 150,000 birds. Around 75,000 are in New Zealand. (NZ birds online, 2021)

Refence

(NZ birds online, 2021) http://nzbirdsonline.org.nz/species/bar-tailed-godwit

(Te ara, 2021) http://www.teara.govt.nz/en/wading-birds/page-7

(Pathwayz, 2021) https://www.pathwayz.org/Tree/Plain/METHODS+OF+NAVIGATION