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There's plenty to see and do at the estuary.
The estuary walkway provides beautiful views, and there are signs along the way providing information about some of the birds you might see.
There is a lot of interesting wildlife at the estuary. As well as birds, the estuary is also home to some interesting plants and is an important habitat for native fish.
The Manawatū Estuary Trust enjoys giving people the opportunity to learn more about this amazing environ
Pest Fauna
It is a well-known fact that Aotearoa New Zealand has a disproportionate number of introduced animal species, many of which are detrimental to the survival of native wildlife. Many species, such as rodents (rats and mice) and mustelids (weasels, stoats and ferrets) are well documented and present around this area. This page will introduce some of these species, plus others that are not so well known. Brief introductions and a list of organisations where these can be reported will be included, as are some control methods.
iNaturalist has a list of exotic species for the Ramsar site but this is a little vague in terms of information. Best to search for the individual species in this link.
Before commencing any trapping of Mustelids, Rats or Possums please consult Department of Conservation booklet Practical Guide to Trapping 3rd edition.
One of the most comprehensive coverages of what is required to start and expand a successful pest control program is contained in a publication by Predator Free Miramar and titled How to kill rats and engage a community. It contains a detailed account of what is needed from trap building to engaging public and everything else in-between. It is a must read.
Predator Free NZ produces a series of excellent guides on the main predator species which can be viewed via this series of links. Ferret, Weasel, Stoat, Ship Rat, Norway Rat and Possum.
Below are listed three of the best guides to mammalian pest control. All slightly different - follow the basics but adapt to your own personal situation as required.
Foxton Beach Predator Trapping Results
With funding and assistance from Horizons Regional Council and Predator Free NZ, Wildlife Foxton Trust with the help of numerous enthusiastic volunteers administer the trapping program in the Foxton Beach area covering the estuary, woodland, farmland and around the township. Results of all this effort is beginning to show as can be seen from the graph below produced by the Traps NZ site, where all our catch details are entered. Various traps are available, on loan, from Wildlife Foxton Trust.
Sections below, in time, will not only cover many of the dominant and well known species but some of the lesser known types which prey on some of Aotearoa New Zealand's other unique wildlife.
possum
MUSTELIDS
Three species make up this most lethal suite of introduced predators that Aotearoa New Zealand has. Weasel, Stoat and Ferret are capable killers being able to decimate entire populations of native species from areas that are not protected with an eradication program.
Traps and boxes can be purchased as a complete unit or separately. Boxes for these traps have a design which must be followed. The DoC 250 for stoats and ferrets and DoC 200 for weasels are the industry standard and design details can be found in this handy guide. More information is available in the three guides listed above.
The video opposite was taken by Cleland Wallace for which we acknowledge his permission to use. This video is of a ferret and was taken on the recent Bittern Muster (survey) at Lake Omanu. Being the domesticated form of the Polecat, they tend to be more confiding than the other two species. Trapping is now underway.
RODENTS
Members of this group need little introduction as they are familiar to most. Four species are found in Aotearoa New Zealand but only three occur in this area, the ubiquitous House Mouse Mus musculus, Norway or Brown Rat Rattus norvegicus and the Ship or Black Rat Rattus rattus. The remaining species is the Kiore Rattus exulans.
Most of what is required to trap these species is covered in the reference list above and these are best consulted for the right equipment and practices. A useful Youtube guide produced by Predator Free NZ Trust on how to differentiate the two main species of rat is included here
Brush-tailed Possum Trichosurus vulpecula
This serious pest of forests and gardens was introduced to Aotearoa New Zealand with a view to creating a fur trade. The first, in 1837 was unsuccessful but it was the 1858 attempt which started the colonisation of this destructive pest.
While some possum fur is still used, usually combined with wool to give extra strength, it is the side effect that is being felt now.
Possums are now trapped extensively to try to eradicate them.
Wildlife Foxton Trust has a trap library and loan out possum specific traps, with instructions for use in the Foxton Beach area. Enquiries via their website wildlifefoxton.org
European Hedgehog Erinaceus europaeus
Introduced. Not assessed.
People have mixed emotions about this prickly wee beastie - on one hand it is a familiar animal and has been for generations through children's literature and as an extremely efficient consumer of snails and slugs.
Since its introduction in the 1870's in an attempt control introduced crop pests it has had a dramatic effect on Aotearoa New Zealand's endemic invertebrates, and also takes birds eggs making a significant pest in
areas where small ground birds nest.It is a common species in the area and many are trapped in farmland around Foxton Beach. Wikipedia-European Hedgehog
INVERTEBRATE PESTS
BLACK AND YELLOW STRIPEY STINGY THINGS
Wasps are in the same order as bees and ants and while most live solitary lives, it is the social wasps that are a real pest, both to native wildlife and to humans and their activities. German wasps are nuisance at certain times of the year especially when outdoor eating is involved.
In terms of their pest status the least troublesome to humans but to native invertebrates they are a real problem are the paper wasps, especially the Asian Polistes chinensis which is particularly abundant in this area, building their nests in a variety of locations including guttering, bushes and in log piles. They are not aggressive and their stings are reputed to be not that painful. They take a heavy toll on native insects and their nests should be destroyed as soon as they are found. Normally only small structures they can sometimes be large. First spray with a commercial fly spray and when there is no sign of wasps in the vicinity, destroy nests which will kill any remaining pupae. If Monarch Butterflies breed in your garden there will be a nest close-by and would be worth checking as these can take a heavy toll.
Perhaps the most familiar of the wasps are the two species of Vespula, those annoying species of the summer months. Depending on several factors both the German V. germanica and Common V. vulgaris can be quite abundant some years. Unlike the paper wasps, both these species build nests where the egg chambers are enclosed with an outer covering with one or more entrance hole. They can be situated underground, in wall cavities or in buildings. Being stung by an individual can not only be very painful but dangerous if allergic, often warenting a visit to hospital
Nests if discovered should not be approached as they are very aggressive creatures. Destruction should only be done by a professional pest control person, but there are traps and baits available for use away from nests to attract them. Details of of one of the most effective is given below for control of Hornets
A recent addition to the list of invasive species is the Yellow-legged Hornet Vespa velutina. This is potentially a very destructive species and has caused havoc with bee populations in an increasing number of countries as it is a very aggressive predator, attacking bee hives.
Populations are spreading worldwide with the first record for Aotearoa New Zealand in 2025. Immediately, MPI/Biosecurity developed a strategy to control this pest and help contain and ultimately eliminate the threat.
Since the initial sighting, a total of 77 queens and 132 have been destroyed as of early April 2026. There is a wealth of information on the MPI/Biosecurity website which covers all aspects associated with what is being done to help eradicate Yellow-legged Hornets, including what to look out for and where to report possible sightings.
An information leaflet is available to download at MPI documents
CONTROL
German and Common Wasps and Yellow-legged Hornets, besides being a threat to native species are potentially a threat to humans because of their sting. Nests of all species need to be reported to the appropriate authority for elimination and not to be attempted by untrained individuals.
However, measures can be taken by individuals to protect personal space by using different types of bait containers and lures with several different types available. The main consideration is bycatch, species for which bait and equipment is not intended.
Sweet sugary liquids in homemade dispensers is not ideal. Best to use a specific wasp attractant which is of low risk to bees and which is placed in a suitable which does not allow easy access to the bait. One of the best is the dome-shaped container which holds the bait.
Trials have been held over a few years by the Department of Conservation with a new bait, developed by Merchento called Vespex. It has proved very effective in controlling both wasps and hornets which take it back to the nest resulting in the killing of the whole colony. Check out the link above for more details.
Lester, P. 2018. The Vulgar Wasp: The Story of a Ruthless Invader and Ingenious Predator. Victoria University Press.
Lester, P. 2022. The Management of Invasive Species, Pests and Diseases in New Zealand. Te Herenga Waka University Press.
Although not considered a pest at the moment it has the potential. The two species are easy to distinguish apart with the native having a blue/purple patch on the inside of the leg. Sexes of both differ with male being smaller than females.
If you see egg cases similar to the white fluffy one immediately to the right please squash them to help prevent populations of the South African spreading further. Hardened egg cases are not easy to differentiate but consult the reference below for help.
Travis Wetland-New Zealand and South African Mantids
South African Preying Mantis Miomantis caffra
Introduced. Not assessed.
This species was first recorded around 1978 in the Auckland area. Over time it has spread further south, including some areas of the north South Island. Because of its aggressive nature, it is now the prominant species, displacing Aotearoa New Zealands endemic species Orthodera novaezealandiae in many areas.
The South African is the larger of the two species with males of the native being attracted to females of the invader and because they can be canabalistic, it reduces breeding potential.Oetheca (egg cases) range from 12-20mm long and are soft creamy brown when first laid before hardening. Nymphs hatch over a period of time and vary in colour from brown to green.
Freshwater Gold Clam Corbicula fluminea
Introduced. Not assessed.
The natural distribution of this small mollusc is Southeast Asia but has been introduced and is now widespread in North America and many parts of Europe. In Aotearoa New Zealand was initially found in the Waikato when and now rather worryingly, in a man made lake.
Measuring only 2-3cm when fully grown and because of its fast rate of reproduction can colonise new areas rapidly, with the increase in numbers potentially creating problems with outlet pipes and drains. It is an easy species to identify because of the deep ribbing on
the shell and the rather elongated shell distinguishes it from several native species. Because of its filter-feeding on watercourse bottoms, it can accumulate toxins and consumption is not recommended. More detail on this potential environmentally devastating species can be had from this MPI poster.
INVASIVE FISH
There are a number of invasive species of fish present in Aotearoa New Zealand waters that cause problems. Rainbow Trout Oncorhynchus mykiss and Brown Trout Salmo trutta, introduced as sport fish are ever present in many areas and can cause great problems. Perch Perca fluviatillis are also present in the main river but it is the two species highlighted below that can cause the most problem as they are small enough to frequent the smaller water courses where many of our native and endemic species are to be found.
Western Mosquitofish Gambusia affinis
Introduced. Not assessed.
A native to North America, this species has been introduced to many parts of the world in the belief that it helps eliminate mosquito larvae and thus helps prevent the spread of malaria. While mosquito larvae form part of their diet, they also consumed other small aquatic invertebrates which are eaten by native populations thus being detrimental to native species.
Introduced to Aotearoa New Zealand around 1933 to several ponds in the Auckland area. It soon spread via several methods and is now widespread through the North Island and several
areas in the north of the South Island. They have shown up in eDNA samples in local streams. Apart from being widespread, they are an aggressive species and out-compete Galaxiids and Bully's for available food supplies.Females can be twice the size of males, reaching 6-7 cms and give birth to live young.Western Mosquitofish - Wikipedia
Goldfish Carassius auratus
Introduce. Not assessed
Goldfish are a popular pet throughout the world, often kept in cramped conditions. Because they are a freshwater species and can tolerate a degree of coldness, they are often released in outdoor ponds and it is from these that they have spread and are now classed as a pest species, including in Aotearoa New Zealand. It is a member of the carp family.
Adults lay eggs which are sticky and adhere to vegetation, hatching within 72 hours. Fry are numerous and may be eaten if adults are present. Normal diet consists of aquatic crustaceans, insects and some plant matter.
Wikipedia-Goldfish
AVIAN PESTS
Not many species of birds are considered pests around the estuary the in true sense of the term but some have their moments. The main ones are waterfowl, namely Mallard and Canada Goose, accounts of which can be found by clicking the link for each. Magpies can also be a problem but there is not much to hold their attention in the estuary.
In terms of predation, several native species can be considered such as Pukeko, Kāhu/Australasian Harrier and Karoro/Southern Black-backed Gull which will take eggs, chicks and small birds if the opportunity arises.
One aspect which is not normally considered is disease and while rodents are a potential problem little traction is given to feral pigeons which can be carriers of several diseases.
Feral Pigeon Columba livia "domestica"
Introduce. Not assessed
This species is, in some literature, still called the Rock Dove but they are not true and have been been domesticated over many years. True Rock Doves are found in Western Europe, North Africa extending to South-east Asia. All seen here are this domestic type. Prolific breeders they can increase quite quickly.
They are abundant in some areas and although not really classed as a pest they can be carriers of a number of diseases which effect humans. E. coli is a zoonotic (can pass to humans) disease and is tested for in most water samples. Large numbers of pigeons roost under bridges over waterways and E. coli is recorded in most water samples
New Zealand birdsonline-Feral Pigeon
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