Oct 29

1 dad + 1 mum + 2.4 children =

…well, a family, but just as this formula is pretty out-dated for most human societies, it turns out that lots of other species have complicated family lives too. Starting simple, there are species in which you see mum and dad raising their own young, for example great tits, emperor penguins and red foxes. But things start to get complicated when you add more individuals into the mix…

+ other families =

In group-living species, lots of families live together in one group, for example chimpanzees. Sometimes these groups can be huge – gelada baboons are regularly observed in groups of 350+ individuals!

+ individuals that don’t breed =

In communal breeding species, females share the costs of raising young by helping each other out. For example, in banded mongooses, females synchronise their pregnancies so that they all give birth on the same day. This means that pups are raised in one huge litter and all group members help to feed and look after them.

+ a pecking order =

In cooperative breeders, dominant individuals do all the breeding within a group whilst subordinate individuals are only allowed to help out with the rearing of young. Meerkats, African wild dogs and Seychelles warblers are all cooperative breeders, but however weird their family lives seem, there’s weirder still…

+ different body types =

In eusocial species, it is easy to tell which individuals breed and which don’t because they look totally different. Now, although they’re not exactly pretty to look at, the naked mole-rat is a great example of a eusocial species. The queen of a naked-mole rat colony is the only female that breeds and she can be twice as big as other colony members (and therefore twice as ugly). Although eusociality is rare in mammals, it is common in ants, bees and wasps. One amazing example is the army ant – in just a few days a single army ant queen can lay up to 300,000 eggs!

So, it’s not just humans that have complicated families. Next time you’re dreading Christmas with the rellies just think yourself lucky that you’re not playing host to a million army ants, or 75 naked mole-rats!

If you want to know more about the family lives of all creatures great and small, visit the ARKive website. I challenge you to find the only other species of eusocial mammal!

Bonnie Metherell, ARKive Media Researcher

Oct 27

One in five vertebrate species are threatened with extinction according to a landmark study launched by the IUCN on Wednesday 27th October 2010 at the Conference of the Parties to the Convention on Biological Diversity (CBD), in Nagoya, Japan. The timely study, which is the most comprehensive assessment of the world’s vertebrates to date, confirms our fears that across the globe vertebrates are experiencing an extinction crisis. However, it also confirms that the situation would be a lot worse if not for conservation efforts.

The study, which involved some 174 authors from 115 institutions and 38 countries, with voluntary contributions from more than 3,000 scientists, is published in the international journal Science, and used the IUCN Red List of Threatened Species to investigate the status of around 25,000 vertebrate species and how this status has changed over time. The results reveal that, on average, 50 species of mammal, bird and amphibian are pushed closer to extinction each year. The situation has been most stark in Southeast Asia where many species are threatened by habitat loss due to the planting of crops like oil palm, deforestation by commercial timber operations, agricultural conversion to rice paddies, and unsustainable hunting.

Commenting on the study’s findings, E.O. Wilson, Professor at Harvard University and Wildscreen Patron, said “The ‘backbone’ of biodiversity is being eroded. One small step up the Red List is one giant leap forward towards extinction. This is just a small window on the global losses currently taking place.”

The Kihansi spray toad (Nectophrynoides asperginis), now classified as Extinct in the Wild, suffered catastrophic habitat loss following the construction of a dam upstream from the Kinhasi Falls, Tanzania, before succumbing to the devastating impacts of the fungal disease chytridiomycosis.

The study largely focused on vertebrates, but also reported that several other groups of species assessed by the IUCN face a similar fate. The ancient group of plants known as cycads are in a particularly critical state with 63 percent of assessed species threatened with extinction, largely due to extremely high levels of illegal harvesting and trade. Dragonflies and reef-building corals also did not fare well, with 13 and 33 percent of assessed species threatened with extinction, respectively.

Seychelles magpie robinThe global population of the Seychelles magpie robin (Copsychus sechellarum) increased from just 15 birds in 1965 to 180 in 2006 thanks to dedicated conservation efforts.

It is not all doom and gloom, however, as the study also reveals the positive impact of conservation efforts for the first time, with the results suggesting that the status of biodiversity would have declined by at least an additional 20 percent if conservation action had not been taken. There are encouraging stories of 64 mammal, bird and amphibian species that have improved in status due to successful conservation action. Conservation efforts have been particularly successful at tackling the effects of invasive alien species on islands. One such species that has benefited from this is the Seychelles magpie robin, which increased from only 15 birds in 1965 to 180 in 2006 thanks to the control of introduced predators, such as the brown rat (Rattus norvegicus), and captive-breeding programmes.

Mauritius kestrelAnother conservation success story, the Mauritius kestrel (Falco punctatus) was rescued from the brink of extinction by a world-renowned conservation programme. Its population has increased from just 4 birds in 1974 to nearly 1,000 today.

The study clearly demonstrates that conservation efforts have not been in vain. But if we are to meet objectives in tackling biodiversity loss, we must also greatly increase conservation efforts as, at present, they are vastly outweighed by the level of threat. As such, policy-makers at the CBD are to call for nations to commit to a 100-fold increase in resources available to remedy this shortfall and mitigate the loss of our planet’s irreplaceable natural wealth.

To explore more threatened species, visit ARKive.

To find our more about the report and the IUCN Red List of Threatened Species, see:

•IUCN Redlist: http://www.iucnredlist.org/
•IUCN Press Release: http://cms.iucn.org/knowledge/news/?6333/Natures-backbone-at-risk

Oct 20

Henderson petrel

The Royal Society for the Protection of Birds (RSPB) has announced plans to remove non-native rats from the Pacific Island of Henderson, in an attempt to prevent the global extinction of a unique seabird, the Henderson petrel (Pterodroma atrata). The introduced Polynesian rats (Rattus exulans) are eating an estimated 25,000 petrel chicks every year, and are also thought to be threatening the island’s other native bird species.

Part of the UK Overseas Territory of the Pitcairn Islands, Henderson Island is a remote, uninhabited island with a unique array of wildlife, including large numbers of breeding seabirds and four endemic land birds. Although still remarkably untouched by humans, the presence of rats is threatening the survival of many of the island’s native species, and may already be responsible for the extinction of four endemic birds. If left unchecked, rat predation will also lead to the eventual extinction of the Henderson petrel, which is not known to breed anywhere else in the world.

In an attempt to save the Henderson petrel, the RSPB is now planning the complete eradication of rats from the island. Speaking about the planned project, Dr Tim Stowe, the RSPB’s International Director, said, “This week, the world’s leaders will be gathering in Japan to discuss how to stem the catastrophic declines in global biodiversity, especially on islands. This project is a good example of how we can make a difference to global conservation, provided more donors can help us reach our funding target.”

Planned to start in August 2011, the eradication programme will cost a total of £1.7 million, of which a further £600,000 is still needed in donations. With 95 percent of petrel chicks on the island lost to rats every year, the need for this project is clear. However, if successful, the eradication should not only save the Henderson petrel, but also benefit Henderson Island’s other threatened wildlife and help restore the natural beauty of this remote Pacific paradise.

Some of the species unique to Henderson Island include:

Henderson crake Found only on Henderson Island, the Henderson crake is a flightless bird whose eggs and chicks are vulnerable to predation by introduced rats.


Henderson fruit-dove

As its name suggests, the Henderson fruit-dove feeds on a variety of fruits. Its restriction to a single island makes this colourful species vulnerable to extinction.


The HendersoHenderson reed-warblern reed-warbler is another bird species unique to Henderson Island. Like all of the island’s species, it is vulnerable to any further introductions of mammalian predators, such as the black rat (Rattus rattus).


Also known Henderson lorikeetas Stephen’s lorikeet, the endemic Henderson lorikeet, along with Henderson Island’s other bird species, is vulnerable to the introduction of avian diseases, such as avian malaria and pox.


To find out more about the planned rat eradication programme on Henderson Island, see:

For more information on conservation in the Pitcairn Islands, see:

Oct 13

On Wednesday 13th October, at the Wildscreen Film Festival, WWF launched their Living Planet Report 2010, an analysis on the health of the planet and the impact of human activity, with the key finding that humanity’s demand is currently exceeding our planet’s capacity to sustain us.

As human well-being is directly connected to the way we treat our planet’s natural resources, it is imperative that we understand how to live sustainably, and learn how to use nature more wisely. The Living Planet Report aims to do just this by describing the changing state of biodiversity and the pressure on the planet from our consumption of natural resources. The report uses two indicators: The Living Planet Index, which reflects the health of the planet’s ecosystems; and the Ecological Footprint, which shows the accumulative impact of human demand on these ecosystems.

Bornean orang-utanPalm oil is a widely-used commodity, but its demand comes with a terrible cost to the environment. As forests are cleared to make room for palm oil plantations, many species, such as the Bornean orang-utan, are pushed closer to extinction.

These indices produced some alarming results. Compared to levels in 1970, global biodiversity has declined by 30 percent, with species loss being greatest in the tropics, where biodiversity has declined by 60 percent. We are using 50 percent more natural resources than we should, with the degradation of our environment most affecting the world’s poorest and most vulnerable people. Our carbon footprint has increased 11-fold since 1961 meaning that, for the first time, carbon emissions exceed our planet’s ability to absorb this waste.

Mangroves provide food, shelter, jobs and protection, but we are replacing them with fish farms, destroying them for timber and reclaimed land, and polluting them. Already we have lost more than half of the planet’s mangroves.

If we are to continue at current levels of consumption, by 2030 we will need two Earths to absorb our carbon dioxide waste and keep up with resource use. Developing countries bear the brunt of the misuse of the planet, with many people left without access to clean water, land, enough food, fuel and materials.

Yet, while the outlook appears bleak, the report makes it clear that conserving nature is in humanity’s own interest, and that destroying it only serves to make life harder for all of us. By setting aside areas for nature to conserve species, ending our addiction of fossil fuels, and changing our levels of food and resource consumption, we can save the ecosystems and species on which we depend.

To read the Living Planet Report 2010 and find out more about WWF’s conservation projects, visit:

Find out more about threatened species by exploring ARKive.


RSS feedArkive.org is the place for films, photos and facts about endangered species. Subscribe to our blog today to keep up to date!

Email updates

Sign up to receive a regular email digest of Arkive blog posts.
Preferred frequency:


Arkive twitter

Twitter: ARKive