Musings: Black Out

Someone who got tired of waiting at the one-lane Hanalei Bridge apparently decided to take matters into his/her own hands recently. Signs that stated local courtesy allows 5-7 cars to cross before the other side gets a turn were blacked out at both ends of the span.

As I reported previously, there is a movement under way by some impatient motorists to eliminate this “local courtesy,” which was endorsed by the community in a 2008 survey. 

Photo from Ivy's Place website.

While state and county officials and community leaders discussed options, someone went rogue and vandalized the signs.

State DOT workers will try to repair the signs today. Has anyone crossed the bridge since the signs were blacked out? And if so, did you notice any difference in the traffic flow or motorists' moods?

Meanwhile, as the Kauai Feral Cat Task Force attempts to hammer out a cat control ordinance, a new scientific study shows toxoplasmosis spread by feral cats is a significant cause of mortality in endangered nene and alala (crows). However, emaciation and trauma (typically vehicle collisions and dog predation) were the primary causes of nene deaths.

In the first systemic investigation into the causes of death in nene, federal researchers studied 300 nene carcasses collected from Hawaii, Maui, Molokai and Kauai between 1992 and 2013. Their findings, newly published in the Journal of Wildlife Diseases, show:

The most common cause of death was emaciation, followed by trauma (vehicular strikes and predation), and infectious/inflammatory diseases of which toxoplasmosis (infection with Toxoplasma gondii) predominated.

Causes of death varied among islands, with trauma dominating on Molokai, emaciation and inflammation on Kauai, emaciation on Hawaii, and inflammation and trauma on Maui.

The leading cause of inflammatory conditions was toxoplasmosis followed by omphalitis.

It concluded:

Specifically, although it might be difficult to reduce impacts of emaciation, the relative impact of human-induced trauma and toxoplasmosis could be decreased with management. Doing so might enhance recovery of Nene in their native range.

The draft State Wildlife Action Plan (SWAP) report also speaks to the deleterious effect that “non-native predators” such as cats, rats and mongooses are having on rare native forest, wetland and seabird populations. To help forest and wetland birds recover, it advises:

Critical conservation actions include protection of remaining native forest habitats from further degradation by ungulates and non-native plant species, control and eradication of introduced predators (primarily rodents and cats)...

For seabirds, it recommends:

Needed conservation actions are protection of existing habitat, eradication of introduced predators (cats, rodents, and mongooses) from additional offshore islands and known breeding colonies.

The report goes on to state:

Hawai‘i’s terrestrial animals evolved in the complete absence of mammalian predators and are extremely vulnerable to depredation by rats, feral cats and the small Indian mongoose. All of these species prey on eggs, nestlings, and adult birds.

Presently, high densities of feral cats, rodents, and mongooses are a major cause of mortality among native birds and may place similar pressures on native terrestrial invertebrates.

Feral cats are extremely skilled predators and are responsible for the extinction of birds on islands worldwide. In Hawai‘i, cats are widely distributed on all of the Main Hawaiian Islands (MHI) from sea level to high elevations. While a single cat can have a devastating effect on a breeding seabird colony, “cat colonies” pose an even greater threat to bird populations because of their concentrated numbers.

So why in the world would anyone who values native wildlife advocate for a trap-neuter-return program that actually supports and establishes feral cat colonies around the island?