In the Hawaiian monk seal world, the term “logging” refers to a behavior performed by monk seals when they float on the surface of the ocean–not actively swimming–for extended periods of time. This time of year, it’s a behavior some very pregnant seals may exhibit in the days leading up to their delivery.
In the coming weeks, several females who regularly pup on Kauai may be seen logging in shallow water. Based on their pupping dates last year, these females anticipated due dates are as follows:
- RK22 – June 22. (Although there’s no sign of her yet.)
- RK30 – July 1.
- RK28 – July 13
- RO28 – July 16
- RH58 – August 1
Logging by near-term pregnant females is natural behavior in monk seals. However, extended periods of logging can also be symptomatic of underlying health problems. When RK13 was healing from a suspected shark bite, she spent a fair amount of time logging in the shallow water of freshwater canals.
Logging can also be a symptom of toxoplasmosis, a disease that can be deadly to monk seals. Toxo is the number one disease threat to Hawaiian monk seals.
The parasite Toxoplasma gondii is a microscopic, single-cell organism. Just one of their eggs—known as oocysts— is enough to kill a monk seal. A single cat can excrete 145 billion eggs per year in its feces, according to DLNR. It’s a staggering number.
According to this NOAA report, “The parasite that causes ‘toxo’ sexually reproduces in cats, which shed T. gondii eggs into the environment via their feces. The feces of just one cat contains millions of T. gondii eggs that survive in the environment for many months.
“Any warm-blooded animal, including humans, can contract toxoplasmosis by ingesting a single T. gondii egg — and cats are essential for the reproduction and spread of the parasite.”
Since 2001, eleven Hawaiian monk seals have died of toxoplasmosis. Logging is one behavioral symptom. Of the 11 confirmed deaths due to toxo, eight were female. At least, two were pregnant. Unfortunately, once the disease progresses to the point of visual symptoms like logging, it can be too late for veterinarians to help. It’s not an easy death, either. It’s suspected the near-shore logging behavior occurs, because it’s too painful for the seal to haul out on the sand. In the days leading up to RB24‘s death due to toxoplasmosis, she was reported logging in canals on Oahu.
It can seem like a weird thing–how can the feces of pet (and feral) cats kill Hawaiian monk seals? To help explain, NOAA created this infographic and fact sheet. More information about toxoplasmosis can be found here and here.
And if you see a logging seal–whether pregnant or not–please report it to the Hawaiian monk seal hotline at 808-651-7668.
