Monday, December 31, 2012

Wart's and Kleenex's Families Grow

The 2013 right whale calving season is only a month old and already twelve calves have been seen and two of our adoptive families have grown.

Kleenex has one of the largest right whale families and her daughter, #2042, had her first calf in December.  This is Kleenex's eight grand-calf and the fourth of five daughters to have calves. Kleenex has had eight calves with the earliest in 1977 (unknown sex and never catalogued), followed by two male calves and five female calves. #2042 has yet to be named and is one of the older new mothers, born in 1990.  The age a female has her first calf varies greatly, from as young as five to over twenty, but the average is around ten years of age.

Right whale diving in the Bay of Fundy.
Wart's family has grown by two so far this calving season.  Her daughter, Black Heart #3540, born in 2005, had her first calf, Wart's tenth grand-calf.  Wart's grand-calf, Millipede #3520, born the same year as Black Heart, and the daughter of Wart's calf, Naevus, #2040, born in 1990, also had her first calf in December, Wart's fourth great-grand-calf.

It is not unusual to have several generations of right whale females with calves in the same year.  In fact, #1612 and her daughter #2912 both have had calves this December.  Researchers are still hoping that perhaps some of the females that were seen in the Gulf of Maine a year ago, a suggested mating area for right whales, will be seen with calves this year.
Right whale diving amongst great and sooty shearwaters in the Bay of Fundy.

Saturday, December 8, 2012

First Calf of 2013 Calving Season

A recreational boater off Hilton Head, SC, reported the first right whale mother and calf for this calving season on November 27, 2012.  While most right whale females have their calves off the coast of Georgia and Florida, winter surveys extend up to North Carolina to cover the range of normal occurrence of right whale females and their calves.
Right whale male, Gemini, diving in the Bay of Fundy September 17, 2011
Of course, we are hopeful for more calves than in 2012 when only seven calves were born with one female loosing her calf, but we shall have to wait and see.  There were certainly more right whales in the Bay of Fundy in 2011 than in 2010, which may bode well.  A year of low food resources for a female would be reflected not the next calving season but the one following, for example 2010 lack of sightings of right whales in the Bay of Fundy and the 2012 low number of calves.  Females need to have a certain amount of blubber to ensure they can nurse their calf for a full year, without that blubber, they will not get pregnant.

In early December, a small group of right whales have been spotted off Jeffrey's Ledge in the Gulf of Maine and spurred a notice for large vessels in those waters to slow down to 10 knots.  This area in the Gulf of Maine is suspected to be a breeding area for right whales.  The calving area is not a breeding area for right whales, unlike humpback and grey whales.

Right whale surface active group in the Bay of Fundy August 24, 2011
Keeping our fingers crossed for more calves.  The season extends from December to March.

Monday, December 3, 2012

Reflections on the Summer in the Bay of Fundy

Right whales were hard to find in the Bay of Fundy in the summer of 2012.  Those that were found were often travelling.  Few settled in the Bay for any length of time other than the mother 3390 and her calf.  They were seen for over a month and were the only right whales to remain for any length of time.

Calf of right whale 3390.  The calf opened its mouth and the baleen can be seen hanging down.  Baleen in calves is very light in colour.  Adult baleen colour is much darker.
Why the instability when the Bay of Fundy is a designated critical habitat for North Atlantic right whales?  Right whales come to the Bay of Fundy for many reasons but an important one is the availability of huge patches of zooplankton, primarily copepods.  When in large quantities, these copepods provide enough energy for the whales to add to their blubber layer for winter months when food may be more scarce and they may need to fast, relying on the blubber reserves.

It is important to photo-document young right whales so they can be followed throughout theirs lives. Each right whale has a unique pattern of callosities on its head, rough patches of skin where we have facial hair. This calf's mother, 3390, was not photographed as a calf and we, therefore, do not know when she was born or to whom she is related. 
The copepod patches were sporadic, never seemed to develop into large patches, and also appeared pale in colour, indicating low energy reserves in the copepods.  Why the change from most years when the copepod patches develop in the Grand Manan Basin, the deepest area in the Bay of Fundy?  The 2011-2012 winter was one of very mild temperatures and hardly any snow.  This resulted in very little runoff into the ocean and, therefore, lower nutrient input for phytoplankton.  Warmer winter temperatures and little cold water runoff from snow melt also meant warmer ocean temperatures.  The counter current gyre that sets up each summer in the Grand Manan Basin and accumulates zooplankton, is temperature dependent and may not have occurred where it normally does in 2012.

Right whale stretching after a nap between dives.  This whale was been down to the bottom because of the muddy head.  It is not sure why right whales and also humpback whales rub in the muddy bottom, whether it is for feeding, relieving an itch or as a mud facial!
Warmer water temperatures can result in many changes.  It is a suggestion of why Atlantic herring didn't come inshore, preferring the deeper, colder waters.  There were several sightings of leatherback turtles, the largest sea turtle.  While the occasional sighting is normal in the Bay of Fundy, there did seem to be more this summer, including one that swam up a tidal river.  Unfortunately, the turtle died despite efforts to rescue it when it stranded on the muddy river bank several times.

Small Atlantic herring (brit) leaping out of the water after being pursued by Bluefin Tuna from below and great shearwaters from above.  Herring are a keystone species in the Bay of Fundy, providing food for many species.  They eat copepods as do right whales.
 What do low copepod resources in the Bay of Fundy mean for right whales?  It can affect calving success.  Right whale females need to have a good fat reserve to get pregnant because of the high energy demands of nursing a calf.  This is the reason right whale females take a resting year after weaning their calf so they can adequately recover their blubber reserves.  If the right whales found large patches of zooplankton elsewhere, then calving may not be affected.  In 2010, few right whales were seen in the Bay of Fundy and this past calving season had only seven calves born.  Low resource availability one summer is reflected in calving rates not that year but the following year.

Right whale 3390 and her calf diving in the Bay of Fundy off Grand Manan Island in August 2012.