PATRICK MINX 1987 TRIP TO LA MESA NAYARIT
VOORWOORD
==========================================================================================
Hierbij wil ik Patrick Minx, bedanken voor toestemming voor de foto's en tekst van zijn reisverslag "'1987 Trip to La Mesa Nayarit"'
Tekst en foto's zijn met credit voor Patrick Minx
Patrick Minx is een Amerikaan die in de jaren 80 onderzoek heeft gedaan naar de Terrapene nelsoni, ik denk niet dat iemand meer Terrapene nelsoni heeft
gezien en onderzocht dan Patrick.
De meest gegevens die bekend zijn over Terrapene nelsoni zijn afkomstig van hem.
Jammer genoeg heeft Patrick nooit zijn onderzoek naar Terrapene nelsoni kunnen voltooien door prive-omstandigheden, toch zie ik hem als de expert op gebied van deze Terrapene, die een mooie en bijzondere bijdrage heeft geleverd zodat we meer weten over de Terrapene nelsoni.
Patrick Bedankt !!!!
Hans
I arrived in La Mesa de Pedro y Pablo in late June (22) as did Dr. Milstead in 1963.
He came to Pedro Pablo at least a week into the rainy season since he described the valley as being lush.
When I arrived I met a totally different situation.
The valley was dry, without a bit of green, and the ground was like rock.
The people said it had not rained in five months and that the rainy season was late.
Everyday we hunted for turtles but none were found.
The people said the turtle burrowed into the ground and remained there for the entire dry season.
The first rain came Saturday, the 27th, however no turtles appeared.
The fourth rain lasted several days it began in the evening and lasted all night.
The next day (July 4th), the turtles were all over.
I found an old male on a large grass covered ledge.
This was on the flat top hill (mesa) directly west of the town.
I found him on the south end just below the summit.
Most of the turtles however were found southwest of the village in the hills.
Seven turtles were found the first day with three people looking for half of a day.
The next day five more were brought in.
Apparently densities are high.
Several people told me the turtle is also found in nearby San Diego to the north (approximately the same altitude) and a man from Santa Cruz said the turtle is common there.
Santa Cruz is at least 500ft. higher than La Mesa and is about seven kilometers east.
The people also told me the turtle is commonly seen in July, August, and less in September.
The same day of capture I witnessed one unsuccessful mating.
The male mounted the female, rear legs hooked to her rear, but the behaviors ceased before copulation occurred.
All the females examined (3) were gravid and apparently deposition would take place shortly.
From these observations I postulate the following:
The turtles aestivate for the dry season and then emerge during the first substantial rainstorm (maybe a week or so into the rainy season).
Turtles emerge en masse and mating and egg-laying occurs simultaneously (unlike the other box turtles).
This is probably due to the short growing season.
The egg probably hatches the following wet season (maybe accounts for the large size of the eggs). T. n. klauberi apparently doesn’t respond to the wet season as T. n. nelsoni, since T. n. klauberi can be found before, during, and after the rainy season.
I believe this is true because at lower elevations (where most T. n. klauberi have been found to date) the rain is less in magnitude and less dependable in arrival (sporadic).
However, I believe T. n. klauberi found in higher elevations (ie Northern ) will behave similarly to T. n. nelsoni and also densities will be higher.
The newly emerged turtles were offered mango, bananas and a variety of insects.
Surprisingly, only two turtles ate and then only one insect each.
Either the turtles are not excessively hungry when they emerge or else they eat something else in the hills.
The turtles are very active and not sluggish in the least.
Temperature was about 75 degrees Farenheit the two days turtles were hunted and found.
(It was much cooler the previous days).
In two days twelve turtles were brought in by five people.
Two turtles were found east of town on the east side of a grassy hill.
Two others were found on the west side of a grassy hill, east southeast of the town.
Another was found on the southwest side (backside) of the grassy little hill that adjoins the southeast side of the town.
The turtles blend in extremely well with the dry leaves and this may account for them being found mostly in the grass and not the leaves.
The turtles had no mud on them as would be expected after burrowing into the ground.
The people suggested they inhabit the many burrows constructed by armadillos.
However the rain could have simply washed it off.
Males usually have red eyes, and often with orange on the chin.
Head colors include yellow on top, oranges, white, black, blue/brown, but never the little yellow dots.
The shields of the front legs are also black orange, white, yellow, brown, and a bluish color.
The male’s tail tapers uniformally but is not long and massive as in the other box turtles.
The hind toe rotates as in ornate males.
The males (rear of the shell) are not flared excessively and the scooped first central is most evident in one of the females.
The older turtles have fewer dots and typically blacker plastrons.
The old males often have overgrown mandibles so that the head appears large and parrot-like.
The old male I found is small with a large head, bright orange on the chin and some on the front legs.
The spots occur only on the carapace. The front edge of the carapace is horn color and not brown.
The eyes are not red like most males but are grayish brown surrounded by a dirty yellow.
The eyes have opaque stuff on them, something like cataracts.
The shell is cracked and extremely worn smooth.
The spots are large.
The upper mandibles are overgrown which probably are a further sign of age.
The front of the beak has grown forward like tusks (two since the beaks has a strong cusp).
The forward growth of the mandibles gives the appearance that the nose is receding.
The lateral portion of the mandibles are also overgrown as seen in several T. o. luteola.
The large head and mandibles give the appearance of a parrot rather than a turtle.
The females have yellow-green eyes, with a browner iris.
The head is olive green with the yellow spots.
The shields are yellow-brown with yellow dots.
The base of the tail is rather bulbous and then the tail quickly tapers and ends.
The hind toe rotates the same as the male!
The females are not as flared, but the first central is scooped as in the males.
Brightly colored males tend to have some orange mixed in with the yellow of the ventral surface of the marginals that make up the bridge.
This has been observed in T. o. ornate also.
An eighty year-old man whose statements proved accurate in things concerning Pedro Pablo stated the turtle is most active and seen in July and August, and it is increasingly less active in September, October, and November.
December to June the turtle is not seen.
One week into the rainy season and many insects are emerging especially beetles (June bugs?).
One turtle scat was observed to contain insect parts and several live worms (nematodes) of some type.
Both juveniles had a keel on the third and fourth centrals, and one turtle also on the second.
The juveniles basically look like the females except the keel and they have more yellow on the plastron.