Conservation: Relocation of Nests

Relocation management criteria have been established for the Island and areas with historically low potential have been identified. An annual Rapid Habitat Analysis is performed to follow longitudinal changes in habitat hatching potential. Nests deposited in areas with low probability of success are relocated to areas with higher probability and placed in new, egg chambers dug with a post-hole digger, then covered and marked as in situ nests.

Management criteria can be established to trigger moving nests to more favorable habitat if it is located in previously unsuccessful stretches of beach, is in jeopardy from ground water inundation, is placed too far out on the beach, or is situated in a highly erosive portion of beach. These criteria have been established with experience and by analysis of success of nests from previous seasons.

St. Catherines Nest-Moving Criteria (1998 as modified to 1999 conditions) were established during 1997, modified in 1998, and modified again in 1999 (Bishop and Marsh, 1999). This island specific nest moving management plan was designed to alleviate negative habitat impacts on loggerhead sea turtle nesting success on St. Catherines Island. A similar plan is envisioned for each of the Georgia barrier islands and is presented here as a model which might be applicable to other islands and their specific complement of habitats.

Sea turtle Intern Hollis has located a clutch of eggs by carefully digging with a shovel. This nest [06-022] was situated on the back of the forebeanch and had to be moved. Eggs are counted one or two at a time into a rigid bucket the top eggs end up in the bottom of the bucket and bottom eggs end up on top of the bucket.
A new egg chamber is dug for the clutch in a nuturery, where the nest will likely hatch, and eggs are carefully transferred two by two into the new egg chamber. (Photograph courtesy of Tracy Burke).

On St. Catherines Island we have developed the following protocols for loggerhead sea turtle nest relocation:

A nest must be moved if at all possible if it:

  1. Was deposited on North Beach South of Sand Pit Road (no historical success)
    2. Was deposited along the margin of St. Catherines Sound. (erosional)
    or
  2. Was deposited on South Beach between 0 and 1.2 km (washover fans)
    3. Was deposited on South Beach between 2.3 and 4.0 km (seaward of Flag Pond)
    Was deposited on South Beach between 6.0 and 8.9 km (washover fans)
    Was deposited on South Beach between 0 and 4.6 km (erosional)
    Was deposited on South Beach between 5.5 and 8.6 km (erosional)
    or
  3. Was deposited on any beach more than 2.0 m in front of scarp or storm tide line.
    4. and
  4. Was deposited within the last 12 hours
    5. or
    Was deposited more than 12 days ago.

A nest should be considered for moving if it:
  1. Was deposited on any beach more than 1.0 m in front of scarp or storm tide line.
  2. Was deposited on a scarped dune undergoing erosion.
  3. Was deposited on a dynamic dune face likely to undergo deposition or erosion.

Nest Moving Protocol:

  1. Move as early as possible; only exceptionally after 12:00 noon.
  2. Move as short a distance as is possible; Chosing the smoothest route to new location.
  3. Move behind storm high tide line into non-rooted dune sand.
  4. Maintain habitat integrity (similarity) if possible.
  5. Transfer eggs gently using rigid container (5 gallon bucket or small cooler)
    1. Remove from nest one or two at a time.
    2. Place on sand layer in bottom of bucket; one or two at a time.
    3. Count out of egg chamber and into bucket (when working in pairs).
    4. Insulate eggs against temperature change by covering with sand or towel, keep in shade.
    5. Ride eggs as low as possible on machine (Foot floor if possible).
    6. Place one or two at a time into new egg chamber.
    7. Cover with sand to neck, tamp sand gently to seal.
  6. Selection of site for new location:
    1. Behind Storm high tide line.
    2. Slope of surface toward sea.
    3. Minimum of vegetation.
  7. After 12 days a nest may be moved again, but eggs must be kept oriented.
During the 9/11 Nor'easter of 2006 nest [06-119] on the north end of South Beach was eroded and exposed on the scarp formed on 9/09/06 … it had to be moved! Note the exposed, hanging plastic screen! The nest was over 12 days into development. Eggs were removed one-by-one from the scarp face, carefully placed into a cooler keeping them in vertical orientation, then relocated about 12 ft back from the scarp by digging a new egg chamber and placing the eggs back in one-at-a-time keeping their vertical orientation.
An overview of the relocation of Nest [06-119] (stake in distance with flagging) and [06-119a] marked by a fluorescent orange float (in right foreground). Note that this translocation (10/09/06) was done 30 days after deposition (9/09/06) with 14 undeveloped eggs removed from the remaining 80 viable eggs in the clutch at that time. This nest hatched 57 of those 80 eggs (71.3 % of viable eggs, 60.6% of total clutch).

Nests that are moved must be moved carefully, within 12 hours of deposition. The new nest is hand-dug or dug with a post-hole digger to conform in size and shape to a typical loggerhead sea turtle nest and is redocumented like any other nest, covered with screen(s), and marked with a stake.

Once relocated each nest is monitored on a daily basis.