DOI: 10.5061/dryad.zw3r228g8
title: Conspecific brood parasitism and nest predation in moorhens

description: Conspecific brood parasitism was investigated in three species of moorhens
 on three different continents: common moorhens in the United Kingdom,
 lesser moorhens in Namibia, and American moorhens in Panama. These are
 nest data used to summarize population-level rates of conspecific brood
 parasitism and nest predation. The data reported here were collected using
 similar field methods, and include nest dates, clutch sizes (number of
 host eggs), number of parasitic eggs, and nest fates.
description: Common moorhens (United Kingdom, 1991-1993)
 Data were collected over three field seasons at Peakirk Waterfowl
 Gardens in Cambridgeshire. Nests were monitored daily, and new eggs were
 uniquely marked with indelible ink upon discovery. Parasitic eggs were
 identified through sequence anomalies (when 2 eggs appeared on one day or
 at least 2 days after the host finished laying. Egg dimensions, color and
 spot pattern maculation helped distinguishing eggs laid in the same nest
 on the same day. All complete clutches were photographed and methods for
 identifying parasitic eggs were verified using DNA fingerprinting. Fates
 and hatching success of nests were determined from daily nest
 checks. Lesser moorhens (Namibia, 1997)
 Data were collected in what is now Nyae Nyae Concession Area in
 Bushmanland, Namibia, about 12 miles south of Tsumkwe. The breeding season
 began after long-awaited rains filled the salt pans and initiated the
 brief growing season in these ephemeral wetlands. Lesser moorhens nested
 within a 6-week period. Nests were monitored daily, and new eggs were
 uniquely marked with indelible ink upon discovery. Parasitic eggs were
 identified through sequence anomalies (when 2 eggs appeared on one day or
 at least 2 days after the host finished laying). In one nest, 2 eggs found
 buried within the nest upon discovery that did not match the host eggs in
 dimensions, background color and spot pattern were considered to be
 parasitic. A sample of complete clutches were photographed. Fates of nests
 were determined from daily nest checks. American
 moorhens (Panama, 1999) Data were collected on moorhen
 nests in floating vegetation on the Rio Chagres, close to Gamboa, Panama.
 Nests were monitored daily, and new eggs were uniquely marked with
 indelible ink upon discovery. Parasitic eggs were identified through
 sequence anomalies (when 2 eggs appeared on one day or at least 2 days
 after the host finished laying). Egg dimensions, color and spot pattern
 maculation helped distinguishing eggs laid in the same nest on the same
 day. Complete clutches were photographed. Fates of nests were determined
 from daily nest checks.
description: # Conspecific brood parasitism and nest predation in moorhens
 [https://doi.org/10.5061/dryad.zw3r228g8](https://doi.org/10.5061/dryad.zw3r228g8) Rates of conspecific brood parasitism and rates of nest loss were investigated in three species of moorhens on three different continents: common moorhens in the U.K., lesser moorhens in Namibia, and American moorhens in Panama. Comparable data from nests at each study site are provided including nest dates, site and nest identity, host clutch size, number of parasitic eggs, and eventual fates of each nest. ## Description of the data and file structure Five separate files are provided, each containing nest data from a single nesting season: three from study of common moorhens in the U.K. (years 1991-1993), one from the 1997 study of lesser moorhens in ephemeral wetlands in Namibia, and one from the 1999 study of American moorhens in Panama. In the U.K. study, an unplanned, natural experiment occurred causing nest predation by rats to increase dramatically in one year: 1991-92 were considered 'low predation' years, and 1993 was the 'high predation' year. Nest losses in Namibia were also mainly due to predation. Whereas, nest losses in Panama also occurred due to flooding and floating downriver followed by desertion. ### Common moorhens (United Kingdom, 1991-1993). Files: `1991PeakirkNestFile`, `1992PeakirkNestFile`, `1993PeakirkNestFile` Common moorhens at this site were multiple brooded and had up to 4 successful nests over the breeding season. Nests were checked daily to determine vital rates of reproduction and nest fates. The designation unk indicates that the value was unknown and therefore missing. An n/a indicates not applicable. A question mark with an integer means that value is a best estimate, such as for how many eggs hatched successfully in a clutch that was partially depredated during hatching. The variables are: * Year (last 2 digits); * Nest ID number; * COOP where C indicates the presence of 2 females - and at least 3 caregivers - in the territory, and no data indicates the territory was occupied by a breeding pair); * GROUP (identity of the breeding unit, unk if unknown); * BROOD NO. is the nesting attempt number for the group (multiples of a number designate false starts, early parasitism or experimental manipulations that immediately preceded a breeding attempt, and the negative sign designates when those occurred in the same nest); * 1st E Julian DATE is the date the first egg was laid expressed as the Julian date (n/a for experiments where only eggs in nests were models); * INC (Julian date begun) is the date incubation began, if recorded (n/a if never incubated); * HATCH Julian DATE is the date the first first chick was fully emerged from the egg (n/a if never hatched); * PRED Julian DATE is the date the nest was depredated, if applicable (DESdate is date of desertion, if applicable); * COOP EGGS (if applicable) is the number of eggs laid by each communal female separated by a comma; * TOTAL EGGS is the number of eggs laid in the nests with one female (host + parasitic eggs, if applicable; unk if found during or post-hatching, n/a for communal nests captured in previous column). In the 1993 file, this is replaced by HOST EGGS (the number of eggs laid by the nest owner only); * \# parasitic eggs is the number laid by one or more brood parasites (0 if laying sequence data known, clutch completed and no evidence of parasitism, n/a if clutch incomplete or nest found with complete clutch, unk if found during hatching and status unknown); two nests that were parasitized interspecifically by ducks are indicated; nests with a non-zero integer in this column are considered parasitised nests; * CC - 1 indicates nests considered complete clutches and 0 were incomplete or excluded as they were part of an experiment; * FATE of nest was considered hatched (H) if at least one egg hatched, depredated during hatching (PH), depredated during host laying (PL), depredated during incubation (PI), deserted (DES), destroyed (DESTR) when pecked-open eggs found in or near the nest (some of these were experimental nests that contained only model eggs introduced to simulate parasitism); COLL denotes when eggs were collected by me and REM when the nest was removed as part of an experiment; failed (FAIL) all eggs disappeared due to sequential predation or other disturbance; * NO. HATCHED is the number of eggs that hatched (nests that did not reach the point of incubation are n/a); * HATCH.SUCCESS is the proportion of eggs hatched, and * NO. FLEDGED is the number of young surviving at 6 weeks. The last three parameters are only included in the 1991 and 1992 files. ### Lesser moorhens (Namibia, 1997). Files: `1997LesserMoorhenNestData` All nests at this site were found in emergent vegetation in ephemeral pools. Nests were checked daily over a period of ~1 month to determine progress and nest fates. The variables in the file are: * Estimated 1st egg date (Month/Day/Year), * Site name, * Nest ID (first initial of nest finder.species=LM.nest number); * HOST EGGS is the number of host eggs; * NO. P'C EGGS is the number of parasitic eggs; * P'C EGGS ADDED details when in the nest cycle the parasitic eggs appeared, if applicable (e.g. 3,4d after CC means 3 and 4 days after the clutch was complete); * FATE of the nest is denoted as Hatched (H), depredated during hatching (PH), depredated during host laying (PL), depredated during incubation (PI), deserted (DES), destroyed (DESTR) when pecked-open eggs or evidence of broken experimental egg models were found in or near the nest. * EXPERIMENTAL NEST designated by EXPT ### American moorhens (Panama, 1999). Files: `1999PanamaMoorhenNestFile` Nests were found on floating mats of vegetation covering the deep waters of the Rio Chagres near where it enters the Panama Canal at Gamboa, Panama. Nests were checked daily to determine progress and nest fates. Italicized date variables are estimates. A question mark with an integer means that value is a best estimate. The variables in the file are: * SITE any of four main and one minor areas surveyed; * NEST ID. nest identity; * TERRITORY specific to a pair of breeders; * SETTLE DATE the first date of occupancy by a breeding pair observed (Day-Month); * CLUTCH INITIATION DATE is the date the first egg was laid (Day-Month); * HATCH DATE the date the first chick was fully emerged from the egg (Day-Month) if applicable; * PREDATION DATE the date of nest predation (Day-Month), if applicable; * DESERTION DATE the date the eggs were found unattended and cold (Day-Month), if applicable; * CLUTCH SIZE is the number of host eggs; * PARA'C EGGS is the number of parasitic eggs; * FATE of the nest was Hatched (H), depredated during hatching (PH), depredated during host laying (PL), depredated during incubation (PI), eggs depredated by an American purple gallinule (PP), deserted (DES), destroyed (DESTR) when pecked-open eggs or evidence of broken eggs found in our around the nest COLL denotes when eggs were collected by me, INF denotes the eggs were infertile and eventually deserted, FL denotes that the island of vegetation that the nest was on nest floated downriver and was deserted; * \# HATCHED is the number of eggs that hatched; * CC - 1 indicates nests considered complete clutches and 0 were incomplete or excluded as they were part of an experiment or affected by disturbance; * REMARKS self-explanatory. ## Sharing/Access information Links to other publicly accessible locations where parts of the datasets are also used: * [https://doi.org/10.2307/6017](https://doi.org/10.2307/6017) * [https://www.jstor.org/stable/4089568](https://www.jstor.org/stable/4089568) * [https://onlinelibrary.wiley.com/doi/10.1002/ece3.26](https://onlinelibrary.wiley.com/doi/10.1002/ece3.26)